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.

Clinical Outcomes of an Optimized Prolate Ablation Procedure for Correcting Residual Refractive Errors Following Laser Surgery.

PURPOSE: The purpose of this study was to investigate the clinical efficacy of an optimized prolate ablation procedure for correcting residual refractive errors following laser surgery. METHODS: We analyzed 24 eyes of 15 patients who underwent an optimized prolate ablation procedure for the correction of residual refractive errors following laser in situ keratomileusis, laser-assisted subepithelial keratectomy, or photorefractive keratectomy surgeries. Preoperative ophthalmic examinations were performed, and uncorrected distance visual acuity, corrected distance visual acuity, manifest refraction values (sphere, cylinder, and spherical equivalent), point spread function, modulation transfer function, corneal asphericity (Q value), ocular aberrations, and corneal haze measurements were obtained postoperatively at 1, 3, and 6 months. RESULTS: Uncorrected distance visual acuity improved and refractive errors decreased significantly at 1, 3, and 6 months postoperatively. Total coma aberration increased at 3 and 6 months postoperatively, while changes in all other aberrations were not statistically significant. Similarly, no significant changes in point spread function were detected, but modulation transfer function increased significantly at the postoperative time points measured. CONCLUSIONS: The optimized prolate ablation procedure was effective in terms of improving visual acuity and objective visual performance for the correction of persistent refractive errors following laser surgery.

Clinical Outcomes of an Optimized Prolate Ablation Procedure for Correcting Residual Refractive Errors Following Laser Surgery

PURPOSE: The purpose of this study was to investigate the clinical efficacy of an optimized prolate ablation procedure for correcting residual refractive errors following laser surgery. METHODS: We analyzed 24 eyes of 15 patients who underwent an optimized prolate ablation procedure for the correction of residual refractive errors following laser in situ keratomileusis, laser-assisted subepithelial keratectomy, or photorefractive keratectomy surgeries. Preoperative ophthalmic examinations were performed, and uncorrected distance visual acuity, corrected distance visual acuity, manifest refraction values (sphere, cylinder, and spherical equivalent), point spread function, modulation transfer function, corneal asphericity (Q value), ocular aberrations, and corneal haze measurements were obtained postoperatively at 1, 3, and 6 months. RESULTS: Uncorrected distance visual acuity improved and refractive errors decreased significantly at 1, 3, and 6 months postoperatively. Total coma aberration increased at 3 and 6 months postoperatively, while changes in all other aberrations were not statistically significant. Similarly, no significant changes in point spread function were detected, but modulation transfer function increased significantly at the postoperative time points measured. CONCLUSIONS: The optimized prolate ablation procedure was effective in terms of improving visual acuity and objective visual performance for the correction of persistent refractive errors following laser surgery.

Management of Three Cases of Decentration after Laser In Situ Keratomileusis

Four hundred one eyes of 219 patients underwent laser in situ keratomileusis(LASIK) at Kangbuk Samsung Hospital from March 1997 to June 1998. Of those, 33 eyes of 25 patients were retreated. Among 33 eyes, we presumed that 3 eyes had decreased visual quality mainly associated with decentration. The mean reftactive error and the amount of decentration of 3 eyes were -1.00 diopter and 2.66mm. After retreatment of these 3 eyes, uncorrected and corrected visual acuity, and visual quality were improved by correction of residual refractive errors, even though the amount of decentration was the same. In cases of decreased visual quality which is suspected to be mainly associated with decentration, we need differentiation between decentration and residual rfractive errors as causes of decreased visual quality. Even though decentration is suspected as a cause of decreased visual quality, visual quality can be improved by correction of residual refractive errors.

Management of Three Cases of Decentration after Laser In Situ Keratomileusis

Four hundred one eyes of 219 patients underwent laser in situ keratomileusis(LASIK) at Kangbuk Samsung Hospital from March 1997 to June 1998. Of those, 33 eyes of 25 patients were retreated. Among 33 eyes, we presumed that 3 eyes had decreased visual quality mainly associated with decentration. The mean reftactive error and the amount of decentration of 3 eyes were -1.00 diopter and 2.66mm. After retreatment of these 3 eyes, uncorrected and corrected visual acuity, and visual quality were improved by correction of residual refractive errors, even though the amount of decentration was the same. In cases of decreased visual quality which is suspected to be mainly associated with decentration, we need differentiation between decentration and residual rfractive errors as causes of decreased visual quality. Even though decentration is suspected as a cause of decreased visual quality, visual quality can be improved by correction of residual refractive errors.