Abstract
Abstract: :
Purpose:There have been many reports on the use of Heidelberg Retinal Tomography (HRT) in glaucoma, where this laser imaging technique is of value in estimating retinal nerve fibre loss. However, there are few reports of its use in neuro-ophthalmology and, in particular, optic atrophy. This study investigates the use of HRT in establishing peripapillary retinal nerve fibre thickness in cases of optic atrophy. Methods: Twenty patients with known bilateral optic atrophy (11 acquired, 9 hereditary) (12 females, 8 males) underwent HRTII analysis. These were compared to 20 age and sex matched controls, and 20 patients with glaucoma. Measurements of global retinal nerve fibre layer thickness and segmental RNFL were made in each group, and compared statistically using Analysis of Variance, and Chi-squared analysis. Results: The group mean global RNFL thickness for the group with optic atrophy was 0.14mm (s.d. 0.09mm), which was not significantly different from the glaucoma group (mean RNFL thickness 0.11mm (s.d. 0.07mm)). However the mean RNFL was significantly less (p<0.005) than the control group (RNFL thickness 0.27 (s.d.0.06mm). Segmental analysis showed that in the optic atrophy group 27/40 eyes had temporal RNFL loss whereas in the glaucoma group 23 eyes had nasal RNFL loss. Conclusions: These findings show that RNFL thickness as measured using HRT is reduced in optic atrophy as it is in glaucoma. The main difference between the two conditions being the preponderance of temporal RNFLloss in optic atrophy. This suggests HRT is of value in the assessment of patients with optic atrophy, whether hereditary or acquired.
Keywords: neuro-ophthalmology: optic nerve • imaging/image analysis: clinical