Assessment of retinal nerve fiber layer internal reflectivity in eyes withand without glaucoma using optical coherence tomography

Objective: To assess the internal reflectivity of the retinal nerve fiber l ayer in normal, ocular hypertensive, and glaucomatous eyes using optical co herence tomography. Methods: All patients underwent complete ophthalmic examination and achroma tic automated perimetry. Intraocular pressure was 21 mm Hg or less for low- tension glaucoma and normal eyes and at least 25 mm Hg on 2 separate occasi ons in ocular hypertensive and high-tension glaucoma eyes. All glaucomatous eyes had characteristic glaucomatous optic neuropathy and associated achro matic automated perimetry defect. Relative retinal nerve fiber layer intern al reflectivity was measured on optical coherence tomography images using a software program of our own design. Results: We enrolled 98 eyes (19 normal, 34 ocular hypertensive, 17 high-te nsion glaucoma, and 28 low-tension glaucoma). Relative internal reflectivit y was less in eyes with glaucoma than in normal (P<.001, t test) and ocular hypertensive eyes (P<.001, t test). There was no difference in relative in ternal reflectivity between normal and ocular hypertensive eyes (P=.32) and between eyes with high-tension glaucoma and low-tension glaucoma (P=.43). Internal reflectivity correlated with mean deviation on achromated automati c perimetry (r(2)=0.49, P<.001, quadratic regression analysis). Conclusion: Relative retinal nerve fiber layer internal reflectivity may pr ovide useful information about the extent of retinal nerve fiber layer inju ry in glaucoma.