Copyright 1999 American Medical Association. All Rights Reserved. Applicable FARS/DFARS Restrictions Apply to Government Use.1999
Drs Lyle and Jin1 are to be commended for their fine study of H-ALK for the treatment of primary hyperopia and consecutive hyperopia after RK. Hyperopic automated lamellar keratoplasty has become the forgotten surgical procedure for hyperopia and the authors clearly show that at least one type of hyperopia, consecutive hyperopia after RK, should not have this procedure. The authors look at 2 groups of eyes, eyes with primary hyperopia and eyes with consecutive hyperopia after RK. In the first group, the results seem reasonably good, with a mean myopic shift of only 0.07 diopters from 3 months to 1 year. The graph in Figure 11(p427) in their article similarly shows a stable time line for this group extending beyond 3 years. By comparison, the same graph shows a progressive myopic shift in the eyes after RK and, in fact, many of these eyes developed iatrogenic keratoconus and required penetrating keratoplasty. Although the authors make a distinction in the surgical results between the 2 groups, they still conclude that H-ALK is contraindicated in both types of hyperopia, especially so after RK is performed. With all due respect to the authors, while the data presented supports their conclusion for eyes after RK, it does not seem to support the same conclusion for eyes with primary hyperopia. The authors' conclusion led me to review some of my own cases of H-ALK for primary hyperopia. The study group includes 39 eyes from 21 consecutive patients at least 1 year (and up to 3.75 years) after H-ALK was performed who had a full eye examination including cycloplegic refraction within the last 6 months. Thirteen women and 8 men were included, aged 39 to 75 years, with a mean (±SD) age of 60.5 (±9.4) years. The mean (±SD) preoperative hyperopia was 2.62 (±1.04) diopters, with a range of 1.12 to 4.75 D. The mean (±SD) postoperative refractions were −0.146 (±0.65) D at 3 months and −0.285 (±0.710) D at 1 year or beyond (last visit). The myopic shift was −0.135 D in these eyes, which is comparable to results of the Lyle and Jin study (−0.07 D between 3 months and 1 year). These small shifts do not seem to be clinically or statistically significant in either data set. Postoperatively, 33 (84%) of 39 eyes were within ±1 D, with a range of +1.37 to −2.00 D at last visit. Similar to the Lyle and Jin study,1 approximately one third of these patients required mini-RKs and astigmatic keratotomies to titrate the result. While many eyes were intentionally overcorrected in 1 eye for monovision, postoperatively, 37 (95%) of 39 eyes had an uncorrected visual acuity of 20/40 or greater. Preoperatively, all patients required both distance and reading correction and, postoperatively, no patients required both distance and reading correction, although some required one or the other at least some of the time. The only complications other than occasional peripheral epithelial ingrowth that did not require treatment were in 2 eyes that lost 2 lines of best-corrected visual acuity from 20/20 to 20/30 secondary to induced astigmatism. Two patients in the group had a myopic shift greater than 1 D at 1 year (−1.12 and −1.25 D), but both showed signs of early nuclear sclerosis, which must be correlated with any myopic change in this largely older age group.
Pulaski JP. Hyperopic Automated Lamellar Keratoplasty. Arch Ophthalmol. 1999;117(3):416-417. doi: