Biomedical subjects

Felipe A Medeiros

Publications and source records attributed to Felipe A Medeiros.

At least 37 records · Page 2Linked to original sources

PubMed2005

Differences in visual function and optic nerve structure between healthy eyes of blacks and whites.

OBJECTIVE: To investigate differences in visual function, optic disc topography, and retinal nerve fiber layer (RNFL) thickness between healthy eyes of blacks and whites. METHODS: Visual function was assessed in healthy eyes of 50 blacks and 50 whites using standard automated perimetry, short-wavelength automated perimetry, and frequency doubling technology perimetry. Optic disc topography and RNFL thickness were measured using the Heidelberg Retina Tomograph and the optical coherence tomograph. RESULTS: Mean standard automated perimetry mean deviations were within the normal range for both groups. Blacks had worse mean deviation values than whites using frequency doubling technology perimetry (mean +/- SD, -1.8 +/- 3.2 dB vs -0.1 +/- 2.4 dB), blacks had larger optic disc areas than whites using the Heidelberg Retina Tomograph (mean +/- SD, 2.1 +/- 0.4 mm2 vs 1.7 +/- 0.4 mm2), the RNFL of blacks was thicker than that of whites by 16.91 microm superiorly and 10.10 microm inferiorly using optical coherence tomography, and blacks had slightly higher intraocular pressures than whites (mean +/- SD, 16.5 +/- 2.5 mm Hg vs 15.2 +/- 3.2 mm Hg) and thinner central corneas (mean +/- SD, 540.5 +/- 43.2 microm vs 560.9 +/- 35.5 microm). No racial differences were found in mean RNFL thickness, pattern standard deviation on all tests, or any of the short-wavelength automated perimetry variables. CONCLUSIONS: Minimal racial differences in visual function were found, but race significantly affected optic disc topography and superior and inferior RNFL thickness measurements in healthy eyes. The racial differences observed for intraocular pressure could theoretically increase after correcting for central corneal thickness. Prospective studies are needed to further investigate these findings.

Anthropometry↗

PubMed2005

Argon laser iridoplasty in the treatment of plateau-like iris configuration as result of numerous ciliary body cysts.

PURPOSE: To report the use of argon laser peripheral iridoplasty in the treatment of plateau-like iris configuration as a result of iris and ciliary body cysts. DESIGN: Case report. METHODS: A 43-year-old male with plateau iris syndrome was demonstrated by high frequency ultrasound biomicroscopy (UBM), to have numerous iris and ciliary body cysts. Bilateral argon laser peripheral iridoplasty was performed. RESULTS: Argon laser iridoplasty opened the drainage angle in both eyes. CONCLUSION: Argon laser iridoplasty is an effective and safe treatment for plateau iris syndrome and may also prove valuable in the treatment of plateau-like iris configuration resulting from iridociliary cysts.

Adult↗

PubMed2005

Evaluation of retinal nerve fiber layer, optic nerve head, and macular thickness measurements for glaucoma detection using optical coherence tomography.

PURPOSE: To compare the ability of optical coherence tomography retinal nerve fiber layer (RNFL), optic nerve head, and macular thickness parameters to differentiate between healthy eyes and eyes with glaucomatous visual field loss. DESIGN: Observational case-control study. METHODS: Eighty-eight patients with glaucoma and 78 healthy subjects were included. All patients underwent ONH, RNFL thickness, and macular thickness scans with Stratus OCT during the same visit. ROC curves and sensitivities at fixed specificities were calculated for each parameter. A discriminant analysis was performed to develop a linear discriminant function designed to identify and combine the best parameters. This LDF was subsequently tested on an independent sample consisting of 63 eyes of 63 subjects (27 glaucomatous and 36 healthy individuals) from a different geographic area. RESULTS: No statistically significant difference was found between the areas under the ROC curves (AUC) for the RNFL thickness parameter with the largest AUC (inferior thickness, AUC = 0.91) and the ONH parameter with largest AUC (cup/disk area ratio, AUC = 0.88) (P = .28). The RNFL parameter inferior thickness had a significantly larger AUC than the macular thickness parameter with largest AUC (inferior outer macular thickness, AUC = 0.81) (P = .004). A combination of selected RNFL and ONH parameters resulted in the best classification function for glaucoma detection with an AUC of 0.97 when applied to the independent sample. CONCLUSIONS: RNFL and ONH measurements had the best discriminating performance among the several Stratus OCT parameters. A combination of ONH and RNFL parameters improved the diagnostic accuracy for glaucoma detection using this instrument.

