BACKGROUND: Aniseikonia is a difference in the size magnification between the two eyes, which most commonly results from spectacle correction of anisometropia. However, it can also occur in patients with an isometropic refractive error following cataract extraction and posterior chamber intraocular lens (CE/PCIOL) implantation, although reports of this in the literature are not as common. This case illustrates how a custom-designed aniseikonic prescription can relieve the asthenopic symptoms of a patient with aniseikonia in the absence of anisometropia after CE/PCIOL surgery.
CASE REPORT(S). A 59-year-old physician presented with a larger image size noted out of his left eye 6 weeks following a CE/PCIOL procedure in the left eye. Eyestrain at intermediate and distant viewing distances was also reported. The evaluation revealed an essentially spherical isometropic refractive error (OD -2.25-0.25x025, OS -2.00-0.25x165) and 2-3% aniseikonia. The treatment plan included single vision iseikonic lenses with 1.28% size magnification over the right eye for distance use. Follow-up at 1 and 2 months revealed comfortable adaptation and significant reduction of symptoms. Iseikonic lenses with full correction of the aniseikonia were also dispensed; however, relief was less optimal with this pair.
CONCLUSIONS. This case demonstrates that (1) application of an aniseikonic prescription is not limited to anisometropic cases, but may also be used in symptomatic isometropic patients with aniseikonia after CE/PCIOL surgery. Iseikonic lenses may be the only accepted treatment option for isometropic aniseikonia, since contact lens correction is not likely to be helpful in such cases. (2) Undercorrection of the aniseikonia may be preferable due to less-noticeable optical distortions.