Purchase this article with an account.
S. J. Bass, J. Sherman; Preserved Visual Acuity in the Absence of the Foveal Pit as Confirmed by Spectral Domain (SD) OCT. Invest. Ophthalmol. Vis. Sci. 2009;50(13):3281.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To report four subjects with good visual acuity and no foveal reflex observed via ophthalmoscopy, and confirmed with spectral domain OCT (SD-OCT)
Four subjects, 3 males and 1 female, ranging in age from 12 years to 54 years, with visual acuities ranging from 20/25 to 20/30 were studied. All subjects had standard ophthalmoscopy performed. SD-OCT of the macula was performed on all subjects, using the 3-D scan or raster scan of the Topcon SD-OCT or the Cirrus SD-OCT. Three subjects had no iris transillumination or nystagmus, and did not have albinism. The fourth subject had oculocutaneous albinism and grade 4+ iris transillumination, but no nystagmus. One subject had optic nerve hypoplasia. Threshold 10-degree visual fields using the M2 program of the Octopus perimeter which measures foveal thresholds and tests points 0.7 degrees apart within the central 4 degrees was performed on one subject. Stratus OCT fast RNFL thickness was performed on one subject.
All four subjects (100%) had no foveal reflex on standard ophthalmoscopy, but no notable macular abnormalities. SD-OCT did not demonstrate any foveal depression in all four subjects (100%). All retinal layers were present and appeared intact. The junction line between the inner and outer segments of the foveal cones was also normal in all four subjects, except that the lengthening of the foveal cone outer segments seen in normal patients with 20/20 visual acuity was absent in all four subjects. Foveal threshold visual fields were normal in the one subject tested. RNFL thickness was normal in the one subject tested with the exception of borderline thickness in the papillomacular RNFL in both eyes.
These cases demonstrate that it is possible to have preservation of central visual function in the absence of a foveal pit. In addition, SD-OCT with its higher resolution revealed preservation of the junction between the inner and outer segments of the foveal cones and absence of the lengthening of the foveal cone outer segments. SD-OCT is a useful adjunct in our understanding of patients with no foveal pit who have preserved visual acuity and preserved visual function in other visual tests. These results corroborate with the work of Marmor, et al who reported preservation of visual acuity in the absence of a foveal pit in one patient (ARVO 2007) and in four subjects in a later publication (Arch Ophthalmol. 2008; 126(7):907-913.) The anatomical foveal pit is not necessary for good visual acuity. Contrastingly, the absence of a foveal pit and the absence of the normal lengthening of the foveal cone outer segments can also explain the inability of an eye to achieve 20/20 visual acuity.
This PDF is available to Subscribers Only