Abstract
Purpose: :
Long standing subretinal fluid at the macula can result in irreversible damage to the photoreceptors, which can lead to severe vision loss. However, in some conditions, such as central serous chorioretinopathy, return to fairly good visual acuity(VA) can be observed after resolution even after months of foveal neurosensory detachment. Therefore, it is unclear how much changes can occur and are tolerated by cone cells in the presence of subretinal fluid before irreversible changes in VA start to occur. Using adaptive optics(AO) retinal camera, we present the cone density(CD) and appearance of a patient who had delayed absorption of subretinal fluid after repair of macula-splitting retinal detachment.
Methods: :
A 27-year-old female patient who had a macula-splitting temporal retinal detachment was treated with scleral buckling procedure 2 days after the onset of symptoms. Although the surgery was successful in reattaching the peripheral retina, there was persistent subretinal fluid involving the fovea and extending to a small portion of temporal macula. This fluid gradually resolved completely over 18 months with a final VA of 20/20. Once the retina flattened, we used the high-speed AO camera built at our institution to image cone cells. In order to compare the CD and cone mosaic of areas of retina that were previously detached versus never detached, images were taken of areas temporal and nasal to fovea. We analyzed the CD and used Voronoi analysis to assess mosaic regularity using custom Matlab Software. The patient’s findings were compared with images taken from a normal control subject.
Results: :
Cone images were taken at 2.5 degrees(about 750 µm) temporal and nasal locations from the center of the fovea and the CD was calculated. In our patient, the CD were 19533 cones/mm2 at temporal and 19240 cones/mm2 at nasal locations. The CD of normal subject at same patches of retina were 28290 cones/mm2 temporally and 31014 cones/mm2 nasally. The percentage of hexagonality was 42.32% temporally and 40.68% nasally in the patient compared to 44.07% temporally and 45.53% nasally in the normal subject.
Conclusions: :
Despite long standing subretinal fluid involving the fovea, there was no significant loss or change in the shape of cone cells when previously detached and attached areas were compared in our patient in whom the loculated fluid eventually reabsorbed and VA improved to 20/20. Comparisons with a normal subject suggest that there may be a wide variation in CD even among patients with 20/20 visual acuity.
Keywords: imaging/image analysis: clinical • retinal detachment • photoreceptors