Preliminary studies on the application of retinal thickness analyzer in the diagnosis of glaucoma

The patients with glaucoma underwent the examination of retinal thickness analyzer (RTA) to explore the diagnostic value of RTA in glaucoma. The retina of 6 mm × 6 mm size (approximately 20°, centered on the macula) at the posterior pole was scanned by using RTA to obtain the images in 35 eyes of 22 patients with glaucoma. The images were processed by using SAS software package. The retinal thickness in the patients with glaucoma showed diffuse or local thinning. Twenty-seven eyes was definitely diagnosed as having glaucoma. There was a very significant difference in retinal thickness measurements by RTA between normal group and glaucomatous group (P= 0.0012). Except the measurements at the detected point 6 having no difference, the measurements at the detected point 3 showed a significant difference and the remaining 7 detected points presented a very significant difference between the two groups. Of the detected 9 points, the changes at the points 4, 8, and 9 were the most obvious. The discrete analysis was performed on the glaucomatous patients by a discriminant function established through the data at the detected points 4, 8 and 9 and the accurate estimate rate for the diagnosis of glaucoma was up to 80.77 %. The measurements of RTA examination was consistent with the results of the vision field test. It was suggested that diffuse or local thinning of retinal thickness exists in the patients with glaucoma. The temporal inferior arcuate fibers and the papillomacular bundle between the macular and optic nerve heads showed a serious damage. The sensitivity of RTA examination was higher than visual field test.