Residual refractive errors in pseudophakic eyes and related factors:a population-based study

AIM: To determine residual refractive error after cataract surgery in pseudophakic eyes and its relationship with age, sex, and axial length(AL).METHODS: In this population-based cross-sectional study, the sampling was performed on individuals aged 60y and above in Tehran, Iran using a multi-stage stratified random cluster sampling method. Pseudophakic eyes with a best-corrected visual acuity of 20/32 or better were analyzed and their refractive results were reported.RESULTS: The mean spherical equivalent(SE) refraction was-0.34±0.97 diopters(D) and the mean absolute SE was 0.72±0.74 D with a median of 0.5 D. Moreover, 32.68%(n=546, 95%CI: 30.27%-35.08%), 53.67%(n=900, 95%CI: 51.23%-56.1%), 68.99%(n=1157, 95%CI: 66.96%-71.02%), and 79.73%(n=1337, 95%CI: 77.69%-81.76%) of the eyes had a residual SE within ±0.25, ±0.50, ±0.75, and ±1.00 D of emmetropia, respectively. According to the multiple logistic regression model, increasing age was associated with a statistically significant decrease in predictability for all cut points. Moreover, the predictability based on all cut points was significantly lower in individuals with an AL longer than 24.5 mm than in those with an AL between 22 to 24.5 mm.CONCLUSION: Based on the results, the accuracy of intraocular lens(IOL) power calculation is lower for those who underwent cataract surgery during the last 5y in Tehran, Iran. Among the most important influential factors, the choice of IOL or it's power disproportionate to eye conditions and age can be mentioned.

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.