Acuity perimetry with speech input for mapping macular visual field in glaucoma
Purpose: Acuity perimetry may be more efficient compared to contrast detection in assessing macular visual field defects. We explored the use of letters as stimuli and speech as a response method to measure macular visual sensitivity in healthy observers and those with glaucoma.
Methods: 11 eyes from 11 healthy observers and 10 eyes from 7 observers with glaucoma (macular mean deviation = -8.40 dB; SD = 5.00; M-pattern, Octopus 900, Haag-Streit, Switzerland) were examined. Letter acuity was estimated at 13 test locations within 4° from fixation (Figure 1A) using a fixed step size staircase. A speech recognition algorithm was employed as an input method to enable participants to perform the task without supervision. The observers’ perceived difficulty of the task was assessed via a questionnaire.
Results: In healthy observers, visual acuities ranged from -0.13 ± 0.03 LogMAR at fovea to 0.36± 0.05 LogMAR at 4° eccentricity (Figure 1B). In observers with glaucoma, resolution thresholds correlated closely with conventional perimetry (r between -0.48 (ST) to -0.85 (IT)). Most observers found the task easy to perform.
Conclusion: The results show that letter acuity perimetry with speech input is a feasible method to capture macular damage in glaucoma. These approaches may lead to more intuitive and patient-friendly tests for macular visual field assessments.