Hydrogel intracorneal lenses in aphakic eyes
R. F. Steinert, B. Storie, P. Smith, M. B. McDonald, G. van Rij, L. D. Bores, J. P. Colin, D. S. Durrie, C. Kelley, F. Price Jr, C. Rostron, G. O. Waring 3rd and L. T. Nordan
Center for Eye Research, Harvard Medical School, Boston, Mass, USA.
BACKGROUND: The theoretical benefits of synthetic keratophakia over
conventional corneal lamellar procedures are the elimination of donor
concerns and superior refractive predictability. Additionally, synthetic
material can be inspected for optical quality and power, and it can be
sterilized. Furthermore, visual recovery should be more rapid since
epithelium is not removed from the central part of the cornea and the need
for keratocyte repopulation is eliminated. OBJECTIVE: To present results on
patients who received an intracorneal implant (Kerato-Gel, Allergan Medical
Optics, Irvine, Calif) that was made from lidofilcon A, a glucose-permeable
hydrogel with an equilibrium water content of 68%. METHODS: The
intracorneal implants were implanted in 35 adult patients for correction of
aphakia. Inclusion criteria excluded patients with aphakia who were
candidates for intraocular lenses. RESULTS: A total of 19 patients were
followed up through 2 years postoperatively. For 16 patients with 2-year
postoperative refractive data, the average spherical equivalent was -0.63
+/- 2.07 diopters (D). At 2 years, 88% of patients were within +/- 3.00 D
of plano and 50% were within +/- 1.00 D. the mean change in Snellen's line
for corrected visual acuity was -3.25 lines at 2 years for all patients and
-2.0 lines for a subgroup of five patients who were free of vision-limiting
preoperative disease. CONCLUSIONS: Results suggest that this intracorneal
implant is well tolerated by the cornea and can provide predictable
refractive results in patients with high-risk aphakia. Limitations of the
procedure are uneven microkeratome resections, loss of best-corrected
visual acuity, and irregular astigmatism in some patients. Although these
data show good evidence of biocompatibility of the implant material,
technical surgical progress is needed to advance this procedure into
clinical therapeutic practice.
