Alterations in optical higher order aberrations after implantable contact lens for high myopia in Indian eyes
Dr. Dhivya Ashok Kumar, Dr. Jayanthi Thangarajan, Dr. Amar Agarwal
Aim: To evaluate the changes in the higher order aberrations and correlation with visual acuity improvement in eyes operated with implantable contact lens (ICL) for high myopia in Indian population. Materials and Methods: 15 eyes of 10 patients underwent ICL implantation. Main outcomes measured were uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), contrast sensitivity and optical higher order aberrations (HOA). Optical higher order aberrations were measured with Hartmann shack aberro meter postoperatively at 4 weeks. Results: Five patients had ICL implantation in both eyes and 5 patients in one eye. The mean preoperative and postoperative UCVA were 0.012±0.009 and 0.762±0.359 respectively. The mean preoperative TRMS and HRMS was 5.16±7.47 and 0.11±0.8 respectively at 6mm pupil. The mean postoperative TRMS and HRMS was 1.17±2.42 and 0.17±0.14 respectively.There was a significant change (p=0.001) in Z40, Z3-3 (p=0.026) and total trefoil (Z3-3 and Z33) (p=0.009) at 6mm pupil. In eyes with postoperative BCVA of ≥1 Snellen decimal equivalent, there was significant change in the mean Z33 (p=0.028) and Z40 (p<0.001) at 6mm pupil.In eyes with post-operative BCVA improvement ≥3 lines, there was significant difference in the Z40 (p=0.014) and (Z5-3 + Z53) (p=0.004) at 6mm pupil. There was no significant change in Z40 at 4mm pupil. Conclusion: ICL implantation produces significant changes in third and fourth optical higher order aberrations. Alteration in spherical aberration was observed to be high at 6mm than at 4mm pupil.