Purchase this article with an account.
Gustavo Kupper Marino, Andre Torricelli, Abirami Santhanam, Jiahui Wu, Steven E Wilson; Time to EBM lamina lucida and lamina densa regeneration in corneas after PRK in rabbits. Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):721.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Epithelial basement membrane (EBM) plays a central role in corneal wound healing process. This study aimed to determine the time to EBM lamina lucida and lamina densa regeneration after -4.5D PRK in rabbit corneas without haze using transmission electron microscopy (TEM).
Rabbits that underwent -4.5D PRK and corneas were processed for TEM at different time points after surgery. PRK was performed with epithelial scrape using a VISX Star S4 IR laser. Any cornea that developed haze or delayed epithelial healing beyond 5 days was excluded. Animals were sacrificed at time points from 7 to 19 days after PRK and tissue was fixed and TEM at 30,000x magnification was performed at several locations in the treated area of the central cornea to determine whether the normal lamina lucida and lamina densa had been regenerated to the point it was indistinguishable from contralateral control corneas that did not have PRK.
Corneal epithelial lamina lucida and lamina densa ultrastructure (Fig. 1) was noted in each cornea at 11 days or more after PRK (Fig. 2). Corneas at 7 days post PRK did not have lamina lucida or lamina densa in the central cornea. At 9 days after PRK, one cornea had fully regenerated lamina lucida and lamina densa in more than one area of the central cornea whereas the other PRK cornea had no evidence of regenerated EBM.
The lamina lucida and lamina densa become fully regenerated between 9 and 11 days after -4.5D PRK in rabbit corneas without haze or delayed epithelial healing. This study suggests that experiments performed to explore the synthesis of EBM components such as perlecan and nidogens should focus on the time from injury to 9 days after -4.5D PRK, where these components are likely to be produced at high levels by the cells that synthesize them.
This PDF is available to Subscribers Only