Evaluation Of Postoperative Visual Outcomes In Cataract And Ocular Comorbidity Subjects Using Trichromatic Critical Flicker Fusion Frequency

Prior to cataract surgery, ophthalmic examinations are performed to identify potential comorbidities that may affect surgical outcomes. However, these exams have limited ability to predict postoperative vision and are often hindered by media opacities. This study aimed to investigate the clinical applicability of the critical flicker fusion frequency (CFF) threshold, which is resistant to image degrading caused by cataracts and highly sensitive to visual function impairments, using trichromatic flicker light.

The Chinese of PLA General Hospital, Beijing, China.

A prospective non-randomized study was conducted on 117 eyes divided into two groups: cataract alone (N=59) and cataract with comorbidities (N=58). CFF measurements of red, green, and yellow monochromatic flicker lights were performed pre-and post-operatively to differentiate between media opacity and ocular comorbidities. A generalized estimating equations model (GEE) was used to examine the relationship between visual acuity and CFF.

The CFF values of all flicker lights were higher in eyes with media opacity (29.17±3.4Hz, 29.92±4.1Hz, 30.64±4.5Hz) compared to eyes with retina/optic nerve disorders (red 24.47±6.7Hz, green 25.07±6.7Hz, yellow 25.62±7.6Hz). The red monochromatic flicker was found to be the most consistent both before (29.17±3.35Hz) and after (29.44±3.34Hz; P=0.06) cataract removal, even in cases where fundus exams were unsuccessful. The yellow flicker had the highest AUC value (0.798, 95% CI, 0.715-0.881) in identifying fundus impairment. The GEE model revealed that eyes with comorbidities and a Red-CFF threshold of less than 26Hz had an 89% lower odds ratio of achieving postoperative visual acuity of 20/40 or better.

The CFF threshold was sensitive to visual function impairment, and the red monochromatic flicker is a robust tool for predicting postoperative visual acuity, particularly in patients with both cataracts and comorbidities. The yellow monochromatic flicker showed higher sensitivity in identifying comorbidities and warrants further investigation.