Purpose
Rhegmatogenous Retinal Detachment (RRD) is a grave condition associated with acute loss of vision caused by anatomic displacement of the photoreceptor layer. It may also lead to chronic loss of vision which may be due to retinal remodeling even if reattachment occurred. This study aims to explore functional electroretinographic (ERG) changes and associated retinal cellular remodeling following experimental retinal detachment in a rabbit model.
Methods
Retinal detachment was created in the right eye of ten New Zealand rabbits, while left eyes served as intact controls. For the detachment a 25G vitrectomy was performed, and the inferior retina was detached by injecting 0.1ml balanced salt solution between the neural retina and retinal pigment epitheelium using a soft tip needle. Indirect ophthalmoscopy was performed pre-operatively and 1, 3, 7 and 14 days postoperatively. ERG recordings were performed pre-operatively and 7 days and 21 days post-operatively. Retinal sections were stained with H&E and studied histopathologically, and immunofluorescence was performed for PKC (All bipolar), mGluR6 (ON bipolar cells) and iGluR4 (OFF bipolar cells) in eyes harvested 21 days post-operatively.
Results
Retinal reattachment was seen approximately two weeks following surgery. The amplitude of the scotopic ERG a-wave was decreased significantly in eyes with retinal detachment. While no attenuation was observed in the mean photopic or scotopic b-waves, we noted the disappearance of a secondary b-wave peak in the ERG recordings of eyes with retinal detachment. Histopathololgical analysis showed thickiening of the outer nuclear layer. Immunofluorescence staining demonstrated extension of ON bipolar cell processes into the outer nuclear layer, which may be responsible for the changes of the b-wave pattern.<br /> <br />
Conclusions
Retinal detachment and reattachment are associated with functional and anatomical changes. Future functional and cellular studies are warranted to more accurately understand the interaction between the 1st and 2nd order retinal neurons, cellular remodeling and ERG patterns.