Abstract
Purpose: :
To determine the relationship between exudative age-related macular degeneration lesion size and abnormal retinal nerve fiber layer measurements using optical coherence tomography.
Methods: :
We performed a retrospective medical record review of our own clinic population to identify patients with exudative age-related macular degeneration in both eyes who also had Cirrus HD-OCT scans of the macula and RNFL on the same day. Subjects were excluded if they had been identified as a glaucoma suspect, had ocular hypertension, or had a prior diagnosis of glaucoma. Central foveal thickness (CFT), as well as the presence or absence of global RNFL thickening, temporal sector thickening, or any clock hour thickening (defined as greater than 95% of the value for the normative population) were recorded. Exudative lesion size was measured from fundus photography, fluorescein angiography, or OCT and designated small or large. Small lesions were defined as less than three disc areas, and large lesions as three or greater disc areas.
Results: :
We identified 42 eyes of 21 patients with a mean age of 80.5 years. 31.8% were female. Small lesions were found in 16 eyes, and large lesions in 26 eyes. The mean CFT was 336 microns. Two eyes were excluded from the RNFL analysis due to RNFL scan segmentation failures. 22.5% had global RNFL thickening, 27.5% had temporal sector RNFL thickening, and 35% had at least one clock hour of RNFL thickening. 45.8% of eyes with large lesions had global RNFL thickening while no eyes with small lesions had global RNFL thickening. A generalized estimating equation logistic regression model was used to determine 95% confidence intervals. Male gender (OR: 0.0377, p = 0.0051, [95% CI: 0.00379-0.374]) was found to be negatively related to the presence of global RNFL thickening. The modeling indicated that small lesion size strongly reduced the probability of global RNFL thickening.
Conclusions: :
Female gender and large AMD lesions are strongly associated with global thickening of the nerve fiber layer measured at the disk. No patients with small AMD lesions were found to have global RNFL thickening. We predict that AMD lesions of increasing size may have influence on global RNFL abnormalities, but larger sample sizes will be required to further elucidate the precise relationship.
Keywords: age-related macular degeneration • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • nerve fiber layer