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PubMed2005

Use of progressive glaucomatous optic disk change as the reference standard for evaluation of diagnostic tests in glaucoma.

PURPOSE: Progressive change in optic disk appearance has been suggested as the best available reference standard for glaucoma diagnosis. We evaluated the accuracy of scanning laser polarimetry (SLP) with variable corneal compensation to discriminate patients with documented progressive optic disk change from healthy subjects. DESIGN: Observational case-control study. METHODS: Glaucoma patients with documented evidence of progressive optic disk change as assessed by stereoscopic photographs were selected. Healthy control subjects had normal visual fields and normal clinical examination. All subjects underwent imaging with the GDx VCC scanning laser polarimeter. Receiver-operating characteristic (ROC) curves, sensitivities at fixed specificities, and likelihood ratios were calculated. RESULTS: Sixty-five eyes were healthy control patients. Seventy-one eyes had progressive optic disk change, of which 41 (58%) had abnormal visual field tests closest to the imaging date (perimetric glaucomatous optic neuropathy [GON]), and 30 (42%) eyes had normal visual fields (preperimetric GON). The GDx VCC parameter nerve fiber indicator performed best for discrimination between perimetric GON and normal eyes (AUC = 0.94; sensitivity = 93% for specificity > or =80%) as well as for the discrimination between preperimetric GON and normal eyes (AUC = 0.89; sensitivity = 83% for specificity > or =80%). CONCLUSION: SLP differentiated patients with documented progressive optic disk change from normal subjects and detected abnormalities in patients with confirmed diagnosis of preperimetric GON, suggesting that it may be useful for early glaucoma diagnosis. We suggest that progressive optic disk change should be used in the evaluation of diagnostic accuracy of imaging instruments for glaucoma.

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PubMed2005

Relationship between central corneal thickness and retinal nerve fiber layer thickness in ocular hypertensive patients.

PURPOSE: To examine the relationship between retinal nerve fiber layer (RNFL) measurements obtained using scanning laser polarimetry with variable corneal compensation and corneal thickness measurements in ocular hypertension (OHT) patients. DESIGN: Observational cross-sectional study. SUBJECTS: The study included 1 eye each from 44 OHT patients and 48 healthy subjects, all of similar age. All subjects had normal optic discs and normal standard automated perimetry (SAP) visual fields. Ocular hypertension patients had intraocular pressure (IOP) measurements higher than 22 mmHg. METHODS: All patients underwent imaging with the GDx VCC (Laser Diagnostic Technologies, Inc., San Diego, CA) scanning laser polarimeter. We examined the relationship between GDx VCC RNFL measurements and central corneal thickness, a risk factor for development of visual field loss among OHT patients. We also examined the relationship of GDx VCC measurements and age, IOP, SAP pattern standard deviation, and vertical cup-to-disc ratio. MAIN OUTCOME MEASURES: Central corneal thickness (CCT) and GDx VCC RNFL thickness parameters. RESULTS: Central corneal thickness measurements in OHT patients were significantly higher than those in healthy subjects (575+/-30 microm vs. 555+/-32 microm; P = 0.002). Higher GDx VCC parameter nerve fiber indicator (NFI) scores, indicating thinner RNFL, were correlated significantly with thinner CCT measurements in OHT patients (r = -0.502; P = 0.001). Ocular hypertension patients with thinner corneas (n = 22; mean CCT, 553+/-21 microm) had significantly higher NFI scores than OHT patients with thicker corneas (n = 22; mean CCT, 598+/-18 microm) and healthy control subjects (NFI mean +/- standard deviation, 26.9+/-9.5, 20.7+/-9.8, and 19.7+/-7.0, respectively; P = 0.004, analysis of variance). The NFI values were not significantly different between OHT patients with thicker corneas and healthy subjects. In multivariate analysis, only age and CCT measurement were associated significantly with GDx VCC RNFL measurements in OHT eyes. CONCLUSIONS: Ocular hypertension patients with thinner corneas had significantly thinner RNFL than OHT patients with thicker corneas and healthy control subjects. These findings support the notion that RNFL defects as assessed by the GDx VCC may represent early glaucomatous damage in OHT eyes.

