Abstract
Purpose:
Optical Coherence Tomography (OCT) of the optic nerve head and macula is a useful adjunct test in monitoring optic nerve disease. Few studies have looked at the utility of spectral domain OCT (SD-OCT) in severe vision loss states. Visual acuity in patients with end stage optic neuropathy (ESON) may be classified using the semiquantitative scale of counting finger (CF), hand motion (HM), light perception (LP), and no light perception (NLP). Correlating peripapillary retinal nerve fiber layer (prNFLT) or macular thickness (MT) with severe vision loss in patients with optic neuropathies may help determine threshold for change, prognosis for change and help guide treatment to prevent further vision loss.
Methods:
A retrospective chart review was performed of patients diagnosed with optic neuropathy and best corrected visual acuity (BCVA) of CF, HM, LP, and NLP. Inclusion criteria were a stable BCVA, disease state present for at least 9 months, and SD-OCT of the MT or prNFLT. The central macular volume of retinal nerve fiber layer, ganglion cell layer, and inner plexiform layer was measured with a manual segmentation procedure. Exclusion criteria were a Q number of <15 and confounding ophthalmic pathology. Non-parametric Spearman Correlation was used to analyze the data.
Results:
68 eyes in 61 patients were reviewed. Of the 68 eyes, 47 had SD-OCTs of the PRNFL and 19 had SD-OCTs of the central macula and met all inclusion and exclusion criteria. Statistical analysis indicated there was no significant difference in PRNFLT or inner macular volume among the four SVL groups.
Conclusions:
Our data suggests that there is no significant difference in SD-OCT prNFLT or MT among low vision states in ESON. Possible explanations include SD-OCT may be detecting non-axonal content when measuring prNFLT, such as glial content and blood vessels. Signal-Noise ratio may be suboptimal in end stage disease. Recruitment of a larger dataset is needed to confirm these findings.
Keywords: 613 neuro-ophthalmology: optic nerve •
550 imaging/image analysis: clinical •
610 nerve fiber layer