Chang John So Min, Liu Sylvia Chui Ting, Ma Nadine Tsz Ching, Ng Jack Chun Man
Department of Ophthalmology, Hong Kong Sanatorium & Hospital, Hong Kong.
Department of Ophthalmology, Grantham Hospital, Hong Kong.
Clin Ophthalmol. 2024 Jan 13;18:139-149. doi: 10.2147/OPTH.S429630. eCollection 2024.
The effect of residual astigmatism and its axis on distance and near visual acuities (VAs) with multifocal intraocular lenses (IOLs) has not been studied extensively. This study compared the tolerance to experimentally induced residual astigmatism among bifocal, trifocal, and extended depth-of-focus (EDOF) IOLs.
This retrospective, comparative study included 70 eyes of 70 patients implanted with bifocal, trifocal, or EDOF IOLs. Distance and near VAs were assessed with experimentally induced astigmatism by placing positive cylindrical lenses in increments of 0.50 diopters to 2.00 diopters at 90° and 180° axes over the best distance correction.
Both distance and near VAs worsened with increasing magnitudes of experimentally induced astigmatism except in the EDOF group, in which the near VA remained within a clinically acceptable limit, ie, within one line from the best corrected VA under all ranges of experimentally induced astigmatism. Furthermore, the EDOF group showed the highest astigmatic threshold for losing VA lines following experimental astigmatic induction at both distance and near. The distance VA was generally better at with-the-rule (WTR) than against-the-rule (ATR) astigmatism for all three IOL groups. On the other hand, the near VA was generally better at WTR than ATR astigmatism in the bifocal group, comparable between WTR and ATR astigmatism in the trifocal group, and generally better at ATR than WTR astigmatism in the EDOF group.
The EDOF IOL demonstrated the highest tolerance to experimentally induced astigmatism at both distance and near. VA was generally less affected by WTR astigmatism than ATR astigmatism, especially at distance. We proposed the residual astigmatism thresholds for clinically acceptable VA reduction in all three IOL groups.
多焦点人工晶状体（IOL）的残余散光及其轴位对远、近视力（VA）的影响尚未得到广泛研究。本研究比较了双焦点、三焦点和扩展景深（EDOF）IOL对实验性诱导残余散光的耐受性。
这项回顾性比较研究纳入了70例接受双焦点、三焦点或EDOF IOL植入的患者的70只眼。通过在最佳远视力矫正基础上，在90°和180°轴位以0.50屈光度至2.00屈光度的增量放置正柱面透镜，评估实验性诱导散光时的远、近VA。
除EDOF组外，实验性诱导散光度数增加时，远、近VA均变差，EDOF组的近VA在所有实验性诱导散光范围内均保持在临床可接受限度内，即与最佳矫正VA相差不超过一行。此外，EDOF组在实验性诱导散光后失去视力行数的散光阈值在远、近视力方面均最高。对于所有三个IOL组，顺规（WTR）散光时的远视力通常优于逆规（ATR）散光。另一方面，双焦点组中WTR散光时的近视力通常优于ATR散光，三焦点组中WTR和ATR散光时的近视力相当，而EDOF组中ATR散光时的近视力通常优于WTR散光。
EDOF IOL在远、近视力方面对实验性诱导散光均表现出最高的耐受性。VA通常受WTR散光的影响小于ATR散光，尤其是在远视力方面。我们提出了所有三个IOL组中临床可接受视力降低的残余散光阈值。
