Limitations of blue field entoptoscopy in evaluating macular function.

Evaluation of macular function in cataract patients using blue field entoptoscopy (BFE) has been reported as useful in all cases by some authors; another found it useful only in patients with moderate visual acuity loss due to cataract. This paper reports findings in 101 cataractous eyes evaluated consecutively with BFE. A strong correlation was found between cataract type and percentage of false negatives, but the correlation between the preoperative acuity level and percentage of false negatives was poor. BFE was also poor in detecting moderate macular dysfunction (20/60-20/80). Four cases with profound visual acuity loss due to macular holes had normal perception of BFE.