Myopic angle-supported intraocular lenses: two-year follow-up

Abstract

Objective: To evaluate clinical and refractive results of myopic angle-supported intraocular lenses (IOLs).

Design: Prospective, noncomparative case series.

Participants: Twenty-one eyes of 12 patients (7 female) with a mean age of 29.5 years and a follow-up of 24 months. The prospective study included highly myopic eyes (more than -11.00 diopters [D]) with spectacle-corrected visual acuity better than 20/200.

Methods: Twenty-one eyes underwent implantation of a single-piece IOL with Z-shaped haptics for angle support (each haptic with two footplates) and an optical zone of 4.5 mm (NuVita, Bausch & Lomb Surgical, Irvine, CA). The dioptric power of the IOL was calculated considering refraction, keratometry, and anterior chamber depth (specific nomogram), and its diameter was determined by adding 0.5 mm to the corneal diameter.

Main outcome measures: We evaluated the following clinical and refractive data: visual acuity without and with correction (VAsc and VAcc), spherical equivalent (SE) obtained under cycloplegia, slit-lamp biomicroscopy, keratometry, applanation tonometry, endothelial cell count, ultrasound pachymetry, gonioscopy, indirect ophthalmoscopy, subjective complaints, and descriptions of complications.

Results: Mean postoperative VAsc was 20/74. Mean preoperative VAcc (20/50) increased to 20/30; 65% gained at least two lines of VAcc, and no eye had a decrease in VAcc. Preoperative SE (-18.95 D) evolved to -2. 06 D, stabilizing after one month. Iris retraction (pupil ovalization) more than 0.5 mm was noted in eight eyes (40%). Mean keratometry, corneal astigmatism, and ultrasound pachymetry were stable during the study (P > 0.01). Significant endothelial cell loss was demonstrated in the second year. Gonioscopy showed 70 (87. 5%) footplates ideally positioned with no iris depression. Reports of glare and haloes in dark environment were considered light in 80% and not referred in 20%, and spectacles were used for residual refraction in 75%. Intraocular lens exchange was needed in one eye because of undersizing, and the IOL was removed in one eye because of chronic inflammatory reaction associated with ocular hypertension (this patient was excluded from the statistical analysis).

Conclusions: This report demonstrates good efficacy for correction of high myopia by the phakic IOL used during the two years of follow-up. Long-term complications (safety) such as iris retraction and endothelial cell loss remain a concern.