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Objective: To evaluate the efficacy and safety of riboflavin-ultraviolet-A (UV-A)-induced corneal collagen cross-linking (CXL) in the management of progressive keratoconus., Methods: It was a retrospective case series study. Twenty-three eyes of 13 patients with progressive keratoconus were included. Corneal collagen crosslinking was performed under topical anesthesia including corneal de-epithelization (8 mm diameter) and instillation of 0.1% riboflavin (in 20% dextran T500 solution) every 3 minutes for a total of 30 minutes. The irradiation is performed for another 30 min using a solid-state UV-A illuminator at 370 nm and an irradiance of 3 mW/cm(2). Average follow-up was 15.23 ± 3.39 months (range: 12 to 22 months). Visual acuity, corneal topography, in vivo confocal microscopy, and endothelial cell count were evaluated at baseline and at 1, 3, 6, and 12 months follow-up., Results: Mean uncorrected visual acuity(UCVA) and best spectacle-corrected visual acuity (BSCVA) increased 0.115 ± 0.158 LogMAR (t = 3.418, P = 0.0026) and 0.114 ± 0.218 LogMAR (t = 2.441, P = 0.0236) 12 months postoperatively respectively. Interim analysis of treated eyes showed a flattening of the steepest simulated keratometry value (K-max) and astigmatism by an average of (1.893 ± 3.713) diopters (D) (t = 2.391, P = 0.0262) and (0.117 ± 1.488) D (t = 0.370, P = 0.715) respectively at 12 months. Central corneal thickness decreased by (27.5 ± 26.8) µm (t = 4.812, P = 0.000) and (1.54 ± 19.4) µm ( t = 0.147, P = 0.885) at one month and 12 months postoperatively respectively.Intraocular pressure, endothelial cell count, lens and fundus didn't change significantly at 12 months follow-up., Conclusions: CXL stabilised and improved the UCVA and BSCVA as well as the maximum k-readings at 1 year postoperatively in our cohort. It seems to be a safe and promising procedure to stop the progression of keratoconus.

Unlabelled: The iris pigment epithelial cells of 10 human eyes were cultivated in vitro., Results: The iris pigment epithelial cells obtained directly by scraping were easier to grow and to be passaged than those obtained by enzyme digestion. Under the inverted light microscope, primary cells appeared multigonal and arranged in monolayer, there were abundant pigment granules in the cytoplasm, and the nuclei each of which contained 1 or 2 nuclei were relatively transparent. Pigment granules diminished in succeeding generations. Under the transmission electron microscope, pigment granules were rich in the cytoplasm and there were plenty of microvilli at the cell membrane. There were maculae occludentes and desmosomes present in the intercellular space. The cultivated cells showed positive reaction of keratin antigen in an immunohistochemical assay. The characteristics mentioned above are consistent with the criteria of iris pigment epithelial cells.