Abstract
Purpose :
OCT has been a great advance in ophthalmology. In most cases, anatomic measurements parallel psychophysical findings (acuity and VF), but there are several reasons for disparity.
Methods :
Retrospective review of 64 patients coded as disparity
Results :
One commonly seen disparity where psychophysics looks better than OCT can be seen in patients with recovered optic neuritis. This phenomenon can be seen following optic nerve decompression. The most common (expected) disparity relates to delay in onset of anatomic changes following optic nerve pathology (acute optic neuritis, compressive optic neuropathy).
A more interesting discordance can occur when NFL dropout may be obscured by disc edema due to compression at the orbital apex. This has traditionally been seen with nerve sheath meningiomas, but also may occur with other pathology in the orbital apex (tumors, other lesions, vascular malformations, and even thyroid orbitopathy). We call this “green disease” (OCT looks normal although the psychophysics are clearly affected). Ganglion cell segmentation algorithm seems to be less prone to this maksing and may be abnormal, even when the NFL looks normal. A much less common anomaly is due to retinal disease. This may cause anomalies in the anatomy, although psychophysics continue to look relatively normal. Even the most common optic neuropathy (glaucoma) may occasionally demonstrate disparity between the anatomy and psychophysics
Transynaptic changes are much more obvious with ganglion cell analysis than NFL assessment and may not occur in all circumstances.
Conclusions :
OCT provides a quantitative reproducible assessment of anatomy of the retina and anterior visual pathways. Although in most cases this parallels psychophysical abnormalities (acuity and VF) cases with discordance can be very instructive. The increasing use of ganglion cell analysis may remove some of the previous discordance.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.