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Purpose:Accumulation of lipoprotein-derived lipids including esterified and unesterified cholesterol in Bruch’s membrane of human eyes is a major age-related change involved in initiating and sustaining soft drusen in age-related macular degeneration (AMD). The apolipoprotein (apo) A-I mimetic peptide 4F is a small anti-inflammatory and anti-atherogenic agent, and potent modifier of plasma membranes. We evaluated the effect of intravitreally-injected 4F on murine Bruch’s membrane. Methods:We tested single intravitreal injections of 4F doses (0.6 µg, 1.2 µg, 2.4 µg, and placebo scrambled peptide) in ApoEnullmice ≥10 months of age. After 30 days, mice were euthanized. Eyes were processed for either direct immunofluorescence detection of esterified cholesterol (EC) in Bruch’s membrane whole mounts via a perfringolysin O-based marker linked to green fluorescent protein or by transmission electron microscopic visualization of Bruch’s membrane integrity. Fluorescein isothiocyanate-conjugated 4F was traced after injection. Results:All injected eyes showed a dose-dependent reduction of Bruch’s membrane EC with a concomitant ultrastructural improvement compared to placebo treated eyes. At a 2.4 µg dose of 4F, EC was reduced on average by ~60% and Bruch’s membrane returned to a regular pentalaminar structure and thickness. Tracer studies confirmed that injected 4F reached intraocular targets. Conclusion:We demonstrated a highly effective pharmacological reduction of EC and restoration of Bruch’s membrane ultrastructure. The apoA-I mimetic peptide 4F is a novel way to treat a critical AMD disease process and thus represents a new candidate for treating the underlying cause of AMD. [ABSTRACT FROM PUBLISHER]

Primary objective: This study uses numerical analysis and validation against clinical data to develop a method to correct intraocular pressure (IOP) measurements obtained using the Corvis Tonometer for the effects of central corneal thickness (CCT), and age. Materials and Methods: Finite element analysis was conducted to simulate the effect of tonometric air pressure on the intact eye globe. The analyses considered eyes with wide variations in IOP (10–30 mm Hg), CCT (445–645 microns),R(7.2–8.4 mm), shape factor,P(0.6–1) and age (30–90 years). In each case, corneal deformation was predicted and used to estimate the IOP measurement by Corvis (CVS-IOP). Analysis of the results led to an algorithm relating estimates of true IOP as a function of CVS-IOP, CCT and age. All other parameters had negligible effect on CVS-IOP and have therefore been omitted from the algorithm. Predictions of corrected CVS-IOP, as obtained by applying the algorithm to a clinical data-set involving 634 eyes, were assessed for their association with the cornea stiffness parameters; CCT and age. Results: Analysis of CVS-IOP measurements within the 634-large clinical data-set showed strong correlation with CCT (3.06 mm Hg/100 microns,r2 = 0.204) and weaker correlation with age (0.24 mm Hg/decade,r2 = 0.009). Applying the algorithm to IOP measurements resulted in IOP estimations that became less correlated with both CCT (0.04 mm Hg/100 microns,r2 = 0.005) and age (0.09 mm Hg/decade,r2 = 0.002). Conclusions: The IOP correction process developed in this study was successful in reducing reliance of IOP measurements on both corneal thickness and age in a healthy European population. [ABSTRACT FROM PUBLISHER]

Purpose: To compare corneal densitometry values after Femtosecond Laser-Assisted In Situ Keratomileusis (Fs-LASIK) and Small Incision Lenticule Extraction (SMILE) using Scheimpflug Imaging. Methods: Our retrospective clinical trial included a total of 146 eyes where 57 eyes underwent Fs-LASIK and 89 eyes underwent SMILE. Examinations with a Pentacam Scheimpflug device (Oculus, Wetzlar, Germany) were performed before surgery, 1 week, 1 month, 3 months, 6 months, and 1 year after surgery. Detailed data of all four concentric optical zones were acquired - central 0-2 mm, 2-6 mm, 6-10 mm and 10-12 mm. The cornea was divided into anterior 120 µm, middle and posterior 60 µm sections. Values were analyzed during follow-up comparing Fs-LASIK and SMILE. Results: No statistically significant differences in corneal density were detected. The central 0-2 mm anterior area demonstrated a mean 1-year value of 17.99 grayscale units (GSU) ± 0.89 (range 16.60-19.50) after Fs-LASIK versus 17.96 GSU ± 0.98 (range 16.40-20.00) after SMILE. Three months after surgery there was a slight temporary density increase in the 6-10 mm anterior annulus in the LASIK group - 22.19 (SD = 3.99, range: 15.60-30.50) compared to SMILE - 20.39 (SD = 3.79, range 14.70-36.30). Conclusion: There were no statistically significant short or long-term differences in postoperative corneal densitometry after LASIK and SMILE, demonstrating SMILE is not inferior in this regard. Known delayed visual acuity recovery after SMILE in relation to LASIK could not be correlated with changes in corneal density. [ABSTRACT FROM AUTHOR]