Abstract
Purpose:
Optic atrophy constitutes the final stage in the evolution of optic neuropathy. The aim of this study is to demonstrate the utility of Spectral Domain OCT (OCT-SD) in the visualisation of hypo reflective microcystic changes (or retinal pseudocysts) in the internal nuclear layer (INL) in several cases of advanced optic atrophy.
Methods:
Patients with a diagnosis of optic nerve atrophy were prospectively studied between October 2011 and July 2012. All patients underwent a complete neuro-ophthalmologic assessment. A retinal nerve fibres (RNFL) analysis of the optic head and of the macula was performed in each patient using the OCT-SD together with a morphological analysis of the macula.
Results:
201 eyes of 131 patients have been analysed. Inner nuclear layer pseudocysts were observed in 77 eyes (38% of cases). In the majority of cases optic atrophy was the result of hereditary neuropathy, glaucoma or inflammatory neuropathy. The evolution of these optic neuropathies varied from 1 to 18 years (average: 5,75 years). Visual acuity ranged from 1/20 to 12/10 (average: 5/10). The sex ratio was 0,5 and patients’ average age was 37 years old. The microcystic changes were visualized as numerous hypo reflective lesions located in the INL. The infrared images revealed a hypo reflective cockade corresponding to the pseudo cysts location in all cases. Fluorescein angiography (performed in 10% of cases) confirmed the absence of macular vascular leakage.
Conclusions:
We report the presence of microcystic changes, or pseudocystic, lesions always associated to severe optic nerve fiber loss. The reason why pseudocystic lesions develop within the retina is not well understood. They might constitute the translation of degeneration in relation to severe optic nerve fiber loss. Recognizing these pseudo cysts is crucial as they may be confused with a cystoid macular edema. Their prognostic value and their implication in the therapeutic process need to be further evaluated.
Keywords: 629 optic nerve •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) •
562 inner retina dysfunction: biochemistry and cell biology