Steep preoperative corneal keratometry associated with poor hyperopic LASIK outcomes

The authors of this article prospectively compared the results of LASIK in hyperopic eyes with preoperative K values less than 43 D to eyes with preoperative K values greater than 44 D. The group with higher preoperative K values had a significantly greater loss of BSCVA and lower level of satisfaction six months after the procedure compared with the higher K value group. The authors advised caution when performing LASIK in patients with moderate to high hyperopia and K values greater than 44 D.

Twenty-six patients with 49 eyes that underwent LASIK for hyperopia were included in the study. The refractive error of the two K groups was similar preoperatively, and mean hyperopia for all 49 eyes was 3.44 D. Keratometric change was similar between the two groups. However, postoperative eye dryness was significantly greater in the 25 eyes in the higher K group, at a mean of 1.84 on a scale from zero to three versus a mean of 0.17 in the 24 lower K value eyes. Ten eyes in the higher K group lost two or more lines of BSCVA and 11 eyes lost one line, whereas one eye in the lower K group lost two BSCVA lines and six eyes lost one line.

The authors suggested dry eye as a possible cause of lower patient satisfaction and worse BSCVA results in the higher K patients. They also mentioned the introduction of higher-order aberrations in the higher K group as a possible cause, as indicated by significantly different postoperative mean sphere measurements of +0.51 in the lower K group and +0.95 in the higher K group.

The authors suggested that modifications in optical zone and transition zone sizes may improve the results of LASIK for hyperopia. They recommended further research on the influence of K values on LASIK in hyperopic patients, about which study results have been conflicting.

Financial Disclosures
Dr. Randleman receives lecture fees from Alcon, Inc., Allergan, Inc., and ISTA Pharmaceuticals.