Purchase this article with an account.
Adam Jacobson, Thaddeus Wandel, Alan D Springer; Unilateral isolated foveal hypoplasia. Invest. Ophthalmol. Vis. Sci. 2016;57(12):79.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Foveal hypoplasia is described as an absent or shallow pit, thickened inner retina, shortened outer segments and an increased retinal thickness. Bilateral foveal hypoplasia is often associated with other ocular comorbidities, including albinism, aniridia, microphthalmia and retinopathy of prematurity. We report the first case of unilateral isolated foveal hypoplasia.
The patient was a 67 year old female glaucoma suspect with a history of bilateral posterior vitreous detachments. A vertical, high density 5 line Cirrus optical coherence tomography (OCT) raster scan was performed (4,096 A-scans/B-scan). The middle B-scan was analyzed using a longitudinal reflectivity profile to determine laminar thicknesses. Mean pixel intensity of the ONL was used to assess for edema. The scan was centered on the foveola as indicated by the presence of a fovea externa.
The patient had 20/20 vision in both eyes, with normal OD foveal morphology (Fig. 1A). The OS scan showed an epiretinal membrane (ERM) overlying a hypoplastic fovea (Fig. 1B). There were no signs of retinal holes, separations or inward “tenting” of the foveal tissue. OS retinal thickness was 3.3 times greater than OD, as measured from the inner (ILM) to the external limiting membrane (ELM; 346.1 µm vs. 104.3 µm). Inner segment ellipsoid (IS-E) to retinal pigment epithelium (RPE) distance was the same for both eyes (66.2 µm) as was ELM-RPE distance (96.6 µm). Thus, photoreceptor lengths for both eyes were the same. Mean pixel intensity of the OD and OS ONLs were 16 and 13, respectively (Fig. 2), suggesting the absence of fluid.
Quantitative analyses suggests the patient presented with unilateral foveal hypoplasia, including an absent foveal pit and greater overall retinal thickness. It is unlikely that the observed morphology is secondary to edema caused by the ERM for several reasons. First, retinal deformation from an ERM is caused by edema, which we ruled out by measuring mean pixel intensity of the ONL and the absence of laminar separations. Furthermore, the high resolution scans allowed us to visualize undisplaced inner retinal laminae, further suggesting that a foveal pit had never been formed. A lower resolution scan might have been misinterpreted as reflecting foveal tenting and edema. Removing the ERM over a hypoplastic fovea should not be expected to restore a foveal pit, and this is often the case. Whether hypoplastic foveas are more prone to having ERMs is unclear.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.
This PDF is available to Subscribers Only