Clinical claification of glaucomatou viual field lo by frequency doubling perimetry Original Reearch Article

Purpoe: To determine whether the frequency doubling perimeter (FDP) can grade glaucomatou viual function lo in a clinically relevant manner. inuoidal grating <1 cpd that undergo counterphae flicker >15 Hz appear to have twice a many band of light, a phenomenon referred to a the “frequency doubling illuion.” Evidence ugget that thi pychophyical effect i mediated in part by large-diameter ganglion cell, which are reported to be lot early in the glaucomatou dieae proce. A portable, commercially available FDP ha already demontrated high diagnotic potential for glaucoma creening. Method: ixty-four eye of 42 glaucomatou patient and 22 eye of 14 normal ubject were evaluated by mean of both frequency doubling perimetry and Humphrey perimetry. A clinical coring algorithm modeled after the Hodapp-Parrih-Anderon criteria for coring Humphrey viual field defect wa derived for the FDP at the halfway point of the tudy, and all participant were reaeed with thi algorithm upon it completion. Reult: FDP mean and pattern deviation howed trong linear correlation with Humphrey 30-2 mean deviation (R = 0.75; P < .0001) and corrected pattern tandard deviation value (R = 0.64; P < .0001). Depite thi, neither global index could conitently categorize the graded glaucomatou viual field in a manner conitent with the Hodapp-Parrih-Anderon criteria. The new FDP coring algorithm did provide good egregation (73% precie parity, 93% parity within one Humphrey grade). Concluion: ixteen-zone frequency doubling perimetry can egregate glaucomatou viual field lo into pathologic categorie approximating thoe obtained with Humphrey 30-2 perimetry by mean of a formula modeled after the Hodapp-Parrih-Anderon criteria.