PURPOSE. Photochemical cross-linking of corneal collagen is an evolving treatment for keratoconus and other ectatic disorders. We evaluated collagen cross-linking by rose bengal plus green light (RGX) in rabbit eyes and investigated factors important for clinical application.METHODS. Rose bengal (RB, 0.1%) was applied to deepithelialized corneas of enucleated rabbit eyes for 2 minutes. The diffusion distance of RB into the stroma was measured by fluorescence microscopy on frozen sections. RB-stained corneas were exposed to green (532-nm) light for 3.3 to 9.9 minutes (50-150 J/cm 2 ). Changes in the absorption spectrum during the irradiation were recorded. Corneal stiffness was measured by uniaxial tensiometry. The spatial distribution of the stromal elastic modulus was assessed by Brillouin microscopy. Viable keratocytes were counted on H&E-stained sections 24 hours posttreatment. RESULTS.RB penetrated approximately 100 lm into the corneal stroma and absorbed >90% of the incident green light. RGX (150 J/cm 2 ) increased stromal stiffness by 3.8-fold. The elastic modulus increased in the anterior approximately 120 lm of stroma. RB was partially photobleached during the 2-minute irradiation, but reapplication of RB blocked light transmission by >70%. Spectral measurements suggested that RGX initiated cross-linking by an oxygen-dependent mechanism. RGX did not decrease keratocyte viability.CONCLUSIONS. RGX significantly increases cornea stiffness in a rapid treatment (@12 minutes total time), does not cause toxicity to keratocytes and may be used to stiffen corneas thinner than 400 lm. Thus, RGX may provide an attractive approach to inhibit progression of keratoconus and other ectatic disorders.

The WIT is well tolerated by the rabbit eye. Its measurements are reproducible and in close concordance with manometry. A downward IOP drift warrants further investigation.

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Background/aimsThe efficacy of mineralocorticoid receptor antagonist eplerenone to treat chronic central serous chorioretinopathy (CSCR) has been established. However, previous studies have been limited by small cohort size and short follow-up duration. This study aims to report 3-year clinical outcomes of patients treated with eplerenone for chronic CSCR.MethodsInstitutional review board-approved retrospective chart analysis at a single institution from 2012 to 2018. Baseline best-corrected visual acuity and anatomical measurements related to degree of subretinal fluid (SRF) were collected at eplerenone initiation. Follow-up data were collected at the closest date to 12, 24 and 36 months.ResultsData were obtained for 100 eyes of 83 patients at 1-year (mean 11.18 ± 4.00 months), 49 eyes at 2-year (24.01 ± 3.33 months) and 33 eyes at 3-year (mean 35.5 ± 7.89 months) follow-up visits. The rate of complete SRF resolution was 31%, 28% and 33%, respectively. At final follow-up, logarithm of the minimum angle of resolution visual acuity change from baseline was +0.10 ± 0.24 (p = 0.130). Average change from baseline at final follow-up for central subfield thickness was −97 ± 140.6 µm (p < 0.001), cube volume was –1.07 ± 1.71 mm3 (p < 0.001), macular thickness –28. 5 ± 47.5 µm (p < 0.001), maximum SRF height was −95.6 ± 160.5 µm (p < 0.001) and maximum SRF diameter was −1169.0 ± 1638.7 µm (p = 0.008).ConclusionAnatomical improvement occurs primarily within the first year of eplerenone treatment for chronic CSCR.