Papers by Daniel Meira Freitas
Arquivos Brasileiros de Oftalmologia, 2013
Abnormal vascular regulation in the ophthalmic artery of chronic heart failure patients Alteração... more Abnormal vascular regulation in the ophthalmic artery of chronic heart failure patients Alteração na regulação vascular da artéria oftálmica em pacientes com insuficiência cardíaca crônica
Brazilian Journal of Infectious Diseases, 2005
BJID 2005; 9 (October) recently, with the availability of HAART, new approaches to relapsed HIV-r... more BJID 2005; 9 (October) recently, with the availability of HAART, new approaches to relapsed HIV-related NHL were tried. A prospective trial was published in 2003 on JCO. Sixteen patients with HIV-related NHL or HD were treated sequentially by salvage chemotherapy, followed by mobilization of PBSC with cyclophosphamide and conditioning with BEAM (BCNU, etoposide, Ara-C and melphalan). Tem patients received the AHSCT, with 7 complete and 2 partial remissions. Six patients maintained remission after 8 months of follow-up. Re A, et al. J Clin Oncol 2003) A retrospective study in France in relapsed HIV-related NHL showed that, after AHSCT, 10 out of 14 patients achieved complete remission. After a median follow-up of 25months, 5/15 patients were alive. (Gabarre J, et al. Haematologica 2004) Recently, the group from City of Hope published a trial where 20 patients with high-risk features, in relapse or refractory, with AHSCT. With a median follow-up of more than 2.5 years, 17 out of 20 were alive in remission and toxicity was low.(Krishnan A, et al. Blood 2005) Recently trial listed above pointed to AHSCT as a valuable alternative to treat high-risk or relapsed HIVrelated NHL. Its results are far superior compared to salvage chemotherapy only. Nevertheless, this results must be taken with caution. This series are relatively small and non-controlled trials. A randomized and larger clinical trial is needed. Epstein-Barr virus (EBV) is a lymphotropic virus associated with some human malignancies such as endemic Burkitt's lymphoma, Hodgkin's lymphoma (HL), AIDS-associated lymphomas. We report the frequency of EBVinfection in pediatric Burkitt's lymphoma (BL), pediatric Hodgkin's lymphoma (HL), adulthood HL and AIDS related non-Hodgkin lymphoma (NHL) occurring in Bahia, Brazil. For comparison we described also the frequency of EBV infection in 28 lymphomas not related to HIV-infection and in 40 tonsils from children living in Bahia and II International Symposium on Oncovirology www.bjid.com.br BJID 2005; 9 (October) 445
Purpose: To examine the relationship between glaucomatous structural damage and ability to divide... more Purpose: To examine the relationship between glaucomatous structural damage and ability to divide attention during simulated driving.
Design: Cross-sectional observational study.
Methods: Setting: Hamilton Glaucoma Center, University of California San Diego.
Patient Population: 158 subjects from the Diagnostic Innovations in Glaucoma Study, including 82 with glaucoma and 76 similarly aged controls.
Observation Procedure: Ability to divide attention was investigated by measuring reaction times to peripheral stimuli (at low, medium or high contrast) while concomitantly performing a central driving task (car following or curve negotiation). All subjects had standard automated perimetry (SAP) and optical coherence tomography was used to measured retinal nerve fiber (RNFL) thickness. Cognitive ability was assessed using the Montreal Cognitive Assessment and subjects completed a driving history questionnaire.
Main outcome measures: Reaction times to the driving simulator divided attention task.
Results: The mean reaction times to the low contrast stimulus were 1.05 s and 0.64 s in glaucoma and controls respectively during curve negotiation (P <0.001), and 1.19 s and 0.77 s (P = 0.025) respectively during car following. There was a non-linear relationship between reaction times and RNFL thickness in the better eye. RNFL thickness remained significantly associated with reaction times even after adjusting for age, SAP mean deviation in the better eye, cognitive ability and central driving task performance.
Conclusions: Although worse SAP sensitivity was associated with worse ability to divide attention, RNFL thickness measurements provided additional information. Information from structural tests may improve our ability to determine which patients are likely to have problems performing daily activities, such as driving.
Introduction The purpose of this study was to evaluate the effect of stereotactic radiosurgery (S... more Introduction The purpose of this study was to evaluate the effect of stereotactic radiosurgery (SRS) on cerebral metastases using the transfer constant (K trans ) assessed by dynamic contrast-enhanced (DCE) MRI. Furthermore, we aimed to evaluate the ability of K trans measurements to predict midterm tumor outcomes after SRS. Methods The study received institutional review board approval, and informed consent was obtained from all subjects. Twenty-six adult patients with a total of 34 cerebral metastases underwent T1-weighted DCE MRI in a 1.5-T magnet at baseline (prior to SRS) and 4-8 weeks after treatment. Quantitative analysis of DCE MRI was performed by generating K trans parametric maps, and region-of-interest-based measurements were acquired for each metastasis. Conventional MRI was performed at least 16 weeks after SRS to assess midterm tumor outcome using volume variation.
Ophthalmology, Mar 6, 2014
Purpose
To identify the most commonly used statistical analyses in the ophthalmic literature and... more Purpose
To identify the most commonly used statistical analyses in the ophthalmic literature and to determine the likely gain in comprehension of the literature that readers could expect if they were to add knowledge of more advanced techniques sequentially to their statistical repertoire.
Design
Cross-sectional study.
Methods
All articles published from January 2012 through December 2012 in Ophthalmology, the American Journal of Ophthalmology, and Archives of Ophthalmology were reviewed. A total of 780 peer-reviewed articles were included. Two reviewers examined each article and assigned categories to each one depending on the type of statistical analyses used. Discrepancies between reviewers were resolved by consensus.
Main Outcome Measures
Total number and percentage of articles containing each category of statistical analysis were obtained. Additionally, we estimated the accumulated number and percentage of articles that a reader would be expected to be able to interpret depending on their statistical repertoire.
Results
Readers with little or no statistical knowledge would be expected to be able to interpret the statistical methods presented in only 20.8% of articles. To understand more than half (51.4%) of the articles published, readers would be expected to be familiar with at least 15 different statistical methods. Knowledge of 21 categories of statistical methods was necessary to comprehend 70.9% of articles, whereas knowledge of more than 29 categories was necessary to comprehend more than 90% of articles. Articles related to retina and glaucoma subspecialties showed a tendency for using more complex analysis when compared with articles from the cornea subspecialty.
Conclusions
Readers of clinical journals in ophthalmology need to have substantial knowledge of statistical methodology to understand the results of studies published in the literature. The frequency of the use of complex statistical analyses also indicates that those involved in the editorial peer-review process must have sound statistical knowledge to appraise critically the articles submitted for publication. The results of this study could provide guidance to direct the statistical learning of clinical ophthalmologists, researchers, and educators involved in the design of courses for residents and medical students.
Ophthalmology, Jan 29, 2014
OBJECTIVE:
To evaluate the ability of a binocular automated pupillograph to discriminate healthy... more OBJECTIVE:
To evaluate the ability of a binocular automated pupillograph to discriminate healthy subjects from those with glaucoma.
DESIGN:
Cross-sectional observational study.
