Prospective Observational Study Evaluating Systemic Hormones and Corneal Crosslinking Effects in Keratoconus.

Purpose: To evaluate associations between hormone levels and corneal parameters in patients with keratoconus (KC), before and after photooxidative corneal collagen crosslinking (CXL). Design: Prospective, observational cohort study. Participants: Twenty-eight patients with KC who were scheduled for CXL at Aarhus University Hospital in Denmark. Methods: Androgen (dehydroepiandrosterone sulfate [DHEA-S]) and estrogen (estrone and estriol) plasma levels were measured and clinical assessments were performed before CXL and 2 to 3 months post-CXL, comparing the CXL eye with the control eye from the same participant. Main Outcome Measures: Associations between hormone levels and maximum corneal curvature (Kmax) and minimum central corneal thickness (CCtmin) before and after CXL. Results: Corneal collagen crosslinking was associated with a 2% reduction in Kmax values in the CXL eye, post-CXL, from baseline (median, 56.8 diopters [D]; 95% confidence interval [CI], 50.4-60.3) to the second visit (55.7 D; 95% CI, 50.4-58.8; P < 0.001). Systemic DHEA-S levels were 5 to 6 orders of magnitude higher than estriol or estrone concentrations in plasma. Importantly, estriol levels, rather than DHEA-S or estrone levels, were more closely correlated with Kmax before CXL (Spearman's r = 0.55, P = 0.01). Post-CXL Kmax and CCtmin were not associated with DHEA-S, estrone, or estriol plasma levels at the same timepoint. Conclusions: This study provides supporting evidence based on a KC clinical population that systemic estrogen levels may influence corneal parameters (curvature and thickness) pre-CXL. Further studies evaluating the interplay between the therapeutic benefits of CXL and systemic hormone distributions are needed to determine if perturbation of the local corneal microenvironment influences endocrine function. Financial Disclosures: The authors have no proprietary or commercial interest in any materials discussed in this article.

Topical dilation as first-line treatment for fibrin membrane pupillary-block glaucoma following uncomplicated cataract surgery.

Fibrin membrane pupillary-block glaucoma is an uncommon complication after phacoemulsification cataract surgery. We present a case treated successfully by pharmacological dilation of the pupil. Previous case reports have recommended the use of Nd:YAG peripheral iridotomy, Nd:YAG membranotomy and intracameral tissue plasminogen activator.The patient presented with intraocular pressure (IOP) of 45 mmHg 2 days after uneventful phacoemulsification cataract surgery. Anterior segment optical coherence tomography revealed that a fibrinous membrane-filled space had formed between the pupillary plane and the implanted intraocular lens.The diagnosis of fibrin membrane pupillary-block glaucoma was made. Initial treatment consisted of IOP-lowering medication and topical pupillary dilation (atropine 1%, phenylephrine hydrochloride 10% and tropicamide 1%). Within 30 min, the dilation broke the pupillary block and the IOP was 15 mmHg. The inflammation was treated with topical dexamethasone, nepafenac and tobramycin. Within a month, the patient reached a visual acuity of 1.0.