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PubMed2005

Bimatoprost.

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Amides↗

PubMed2005

Five rules to evaluate the optic disc and retinal nerve fiber layer for glaucoma.

A systematic approach for the examination of the optic disc and retinal nerve fiber layer is described that will aid in the detection of glaucoma. This approach encompasses 5 rules: evaluation of optic disc size, neuroretinal rim size and shape, retinal nerve fiber layer, presence of parapapillary atrophy, and presence of retinal or optic disc hemorrhages. A systematic process enhances the ability to detect glaucomatous damage as well as the detection of progression, and facilitates appropriate management.

Disease Progression↗

PubMed2005

Comparability of retinal nerve fiber layer thickness measurements of optical coherence tomography instruments.

PURPOSE: To compare retinal nerve fiber layer (RNFL) measurements between two ocular coherence tomography (OCT) instruments (OCT 2000 and Stratus OCT; Carl Zeiss Meditec, Dublin, CA) and compare their diagnostic precision. METHODS: One hundred thirty-nine consecutive subjects were imaged (3 x 3.4-mm diameter circular scans) on the same day with each instrument. Thirty-five patients were excluded due to poor-quality images. RNFL thicknesses measured by the two instruments were compared, and receiver operating characteristic (ROC) curves were used to determine diagnostic precision. RESULTS: A randomly selected eye of each of 104 participants (28 with open-angle glaucoma, 40 with suspected glaucoma, and 36 healthy subjects) was analyzed. RNFL thickness measurements generally were thicker with OCT 2000 than with Stratus OCT. The difference in global RNFL thickness between instruments was within 20 microm in 66 (65%) of subjects and within 10 microm (the instrument's limit of resolution) in 25 (25%) subjects. Application of a correction factor to OCT 2000 measurements predicted Stratus OCT RNFL thickness within 10 microm of the observed measurement in 75% of the eyes. For both instruments, highest ROC curve areas (better discrimination between glaucomatous and normal eyes) were found in the inferior sector. Discrimination using global RNFL thickness was better with Stratus OCT than OCT 2000 (P = 0.043). CONCLUSIONS: RNFL thickness measurements measured by OCT 2000 can be approximated to measurements made by Stratus OCT using correction factors calculated by this study. However, there remains considerable variability that exceeds the limits of resolution afforded by the instruments themselves. Therefore comparisons between instruments using these approximations should be interpreted with caution.

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PubMed2005

Relationship of SITA and full-threshold standard perimetry to frequency-doubling technology perimetry in glaucoma.

PURPOSE: To compare full-threshold (FT) and SITA algorithms for standard automated perimetry (SAP) with frequency-doubling technology perimetry (FDT) in glaucoma, to help clinicians to relate results in patients who have had two or more of these tests during follow-up. METHODS: This study was a retrospective analysis of data from a longitudinal prospective study at the University of California, San Diego. One hundred four eyes of 104 patients with glaucomatous optic neuropathy detected by optic disc stereophotographs were included. All patients had standard perimetry (SITA and FT) and FDT within 3 months of each other. Global indices, abnormality and severity using two threshold algorithms of standard perimetry were compared with FDT. RESULTS: More eyes had normal visual fields by SAP-FT (57 eyes) than by either SAP-SITA (42 eyes) or FDT (45 eyes), although SAP-FT agreed more closely with FDT (kappa = 0.54 +/- 0.08) on the presence of a visual field defect than did SAP-SITA (kappa = 0.34 +/- 0.08). Correlations of FDT to standard perimetry global indices were similar regardless of the threshold strategy used for standard perimetry, yielding r2= 0.38-0.57 for SAP-FT with FDT, 0.36-0.54 for SAP-SITA with FDT. CONCLUSIONS: Despite many similarities of SAP-SITA and SAP-FT, switching the standard of comparison from SAP-FT to SAP-SITA changes the relationship to FDT with regard to visual field abnormality, but not correlations of global indices. FDT detected abnormal fields in more eyes than SAP-FT. SAP-FT tended to detect a subset of eyes found abnormal by FDT. Visual field defects may be detected more often by FDT and SAP-SITA in eyes with early visual field loss, but these two tests may not agree on which eyes show field loss in patients who undergo both tests at follow-up.

