Journal of Korean Ophthalmic Optics Society (한국안광학회지)

The Korean Ophthalmic Optics Society (한국안광학회)
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Comparison of Tear Distributions by the Corneal Eccentricity when Fitted with Spherical and Aspherical RGP Lenses

구면 및 비구면 RGP렌즈 피팅 시 각막 이심률별 눈물분포 비교

  • Kim, Jihye (Dept. of Optometry, Seoul National University of Science and Technology) ;
  • Kim, So Ra (Dept. of Optometry, Seoul National University of Science and Technology) ;
  • Park, Mijung (Dept. of Optometry, Seoul National University of Science and Technology)
  • 김지혜 (서울과학기술대학교 안경광학과) ;
  • 김소라 (서울과학기술대학교 안경광학과) ;
  • 박미정 (서울과학기술대학교 안경광학과)
  • Received : 2016.05.01
  • Accepted : 2016.06.09
  • Published : 2016.06.30
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Abstract

Purpose: The present study was aimed to compare the tear volume and distribution by corneal eccentricity when fitted with spherical and aspherical RGP lenses. Methods: Spherical and aspherical RGP lenses were fitted in best alignment on a total of 77 subjects (136 eyes) in their twenties and thirties without any ocular disease or ocular surgery experience. The tear volume was analyzed by estimating the concentration of tear stained with fluorescein in the center of RGP lens as well as at the mid-peripheral and peripheral areas, and the difference of tear distributions was analyzed according to corneal eccentricity. Results: Tear distribution from the center to the peripheral area was not significantly different when spherical RGP lenses were fitted on the corneal eccentricities of e < 0.38 and $0.68{\leq}e$, indicating the relatively even tear distribution compared with other corneal eccentricity. In the case of aspherical RGP lenses, the difference of tear distribution between the central and peripheral areas was smaller than spherical RGP lenses. The significant difference of tear distribution according to RGP lens design was observed in the corneal eccentricity of 0.48 < e < 0.68. In other words, more even tear distribution was shown when aspherical RGP lenses were fitted on the cornea with eccentricity of $0.48{\leq}e<0.68$ and spherical RGP lenses were fitted on the cornea with eccentricity $0.68{\leq}e$. Furthermore, tear volume in the mid-peripheral area increased with higher corneal eccentricity. Conclusions: The results suggest that the appropriate selection of RGP lens design according to corneal eccentricity is necessary since tear volume and distribution by the regions of spherical and aspherical lenses are affected by corneal eccentricity.

목적: 구면 및 비구면 RGP렌즈 피팅 시 각막 이심률별 눈물양 및 눈물분포를 비교하고자 하였다. 방법: 안질환 및 안과적 수술경험이 없는 20~30대 77명(136안)을 대상으로 가장 양호한 상태로 구면 및 비구면 RGP렌즈를 피팅하였다. 피팅된 RGP렌즈의 중심부, 중간주변부 및 주변부의 플루레신으로 염색된 눈물의 농도를 분석하여 눈물량을 분석하였고 이심률별로 눈물분포의 차이를 분석하였다. 결과: 구면 RGP렌즈 피팅 시 이심률 e < 0.38 범위와 $0.68{\leq}e$ 범위는 중심부부터 주변부까지의 눈물분포량이 통계적으로 차이가 없어 다른 이심률 각막보다 상대적으로 고른 눈물분포량을 보이는 것으로 나타났다. 비구면 RGP렌즈의 경우는 구면 렌즈에 비해 중심부와 주변부의 눈물분포량 차이가 적었으며, 이심률 범위 0.48 < e < 0.68 각막에서는 두 렌즈 디자인 간에 통계적으로 유의한 눈물분포 차이가 나타났다. 즉, 이심률 범위 $0.48{\leq}e<0.68$ 범위의 각막은 비구면 RGP렌즈 피팅 시, 이심률 $0.68{\leq}e$ 범위에서는 구면 RGP렌즈 피팅 시 더 고른 분포를 보였다. 또한 이심률이 증가할수록 중간주변부 눈물양이 증가하는 것으로 나타났다. 결론: 구면 및 비구면 RGP 렌즈 부분별 눈물양 및 눈물분포는 각막 이심률에 영향을 받기 때문에 각막 이심률에 따른 적절한 RGP렌즈 디자인의 선택이 필요함을 제안한다.

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