Intraocular lens exchange or explantation post cataract surgery

AIM:To report incidence,indications,and visual outcomes of intraocular lens(IOL)exchange/explantation surgery.METHODS:Retrospective analysis of 60 eyes requiring IOL exchange/explantation surgery between 1^(st) January 2017 and 31^(st) December 2022.The overall outcomes as well as comparison between the trainee versus experienced surgeons were analyzed.RESULTS:Out of 39778 cataract surgeries(with no preexisting ocular co-morbidities)during a six-year period(2017-2022),60(0.15%)needed IOL exchange/explantation.Surgeons-under-training performed 36/60 cases(60%)while 24/60(40%)were by experienced surgeons.The commonest indication was subluxated IOL in 26(43.3%),followed by dislocated IOL in 20(33.3%),postoperative refractive surprise in 7(11.6%),IOL induced uveitis in five and broken haptic in two eyes.Twenty-four(40%)eyes had intraoperative complications during primary surgery.Posterior chamber IOL(PCIOL)was the commonest secondary IOL in 21(35%)eyes,scleral fixated in 20(31.6%),anterior chamber IOL(ACIOL)in 13(21.6%),iris fixated IOL in three(5%)and three eyes(5%)were left aphakic.The mean time between primary and secondary surgery was 168d(168±338.8).Best corrected visual acuity(BCVA)of>20/60 was obtained in 43 eyes(71.66%),20/80-20/200 in 14(23.33%),20/250 in two and hand movements in one.No statistically significant difference in visual outcome was noted at post-op one month between trainees versus experienced surgeons(UCVA 0.45±0.29 vs 0.53±0.32,P=0.20,BCVA 0.34±0.25 vs 0.37±0.26,P=0.69).CONCLUSION:IOL subluxation as the commonest indication and posterior capsular rupture is the commonest intraoperative risk factor.This complication can be effectively addressed with selection of the appropriate secondary IOL achieving good visual outcomes in over 70% of patients.

Intraocular lens exchange-removing the optic intact

Current practice for intraocular lens （IOL） exchange is to cut the optic of the posterior chamber intraocular lens （PCIOL） prior to removing it. Great care must be taken during this maneuver to avoid a posterior capsular tear. Removing the haptics from the fibrosed capsule can also be hazardous, as it may result in zonular stress and dehiscence. A technique is described for performing foldable （one-piece acrylic） IOL removal without cutting the optic. Careful visco-dissection of the haptics with a low viscosity ophthalmic viscosurgical device （OVD） in the fibrosed peripheral capsular tunnel avoids zonular or capsular stress. Internal wound enlargement permits foldable IOL removal in one piece, whilst preserving a self-sealing sutureless corneal wound. This technique may enhance the safety and efficacy of foldable IOL exchange.

Surgical options for correction of refractive error following cataract surgery

Refractive errors are frequently found following cataract surgery and refractive lens exchange.Accurate biometric analysis,selection and calculation of the adequate intraocular lens(IOL)and modern techniques for cataract surgery all contribute to achieving the goal of cataract surgery as a refractive procedure with no refractive error.However,in spite of all these advances,residual refractive error still occasionally occurs after cataract surgery and laser in situ keratomileusis(LASIK)can be considered the most accurate method for its correction.Lens-based procedures,such as IOL exchange or piggyback lens implantation are also possible alternatives especially in cases with extreme ametropia,corneal abnormalities,or in situations where excimer laser is unavailable.In our review,we have found that piggyback IOL is safer and more accurate than IOL exchange.Our aim is to provide a review of the recent literature regarding target refraction and residual refractive error in cataract surgery.