PARTICIPANTS:
Both eyes of 116 subjects, including 66 patients with glaucoma in at least 1 eye and 50 healthy subjects from the Diagnostic Innovations in Glaucoma Study. Eyes were classified as glaucomatous by repeatable abnormal standard automated perimetry (SAP) or progressive glaucomatous changes on stereophotographs.
METHODS:
All subjects underwent automated pupillography using the RAPDx pupillograph (Konan Medical USA, Inc., Irvine, CA).
MAIN OUTCOME MEASURES:
Receiver operating characteristic (ROC) curves were constructed to assess the diagnostic ability of pupil response parameters to white, red, green, yellow, and blue full-field and regional stimuli. A ROC regression model was used to investigate the influence of disease severity and asymmetry on diagnostic ability.
RESULTS:
The largest area under the ROC curve (AUC) for any single parameter was 0.75. Disease asymmetry (P <0.001), but not disease severity (P = 0.058), had a significant effect on diagnostic ability. At the sample mean age (60.9 years), AUCs for arbitrary values of intereye difference in SAP mean deviation (MD) of 0, 5, 10, and 15 dB were 0.58, 0.71, 0.82, and 0.90, respectively. The mean intereye difference in MD was 2.2±3.1 dB. The best combination of parameters had an AUC of 0.85; however, the cross-validated bias-corrected AUC for these parameters was only 0.74.
CONCLUSIONS:
Although the pupillograph had a good ability to detect glaucoma in the presence of asymmetric disease, it performed poorly in those with symmetric disease.
Ophthalmology, Nov 26, 2013
Purpose
To evaluate the ability of longitudinal frequency doubling technology (FDT) to predict t... more Purpose
To evaluate the ability of longitudinal frequency doubling technology (FDT) to predict the development of glaucomatous visual field loss on standard automated perimetry (SAP) in glaucoma suspects.
Design
Prospective, observational cohort study.
Participants
The study included 587 eyes of 367 patients with suspected glaucoma at baseline selected from the Diagnostic Innovations in Glaucoma Study (DIGS) and the African Descent and Glaucoma Evaluation Study (ADAGES). These eyes had an average of 6.7±1.9 FDT tests during a mean follow-up time of 73.1±28.0 months.
Methods
Glaucoma suspects had intraocular pressure (IOP) >21 mmHg or an optic disc appearance suspicious of glaucoma. All patients had normal or nonrepeatable abnormal SAP at baseline. Humphrey Matrix FDT (Carl Zeiss Meditec, Inc, Dublin, CA) testing was performed within 6 months of SAP testing. The study end point was the development of 3 consecutive abnormal SAP test results. Joint longitudinal survival models were used to evaluate the ability of rates of FDT pattern standard deviation (PSD) change to predict the development of visual field loss on SAP, adjusting for confounding variables (baseline age, mean IOP, corneal thickness, and follow-up measurements of SAP PSD).
Main Outcome Measures
The R2 index was used to evaluate and compare the predictive abilities of the model containing longitudinal FDT PSD data with the model containing only baseline data.
Results
Sixty-three of 587 eyes (11%) developed SAP visual field loss during follow-up. The mean rate of FDT PSD change in eyes that developed SAP visual field loss was 0.07 dB/year versus 0.02 dB/year in those that did not (P < 0.001). Baseline FDT PSD and slopes of FDT PSD change were significantly predictive of progression, with hazard ratios of 1.11 per 0.1 dB higher (95% confidence interval [CI], 1.04–1.18; P = 0.002) and 4.40 per 0.1 dB/year faster (95% CI, 1.08–17.96; P = 0.04), respectively. The longitudinal model performed significantly better than the baseline model with an R2 of 82% (95% CI, 74–89) versus 11% (95% CI, 2–24), respectively.
Conclusions
Rates of FDT PSD change were highly predictive of the development of SAP visual field loss in glaucoma suspects. This finding suggests that longitudinal FDT evaluation may be useful for risk stratification of patients with suspected glaucoma.
IOVS, 2013
Citation: Tatham AJ, Meira-Freitas D, Weinreb RN, Marvasti AH, Zangwill LM, Medeiros FA. Estimati... more Citation: Tatham AJ, Meira-Freitas D, Weinreb RN, Marvasti AH, Zangwill LM, Medeiros FA. Estimation of retinal ganglion cell loss in glaucomatous eyes with a relative afferent pupillary defect. Invest Ophthalmol Vis Sci.
Clinical ophthalmology (Auckland, N.Z.), 2012
Purpose
To evaluate the association between chronic heart failure (CHF) and optic nerve head a... more Purpose
To evaluate the association between chronic heart failure (CHF) and optic nerve head alterations.
Methods
A cross-sectional study was performed. Heart failure patients with recent echocardiograms were subjected to ophthalmologic examinations, including intraocular pressure measurement, optic nerve head, and retinal nerve fiber layer evaluation using stereophotography, Heidelberg retinal tomography, and standard automated perimetry. The ocular findings were correlated with the cardiological evaluation, and compared with a control group without cardiopathy.
Results
A total of 30 patients with CHF and 30 individuals without cardiopathy were enrolled in this study. The mean (standard deviation [SD]) intraocular pressure was 12.3 (2.5) mmHg in the CHF group, and 14.7 (2.9) mmHg in the control group (P < 0.001). The mean (SD) arterial blood pressure was 86.9 (17.1) mmHg in the CHF group, and 103.6 (15.2) mmHg in the control group (P < 0.001). The mean (SD) ocular perfusion pressure was 45.6 (11.1) mmHg in the CHF group, and 54.4 (10.4) mmHg in the control group (P = 0.001). The mean (SD) rim area was 1.41 (0.3) mm2 in the CHF group, and 1.60 (0.26) mm2 in the control group (P = 0.003). The mean (SD) vertical cup/disc ratio was 0.51 (0.17) in the CHF group, and 0.41 (0.18) in the control group (P = 0.02). The Moorfields regression analysis was outside the normal limits in 16 out of 58 (27.6%) eyes of the CHF subjects, and in 4 out of 60 (6.7%) eyes of the control subjects (P = 0.01). The frequency of glaucoma was 10% in the CHF group, whereas none of the control subjects met the criteria for the diagnosis of glaucoma (P = 0.24).
Conclusion
CHF is associated with lower ocular perfusion pressure, and glaucomatous optic nerve head changes.
Arquivos brasileiros de oftalmologia
Purpose: To evaluate the ophthalmic artery hemodynamics in patients with chronic heart failure.
... more Purpose: To evaluate the ophthalmic artery hemodynamics in patients with chronic heart failure.
Methods: Doppler parameters of ophthalmic artery of 18 patients with chronic heart failure in different stages of the disease were compared with 21 healthy volunteers (control group). These parameters were also correlated with echocardiographic assessments and clinical cardiologic status.
