A new, two-stage surgical approach to manage visually significant corneal opacity and cataract may provide a viable alternative to existing treatments, a study in Cornea suggests.
To achieve the optimal postoperative target refraction with preservation of the corneal endothelium, researchers performed a two-step procedure: simultaneous penetrating keratoplasty (PKP) and cataract surgery followed by a postponed intraocular lens (IOL) implantation until all corneal sutures were removed and keratometric readings stabilized.
“With this technique, IOL power calculation will be more accurate and based on actual keratometric values, and the endothelium of the corneal graft will not be damaged by mechanical trauma or ultrasonic power during phacoemulsification,” the researchers said in their paper.
Current options include a triple procedure consisting of simultaneous PKP, cataract extraction and IOL implantation that allows rapid visual recovery and avoids a second surgery. However, postoperative refraction is often far removed from the target refraction, researchers said. The second option, keratoplasty followed months later by cataract extraction and IOL implantation, provides a postoperative refraction closer to emmetropia because of better calculation of the IOL power using keratometric readings of the transplanted clear cornea. But this option also poses drawbacks, since visual recovery is delayed for months and a risk of graft failure is present due to endothelial loss during subsequent phacoemulsification, investigators noted.
The study included 29 eyes with mean baseline uncorrected distance visual acuity (UDVA) of 1.94 ± 0.46 and best-corrected distance visual acuity of 1.56 ± 0.42. The mean spherical equivalent was 11.75 ± 3.38D. The time between the two surgical interventions was approximately 13 months. Just before secondary IOL implantation, the mean endothelial cell density was 2198 ± 311 cells. Six months after the second IOL implantation, the mean corneal endothelial cell loss was 7.3%, mean spherical equivalent improved to -0.19 ± 0.93D, mean UDVA improved to 0.34 ± 0.18 and the mean corrected distance visual acuity improved to 0.18 ± 0.29. All grafted corneas maintained their clarity until the final follow-up visit.
“In eyes with coexisting corneal opacities and cataract, if it is feasible for the patient to undergo a two-stage procedure, performing PKP and cataract extraction as a first step and then delaying IOL implantation until removal of corneal sutures will allow accurate IOL power calculation and favorable refractive outcome,” the investigators wrote. “Moreover, this new approach saves the corneal graft’s endothelium and avoids its damage, the brunt of cataract surgery, thus promoting graft survival.”
|Solaiman KAM, El-Haig WM, Bor’i A, et al. Secondary intraocular lens implantation after simultaneous penetrating keratoplasty and cataract extraction for coexisting corneal and lens opacities. Cornea. January 9, 2019. [Epub ahead of print].