Singh Archana, Pesala Veerendranath, Garg Prashant, Bharadwaj Shrikant R
Cornea and Anterior Segment Services and Prof. Brien Holden Centre for Eye Research, Hyderabad Eye Research Foundation, L. V. Prasad Eye Institute, Hyderabad, Andhra Pradesh, India.
Optom Vis Sci. 2013 Apr;90(4):378-84. doi: 10.1097/OPX.0b013e318288afb5.
PURPOSE.: The end point of astigmatic correction after cataract surgery will depend on how uncorrected astigmatism impacts distance and near vision of pseudophakic eyes. This study determined the impact of induced astigmatism and pupil size on the distance and near acuity of otherwise emmetropic pseudophakic eyes implanted with monofocal intraocular lenses. METHODS.: Monocular high-contrast distance (4 m) and near (40 cm) logMAR acuity was determined in 15 subjects (mean ± 1 SD, 57.9 ± 9.0 years) without astigmatism and with 2.5 diopters (D) myopic to 2.0 D hyperopic astigmatic lenses induced in 0.5-D steps at 0-, 45-, 90-, and 135-degree axes. This experiment was repeated for the same range of induced astigmatism with 1.5-, 3-, and 6-mm artificial pupil diameters placed before one eye of 10 subjects dilated with 10% phenylephrine HCl. RESULTS.: Distance acuity deteriorated with astigmatism for all axes tested (p < 0.01). Near acuity deteriorated with hyperopic astigmatism (p < 0.1), whereas it improved with up to 1 D of myopic astigmatism before saturating for all axes tested (p < 0.01). Distance and near acuity improved with a reduction in pupil diameter (p < 0.01). The change in distance and near acuity with induced astigmatism was smaller for 1.5-mm than for 3-mm and 6-mm pupil diameters (p < 0.01). CONCLUSIONS.: Partial restoration of near acuity with uncorrected myopic astigmatism comes with a proportional loss of distance acuity in pseudophakic eyes. Uncorrected myopic astigmatism more than 1 D results in a large loss of distance acuity at no additional benefit to near acuity. Both distance and near acuities with and without astigmatism are benefited with a reduction in pupil diameter. Uncorrected hyperopic astigmatism results in deterioration of both distance and near acuities of pseudophakic eyes.
白内障手术后散光矫正的终点将取决于未矫正散光如何影响人工晶状体眼的远视力和近视力。本研究确定了诱导散光和瞳孔大小对植入单焦点人工晶状体的正视人工晶状体眼的远视力和近视力的影响。方法：对15名受试者（平均±1标准差，57.9±9.0岁）进行单眼高对比度远视力（4米）和近视力（40厘米）的对数最小分辨角视力测定，这些受试者无散光，分别在0°、45°、90°和135°轴上以0.5屈光度（D）的步长诱导2.5 D近视至2.0 D远视散光镜片。对10名用10%盐酸去氧肾上腺素散瞳的受试者的一只眼睛，在相同的诱导散光范围内，分别使用直径为1.5毫米、3毫米和6毫米的人工瞳孔重复该实验。结果：在所有测试轴上，远视力随散光而下降（p<0.01）。近视力随远视散光而下降（p<0.1），而在所有测试轴上达到饱和之前，近视散光高达1 D时近视力有所改善（p<0.01）。远视力和近视力随瞳孔直径减小而提高（p<0.01）。对于1.5毫米瞳孔直径，诱导散光引起的远视力和近视力变化小于3毫米和6毫米瞳孔直径（p<0.01）。结论：在人工晶状体眼中，未矫正的近视散光使近视力部分恢复的同时，远视力会成比例下降。未矫正的近视散光超过1 D会导致远视力大幅下降且对近视力无额外益处。无论有无散光，瞳孔直径减小都有利于远视力和近视力。未矫正远视散光会导致人工晶状体眼的远视力和近视力均下降。
