ANALYSIS OF INTRA OCULAR LENS POWER ESTIMATION IN PATIENTS ADMITTED FOR CATARACT SURGERY

Background: According to Pakistan National Blindness and Visual Impairment Survey, cataract accounts for 51.5% of blindness and visual impairment in Pakistan. In most of the camp and primary level facilities intra-ocular lenses are implanted without proper estimation. The purpose of this study was to know the common keratometric, axial length values, IOL powers and whether or not it is advisable to implant intraocular lenses without proper pre-operative assessment. Material & Methods: It was a retrospective study conducted at Department of Ophthalmology, DHQ Teaching Hospital, D.I.Khan. Review of estimated power of IOL of 1000 admitted patients was done. Results: Out of 1000 patients, 473(47.3%) were males and 527(52.7%) females. The youngest patient was 10 years while the oldest was 80. Maximum patients presented in 51-60 years age group. Only 25(2.5%) patients were below 20 years. The range of axial length was 19.50-28.0mm. 581(58.1%) patients were having axial length 22-23.50mm. Ten (1.0%) had axial length >= 26mm and 6(0.6%) <20.0mm. The range of estimated IOL power by SRK II formula with 118.0A constant was 10-33D. Maximum patients, 140(14.0%) were having IOL power of 20.50D. 522(52.2%) patients were having IOL power 20-22.0D. Only 26(2.6%) patients had IOL power of <= 15.0D and 56(5.6%) >= 25D. Conclusion: The estimated power of IOL differs from patient to patient with a wide range of 10D to 33D. Therefore assessment of IOL power by proper keratomery and biometry is desirable for good post-operative vision.