Visual response properties of cat retinal ganglion cells after retinal detachment

Abstract

Purpose:: To evaluate early changes in the physiological properties of feline retinal ganglion cells after retinal detachment.

Methods:: The retinas of young adult cats were detached by injecting a solution of 0.25% sodium hyalurontae in balanced salt solution between the neural retina and retinal pigment epithelium with a glass micropipette. At one or three days after detachment the eyes were removed. The eyecup was flat mounted in recording chamber and superfused with Ames medium. Retinal ganglion cells were labeled by placing two drops of 0.002% Acridine orange in the chamber. Visual stimuli were generated by programming a graphic card and projected to retinal surface through the microscope optic path. Single-unit responses from ganglion cells on wholemount retina were recorded in vitro under visual control.

Results:: One, three, and seven days after the retinal detachment surgery, we investigated visual response properties of retinal ganglion cells. Recorded cells showed clear signs of progressive visual function deterioration. Compared to cells recorded from normal retinas (n=12), cells in detached retinas showed a different degree of decline in average threshold sensitivity and contrast responses. An early decline in threshold sensitivity was detected after 1-day detachment (0.06 log unit, n=5). The deterioration progressed in 3- (0.12 log unit, n=6) and 7-day (0.27 log unit, n=3) groups. Parallel drops in contrast responses were also evident. In addition, we noticed increased spontaneous discharges in some recorded ganglion cells.

Conclusions:: The present study reveals that retinal detachment induced visual function loss, which is reflected in the declined response properties of retinal ganglion cells. This study offers physiological evidence for early visual function deterioration in detached feline retinas.