Abstract
Purpose: :
To evaluate Humphrey (HVF) and Goldmann (GVF) visual field data for significant changes in central and peripheral visual field (VF) among 20 legally blind retinitis pigmentosa (RP) subjects implanted with Optobionics’ ASR® device.
Methods: :
HVF 30–2 Fastpac perimetry was performed six times pre–op, and at post–op months 1, 2, 3, 4, and 6. Pre–op mean thresholds and 95% confidence intervals (CI.95) were determined for each subject by ring eccentricity (1–5) and quadrant for test locations that were seen consistently at all pre–op tests. Post–op mean thresholds for the same test locations by ring eccentricity and quadrant were considered significantly improved if they exceeded the CI.95. GVF was performed in some cases pre–op, and at 6 or 9 months post–op for subjects at one site reporting improved far peripheral vision.
Results: :
Analysis of our center’s 8 subjects’ GVF results reveals that one subject had temporal far peripheral VF areas that expanded from 3 and 1 mm2 of retina pre–op, to 9 and 18 mm2 at 9 months post–op, for the operative eye and fellow eye, respectively. Two other subjects had only central VF pre–op, and developed between 15–37 mm2 of far peripheral GVF in both eyes located ∼70–90º temporally. The mean CI.95 for both central and far peripheral GVF measurements in RP is 0.17 log units and our subjects’ peripheral VF improvements exceed the CI.95. At 4–6 months post–op, one of these subjects improved significantly in HVF sensitivity for all quadrants and rings, while the other improved significantly in outer rings 3–4. Four out of eight patients at our center showed a deterioration in HVF sensitivity at 3–6 months post–op. One case was due to surgical complications, another to a non–study–related injury; and three subjects developed significant cataracts. For all 40 eyes, the HVF mean CI.95 ranged from 3.4 to 5.2 dB across ring eccentricities. Additional HVF results from other subjects among the 3 centers will be presented.
Conclusions: :
In addition to HVF assessment, the GVF should be administered in RP subjects implanted with a sub–retinal microarray chip, to quantify improvements in far peripheral retinal sensitivity in areas far from the device.
Keywords: clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • retinal degenerations: hereditary • low vision