Algorithms↗

PubMed2005

Relevance vector machine and support vector machine classifier analysis of scanning laser polarimetry retinal nerve fiber layer measurements.

PURPOSE: To classify healthy and glaucomatous eyes using relevance vector machine (RVM) and support vector machine (SVM) learning classifiers trained on retinal nerve fiber layer (RNFL) thickness measurements obtained by scanning laser polarimetry (SLP). METHODS: Seventy-two eyes of 72 healthy control subjects (average age = 64.3 +/- 8.8 years, visual field mean deviation = -0.71 +/- 1.2 dB) and 92 eyes of 92 patients with glaucoma (average age = 66.9 +/- 8.9 years, visual field mean deviation = -5.32 +/- 4.0 dB) were imaged with SLP with variable corneal compensation (GDx VCC; Laser Diagnostic Technologies, San Diego, CA). RVM and SVM learning classifiers were trained and tested on SLP-determined RNFL thickness measurements from 14 standard parameters and 64 sectors (approximately 5.6 degrees each) obtained in the circumpapillary area under the instrument-defined measurement ellipse (total 78 parameters). Ten-fold cross-validation was used to train and test RVM and SVM classifiers on unique subsets of the full 164-eye data set and areas under the receiver operating characteristic (AUROC) curve for the classification of eyes in the test set were generated. AUROC curve results from RVM and SVM were compared to those for 14 SLP software-generated global and regional RNFL thickness parameters. Also reported was the AUROC curve for the GDx VCC software-generated nerve fiber indicator (NFI). RESULTS: The AUROC curves for RVM and SVM were 0.90 and 0.91, respectively, and increased to 0.93 and 0.94 when the training sets were optimized with sequential forward and backward selection (resulting in reduced dimensional data sets). AUROC curves for optimized RVM and SVM were significantly larger than those for all individual SLP parameters. The AUROC curve for the NFI was 0.87. CONCLUSIONS: Results from RVM and SVM trained on SLP RNFL thickness measurements are similar and provide accurate classification of glaucomatous and healthy eyes. RVM may be preferable to SVM, because it provides a Bayesian-derived probability of glaucoma as an output. These results suggest that these machine learning classifiers show good potential for glaucoma diagnosis.

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PubMed2005

Unsupervised machine learning with independent component analysis to identify areas of progression in glaucomatous visual fields.

PURPOSE: To determine whether a variational Bayesian independent component analysis mixture model (vB-ICA-mm), a form of unsupervised machine learning, can be used to identify and quantify areas of progression in standard automated perimetry fields. METHODS: In an earlier study, it was shown that a model using vB-ICA-mm can separate normal fields from fields with six different patterns of visual field loss related to glaucomatous optic neuropathy (GON) along maximally independent axes. In the present study, an independent group of 191 patient eyes (66 with ocular hypertension (OHT), 12 with suspected glaucoma by field, 61 with suspected glaucoma by disc, and 52 with glaucoma) with five or more standard visual fields under observation for a mean of 6.24 +/- 2.65 years and 8.11 +/- 2.42 visual fields were evaluated with the vB-ICA-mm. In addition, eyes with progressive GON (PGON) were identified (n = 39). Each participant had a series of fields tested, with each field entered independently and placed along the axes of the previously developed model. This allowed change in one pattern of visual field defect (along one axis) to be assessed relative to results other areas of that same field (no change along other axes). Progression was based on a slope falling outside the 5th and the 95th percentile limits of all slopes, with at least two axes not showing such a deviation in a given individual's series of fields. Fields were also scored using Advanced Glaucoma Intervention Study (AGIS) and the Early Manifest Glaucoma Treatment Trial (EMGT) criteria. RESULTS: Thirty-two of 191 eyes progressed on vB-ICA-mm by this definition. Of the 32, 22 had field loss at baseline, 7 had only GON, 3 were OHTs and 12 were from the 39 eyes (31%) with PGON. The vB-ICA-mm identified a higher percentage of progressing eyes in each diagnostic category than did AGIS or and the EMGT. CONCLUSIONS: The vB-ICA-mm can quantitatively identify progression in eyes with glaucoma by evaluating change in one or more patterns of the visual field loss while other areas or patterns remain stable. This may enable each eye to contribute to the determination of whether change is caused by true progression or by variability.