Results: Mean diastolic velocity was 5.14 ± 2.4 cm/s in the chronic heart failure group and 7.44 ± 3.5 cm/s in the control group (p=0.007). Mean resistance index of the ophthalmic artery was 0.76 ± 0.08 in the chronic heart failure group and 0.70 ± 0.08 in the control group (p=0.04). Mean systolic velocity of the ophthalmic artery was 22.03 ± 7.7 cm/s in the chronic heart failure group and 25.32 ± 9.2 cm/s in the control group (p=0.24). There was a negative correlation between the resistance index of the ophthalmic artery and systemic blood pressure of patients with chronic heart failure (r= -0.47, p=0.007). Diastolic velocity of the ophthalmic artery correlated positively with systemic blood pressure (r=0.44, p=0.02).
Conclusion: Lower diastolic velocity and higher resistance index were observed in the ophthalmic artery of chronic heart failure patients when compared to the control group, which probably reflects the presence of orbital vasoconstriction in response to low cardiac output. Therefore, the influence of these findings on the structure and function of the optic nerve head deserves investigation.
Arquivos Brasileiros de Oftalmologia, 2013
Arquivos Brasileiros de Oftalmologia, 2013
Purpose: To describe an adjustable suture (AS) experimental model that allows for tightening, loo... more Purpose: To describe an adjustable suture (AS) experimental model that allows for tightening, loosening and retightening of the suture tension in trabeculectomy. Methods: Standard trabeculectomy was performed in fifteen pig eyeballs. All pig eyes were tested twice: one test with conventional suture in both flap’s corners (conventional suture group) and another test with a conventional suture at one corner and an adjustable suture in the other corner (AS group). The order in which each test was performed was defined by randomization. Intraocular pressure was measured at three time points: T1) when the knots were tightened; T2) when the AS was loosened or the conventional knot was removed; and T3) when the AS was retightened in the AS group or five minutes after the knot removal in the conventional suture group.
Results: The mean Intraocular pressure was similar between the two groups at time point 1 (p=0.97). However, significant Intraocular pressure differences were found between eyes in the conventional and adjustable suture groups at time points 2 (12.6 ± 4.2 vs 16.3 ± 2.3 cmH2O, respectively, p=0.006) and 3 (12.2 ± 4.0 vs 26.4±1.7cmH2O,respectively;p=0.001).Whiletheconventionaltechniqueallowed only Intraocular pressure reduction (following the knot removal; T2 and T3), the AS technique allowed both Intraocular pressure reduction (T2) and elevation (T3) through the management (loosening and retightening) of the suture. conclusion: This experimental model provides an effective noninvasive posto- perative mechanism of suture tension adjustment.
Optical coherence tomography (OCT) is capable of providing quantitative and objective assessments... more Optical coherence tomography (OCT) is capable of providing quantitative and objective assessments of the optic disc, macula and retinal nerve fiber layer in glaucoma. The recent advent of spectral domain OCT (SD-OCT) has enhanced the resolution, decreased scan acquisition time, and improved the reproducibility of measurements compared to older versions of this technology. However, although OCT has been successfully used for detection of disease and evaluation of progression, the limited agreement between structural and functional tests indicates the strong need for a combined approach for detecting and monitoring the disease. A recently described approach for estimation of rates of retinal ganglion cell loss from a combination of SD-OCT and functional data is a promising method for diagnosing, staging, detecting progression, and estimating rates of glaucomatous deterioration.
Investigative ophthalmology & visual science, 2013
Purpose: To evaluate the ability of baseline and longitudinal estimates of retinal ganglion cell ... more Purpose: To evaluate the ability of baseline and longitudinal estimates of retinal ganglion cell (RGC) counts in predicting progression in eyes suspected of having glaucoma. Methods: The study included 288 glaucoma suspect eyes of 288 patients followed for an average of 3.8 ± 1.0 years. Participants had normal standard automated perimetry (SAP) at baseline. Retinal nerve fiber layer thickness assessment was performed with optical coherence tomography (OCT). Progression was defined as development of repeatable abnormal SAP or glaucomatous progressive optic disc changes. Estimates of RGC counts were obtained by combining data from SAP and OCT according to previously described method. Joint longitudinal survival models were used to evaluate the ability of baseline and rates of change in estimated RGC counts for predicting progression over time, adjusting for confounding variables. Results: Forty-eight eyes (17%) showed progression during follow-up. The mean rate of change in estimated RGC counts was -18,987 cells/year in progressors versus -8,808 cells/year for nonprogressors (P<0.001). Baseline RGC counts and slopes of RGC loss were significantly predictive of progression, with HRs of 1.56 per 100,000 cells lower (95% CI: 1.18 - 2.08; P=0.002) and 2.68 per 10,000 cells/year faster loss (95% CI: 1.22 - 5.90; P=0.014), respectively. The longitudinal model including estimates of RGC counts performed significantly better than models including only structural or functional indexes separately. Conclusion: Baseline and longitudinal estimates of RGC counts may be helpful in predicting progression and performed significantly better than conventional approaches for risk stratification of glaucoma suspects.
Ophthalmology, 2013
Purpose
To evaluate the role of corneal hysteresis (CH) as a risk factor for the rate of visual ... more Purpose
To evaluate the role of corneal hysteresis (CH) as a risk factor for the rate of visual field progression in a cohort of patients with glaucoma followed prospectively over time.
Design
Prospective observational cohort study.
Participants
The study group included 114 eyes of 68 patients with glaucoma followed for an average of 4.0±1.1 years. Visual fields were obtained with standard automated perimetry. Included eyes had a median number of 7 (range, 5–12) tests during follow-up.
Methods
The CH measurements were acquired at baseline using the Ocular Response Analyzer (Reichert Instruments, Depew, NY). Evaluation of rates of visual field change during follow-up was performed using the visual field index (VFI). Linear mixed models were used to investigate the relationship between rates of visual field loss and baseline CH, baseline intraocular pressure (IOP), and central corneal thickness (CCT), while adjusting for potentially confounding factors. An interaction term between IOP and CH was included in the model to investigate whether the effect of IOP on rates of progression depended on the level of CH.
Main Outcome Measures
Effects of CH, IOP, and CCT on rates of VFI loss over time.
Results
The CH had a significant effect on rates of visual field progression over time. In the univariable model including only CH as a predictive factor along with time and their interaction, each 1 mmHg lower CH was associated with a 0.25%/year faster rate of VFI decline over time (P < 0.001). The multivariable model showed that the effect of IOP on rates of progression depended on CH. Eyes with high IOP and low CH were at increased risk for having fast rates of disease progression. The CH explained a larger proportion of the variation in slopes of VFI change than CCT (17.4% vs. 5.2%, respectively).
Conclusions
The CH measurements were significantly associated with risk of glaucoma progression. Eyes with lower CH had faster rates of visual field loss than those with higher CH. The prospective longitudinal design of this study supports the role of CH as an important factor to be considered in the assessment of the risk of progression in patients with glaucoma.
Arquivos brasileiros de oftalmologia
Purpose: To determine factors associated with the test-retest variability of
optic nerve head (O... more Purpose: To determine factors associated with the test-retest variability of
optic nerve head (ONH) topography measurements with confocal scanning
laser ophthalmoscopy (CSLO) in newly diagnosed glaucomatous patients.
