[Measurement of human retinal thickness at posterior pole with retinal thickness analyzer in normal and glaucomatous eyes]

Abstract

Objective: To determine the diagnostic value of retinal thickness analyzer (RTA) in glaucoma.

Methods: RTA was used to measure the retinal thickness at the posterior pole in 77 normal persons (116 eyes) at various ages and 22 cases (35 eyes) with glaucoma. The obtained images were processed by a computer to yield the retinal thickness value and the thickness map at this location, and the data were analyzed with SAS software package.

Results: The mean retina thickness of normal subjects was (171.83 +/- 18.50) microm with no significant difference among the various age groups (F = 2.68, P > 0.05), and very significant between the sexes; the thickest retina was at the location between macula and optic nerve head, and the macular nasal retina is 11.7% thicker than its temporal side. The upper and lower retinas of the fovea were basically symmetrical. The retinal thickness in glaucoma patients showed diffuse or local thinning, and there was a very significant difference between the normal group and the glaucomatous group in retina thickness (F = 11.98, P = 0.0001). The sensitivity rate for detecting glaucoma with RTA was up to 80.8%, and specificity to 78.5%.

Conclusions: The thickness map for the retina at posterior pole across the macula in normal subjects is "horse shoe" shaped, that is well matched with the topography of retinal ganglion cell and the retinal nerve fibers in human retina. Diffuse or local thinning of retinal thickness in glaucomatous patients, which is in agreement with the corresponding visual field defect, and the sensitivity of RTA is higher than that of perimeter. The RTA examination is easy to operate, has high reproducibility, no invasion, therefore it is an ideal method to measure the human retinal thickness in vivo.