Evaluation of Visual Outcomes, Postoperative Angle Alpha, and Angle Kappa After Implantation of Isofocal Intraocular Lenses

Ahmed Hassan Assaf,1,2 Hams Samy,2 Noha Fawky,2 Menna Ahmed Kamel1 1Department of Ophthalmology, Ain Shams University, Cairo, Egypt; 2Watany Eye Hospital, Cairo, EgyptCorrespondence: Ahmed Hassan Assaf, Ain Shams University, Abbassia, Cairo, Egypt, Email [email protected]: To evaluate the effect of angles kappa and alpha on the visual outcomes after implantation of isofocal intraocular lens (IOL) during cataract surgery.Methods: This prospective study involved 66 eyes undergoing cataract surgery with Isopure IOLs. Exclusion criteria comprised irregular corneal astigmatism exceeding 1.0D, and ocular co-morbidities affecting visual outcomes post-surgery. Evaluation parameters included postoperative refraction, uncorrected and corrected-distance visual acuity (UDVA, CDVA), uncorrected intermediate visual acuity (UIVA), and distance-corrected intermediate visual acuity (DCIVA) at 80 cm. Additionally, postoperative angles alpha, kappa, and wavefront aberrations at a 3-mm pupil using ray tracing were assessed post-surgery at least 60 days later.Results: Patients had a mean age of 64.48 ± 9.92 years. Mean postoperative manifest refraction spherical equivalent (MRSE) was − 0.21 ± 0.27 D. Mean UDVA and CDVA were LogMAR 0.06 ± 0.04 and 0.02 ± 0.06, respectively. Mean UIVA LogMAR 0.32 ± 0.08 while mean DCIVA was LogMAR 0.29 ± 0.08. Postoperative angles kappa and alpha were 0.39 ± 0.14 mm and 0.45 ± 0.15 mm, respectively. Mean postoperative ocular RMS higher-order aberrations (HOAs) 0.23 ± 0.08. Spherical aberration, coma, and trefoil averaged 0.05 ± 0.07, 0.12 ± 0.03, and 0.07 ± 0.03, respectively. No significant correlations were observed between postoperative angle kappa and alpha with UDVA, CDVA, or HOAs. A non-significant weak positive correlation was noted between angle kappa and UIVA/DCIVA, while no correlation was found between angle alpha and UIVA/DCIVA.Conclusion: No substantial correlations were found between various postoperative angles kappa and alpha values and postoperative visual acuity metrics (UDVA, CDVA, UIVA, and DCIVA) or higher order ocular aberrations (including, spherical aberration, coma, and trefoil with a 3.0 mm diameter) in pseudophakic eyes implanted with isofocal intraocular lenses (IOLs).Keywords: intraocular lens, cataract, optical quality, angle alpha, angle kappa