Purpose
To analyze refractive outcomes of highly myopic astigmats an average of 566 days post-operatively after first undergoing phakic intraocular lens implantation for myopia followed three months later by WFG PRK or LASIK.
Methods
Five women and two men (14 eyes) with a mean age 28.3 years (range 21-45), and an average spherical equivalent refraction of -10.78 diopters (D) ± 1.85 D and average cylinder of 2.80 D ± 0.76 D underwent dual refractive procedures. First an implantable collamer lens was inserted through a self sealing corneal incision. Three months or more post-implantation, after documenting refractive stability, four patients underwent WFG (VISX CustomVue STAR S4 IR) PRK (three with mitomycin-C) and three underwent WFG LASIK. Uncorrected distance visual acuities (UDVA), manifest refraction (MR), corrected distance visual acuities (UDVA), corneal topography, corneal pachymetry, wavefront higher order aberrations (HOA), and endothelial cell densities (ECD) were determined preoperatively and postoperatively.
Results
Final visual outcomes [mean 566 days (range 347-898 days)], 14/14 eyes (100%) achieved UDVA of 20/20 or better and 8/14 (57%) achieved UDVA of 20/15 or better. No eye lost more than one line of corrected distance visual acuity (CDVA). Regression analysis showed strong correlation between attempted and achieved refractive correction (R2=0.98). Manifest Refractive Spherical Equivalent (MRSE) were within 0.50 D of emmetropia in 86% of eyes and were within 1.00 D of emmetropia in 100% of eyes. Postoperative refractive cylinder was less than 0.50 D in 93% and less than 1.00 D in 100% of treated eyes. Regression analysis showed a strong correlation between target induced astigmatism and surgically induced astigmatism (R2=0.89). Between six months and the final postoperative visit, refractive stability was achieved in 83% of eyes. Pre and postoperative keratometry, pachymetry, HOA, and ECD results are shown in Table 1.
Conclusions
Refractive correction using bioptics enabled effective treatment of high myopia with astigmatism with excellent predictability and few adverse effects in the intermediate term. This approach can be appropriate in settings where laser vision correction as a sole procedure is inadvisable and where a toric phakic IOL is not available.