Methods: Consecutive patients with newly diagnosed primary open-angle
glaucoma were prospectively enrolled. Patients presenting with any ocular
disease other than glaucoma were excluded. All patients underwent CSLO
using the Heidelberg Retina Tomograph III (HRT-III) in one randomly selected
eye (three consecutive scans; performed by the same examiner). For each
Heidelberg Retina Tomograph III parameter, repeatability was assessed using
within subject standard deviation (Sw) and coefficient of variation (CVw), repeatability
coefficient (RC) and intraclass correlation coefficient (ICC). Scatter
plots and regression lines were constructed to identify which factors influenced
test-retest measurement variability.
Results: A total of 32 patients were included (mean age, 65.4 ± 13.8 years).
Most patients were female (65%) and white (50%). Among all Heidelberg
Retina Tomograph III parameters evaluated, rim area and mean cup depth had
the best measurement repeatability. Vertical cup-to-disc ratio (CDR, as determined
by optic disc stereophotograph examination) was significantly associated
(R2=0.21, p<0.01) with test-retest measurement variability. Eyes with larger
CDR showed less variable measurements. Other factors, including age, disc
area, central corneal thickness and intraocular pressure were not significant
(p>0.14).
Conclusion: Heidelberg Retina Tomograph III showed good test-retest repeatability
for all ONH topographic measurements, mainly for rim area and
mean cup depth. Test-retest repeatability seemed to improve with increasing
CDR. These findings suggest that HRT-III topographic measurements should
be cautiously interpreted when evaluating longitudinally glaucoma patients
with early structural damage (small CDR).
Acupuncture in Medicine, 2010
Purpose To evaluate the short-term effect of acupuncture on the intraocular pressure (IOP) in hea... more Purpose To evaluate the short-term effect of acupuncture on the intraocular pressure (IOP) in healthy subjects.
Methods A randomised controlled double-blinded trial was performed. 48 healthy volunteers (94 eyes) were randomly allocated to three groups: acupuncture group—19 subjects (38 eyes) were submitted to a 20 min session of acupuncture (GB1, GB14 and BL1); sham group—14 subjects (27 eyes) were submitted to a 20 min session of acupuncture with needles inserted in false points; and control group—15 subjects (29 eyes) who underwent no intervention. All subjects had the IOP measured by a masked investigator using Goldmann applanation tonometry immediately before intervention, as well as 20 min and 24 h after.
Results The mean (SD) IOP in the acupuncture group was 17.9 (3.3) mm Hg at baseline, 16.4 (3.9) mm Hg at 20 min and 16.3 (3.3) mm Hg at 24 h. The mean (SD) IOP in the sham group was 18.6 (3.3) mm Hg at baseline, 17.7 (2.6) mm Hg at 20 min and 15.9 (3.6) mm Hg at 24 h. The mean (SD) IOP in the control group was 16.9 (3.5) mm Hg at baseline, 16.5 (3.8) mm Hg at 20 min and 15.8 (3.3) mm Hg at 24 h. There was no statistically significant difference in the IOP variation (post-intervention minus baseline measurements) between groups after 20 min (p=0.13) and 24 h (p=0.21).
Conclusion Acupuncture in the studied points did not produce significant short-term effect on the IOP of healthy individuals in comparison with control groups.
Arquivos Brasileiros De Oftalmologia, 2009
The optical coherence tomography (OCT) and indocyanine green angiography (ICGA) findings of a 58-... more The optical coherence tomography (OCT) and indocyanine green angiography (ICGA) findings of a 58-year-old male with acute syphilitic posterior placoid chorioretinitis are reported herein. Best-corrected visual acuity was 20/150 in the right eye (OD) and 20/30 in the left eye (OS) at presentation. On funduscopy, there was a central subretinal placoid yellowish lesion in OD. VDRL and serum FTA-ABS were positive. OCT showed increased reflectance and thickening of the subfoveal RPE choriocapillaris complex corresponding to the lesion in OD. ICGA revealed a hypofluorescent spot corresponding to the lesion in OD and confluent small dots extending to periphery, without any correspondence in fundus examination. The same dots were also seen in OS, even though no lesions could be observed clinically. Intravenous ceftriaxone 2 g daily was given for 10 days. One month after the first visit, visual acuity improved to 20/30 and marked improvement of the lesion was seen. OCT was normal in both eyes at the final visit.
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Papers by Daniel Meira Freitas
Design: Cross-sectional observational study.
Methods: Setting: Hamilton Glaucoma Center, University of California San Diego.
Patient Population: 158 subjects from the Diagnostic Innovations in Glaucoma Study, including 82 with glaucoma and 76 similarly aged controls.
Observation Procedure: Ability to divide attention was investigated by measuring reaction times to peripheral stimuli (at low, medium or high contrast) while concomitantly performing a central driving task (car following or curve negotiation). All subjects had standard automated perimetry (SAP) and optical coherence tomography was used to measured retinal nerve fiber (RNFL) thickness. Cognitive ability was assessed using the Montreal Cognitive Assessment and subjects completed a driving history questionnaire.
Main outcome measures: Reaction times to the driving simulator divided attention task.
Results: The mean reaction times to the low contrast stimulus were 1.05 s and 0.64 s in glaucoma and controls respectively during curve negotiation (P <0.001), and 1.19 s and 0.77 s (P = 0.025) respectively during car following. There was a non-linear relationship between reaction times and RNFL thickness in the better eye. RNFL thickness remained significantly associated with reaction times even after adjusting for age, SAP mean deviation in the better eye, cognitive ability and central driving task performance.
Conclusions: Although worse SAP sensitivity was associated with worse ability to divide attention, RNFL thickness measurements provided additional information. Information from structural tests may improve our ability to determine which patients are likely to have problems performing daily activities, such as driving.
To identify the most commonly used statistical analyses in the ophthalmic literature and to determine the likely gain in comprehension of the literature that readers could expect if they were to add knowledge of more advanced techniques sequentially to their statistical repertoire.
Design
Cross-sectional study.
Methods
All articles published from January 2012 through December 2012 in Ophthalmology, the American Journal of Ophthalmology, and Archives of Ophthalmology were reviewed. A total of 780 peer-reviewed articles were included. Two reviewers examined each article and assigned categories to each one depending on the type of statistical analyses used. Discrepancies between reviewers were resolved by consensus.
Main Outcome Measures
Total number and percentage of articles containing each category of statistical analysis were obtained. Additionally, we estimated the accumulated number and percentage of articles that a reader would be expected to be able to interpret depending on their statistical repertoire.
Results
Readers with little or no statistical knowledge would be expected to be able to interpret the statistical methods presented in only 20.8% of articles. To understand more than half (51.4%) of the articles published, readers would be expected to be familiar with at least 15 different statistical methods. Knowledge of 21 categories of statistical methods was necessary to comprehend 70.9% of articles, whereas knowledge of more than 29 categories was necessary to comprehend more than 90% of articles. Articles related to retina and glaucoma subspecialties showed a tendency for using more complex analysis when compared with articles from the cornea subspecialty.
Conclusions
Readers of clinical journals in ophthalmology need to have substantial knowledge of statistical methodology to understand the results of studies published in the literature. The frequency of the use of complex statistical analyses also indicates that those involved in the editorial peer-review process must have sound statistical knowledge to appraise critically the articles submitted for publication. The results of this study could provide guidance to direct the statistical learning of clinical ophthalmologists, researchers, and educators involved in the design of courses for residents and medical students.
