Comparison Of The Accuracies Of Intraocular Lens Power Formulas In High Myopic Eyes By The Intentional Myopia Versus Emmetropia.

To compare the accuracies of the formulas used to calculate the intraocular lens (IOL) power in the high myopic eye when targeting emmetropia or intentional myopia.

Retrospective study conducted at Pusan National University Hospital, Pusan, Korea. The medical records of consecutive eyes with cataract surgeries performed by a single surgeon were reviewed.

This study included 70 eyes of 70 patients with high myopia who underwent uncomplicated cataract surgery with single-type IOL implantation of emmetropia (plano to -0.5 diopter) or intentional myopia (-2.0 to -3.0 diopter). Preoperative, 1 week and 1 month postoperative refractions were measured by autorefractokeratometer. Ocular biometry was measured by IOLMaster 700 in all eyes. Mean absolute refractive prediction errors (MAE) of 4 formulas (Hagis, SRK/T, Holloday 2, Barrett) after 1 week and 1 months were reviewed.

The two groups of MAE were significantly differed by 4 formulas (p = 0.031, p = 0.025, p= 0.045, and p = 0.047). And the MAE were smaller in emmetropic eyes than intentional myopic eyes, showing relatively myopic outcome in intentional myopia. In intentional myopic subgroup analysis, postoperative 1 month MAE of Barrett formula was smaller than other formulas (p = 0.046, p = 0.043, and p = 0.032). Otherwise Holloday 2 formula showed statistically lager MAE (p = 0.032, p = 0.002, and p = 0.032). 

In patients with high myopia, postoperative MAE showed a tendency toward larger error in the refractive outcome when targeting intentional myopia compared to emmetropia.