Adult↗

PubMed2005

Effect of bimatoprost on intraocular pressure in prostaglandin FP receptor knockout mice.

PURPOSE: To determine the effect of bimatoprost on intraocular pressure in the prostaglandin FP receptor knockout mouse. METHODS: The IOP response to a single 1.2-microg (4 microL) dose of bimatoprost was measured in the treated and untreated fellow eyes of homozygote (FP+/+, n = 9) and heterozygote (FP+/-, n = 10) FP-knockout mice, as well as in wild-type C57BL/6 mice (FP+/+, n = 20). Serial IOP measurements were also performed after topical bimatoprost in a separate generation of homozygous FP-knockout mice and wild-type littermate control animals (n = 4 per group). Aqueous humor protein concentrations were measured to establish the state of the blood-aqueous barrier. Tissue, aqueous humor and vitreous concentrations of bimatoprost, latanoprost, and their C-1 free acids were determined by liquid chromatography and tandem mass spectrometry. RESULTS: A significant reduction in IOP was observed in the bimatoprost-treated eye of wild-type mice at 2 hours, with a mean difference and 95% confidence interval (CI) of the difference in means of -1.33 mm Hg (-0.81 to -1.84). Bimatoprost did not lead to a significant reduction in IOP in either the heterozygous knockout -0.36 mm Hg (-0.82 to +0.09) or homozygous FP-knockout mice 0.25 mm Hg (-0.38 to +0.89). The lack of an IOP response in the FP-knockout mice was not a consequence of blood-aqueous barrier breakdown, as there was no significant difference in aqueous humor protein concentration between treated and fellow eyes. Tissue and aqueous humor concentrations of bimatoprost, latanoprost, and their C-1 free acids indicate that latanoprost, but not bimatoprost, is hydrolyzed in the mouse eye after topical administration. CONCLUSIONS: An intact FP receptor gene is critical to the IOP response to bimatoprost in the mouse eye.

Amides↗

PubMed2004

Comparison of scanning laser polarimetry using variable corneal compensation and retinal nerve fiber layer photography for detection of glaucoma.

OBJECTIVE: To compare retinal nerve fiber layer (RNFL) measurements obtained with scanning laser polarimetry (SLP) using variable corneal polarization compensation with standard red-free photography for detection of RNFL damage in glaucoma. METHODS: This observational, cross-sectional study included 1 eye of each of 42 patients with open-angle glaucoma, 32 patients suspected of having glaucoma, and 40 healthy subjects. The RNFL measurements using SLP with variable corneal compensation were obtained within 3 months of red-free photographs. Two independent observers graded RNFL photographs using a standardized protocol. Superior and inferior hemiretinas were scored separately, and a global score was obtained by averaging scores from each hemiretina. MAIN OUTCOME MEASURES: The RNFL photography scores were compared with RNFL thickness measurements obtained with SLP. The receiver operating characteristic (ROC) curves were constructed to assess the abilities of the different methods to differentiate glaucoma patients from healthy subjects. RESULTS: The RNFL thickness decreased with increased RNFL damage as assessed by photographs in both hemiretinas (R(2) = 15%-47%). The area under the ROC curve for the best SLP parameter, Nerve Fiber Indicator, was significantly greater than the area under the ROC curve for the global RNFL photography score (0.91 vs 0.84, P =.03). CONCLUSIONS: A moderate correlation was found between RNFL thickness measurements obtained with SLP and RNFL scores from red-free photographs. Compared with semiquantitative RNFL photography scores, the best SLP parameter had a higher diagnostic accuracy to separate glaucoma patients from healthy subjects.

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PubMed2004

Comparison of the GDx VCC scanning laser polarimeter, HRT II confocal scanning laser ophthalmoscope, and stratus OCT optical coherence tomograph for the detection of glaucoma.

