Scanning laser polarimetry in a selected group of patients with glaucoma and normal controls.

PURPOSE: To evaluate the ability of scanning laser polarimetry to discriminate between subjects with glaucoma with specific patterns of visual field defect and normal controls. METHODS: This cross-sectional, prospective study in a glaucoma practice, focused on subjects with glaucoma with predefined types of visual field defect, including advanced (group A, n = 14), localized (group L, n = 46), or mixed (diffuse and localized) defects (group M, n = 22) and normal controls (n = 32). Scanning laser polarimetry was performed in one study eye per subject. Two methods of analysis were used: a subjective analysis, in which examination printouts with the image of the optic disk manually blocked were classified by two observers masked to the diagnosis, and a logistic regression analysis of the retardation parameters included in the printouts. RESULTS: The observers correctly identified 97% of the controls and 68% of subjects with glaucoma (overall correct classification of 77%), with 93%, 70%, and 47% of patients from groups A, L, and M, respectively, being correctly identified. The best discrimination obtained with the logistic regression correctly identified 69% of controls and 94% of glaucoma subjects (overall correct classification of 87%). The performance was only slightly better for cases from group A compared with L and M. CONCLUSIONS: Subjective assessment of the scanning laser polarimetry standard printout of single eyes might not be sensitive enough to detect cases of glaucoma with localized or milder mixed types of visual field defect. The discriminating ability of scanning laser polarimetry improves slightly when logistic regression analysis is employed.

Intraocular pressure and progression of glaucomatous visual field loss.

PURPOSE: To evaluate the relationship between intraocular pressure and visual field progression in patients with primary open-angle glaucoma. METHODS: We prospectively followed 113 patients with early to moderate glaucomatous field damage. Conventional automated static perimetry, high-pass resolution perimetry, and intraocular pressure measurements were carried out at 6-month intervals. The mean and the highest intraocular pressure in the follow-up were compared in stable and progressing patients with each perimetric technique. RESULTS: The mean (+/- SD) follow-up was 4.5 +/- 0.9 years. The mean (+/- SD) intraocular pressure in patients remaining stable with conventional perimetry [18.2 +/- 3.3 mm Hg, n = 81 (71.7%)] was not significantly different (P =.65) from those in whom it progressed (17.9 +/- 3.3 mm Hg, n = 32 [28.3%]). The mean intraocular pressure in patients remaining stable with high-pass resolution perimetry (17. 9 +/- 3.5 mm Hg, n = 63 [55.8%]) was not significantly different (P =.33) from those in whom it progressed (18.5 +/- 3.0 mm Hg, n = 50 [44.2%]). The mean (+/- SD) of the highest (single or three highest) pressure during follow-up for stable and progressing patients with conventional perimetry was not significantly different (22.6 +/- 5.0 and 23.0 +/- 4.6 mm Hg, respectively, P =.76). However, for high-pass resolution perimetry, the difference was highly significant (21.6 +/- 4.5 and 24.1 +/- 4.9 mm Hg, respectively, P <. 01). Furthermore, patients who progressed with high-pass resolution perimetry had more damaged baseline fields compared with those who remained stable (P <.01). CONCLUSIONS: The mean level of intraocular pressure does not differentiate glaucoma patients with progressive visual field loss from ones who remained stable. Baseline visual field status and peak intraocular pressure of patients who progress with high-pass resolution perimetry are significantly different from those who remain stable.

Changes in anterior chamber depth and angle width after filtration surgery: a quantitative study using ultrasound biomicroscopy.

PURPOSE: To evaluate the anterior chamber configuration by means of ultrasound biomicroscopy in patients with glaucoma and control subjects, and to determine quantitative changes in this configuration after glaucoma filtration surgery (trabeculectomy) and combined cataract and filtration surgery. METHODS: The study included 33 eyes of 33 patients with glaucoma (diagnosed with primary open-angle or exfoliative glaucoma) in which filtration surgery (n = 17) or combined cataract and filtration surgery (n = 16) was performed, and 25 eyes of 25 age-matched control subjects. Ultrasound biomicroscopy was used to measure anterior chamber depth and the angle width at 500 microm from the scleral spur in all eyes. The patients with glaucoma were examined 2 days before surgery and 3 and 6 months after surgery. RESULTS: There were no significant differences in anterior chamber depth and angle width between patients with glaucoma before surgery and control subjects. Postoperative values for anterior chamber depth were significantly greater in patients with glaucoma who underwent combined surgery, but no significant changes were observed in those who underwent filtration surgery alone. In contrast, angle width was significantly greater after surgery both in patients who underwent combined surgery and in those who underwent filtration surgery alone. CONCLUSION: On ultrasound biomicroscopic evaluation, there were no differences in anterior chamber depth and angle width between patients with glaucoma and control subjects. Trabeculectomy alone widens the angle but does not affect the anterior chamber depth; however, combined surgery both deepens the anterior chamber depth and widens the angle.

Ultrasound biomicroscopy in the diagnosis of supraciliochoroidal fluid after trabeculectomy.

PURPOSE: To report supraciliochoroidal effusion after trabeculectomy with the use of ultrasound biomicroscopy. METHODS: In a prospective study, 28 eyes of 19 patients with primary open-angle glaucoma that underwent trabeculectomy were evaluated preoperatively and postoperatively by ultrasound biomicroscopy. RESULTS: Four eyes showed a hypoechogenic suprachoroidal space that remained stable for 6 months postoperatively. These four eyes had intraocular pressures of 11 mm Hg or less on no antiglaucoma medications and without signs of choroidal detachment. CONCLUSION: Ultrasound biomicroscopy proved to be a useful method of detecting, after trabeculectomy, supraciliochoroidal fluid without clinically detectable choroidal detachment. This fluid may signify an iatrogenic cyclodialysis during surgery or, less likely, subclinical ciliochoroidal detachment.