To evaluate the ability of a binocular automated pupillograph to discriminate healthy subjects from those with glaucoma.
DESIGN:
Cross-sectional observational study.
PARTICIPANTS:
Both eyes of 116 subjects, including 66 patients with glaucoma in at least 1 eye and 50 healthy subjects from the Diagnostic Innovations in Glaucoma Study. Eyes were classified as glaucomatous by repeatable abnormal standard automated perimetry (SAP) or progressive glaucomatous changes on stereophotographs.
METHODS:
All subjects underwent automated pupillography using the RAPDx pupillograph (Konan Medical USA, Inc., Irvine, CA).
MAIN OUTCOME MEASURES:
Receiver operating characteristic (ROC) curves were constructed to assess the diagnostic ability of pupil response parameters to white, red, green, yellow, and blue full-field and regional stimuli. A ROC regression model was used to investigate the influence of disease severity and asymmetry on diagnostic ability.
RESULTS:
The largest area under the ROC curve (AUC) for any single parameter was 0.75. Disease asymmetry (P <0.001), but not disease severity (P = 0.058), had a significant effect on diagnostic ability. At the sample mean age (60.9 years), AUCs for arbitrary values of intereye difference in SAP mean deviation (MD) of 0, 5, 10, and 15 dB were 0.58, 0.71, 0.82, and 0.90, respectively. The mean intereye difference in MD was 2.2±3.1 dB. The best combination of parameters had an AUC of 0.85; however, the cross-validated bias-corrected AUC for these parameters was only 0.74.
CONCLUSIONS:
Although the pupillograph had a good ability to detect glaucoma in the presence of asymmetric disease, it performed poorly in those with symmetric disease.
To evaluate the ability of longitudinal frequency doubling technology (FDT) to predict the development of glaucomatous visual field loss on standard automated perimetry (SAP) in glaucoma suspects.
Design
Prospective, observational cohort study.
Participants
The study included 587 eyes of 367 patients with suspected glaucoma at baseline selected from the Diagnostic Innovations in Glaucoma Study (DIGS) and the African Descent and Glaucoma Evaluation Study (ADAGES). These eyes had an average of 6.7±1.9 FDT tests during a mean follow-up time of 73.1±28.0 months.
Methods
Glaucoma suspects had intraocular pressure (IOP) >21 mmHg or an optic disc appearance suspicious of glaucoma. All patients had normal or nonrepeatable abnormal SAP at baseline. Humphrey Matrix FDT (Carl Zeiss Meditec, Inc, Dublin, CA) testing was performed within 6 months of SAP testing. The study end point was the development of 3 consecutive abnormal SAP test results. Joint longitudinal survival models were used to evaluate the ability of rates of FDT pattern standard deviation (PSD) change to predict the development of visual field loss on SAP, adjusting for confounding variables (baseline age, mean IOP, corneal thickness, and follow-up measurements of SAP PSD).
Main Outcome Measures
The R2 index was used to evaluate and compare the predictive abilities of the model containing longitudinal FDT PSD data with the model containing only baseline data.
Results
Sixty-three of 587 eyes (11%) developed SAP visual field loss during follow-up. The mean rate of FDT PSD change in eyes that developed SAP visual field loss was 0.07 dB/year versus 0.02 dB/year in those that did not (P < 0.001). Baseline FDT PSD and slopes of FDT PSD change were significantly predictive of progression, with hazard ratios of 1.11 per 0.1 dB higher (95% confidence interval [CI], 1.04–1.18; P = 0.002) and 4.40 per 0.1 dB/year faster (95% CI, 1.08–17.96; P = 0.04), respectively. The longitudinal model performed significantly better than the baseline model with an R2 of 82% (95% CI, 74–89) versus 11% (95% CI, 2–24), respectively.
Conclusions
Rates of FDT PSD change were highly predictive of the development of SAP visual field loss in glaucoma suspects. This finding suggests that longitudinal FDT evaluation may be useful for risk stratification of patients with suspected glaucoma.
To evaluate the association between chronic heart failure (CHF) and optic nerve head alterations.
Methods
A cross-sectional study was performed. Heart failure patients with recent echocardiograms were subjected to ophthalmologic examinations, including intraocular pressure measurement, optic nerve head, and retinal nerve fiber layer evaluation using stereophotography, Heidelberg retinal tomography, and standard automated perimetry. The ocular findings were correlated with the cardiological evaluation, and compared with a control group without cardiopathy.
Results
A total of 30 patients with CHF and 30 individuals without cardiopathy were enrolled in this study. The mean (standard deviation [SD]) intraocular pressure was 12.3 (2.5) mmHg in the CHF group, and 14.7 (2.9) mmHg in the control group (P < 0.001). The mean (SD) arterial blood pressure was 86.9 (17.1) mmHg in the CHF group, and 103.6 (15.2) mmHg in the control group (P < 0.001). The mean (SD) ocular perfusion pressure was 45.6 (11.1) mmHg in the CHF group, and 54.4 (10.4) mmHg in the control group (P = 0.001). The mean (SD) rim area was 1.41 (0.3) mm2 in the CHF group, and 1.60 (0.26) mm2 in the control group (P = 0.003). The mean (SD) vertical cup/disc ratio was 0.51 (0.17) in the CHF group, and 0.41 (0.18) in the control group (P = 0.02). The Moorfields regression analysis was outside the normal limits in 16 out of 58 (27.6%) eyes of the CHF subjects, and in 4 out of 60 (6.7%) eyes of the control subjects (P = 0.01). The frequency of glaucoma was 10% in the CHF group, whereas none of the control subjects met the criteria for the diagnosis of glaucoma (P = 0.24).
Conclusion
CHF is associated with lower ocular perfusion pressure, and glaucomatous optic nerve head changes.
Methods: Doppler parameters of ophthalmic artery of 18 patients with chronic heart failure in different stages of the disease were compared with 21 healthy volunteers (control group). These parameters were also correlated with echocardiographic assessments and clinical cardiologic status.
Results: Mean diastolic velocity was 5.14 ± 2.4 cm/s in the chronic heart failure group and 7.44 ± 3.5 cm/s in the control group (p=0.007). Mean resistance index of the ophthalmic artery was 0.76 ± 0.08 in the chronic heart failure group and 0.70 ± 0.08 in the control group (p=0.04). Mean systolic velocity of the ophthalmic artery was 22.03 ± 7.7 cm/s in the chronic heart failure group and 25.32 ± 9.2 cm/s in the control group (p=0.24). There was a negative correlation between the resistance index of the ophthalmic artery and systemic blood pressure of patients with chronic heart failure (r= -0.47, p=0.007). Diastolic velocity of the ophthalmic artery correlated positively with systemic blood pressure (r=0.44, p=0.02).
Conclusion: Lower diastolic velocity and higher resistance index were observed in the ophthalmic artery of chronic heart failure patients when compared to the control group, which probably reflects the presence of orbital vasoconstriction in response to low cardiac output. Therefore, the influence of these findings on the structure and function of the optic nerve head deserves investigation.
