Abstract
Purpose :
The cornea is susceptible to trauma and infections, resulting in fibrosis and, in many cases, blindness. We previously showed that the intrastromal injection of cultivated human stromal keratocytes (CSKs) was efficacious in resolving acute corneal haze in a rat model of irregular phototherapeutic keratectomy. Here, we investigated the potential therapeutic efficacy of CSK injection in developed corneal haze using lumican knockout (Lum-KO) mice.
Methods :
A total of 30,000 cells were injected into the stroma of 6-week-old Lum-KO mice. Topical tobramycin and dexamethasone were given 4 times/day for 7 days postoperatively. The treatment outcome was compared to wild-type (WT), non-treated, and phosphate-buffered saline (PBS) and human corneal fibroblasts (SFs)-injected corneas. Each treatment group was comprised of 3 mice. The corneas were imaged under slit-lamp biomicroscopy, anterior segment-optical coherence tomography (AS-OCT), and in vivo confocal microscopy (IVCM) 3 weeks later. Corneal thickness was measured from AS-OCT scans and haze density was quantified from IVCM scans. Following euthanasia, the corneas were harvested for immunofluorescence staining (IF) of keratocan, lumican, decorin, and biglycan.
Results :
Intrastromal injection of CSKs improved the corneal clarity, whereas the SF- and PBS-injected and non-treated Lum-KO mice did not. Quantitatively, on IVCM, the haze density was significantly lowered by 21.7% after CSK injection (p=0.004). PBS and SF injections resulted in 1.4% less (p=0.997) and 13.6% higher (p=0.063) haze density, respectively. On AS-OCT, non-treated Lum-KO mice exhibited thinner corneas with an average central thickness of 69.3±6.6 µm than the WT mice (80.1±3.3 µm; p=0.029). CSK injection partially restored the corneal thickness (74.7±9.1 µm; p=0.334 vs. WT). The corneal thickness remained significantly lower than WT after PBS (p=0.033) and SF (p=0.005) injections. The IF demonstrated that CSK administration also partially recovered lumican, keratocan, decorin, and biglycan expression, which were either absent or expressed in lower intensities in the non-treated and PBS and SF-injected corneas.
Conclusions :
Injection of cultivated CSKs improved the corneal clarity in the developed haze of Lum-KO mice. The improvement was likely due to the partial recovery of the proteoglycans, which also resulted in the restoration of the corneal thickness in the mice.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.