Long-term follow-up of hydrogel intracorneal lenses in 2 aphakic eyes

Abstract

We report the outcome of hydrogel intracorneal lens implantation in 2 patients. The lenses were implanted at approximately 50% depth in the cornea to correct high hyperopic refractive errors of 10.5 diopters (D) and 14.0 D, respectively. Both patients were contact lens intolerant and not suitable for intraocular lens implantation. Surgery was performed in 1988, and the patients were followed until early 2010. The patients showed good tolerance for the intracorneal lenses, but both developed opacities around the implant, leading to reduced visual acuity in 1 patient. Long-term patient monitoring is essential since corneal opacities can develop after many years. Removing the implant is not necessary as the lens can easily be rinsed by lifting the corneal cap.

Confocal and Histological Features After Poly(Ethylene Glycol) Diacrylate Corneal Inlay Implantation

“…Similar results with an absence of endothelial cell density changes have been previously reported after LASIK and after hydrogel intrastromal inlay implantation in rabbits and in humans 22,24,55,67,70. However, an endothelial cell density reduction has also been described after long-term follow-up with a lidofilcon A inlay in a human cornea 29. To our knowledge, results regarding qualitative features (polymorphism and polymegethism) of the endothelium after intrastromal hydrogel inlays in rabbit corneas have not been previously reported.…”

“…Optical properties and permeability of hydrogels have been known since the early 1960s, but it was not until 1967 that Dohlman first used hydrogel material as an intrastromal inlay 15. Since then, several articles have documented the biocompatibility of different hydrogel inlays in humans and animals in the long term 16–29. More recently, there has been emerging interest in corneal inlays as potential methods for the correction of presbyopia, and implants made of different materials and designs have been developed for this purpose 30–42…”

Intracorneal Inlays for the Correction of Ametropias

“…28 There were other reports of this Permalens hydrogel being implanted in humans for the correction of hyperopia and aphakia. [29][30][31][32][33][34] In 1989, I personally received approval to implant 5 myopic hydrogels (Fig. 3B) under the sponsorship of CooperVision, Inc. using a Steinway microkeratome (the precursor of the Chiron Automated Corneal Shaper) using their hydrogel inlay.…”

“…The development of excimer laser technology in the late 1990s supplanted the need for intracorneal inlays at that time. Some of these lenses remained in situ for many years 33 (Fig. 3C).…”