ABSTRACT

Objectives:

To examine the fellow eyes in unilateral non-arteritic ischemic optic neuropathy (NAION) and to compare their optic disc parameters and peripapillary retinal nerve fiber layer (RNFL) thickness with age-and refraction-matched normal controll subjects, using Heidelberg Retinal Tomograph 2 (HRT II).

Ma­te­ri­als and Met­hods:

The fellow eyes of 40 patients with typical unilateral NAION (study group) and one randomly chosen eye of 42 age-, sex-, and refraction-matched normal control subjects were enrolled in the study. Optic disc morphologic features (average disc area, cup area, rim area, disc volume, rim volume, cup/disc area ratio, cup depth) and peripapillary RNFL thickness were evaluated using HRT II, a confoal scanning ophtalmoscopy.

Re­sults:

In the study group, there were 26 (65%) men and 14 (35%) women, whereas there were 27 (64%) men and 15 (36%) women in the control group (Chi square test, p=0.89). Mean age of the patients in the study and control groups was 59.4±10.3 and 57.7±9.1 years, respectively (T test, p=0.72). There was not any statistically significant difference regarding mean spheric equivalent between the two groups (Mann-Whitney U-test, p=0.203). The NAION unaffected fellow eyes had significantly smaller disc areas, cup areas, cup volumes, cup-disc area ratios (vertical and lineer), and cup depths than the control eyes (Mann-Whitney U-test; p<0.05), whereas there was no significant difference in the RNFL thickness between the two.

Conclusion:

A comparison of the fellow eyes in patients with unilateral NAION and the control eyes showed a significant difference in optic disc parameters and the morphology of RNFL. These differences could be important in the pathogenesis of NAION and needs to have further investigated.