OBJECTIVE: To compare the abilities of current commercially available versions of 3 optical imaging techniques: scanning laser polarimetry with variable corneal compensation (GDx VCC), confocal scanning laser ophthalmoscopy (HRT II [Heidelberg Retina Tomograph]), and optical coherence tomography (Stratus OCT) to discriminate between healthy eyes and eyes with glaucomatous visual field loss. METHODS: We included 107 patients with glaucomatous visual field loss and 76 healthy subjects of a similar age. All individuals underwent imaging with a GDx VCC, HRT II, and fast retinal nerve fiber layer scan with the Stratus OCT as well as visual field testing within a 6-month period. Receiver operating characteristic curves and sensitivities at fixed specificities (80% and 95%) were calculated for parameters reported as continuous variables. Diagnostic categorization (outside normal limits, borderline, or within normal limits) provided by each instrument after comparison with its respective normative database was also evaluated, and likelihood ratios were reported. Agreement on categorization between methods (weighted kappa) was assessed. RESULTS: After the exclusion of subjects with unacceptable images, the final study sample included 141 eyes of 141 subjects (75 with glaucoma and 66 healthy control subjects). Mean +/- SD mean deviation of the visual field test result for patients with glaucoma was -4.87 +/- 3.9 dB, and 70% of these patients had early glaucomatous visual field damage. No statistically significant difference was found between the areas under the receiver operating characteristic curves (AUCs) for the best parameters from the GDx VCC (nerve fiber indicator, AUC = 0.91), Stratus OCT (retinal nerve fiber layer inferior thickness, AUC = 0.92), and HRT II (linear discriminant function, AUC = 0.86). Abnormal results for each of the instruments, after comparison with their normative databases, were associated with strong positive likelihood ratios. Chance-corrected agreement (weighted kappa) among the 3 instruments ranged from moderate to substantial (0.50-0.72). CONCLUSIONS: The AUCs and the sensitivities at high specificities were similar among the best parameters from each instrument. Abnormal results (as compared with each instrument's normative database) were associated with high likelihood ratios and large effects on posttest probabilities of having glaucomatous visual field loss. Calculation of likelihood ratios may provide additional information to assist the clinician in diagnosing glaucoma with these instruments.

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PubMed2004

Total plasma homocysteine and primary open-angle glaucoma.

PURPOSE: To evaluate total plasma homocysteine (tHcy) levels in patients diagnosed with primary open-angle glaucoma (POAG) and normal subjects. DESIGN: Case-control study. METHODS: This study involved 55 POAG patients, 16 patients with secondary open-angle glaucoma or angle-closure glaucoma (non-POAG group), and 39 control healthy subjects undergoing ocular surgery. All glaucoma patients had characteristic glaucomatous optic disk damage and visual field loss. Fasting tHcy concentrations of all study participants were determined using high-performance liquid chromatography. Analysis of variance was used to compare homocysteine levels among the three diagnostic groups, and multivariate analysis was conducted to assess the associations between tHcy and diagnostic group, age, gender, smoking status, systemic hypertension, hyperlipidemia, and cardiovascular or cerebrovascular disease. RESULTS: Mean +/- standard deviation of tHcy levels in POAG individuals, non-POAG patients and control subjects was 14.90 +/- 6.45 micromol/l, 14.30 +/- 4.35 micromol/l, and 14.81 +/- 4.56 micromol/l, respectively (P =.93; ANOVA). No statistically significant difference was found in the proportion of patients with abnormal tHcy levels among the three diagnostic groups. In multivariate analysis, only age and positive smoking status were significantly correlated with total plasma homocysteine levels. CONCLUSION: No significant difference was found in plasma homocysteine levels among POAG patients and normal control individuals.

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PubMed2004

Frequency doubling technology perimetry abnormalities as predictors of glaucomatous visual field loss.

PURPOSE: To determine whether frequency doubling technology (FDT) perimetry results predict glaucomatous visual field defects, as assessed by standard automated perimetry (SAP), in a glaucoma suspect population. DESIGN: Longitudinal observational study. METHODS: The study included 105 eyes of 105 glaucoma suspect patients, with a mean follow-up time of 41 +/- 17 months. Glaucoma suspects had either intraocular pressure (IOP) higher than or equal to 23 mm Hg or glaucomatous optic neuropathy by stereophotograph assessment. All patients had normal SAP visual fields at baseline. A baseline FDT test was performed within 3 months of the normal SAP examination. Several baseline FDT parameters and other variables (age, gender, IOP, central corneal thickness, SAP visual field indices, and stereophotograph assessment) were investigated by univariate and multivariate Cox proportional hazards models to obtain hazard ratios (HR) and identify factors that predicted which patients had SAP glaucomatous visual field loss during follow-up. RESULTS: Seventeen patients (16%) developed repeatable SAP visual field abnormality during follow-up. An abnormal FDT examination at baseline predicted the development of SAP visual field conversion in both univariate (HR = 3.17; 95% confidence interval [CI] = 1.22-8.25; P =.018) and multivariate models (Adjusted HR = 3.68; 95% CI = 1.06-12.8; P =.04). The analysis of FDT examinations during follow-up revealed that in 59% of converters the FDT abnormalities preceded SAP visual field loss by as much as 4 years. Also, the initial development of glaucomatous visual field loss as measured by SAP occurred in regions that had previously demonstrated abnormalities on FDT testing. CONCLUSION: Functional abnormalities detected by FDT perimetry were predictive of the future onset and location of SAP visual field loss among glaucoma suspect patients.

