Entoptic perimetry screening for central diabetic scotomas and macular edema

Objective: The aim of this study was to compare entoptic perimetry, using c onventional television, to Amsler grid and patient-reported visual loss for the detection of functional diabetic maculopathy and macular edema. Design: Observational case series. Participants: A single eye from each of 104 consecutive patients with diabe tes in an academic retina clinic. Intervention: Each eye was screened by Amsler grid, entoptic perimetry, and Humphrey 10-2 threshold visual field testing (HVF 10-2; Humphrey instrumen ts Inc., San Leandro, CA) in random order. Eyes were then examined clinical ly. Main Outcome Measures: The presence or absence of new visual decline since the patient's last clinical examination, the presence or absence of central visual field abnormalities using an Amsler grid, entoptic perimetry, HVF 1 0-2, and the presence or absence of clinically significant macular edema (C SME). Results: The sensitivities and specificities for the detection of central d iabetic scotomas as evidenced by HVF 10-2 abnormalities were: subjective im pression, 31 of 90 eyes (34.4%) and II of 14 eyes (78.6%); Amsler grid, 29 of 90 eyes (32.2%) and 13 of 14 eyes (92.9%); and entoptic perimetry, 58 of 90 eyes (64.4%) and 11 of 14 eyes (78.6%). Entoptic perimetry was statisti cally more sensitive than both subjective impression (P < 0.001) and Amsler grid (P < 0.001), but the specificities were statistically indistinguishab le. The sensitivities and specificities for the detection of CSME were: sub jective impression, 6 of 24 eyes (25.0%) and 52 of 80 eyes (65.0%); Amsler grid, 9 of 24 eyes (37.5%) and 59 of 80 eyes (73.8%); and entoptic perimetr y, 17 of 24 eyes (70.8%) and 44 of 80 (55.0%) eyes. These results are also statistically significant, with entoptic perimetry being more sensitive and less specific than both subjective impression (P = 0.007 and P = 0.011, re spectively) and Amsler grid (P = 0.008 and P < 0.001, respectively) in this subset of patients. Conclusions: Entoptic perimetry is 87% more sensitive than the subjective i mpression of visual decline (P < 0.001) and 100% more sensitive than Amsler grid (P < 0.001) for the detection of central scotomas in diabetic patient s. For the detection of CSME, entoptic perimetry is 183% more sensitive tha n subjective impression (P = 0.007) and 89% more sensitive than Amsler grid (P = 0.008). Hence, entoptic perimetry, performed using conventional telev ision, has the potential to be an effective, inexpensive, and widespread ad junct to surveillance examinations for the early detection of diabetic macu lopathy. (C) 2000 by the American Academy of Ophthalmology.