Posters

Predicting the amount of change in corneal refractive power after excision of pterygium

Poster Details

First Author: M.Jung SOUTH KOREA

Co Author(s):    J. Lee   J. Lee   E. Lee              

Abstract Details

Purpose:

To investigate the relationship between the size of the ptrygium and the amount of change in corneal refractive power after the excision of the pterygium and to predict the change of corneal power in simultaneous pterygium and cataract surgery.

Setting:

Retrospective study.

Methods:

Sixty eyes had undergone pterygium excision and conjuctival autogrft. at the Soonchunhyang University Hospital were included in this study. Corneal refractive power was measured by a corneal topography and an automatic refractokeratometer  before and 1 month and 3 months after surgery. Using a imaging program, we measured the length, width, and area percentage of the pterygium size before surgery and investigated the relationship between preoperative and postoperative corneal refractive power. A linear regression analysis was used to derive a formula for predicting the size of the pterygium and the change in mean refractive power (mean ΔK) after surgery.

Results:

The mean preoperative corneal refractive power was 43.15±1.64D in ARK, and 42.59±1.68D. At 1 month postoperatively, it increased to 43.91 ± 1.43D and 44.24 ± 1.70D, respectively(p<0.01) and increased at 3 months postoperatively(p<0.01). The length, width, and percentage of the area of ​​the pterygium were positively correlated with the change in mean corneal power, and the percentage of areas were showed the most significant positive correlation (r=0.70, P<0.01). The change in mean corneal power using the percentage of area could be predicted by the formula "Mean ΔK = 0.171×Area ratio (%) - 0.402" (R2=0.49, p<0.01).

Conclusions:

The mean corneal power increased after pterygium excision and it  was stable at 1 month postoperatively. In the case of simultaneous cataract and pterygium surgery, the formula for predicting the change in mean corneal power using the percentage of area of the pterygium will be helpful in determining intraocular lens power.

Financial Disclosure:

None