Comparison of intraocular lens power calculation in simultaneous and sequential pterygium and cataract surgery

Objective: To evaluate the effect of pterygium excision on intraocular lens (IOL) power and refraction. Methods: The present study was carried out on patients with combined cataract and pterygium excision (combined group) and pterygium surgery first and cataract surgery after one month (sequential group). Parameters such as mean keratometry (K) values, axial length, IOL power, and corneal astigmatism were compared pre and postoperatively in the combined and sequential groups. Results: 70 eyes of 70 patients were included in the present study. The mean age of the participants in the combined group was 70.46±10.12, whereas that in the sequential group was 68.68±11.22 (p=0.243). The mean horizontal length of the pterygium in the combined group was 2.64±0.17 mm and 2.57±0.17 mm in the sequential group. The mean postoperative K values (p=0.03) and IOL power (p=0.04) in the combined group were significantly higher than the preoperative values. The estimated postoperative refractive error in the combined group was -0.50±1.00 D and 0.25±0.5 D in the sequential group (p=0.04). On the other hand, the postoperative refraction in the sequential group was predictable. Corneal visibility was diminished on the nasal side in almost all the patients in the combined group as compared to the sequential group. Conclusion: The postoperative refraction errors were positively correlated with the length of pterygium in the combined group. The unpredictability of these errors recommends sequential surgery in cases with concurrent pterygium and cataract.