Elite School of Optometry, Unit of Medical Research Foundation, Sankara Nethralaya, Chennai, India.
Department of Contact Lens, Unit of Medical Research Foundation, Sankara Nethralaya, Chennai, India.
Ophthalmic Physiol Opt. 2022 Jan;42(1):178-184. doi: 10.1111/opo.12908. Epub 2021 Oct 25.
To investigate the effect of varying the fluid reservoir (FR) thickness of scleral lenses (SL) on corrected distance visual acuity (CDVA), contrast sensitivity (CS) and higher-order aberrations (HOAs) in keratoconic eyes.
Forty eyes with keratoconus were fitted with a diagnostic Boston Sight SL having three different FR thicknesses. CDVA, CS and HOAs were measured before and after 30 min of lens wear. An i-Trace aberrometer and anterior segment optical coherence tomography (AS-OCT) were used to measure HOAs and FR thickness, respectively.
Statistically significant improvements in CDVA and CS were seen with different FR thickness lenses (p < 0.01). Baseline CDVA (0.22 ± 0.15) improved to 0.03 ± 0.06, 0.04 ± 0.07 and 0.07 ± 0.08 with low, standard and high FR lenses, respectively. Post-hoc testing showed better CDVA with low (p = 0.006) and standard FR (p = 0.009) lenses compared to high FR lenses. Before lens wear, CS was 1.27 ± 0.27, which improved to 1.67 ± 0.11, 1.73 ± 0.12 and 1.66 ± 0.89 with low, standard and high FR lenses, respectively. Lenses with standard FR showed better CS compared with those having low (p = 0.009) and high FRs (p < 0.001). A statistically significant reduction of higher order-root mean square aberrations (HO-RMS), coma, spherical aberration, secondary astigmatism and trefoil were found with all FR thickness lenses compared to baseline (p < 0.01). No significant difference was noted between lenses (p = 0.01). All three lenses corrected almost equal amount of HOAs. A moderate positive correlation was observed between CDVA and HO-RMS (r = 0.61, p < 0.001) for low FR lenses.
BostonSight SCLERALs were found to be very effective in improving vision, CS and reducing HOAs in keratoconus. Lenses with varying FR thickness showed equal effectiveness in visual performance and reducing HOAs. FR thickness should be considered an important factor to provide better vision and CS by minimising HOAs, as well as to maintain the normal physiology of eyes with keratoconus.
研究巩膜镜片（SL）的储液腔（FR）厚度变化对圆锥角膜眼矫正远距视力（CDVA）、对比敏感度（CS）和高阶像差（HOAs）的影响。
对 40 只圆锥角膜眼进行诊断性波士顿 Sight SL 镜片适配，该镜片有三种不同的 FR 厚度。佩戴镜片 30 分钟前后分别测量 CDVA、CS 和 HOAs。使用 i-Trace 像差仪和眼前节光学相干断层扫描（AS-OCT）分别测量 HOAs 和 FR 厚度。
不同 FR 厚度镜片均能显著提高 CDVA 和 CS（p<0.01）。基础 CDVA（0.22±0.15）分别提高至低 FR 镜片 0.03±0.06、标准 FR 镜片 0.04±0.07 和高 FR 镜片 0.07±0.08。事后检验显示，低 FR（p=0.006）和标准 FR（p=0.009）镜片的 CDVA 优于高 FR 镜片。戴镜前 CS 为 1.27±0.27，分别提高至低 FR 镜片 1.67±0.11、标准 FR 镜片 1.73±0.12 和高 FR 镜片 1.66±0.89。标准 FR 镜片的 CS 优于低 FR（p=0.009）和高 FR 镜片（p<0.001）。与基础值相比，所有 FR 厚度镜片均显著降低了高阶均方根像差（HO-RMS）、彗差、球差、二次散光和三叶差（p<0.01）。各镜片之间无显著差异（p=0.01）。所有三种镜片矫正的 HOAs 量几乎相同。低 FR 镜片的 CDVA 与 HO-RMS 呈中度正相关（r=0.61，p<0.001）。
BostonSight SCLERAL 镜片对改善圆锥角膜患者的视力、CS 和降低 HOAs 非常有效。具有不同 FR 厚度的镜片在视力表现和降低 HOAs 方面具有同等效果。FR 厚度应被视为一个重要因素，通过最小化 HOAs 来提供更好的视力和 CS，并维持圆锥角膜眼的正常生理状态。
