ROLE OF OPTICAL COHERENCE TOMOGRAPHY IN MEASURING RETINl)' ; NERVE FIBER LAYER 'fHICKNESS I NORMAL, OCULAR HYPERTENSIVE PATIENTS AND PATIENTS WITH PRIMARY OPEN ANGLE GLAUCOMA

Abstract

laucomas are a heterogeneous group of diseases which have in common the glaucomatous loss of ON fibers. They show a multitude of morphological and psychological changes, such as a decrease in neuroretinal rim, secondary enlargement of the optic cup, deepening of the optic cup,. enlargement of parapapillary atrophy and loss ofRNFL (Hom et al, 1997 aud Joues et aL, 1999).

So, early detection of the disease with rapid initiation of proper treatment is the key for tight control of such a "silent blinder" (Colemau, 1999).

Markers for early structural damage will help identify patients who require preventive therapy because they are at high risk for visual loss and will spare patients without damage the costs and morbidity of treatment (Caprioli et at., 1996).

Optical coherence tomography is a new, noninvasive, noncontact, transpupillary imaging technique that can image retinal structures in vivo with a high axial resolution of about 10 Lm. Cross sectional images of the retina are produced using optical backscattering of light in a fashion analogous to 8-scan US. The anatomic layers within the retina can be differentiated and the RNFL thickness can be measured (Pieroth et al., 1999). Thus, OCT cross-sectionally illustrates the activity occurring in RNFL, a site of particular interest in glaucoma (Sclmmau eta/., 1995).

Using OCT with the latest iteration of the operating software and a scan protocol with a scan circle of 3.4 111111 diameter, we have studied I 0 normal, 10 01-IT and 10