JCRS Highlights April 2020
April 2020 - Volume 46 - Issue 4
Journal Of Cataract And Refractive Surgery
Accelerated CXL in paediatric keratoconus
A five-year follow-up study supports the use of corneal collagen cross-linking (CXL) in paediatric keratoconus and suggests advantages for using an approach with increased irradiance over a shorter application time. The retrospective case-controlled study compared two different accelerated CXL protocols in 143 eyes of 86 patients with a mean age of 15 years. One group received four minutes of illumination at 30mW/cm2, and the second group received five minutes of illumination at 18mW/cm2. Both treatments halted progression of keratoconus. Patients in the second group showed a statistically significant reduction in total higher order aberrations and coma during the five-year visit when compared with the preoperative visit. This was not seen in the first group.
A Agca et al., “Accelerated corneal crosslinking in children with keratoconus”, Volume 46, Issue 4, pp517-523.
Toric IOLs after corneal refractive surgery
Patients who have had LASIK or PRK in the past show significant decreases in astigmatism when implanted with toric IOLs according to a retrospective study.
The study included 56 eyes with previous myopic LASIK/PRK and 19 eyes with previous hyperopic LASIK/PRK. Vector analysis was used to assess the preoperative corneal and postoperative refractive astigmatism. Mean corneal astigmatism in myopic cases declined from 1.34D preoperatively to 0.36 after IOL implantation. Hyperopic cases showed similar improvement, from a mean 1.66D before surgery to 0.34D after toric IOL surgery. A majority of eyes, 80% of myopic cases and 84% of hyperopic cases, had refractive astigmatism of 0.50D or less at postoperative follow-up.
D Cao et al., “Outcome of toric intraocular lenses implanted in eyes with previous corneal refractive surgery”, Volume 46, Issue 4, pp534-539.
ROCK inhibitors and eye banks
Rho-associated protein kinase (ROCK) inhibitors, better known as a glaucoma treatment, may have a role to play in preserving corneal tissue in eye banks. Apoptosis of corneal endothelial cells is a known problem in grafts stored in storage medium and is related to graft suitability for transplantation. Corneal endothelial cell survival in donor corneal tissue is essential for the transparency of the graft. Selective ROCK inhibitors have been shown to decrease apoptosis of cultured human corneal epithelial cells. A study conducted in human donor corneolimbal rings stored in commercial storage medium demonstrated a reduced rate of early apoptosis and late cell death at one week when a ROCK inhibitor (Y-27632). This could have important implications for corneal tissue storage in eye banks. Moreover, ROCK inhibition could prove to be useful in promoting future graft survival, the investigators note. Future studies are planned.
A Achiron et al., “Effect of Rho-associated kinase inhibitor on human corneal endothelial cell apoptosis”, Volume 46, Issue 4, pp612-616.