Results: The mean Intraocular pressure was similar between the two groups at time point 1 (p=0.97). However, significant Intraocular pressure differences were found between eyes in the conventional and adjustable suture groups at time points 2 (12.6 ± 4.2 vs 16.3 ± 2.3 cmH2O, respectively, p=0.006) and 3 (12.2 ± 4.0 vs 26.4±1.7cmH2O,respectively;p=0.001).Whiletheconventionaltechniqueallowed only Intraocular pressure reduction (following the knot removal; T2 and T3), the AS technique allowed both Intraocular pressure reduction (T2) and elevation (T3) through the management (loosening and retightening) of the suture. conclusion: This experimental model provides an effective noninvasive posto- perative mechanism of suture tension adjustment.
To evaluate the role of corneal hysteresis (CH) as a risk factor for the rate of visual field progression in a cohort of patients with glaucoma followed prospectively over time.
Design
Prospective observational cohort study.
Participants
The study group included 114 eyes of 68 patients with glaucoma followed for an average of 4.0±1.1 years. Visual fields were obtained with standard automated perimetry. Included eyes had a median number of 7 (range, 5–12) tests during follow-up.
Methods
The CH measurements were acquired at baseline using the Ocular Response Analyzer (Reichert Instruments, Depew, NY). Evaluation of rates of visual field change during follow-up was performed using the visual field index (VFI). Linear mixed models were used to investigate the relationship between rates of visual field loss and baseline CH, baseline intraocular pressure (IOP), and central corneal thickness (CCT), while adjusting for potentially confounding factors. An interaction term between IOP and CH was included in the model to investigate whether the effect of IOP on rates of progression depended on the level of CH.
Main Outcome Measures
Effects of CH, IOP, and CCT on rates of VFI loss over time.
Results
The CH had a significant effect on rates of visual field progression over time. In the univariable model including only CH as a predictive factor along with time and their interaction, each 1 mmHg lower CH was associated with a 0.25%/year faster rate of VFI decline over time (P < 0.001). The multivariable model showed that the effect of IOP on rates of progression depended on CH. Eyes with high IOP and low CH were at increased risk for having fast rates of disease progression. The CH explained a larger proportion of the variation in slopes of VFI change than CCT (17.4% vs. 5.2%, respectively).
Conclusions
The CH measurements were significantly associated with risk of glaucoma progression. Eyes with lower CH had faster rates of visual field loss than those with higher CH. The prospective longitudinal design of this study supports the role of CH as an important factor to be considered in the assessment of the risk of progression in patients with glaucoma.
optic nerve head (ONH) topography measurements with confocal scanning
laser ophthalmoscopy (CSLO) in newly diagnosed glaucomatous patients.
Methods: Consecutive patients with newly diagnosed primary open-angle
glaucoma were prospectively enrolled. Patients presenting with any ocular
disease other than glaucoma were excluded. All patients underwent CSLO
using the Heidelberg Retina Tomograph III (HRT-III) in one randomly selected
eye (three consecutive scans; performed by the same examiner). For each
Heidelberg Retina Tomograph III parameter, repeatability was assessed using
within subject standard deviation (Sw) and coefficient of variation (CVw), repeatability
coefficient (RC) and intraclass correlation coefficient (ICC). Scatter
plots and regression lines were constructed to identify which factors influenced
test-retest measurement variability.
Results: A total of 32 patients were included (mean age, 65.4 ± 13.8 years).
Most patients were female (65%) and white (50%). Among all Heidelberg
Retina Tomograph III parameters evaluated, rim area and mean cup depth had
the best measurement repeatability. Vertical cup-to-disc ratio (CDR, as determined
by optic disc stereophotograph examination) was significantly associated
(R2=0.21, p<0.01) with test-retest measurement variability. Eyes with larger
CDR showed less variable measurements. Other factors, including age, disc
area, central corneal thickness and intraocular pressure were not significant
(p>0.14).
Conclusion: Heidelberg Retina Tomograph III showed good test-retest repeatability
for all ONH topographic measurements, mainly for rim area and
mean cup depth. Test-retest repeatability seemed to improve with increasing
CDR. These findings suggest that HRT-III topographic measurements should
be cautiously interpreted when evaluating longitudinally glaucoma patients
with early structural damage (small CDR).
Methods A randomised controlled double-blinded trial was performed. 48 healthy volunteers (94 eyes) were randomly allocated to three groups: acupuncture group—19 subjects (38 eyes) were submitted to a 20 min session of acupuncture (GB1, GB14 and BL1); sham group—14 subjects (27 eyes) were submitted to a 20 min session of acupuncture with needles inserted in false points; and control group—15 subjects (29 eyes) who underwent no intervention. All subjects had the IOP measured by a masked investigator using Goldmann applanation tonometry immediately before intervention, as well as 20 min and 24 h after.
Results The mean (SD) IOP in the acupuncture group was 17.9 (3.3) mm Hg at baseline, 16.4 (3.9) mm Hg at 20 min and 16.3 (3.3) mm Hg at 24 h. The mean (SD) IOP in the sham group was 18.6 (3.3) mm Hg at baseline, 17.7 (2.6) mm Hg at 20 min and 15.9 (3.6) mm Hg at 24 h. The mean (SD) IOP in the control group was 16.9 (3.5) mm Hg at baseline, 16.5 (3.8) mm Hg at 20 min and 15.8 (3.3) mm Hg at 24 h. There was no statistically significant difference in the IOP variation (post-intervention minus baseline measurements) between groups after 20 min (p=0.13) and 24 h (p=0.21).
Conclusion Acupuncture in the studied points did not produce significant short-term effect on the IOP of healthy individuals in comparison with control groups.
Design: Cross-sectional observational study.
Methods: Setting: Hamilton Glaucoma Center, University of California San Diego.
Patient Population: 158 subjects from the Diagnostic Innovations in Glaucoma Study, including 82 with glaucoma and 76 similarly aged controls.
Observation Procedure: Ability to divide attention was investigated by measuring reaction times to peripheral stimuli (at low, medium or high contrast) while concomitantly performing a central driving task (car following or curve negotiation). All subjects had standard automated perimetry (SAP) and optical coherence tomography was used to measured retinal nerve fiber (RNFL) thickness. Cognitive ability was assessed using the Montreal Cognitive Assessment and subjects completed a driving history questionnaire.
Main outcome measures: Reaction times to the driving simulator divided attention task.
Results: The mean reaction times to the low contrast stimulus were 1.05 s and 0.64 s in glaucoma and controls respectively during curve negotiation (P <0.001), and 1.19 s and 0.77 s (P = 0.025) respectively during car following. There was a non-linear relationship between reaction times and RNFL thickness in the better eye. RNFL thickness remained significantly associated with reaction times even after adjusting for age, SAP mean deviation in the better eye, cognitive ability and central driving task performance.
Conclusions: Although worse SAP sensitivity was associated with worse ability to divide attention, RNFL thickness measurements provided additional information. Information from structural tests may improve our ability to determine which patients are likely to have problems performing daily activities, such as driving.
