Comparison of retinal nerve fibre layer thickness and visual field loss between different glaucoma groups

Background/aims: Scanning laser polarimetry (SLP) uses a confocal scanning laser ophthalmoscope with an integrated polarimeter to evaluate the thickness of the retinal nerve fibre layer (RNFL). The aim of this study was to verify the ability of the SLP to detect differences in RNFL thickness between normal and glaucomatous eyes and between glaucomatous eyes subdivided in groups by the severity of visual field damage. Methods: This was a cross sectional retrospective study. The charts of 40 healthy subjects and 68 glaucoma patients who underwent complete ophthalmological examination, optic disc stereophotography, peripapillary, and macular SLP imaging were reviewed. The right eye of subjects eligible for the study was enrolled. Only eyes with SLP examinations indicating a minimised effect of anterior segment birefringence based on macular image were included. The ability of retardation parameters to discriminate between healthy and glaucomatous eyes was evaluated. Based on visual field loss, glaucoma patients were subdivided in three subgroups (early, moderate, and severe). RNFL thickness between healthy control group and glaucoma subgroups was compared. RNFL thickness and visual field loss correlation was evaluated. Results: There was a significant difference in superior and inferior maximum RNFL thickness between normal and glaucomatous eyes (p<0.001). With these two parameters, the area under receiver operator characteristic curve was 0.75 and 0.74, respectively. Superior and inferior RNFL thickness was significantly different between healthy control group and all glaucoma subgroups (p<0.001) and between glaucoma subgroups (p<0.05), except for early and moderate glaucoma subgroups (p>0.05). Linear regression showed a weak correlation between RNFL thickness and visual field loss. Conclusion: These results suggest that once visual field loss is established, smaller reductions in the RNFL thickness detected by SLP are necessary for a given reduction of mean defect value

The relation between intraocular pressure peak in the water drinking test and visual field progression in glaucoma

Aim: To compare the results of the water drinking test between glaucomatous eyes with and without visual field progression. Methods: Retrospective analysis of 76 eyes of 76 open angle glaucoma patients followed for a mean period of 26.0 (SD 13.8) months. Patients were submitted to the water drinking test at the beginning of the follow up period. Reliable achromatic automated perimetry tests performed during the studied period were used to characterise visual field progression. All subjects were under clinical therapy and had an intraocular pressure (IOP) lower than 17 mm Hg monitored by isolated measurements during the follow up period. The results of the water drinking test were compared between glaucomatous eyes with and without visual field progression. Results: Twenty eight eyes reached definite visual field progression. There were no significant differences in the mean age, sex, race, basal IOP, number of antiglaucomatous drugs, initial mean deviation (MD), and corrected pattern standard deviation (CPSD) between eyes that showed visual field progression and the ones who did not progress. A significant difference of 1.9 (SD 0.6) mm Hg (p = 0.001, analysis of covariance; 95% CI 0.8 to 3.0) was observed between glaucomatous eyes that showed visual field deterioration and glaucomatous eyes that did not progress. A significant difference of 16.8% (SD 4.6%) in the mean percentage of IOP variation was also observed between the two groups (p<0.001, analysis of covariance; 95% CI 7.7 to 26.0). Conclusions: Mean IOP peak and percentage of IOP variation during water drinking test were significantly higher in patients with visual field progression compared with patients who did not progress

The Effect of Prostaglandin Analogs and Prostamide on Central Corneal Thickness

Objective: The aim of this study was to verify the influence of prostaglandin analogs and prostamide on central corneal thickness (CCT). Methods: A prospective analysis was done of CCT in glautomatous patients submitted to monotherapy with prostaglandin analogs (latanoprost 0.005% or travoprost 0.004%) or prostamide (bimatoprost 0.03%) during an 8-week period. A control group of patients without any ocular medication was also evaluated. CCT measurements were performed with a commercially available ultrasound pachymeter. A total of 73 patients were included in this study. Mean age was 68.5 +/- 9.2 (range, 48-85) years old. Results: A statistically significant reduction in CCT was observed in all groups, except the control group (n = 21): Bimatoprost 0.03% group (n = 21): 544.41 +/- 35.4 vs. 540.35 +/- 35.9 mu m (P = 0.039); travoprost 0.004% group (n = 17): 538.47 +/- 32.0 vs. 532.25 +/- 30.4 mu m (P = 0.009); latanoprost 0.005% group (n = 14): 548.57 +/- 32.4 vs. 543.88 +/- 35.6 mu m (P = 0.036). Conclusion: Topical therapy with prostaglandin analogs and bimatoprost is associated with CCT reduction over a period of at least 8 weeks

Evaluation of retinal nerve fiber layer and ganglion cell complex thickness after ocular blunt trauma

Purpose:To evaluate circumpapillary retinal nerve fiber layer (cpRNFL) and ganglion cell complex (GCC) after ocular blunt trauma.MethodsBest-corrected visual acuity (BCVA), cpRNFL and GCC were evaluated by RTVue-100 OCT in all consecutive patients with previous monocular blunt trauma seen between January 2012 and December 2012.ResultsTwenty-two patients (11 females, 11 males, mean age 43.9±14.2 years) were included in the study. Patients were seen after a mean of 8.42±13.3 (range, 0.08-55.3) years from ocular blunt trauma. BCVA was normal in 11 cases and was less than 0.4 LogMAR in all cases. In 9/22 patients (40.9%), cpRNFL and GCC were reduced, whereas in one case an isolated reduction of GCC with normal cpRNFL was present. In patients with reduction of cpRNFL and GCC, mean BCVA was 0.17±0.17 LogMAR. In 6/9 patients (66.6%) with cpRNFL and GCC reduction, BCVA was ≤0.1 LogMAR.ConclusioncpRNFL and GCC reduction may be present after ocular blunt trauma and may be associated with preserved visual acuity