Influence of angle kappa and angle alpha on visual outcomes after implantation of a nondiffractive extended-depth-of-focus intraocular lens: a prospective observation study.

backgroundWhile large angle kappa (chord µ) and angle alpha (chord α) have been reported to adversely affect visual quality with diffractive multifocal intraocular lenses (MIOLs), their impact on the postoperative visual outcomes of nondiffractive extended depth of focus (EDOF) IOLs remains unclear. This study aimed to evaluate the influence of postoperative angle kappa and angle alpha on visual and optical outcomes following implantation of a nondiffractive EDOF IOL.

methodsThis prospective observational study included 115 cataract patients (115 eyes) who underwent implantation of the AcrySof

resultsAt 3 months postoperatively, most postoperative angle kappa and angle alpha values were within physiological ranges, with only a small number of eyes having values ≥ 0.5 mm (photopic angle kappa: n = 7; mesopic angle kappa: n = 10; angle alpha: n = 29). Partial correlation analyses demonstrated no significant associations between photopic or mesopic angle kappa and postoperative visual acuity, objective optical quality metrics, or subjective visual disturbance scores (all P > 0.05). Angle alpha showed weak but statistically significant positive correlations with uncorrected distance visual acuity and contrast threshold (P < 0.05), indicating slightly better visual performance with larger angle alpha values. No significant differences in visual outcomes were observed among angle kappa and angle alpha subgroups.

conclusionsWithin the observed postoperative range, angle kappa and angle alpha were not associated with clinically meaningful deterioration in visual performance following implantation of a nondiffractive EDOF IOL. These findings suggest that wavefront-shaping EDOF designs may be tolerant to moderate angular offsets in routine clinical practice.