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PubMed2004

Conjunctival hyperemia associated with bimatoprost use: a histopathologic study.

PURPOSE: To evaluate histopathologic signs of conjunctival inflammation in patients with conjunctival hyperemia induced by bimatoprost treatment. DESIGN: Prospective interventional study. METHODS: The study included 15 eyes of 15 patients scheduled for cataract surgery. Patients in the treatment group (n = 9) exhibited trace to moderate conjunctival hyperemia when treated with bimatoprost 0.03% every day for 15 to 30 days before surgery. The control group (n = 6) included untreated patients with no ocular disease other than cataract. Conjunctival biopsies were obtained for histologic evaluation with light microscopy. RESULTS: Vascular congestion was observed in biopsies from 7 patients (78%) in the bimatoprost group and 5 patients (83%) in the control group. Signs of inflammation were found in biopsies from 2 patients (22%) in the bimatoprost group and 2 patients (33%) in the control group. CONCLUSIONS: Histopathologic signs of inflammation were no more frequent in conjunctival specimens from bimatoprost-treated patients with trace to moderate hyperemia than in those from untreated control subjects.

Amides↗

PubMed2004

Retinal nerve fiber layer thickness measurements with scanning laser polarimetry predict glaucomatous visual field loss.

PURPOSE: To assess whether baseline retinal nerve fiber layer (RNFL) measurements obtained with a scanning laser polarimeter, the GDx Nerve Fiber Analyzer, (Laser Diagnostic Technologies Inc., San Diego, California) are predictive of development of repeatable glaucomatous visual field damage in glaucoma suspect eyes. DESIGN: Cohort study. METHODS: Participants were recruited from the UCSD longitudinal Diagnostic Innovations in Glaucoma Study (DIGS). One eye from each of 160 glaucoma suspects with normal standard automated perimetry (SAP) visual fields at baseline was studied. Study eyes were divided into convert and nonconvert groups based on the development of three consecutive glaucomatous visual fields during follow-up. SLP parameters, IOP, vertical cup disk ratio, stereophotograph assessment as glaucoma or normal, corneal thickness, and visual field indices were included in univariate and multivariate Cox proportional hazards models to determine which SLP RNFL and ocular parameters were predictive of visual field conversion. RESULTS: Sixteen (10%) eyes developed repeatable visual field damage (converts) and 144 (90%) did not (nonconverts). Mean (95%CI) follow-up time until visual field conversion for convert eyes was 2.7 (1.7, 3.6) years. Mean total follow-up of nonconvert eyes was 3.8 (3.5, 4.1) years. Four out of thirteen examined baseline SLP parameters and baseline SAP Mean Deviation (MD), SAP Pattern Standard Deviation (PSD), and glaucomatous stereophotograph assessment were significant univariate predictors of visual field conversion. In multivariate models adjusted for age, IOP and CCT, SLP parameters inferior ratio, ellipse modulation, and UCSD linear discriminant function (LDF) were significant predictors of visual field conversion. When SAP PSD and stereophotograph assessment were also included in the multivariate model inferior ratio and UCSD LDF remained independently predictive of visual field loss. CONCLUSIONS: Thinner baseline SLP RNFL measurements were independent predictors of visual field damage. In addition to thinner SLP RNFL measurements, higher baseline SAP PSD, and baseline glaucomatous stereophotograph assessment each contributed to an increased risk of the development of abnormal visual fields in glaucoma suspect patients. SLP RNFL measurements were independently predictive of future visual loss even when age, IOP, CCT, vertical cup disk ratio, and SAP PSD were included in the model.

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