To identify the most commonly used statistical analyses in the ophthalmic literature and to determine the likely gain in comprehension of the literature that readers could expect if they were to add knowledge of more advanced techniques sequentially to their statistical repertoire.
Design
Cross-sectional study.
Methods
All articles published from January 2012 through December 2012 in Ophthalmology, the American Journal of Ophthalmology, and Archives of Ophthalmology were reviewed. A total of 780 peer-reviewed articles were included. Two reviewers examined each article and assigned categories to each one depending on the type of statistical analyses used. Discrepancies between reviewers were resolved by consensus.
Main Outcome Measures
Total number and percentage of articles containing each category of statistical analysis were obtained. Additionally, we estimated the accumulated number and percentage of articles that a reader would be expected to be able to interpret depending on their statistical repertoire.
Results
Readers with little or no statistical knowledge would be expected to be able to interpret the statistical methods presented in only 20.8% of articles. To understand more than half (51.4%) of the articles published, readers would be expected to be familiar with at least 15 different statistical methods. Knowledge of 21 categories of statistical methods was necessary to comprehend 70.9% of articles, whereas knowledge of more than 29 categories was necessary to comprehend more than 90% of articles. Articles related to retina and glaucoma subspecialties showed a tendency for using more complex analysis when compared with articles from the cornea subspecialty.
Conclusions
Readers of clinical journals in ophthalmology need to have substantial knowledge of statistical methodology to understand the results of studies published in the literature. The frequency of the use of complex statistical analyses also indicates that those involved in the editorial peer-review process must have sound statistical knowledge to appraise critically the articles submitted for publication. The results of this study could provide guidance to direct the statistical learning of clinical ophthalmologists, researchers, and educators involved in the design of courses for residents and medical students.
To evaluate the ability of a binocular automated pupillograph to discriminate healthy subjects from those with glaucoma.
DESIGN:
Cross-sectional observational study.
PARTICIPANTS:
Both eyes of 116 subjects, including 66 patients with glaucoma in at least 1 eye and 50 healthy subjects from the Diagnostic Innovations in Glaucoma Study. Eyes were classified as glaucomatous by repeatable abnormal standard automated perimetry (SAP) or progressive glaucomatous changes on stereophotographs.
METHODS:
All subjects underwent automated pupillography using the RAPDx pupillograph (Konan Medical USA, Inc., Irvine, CA).
MAIN OUTCOME MEASURES:
Receiver operating characteristic (ROC) curves were constructed to assess the diagnostic ability of pupil response parameters to white, red, green, yellow, and blue full-field and regional stimuli. A ROC regression model was used to investigate the influence of disease severity and asymmetry on diagnostic ability.
RESULTS:
The largest area under the ROC curve (AUC) for any single parameter was 0.75. Disease asymmetry (P <0.001), but not disease severity (P = 0.058), had a significant effect on diagnostic ability. At the sample mean age (60.9 years), AUCs for arbitrary values of intereye difference in SAP mean deviation (MD) of 0, 5, 10, and 15 dB were 0.58, 0.71, 0.82, and 0.90, respectively. The mean intereye difference in MD was 2.2±3.1 dB. The best combination of parameters had an AUC of 0.85; however, the cross-validated bias-corrected AUC for these parameters was only 0.74.
CONCLUSIONS:
Although the pupillograph had a good ability to detect glaucoma in the presence of asymmetric disease, it performed poorly in those with symmetric disease.
To evaluate the ability of longitudinal frequency doubling technology (FDT) to predict the development of glaucomatous visual field loss on standard automated perimetry (SAP) in glaucoma suspects.
Design
Prospective, observational cohort study.
Participants
The study included 587 eyes of 367 patients with suspected glaucoma at baseline selected from the Diagnostic Innovations in Glaucoma Study (DIGS) and the African Descent and Glaucoma Evaluation Study (ADAGES). These eyes had an average of 6.7±1.9 FDT tests during a mean follow-up time of 73.1±28.0 months.
Methods
Glaucoma suspects had intraocular pressure (IOP) >21 mmHg or an optic disc appearance suspicious of glaucoma. All patients had normal or nonrepeatable abnormal SAP at baseline. Humphrey Matrix FDT (Carl Zeiss Meditec, Inc, Dublin, CA) testing was performed within 6 months of SAP testing. The study end point was the development of 3 consecutive abnormal SAP test results. Joint longitudinal survival models were used to evaluate the ability of rates of FDT pattern standard deviation (PSD) change to predict the development of visual field loss on SAP, adjusting for confounding variables (baseline age, mean IOP, corneal thickness, and follow-up measurements of SAP PSD).
Main Outcome Measures
The R2 index was used to evaluate and compare the predictive abilities of the model containing longitudinal FDT PSD data with the model containing only baseline data.
Results
Sixty-three of 587 eyes (11%) developed SAP visual field loss during follow-up. The mean rate of FDT PSD change in eyes that developed SAP visual field loss was 0.07 dB/year versus 0.02 dB/year in those that did not (P < 0.001). Baseline FDT PSD and slopes of FDT PSD change were significantly predictive of progression, with hazard ratios of 1.11 per 0.1 dB higher (95% confidence interval [CI], 1.04–1.18; P = 0.002) and 4.40 per 0.1 dB/year faster (95% CI, 1.08–17.96; P = 0.04), respectively. The longitudinal model performed significantly better than the baseline model with an R2 of 82% (95% CI, 74–89) versus 11% (95% CI, 2–24), respectively.
Conclusions
Rates of FDT PSD change were highly predictive of the development of SAP visual field loss in glaucoma suspects. This finding suggests that longitudinal FDT evaluation may be useful for risk stratification of patients with suspected glaucoma.
To evaluate the association between chronic heart failure (CHF) and optic nerve head alterations.
Methods
A cross-sectional study was performed. Heart failure patients with recent echocardiograms were subjected to ophthalmologic examinations, including intraocular pressure measurement, optic nerve head, and retinal nerve fiber layer evaluation using stereophotography, Heidelberg retinal tomography, and standard automated perimetry. The ocular findings were correlated with the cardiological evaluation, and compared with a control group without cardiopathy.
Results
A total of 30 patients with CHF and 30 individuals without cardiopathy were enrolled in this study. The mean (standard deviation [SD]) intraocular pressure was 12.3 (2.5) mmHg in the CHF group, and 14.7 (2.9) mmHg in the control group (P < 0.001). The mean (SD) arterial blood pressure was 86.9 (17.1) mmHg in the CHF group, and 103.6 (15.2) mmHg in the control group (P < 0.001). The mean (SD) ocular perfusion pressure was 45.6 (11.1) mmHg in the CHF group, and 54.4 (10.4) mmHg in the control group (P = 0.001). The mean (SD) rim area was 1.41 (0.3) mm2 in the CHF group, and 1.60 (0.26) mm2 in the control group (P = 0.003). The mean (SD) vertical cup/disc ratio was 0.51 (0.17) in the CHF group, and 0.41 (0.18) in the control group (P = 0.02). The Moorfields regression analysis was outside the normal limits in 16 out of 58 (27.6%) eyes of the CHF subjects, and in 4 out of 60 (6.7%) eyes of the control subjects (P = 0.01). The frequency of glaucoma was 10% in the CHF group, whereas none of the control subjects met the criteria for the diagnosis of glaucoma (P = 0.24).
