Human retinal senescence measured histologically: as an aid to clinical diagnosis by ocular coherence tomography

Spectral domain optical coherence tomography (SD-OCT) has become an established diagnostic tool for the clinical assessment of retinal pathology and its progression, in OPD setting. The aim of our study was to do in vitro quantification of relevant retinal layers to collect baseline data at different age groups, against which OCT findings can be interpreted. Thirty eyeballs (20-99 years) were used to study the retinal nerve fibre layer (RNFL), ganglion cells and inner plexiform layer (GC+IPL) and outer nuclear layer (ONL) thickness using V-Test software, 198035 on the H&E stained histological specimens. Mean thickness of these retinal layers was studied. To estimate the decrease from the optimal stage, absolute percentage decline (APD) was calculated for each decade. The mean thickness of RNFL at was 77.8 μm, 77.1 μm, 73.6 μm, 70.6 μm, 69.2μm, 54.1μm, 36.5μm 26.8μm from 3 to 10 decade respectively. Significant APD of 30% was evident between 7 and 8 decades. APD graphs for RNFL and GC+IPL were almost parallel to each other. The absolute percentage decline (APD) for the thickness of ONL was 0.2%, 4.6%, 13%, 35%, 60%, 62% and 64% for 4, 5, 6, 7, 8, 9 and 10 decade respectively. This study has provided normative base line histological data for ready reference. Decade wise changes in thickness of different layers can be used by ophthalmologist to differentiate senescent from pathological changes and to monitor progression of disease.