원추각막 환자에서 비구면 RGP 렌즈착용이 각막지형도 및 내피세포에 미치는 효과

Effect of the Aspheric RGP Lens on Corneal Topography and Endothelial Cell in Keratoconus

목적: 원추각막 환자에서 비구면RGP(R gi d Gas Perneable)렌즈의 착용이 각막 지형도와 각막내피세포에 미치는 영향을 알아보고자 하였다. 대상과 방법: 원추각막환자중 6개월이상 추적관찰된 35명(65안)에서 비구면RGP렌즈를 착용한 16명(30안)과 렌즈를 착용하지 않은 19명(35안)의 의무기록을 후향적으로 분석하였다. 비구면렌즈착용후 최대교정시력, 현성굴절력, 전안부소견을 6개월간 관찰하였고, 첫 내원시와 렌즈착용 6개월후의 각막지형도 및 각막내피세포 소견을 분석하였다. 결과: 렌즈착용후 28안(93.3%)에서 20/25이상의 최대교정시력을 보였다. 난시의 변화량, Sim-k, surface asynmetry index, Surface regul arity index, 원추정점 굴절력의 변화량은 비구면 RGP 렌즈를 착용한 군에서 대조군보다 유의하게 높았다(P<0.05). 각막내피세포밀도와 평균내피세포크기의 변화는 두 군 사이에 유의한 차이는 없었다. 결론: 원추각막환자에서 비구면 RGP렌즈의 단기간 착용은 내피세포에는 영향이 없으나 각막의 불규칙성 및 비대칭성을 증가시키고 각막곡률반경을 가파르게 변화시켜 원추각막의 주변부각막과 비구면렌즈의 관계가 부적절할 가능성을 시사하였다.

Purpose: To analyze the effects of the aspheric rigid gas permeable (RGP) lens on the corneal topography and endothelial cells in eyes with keratoconus. Methods: Sixty five eyes of 35 keratoconic patients who had follow-up of more than 6 months were included in the study. Thirty eyes of 16 patients wore aspheric RGP lens, and the remaining control eyes did not wear any lens. Afer aspheric RGP lens fitting, visual acuity and manifest refractive error were evaluated, Slit lamp examination and crneal topography were also done. Mean cell area and density of corneal endothelial cell were measured by specular microscopy at first visit and 6 months after lens fitting. Results: After lens fitting, the percentage of best corrected visual acuity of better than 20/25 was 93.3% (28 eyes). The change of astigmatism, the Steepest Simulated keratometry reading, Surface asymmetry index, Surface regularity index, and apical corneal power were significantly increased in the keratoconic cornea in aspheric lens fitting group compared to the control group (p<0.05) There was no significant difference in corneal endothelial cell counts and mean cell areas between the two groups (p>0.05). Conclusions: Short-term wearing of aspheric RGP lens in keratoconic patients showed no effect on corneal endothelial cells. However, it increased the irregularity and steepening of the keratoconic cornea. It may indicate that mid-peripheral corneal-to-lens relationship may be inappropriate when keratoconus is fitted with aspheric lens.