[Retinal nerve fiber layer thickness in glaucomatous eyes. A comparative study between OCT and visual field].

PURPOSE

To investigate the retinal nerve fiber layer (RNFL) thickness in glaucomatous eyes using Optical Coherence Tomography (OCT). To compare the RNFL thickness with visual field damage (Humphrey field analyzer).

MATERIAL AND METHODS

The mean RNFL thickness in glaucomatous eyes (n = 80) was compared with age-matched normal eyes (n = 40). Three circular scans were obtained for each eye using OCT (3.4 mm diameter). In each eye, average RNFL, 4 quadrants and 12 meridians were calculated and compared. The superior-inferior asymmetry of RNFL was studied. The average RNFL thickness was compared with mean deviation (MD) and mean standard deviation (MSD) of SITA 24-2 visual field program.

RESULTS

Mean RNFL was significantly thinner in glaucomatous eyes than in normal eyes (p<0.001). The RNFL thickness was decrease in the 4 quadrants and 11 of 12 meridians studied in glaucomatous eyes (p<0.05). The superior-inferior asymmetry showed a significant difference in RNFL thickness at 30 degrees central meridian (p<0.05). Mean RNFL thickness was significantly associated with DM and DSM of visual field (p<0.001) in glaucomatous eyes.

CONCLUSIONS

OCT revealed significant quantitative differences in RNFL thickness between glaucomatous and normal eyes. OCT showed a considerable measurements overlap between glaucomatous and normal eyes, which can limit the sensitivity and specificity of this instrument (Arch Soc Esp Oftalmol 2002; 77: 435-442).