Conclusion
CHF is associated with lower ocular perfusion pressure, and glaucomatous optic nerve head changes.
Methods: Doppler parameters of ophthalmic artery of 18 patients with chronic heart failure in different stages of the disease were compared with 21 healthy volunteers (control group). These parameters were also correlated with echocardiographic assessments and clinical cardiologic status.
Results: Mean diastolic velocity was 5.14 ± 2.4 cm/s in the chronic heart failure group and 7.44 ± 3.5 cm/s in the control group (p=0.007). Mean resistance index of the ophthalmic artery was 0.76 ± 0.08 in the chronic heart failure group and 0.70 ± 0.08 in the control group (p=0.04). Mean systolic velocity of the ophthalmic artery was 22.03 ± 7.7 cm/s in the chronic heart failure group and 25.32 ± 9.2 cm/s in the control group (p=0.24). There was a negative correlation between the resistance index of the ophthalmic artery and systemic blood pressure of patients with chronic heart failure (r= -0.47, p=0.007). Diastolic velocity of the ophthalmic artery correlated positively with systemic blood pressure (r=0.44, p=0.02).
Conclusion: Lower diastolic velocity and higher resistance index were observed in the ophthalmic artery of chronic heart failure patients when compared to the control group, which probably reflects the presence of orbital vasoconstriction in response to low cardiac output. Therefore, the influence of these findings on the structure and function of the optic nerve head deserves investigation.
Results: The mean Intraocular pressure was similar between the two groups at time point 1 (p=0.97). However, significant Intraocular pressure differences were found between eyes in the conventional and adjustable suture groups at time points 2 (12.6 ± 4.2 vs 16.3 ± 2.3 cmH2O, respectively, p=0.006) and 3 (12.2 ± 4.0 vs 26.4±1.7cmH2O,respectively;p=0.001).Whiletheconventionaltechniqueallowed only Intraocular pressure reduction (following the knot removal; T2 and T3), the AS technique allowed both Intraocular pressure reduction (T2) and elevation (T3) through the management (loosening and retightening) of the suture. conclusion: This experimental model provides an effective noninvasive posto- perative mechanism of suture tension adjustment.
To evaluate the role of corneal hysteresis (CH) as a risk factor for the rate of visual field progression in a cohort of patients with glaucoma followed prospectively over time.
Design
Prospective observational cohort study.
Participants
The study group included 114 eyes of 68 patients with glaucoma followed for an average of 4.0±1.1 years. Visual fields were obtained with standard automated perimetry. Included eyes had a median number of 7 (range, 5–12) tests during follow-up.
Methods
The CH measurements were acquired at baseline using the Ocular Response Analyzer (Reichert Instruments, Depew, NY). Evaluation of rates of visual field change during follow-up was performed using the visual field index (VFI). Linear mixed models were used to investigate the relationship between rates of visual field loss and baseline CH, baseline intraocular pressure (IOP), and central corneal thickness (CCT), while adjusting for potentially confounding factors. An interaction term between IOP and CH was included in the model to investigate whether the effect of IOP on rates of progression depended on the level of CH.
Main Outcome Measures
Effects of CH, IOP, and CCT on rates of VFI loss over time.
Results
The CH had a significant effect on rates of visual field progression over time. In the univariable model including only CH as a predictive factor along with time and their interaction, each 1 mmHg lower CH was associated with a 0.25%/year faster rate of VFI decline over time (P < 0.001). The multivariable model showed that the effect of IOP on rates of progression depended on CH. Eyes with high IOP and low CH were at increased risk for having fast rates of disease progression. The CH explained a larger proportion of the variation in slopes of VFI change than CCT (17.4% vs. 5.2%, respectively).
Conclusions
The CH measurements were significantly associated with risk of glaucoma progression. Eyes with lower CH had faster rates of visual field loss than those with higher CH. The prospective longitudinal design of this study supports the role of CH as an important factor to be considered in the assessment of the risk of progression in patients with glaucoma.
optic nerve head (ONH) topography measurements with confocal scanning
laser ophthalmoscopy (CSLO) in newly diagnosed glaucomatous patients.
Methods: Consecutive patients with newly diagnosed primary open-angle
glaucoma were prospectively enrolled. Patients presenting with any ocular
disease other than glaucoma were excluded. All patients underwent CSLO
using the Heidelberg Retina Tomograph III (HRT-III) in one randomly selected
eye (three consecutive scans; performed by the same examiner). For each
Heidelberg Retina Tomograph III parameter, repeatability was assessed using
within subject standard deviation (Sw) and coefficient of variation (CVw), repeatability
coefficient (RC) and intraclass correlation coefficient (ICC). Scatter
plots and regression lines were constructed to identify which factors influenced
test-retest measurement variability.
Results: A total of 32 patients were included (mean age, 65.4 ± 13.8 years).
Most patients were female (65%) and white (50%). Among all Heidelberg
Retina Tomograph III parameters evaluated, rim area and mean cup depth had
the best measurement repeatability. Vertical cup-to-disc ratio (CDR, as determined
by optic disc stereophotograph examination) was significantly associated
(R2=0.21, p<0.01) with test-retest measurement variability. Eyes with larger
CDR showed less variable measurements. Other factors, including age, disc
area, central corneal thickness and intraocular pressure were not significant
(p>0.14).
Conclusion: Heidelberg Retina Tomograph III showed good test-retest repeatability
for all ONH topographic measurements, mainly for rim area and
mean cup depth. Test-retest repeatability seemed to improve with increasing
CDR. These findings suggest that HRT-III topographic measurements should
be cautiously interpreted when evaluating longitudinally glaucoma patients
with early structural damage (small CDR).
Methods A randomised controlled double-blinded trial was performed. 48 healthy volunteers (94 eyes) were randomly allocated to three groups: acupuncture group—19 subjects (38 eyes) were submitted to a 20 min session of acupuncture (GB1, GB14 and BL1); sham group—14 subjects (27 eyes) were submitted to a 20 min session of acupuncture with needles inserted in false points; and control group—15 subjects (29 eyes) who underwent no intervention. All subjects had the IOP measured by a masked investigator using Goldmann applanation tonometry immediately before intervention, as well as 20 min and 24 h after.
Results The mean (SD) IOP in the acupuncture group was 17.9 (3.3) mm Hg at baseline, 16.4 (3.9) mm Hg at 20 min and 16.3 (3.3) mm Hg at 24 h. The mean (SD) IOP in the sham group was 18.6 (3.3) mm Hg at baseline, 17.7 (2.6) mm Hg at 20 min and 15.9 (3.6) mm Hg at 24 h. The mean (SD) IOP in the control group was 16.9 (3.5) mm Hg at baseline, 16.5 (3.8) mm Hg at 20 min and 15.8 (3.3) mm Hg at 24 h. There was no statistically significant difference in the IOP variation (post-intervention minus baseline measurements) between groups after 20 min (p=0.13) and 24 h (p=0.21).
Conclusion Acupuncture in the studied points did not produce significant short-term effect on the IOP of healthy individuals in comparison with control groups.