We present imaging of corneal pathologies using optical coherence tomography (OCT) with high resolution. To this end, an ultrahigh-resolution spectral domain OCT (UHR-OCT) system based on a broad bandwidth Ti:sapphire laser is employed. With a central wavelength of 800 nm, the imaging device allows to acquire OCT data at the central, paracentral and peripheral cornea as well as the limbal region with 1.2 µm x 20 µm (axial x lateral) resolution at a rate of 140 000 A-scans/s. Structures of the anterior segment of the eye, not accessible with commercial OCT systems, are visualized. These include corneal nerves, limbal palisades of Vogt as well as several corneal pathologies. Cases such as keratoconus and Fuchs's endothelial dystrophy as well as infectious changes caused by diseases like Acanthamoeba keratitis and scarring after herpetic keratitis are presented. We also demonstrate the applicability of our system to visualize epithelial erosion and intracorneal foreign body after corneal trauma as well as chemical burns. Finally, results after Descemet's membrane endothelial keratoplasty (DMEK) are imaged. These clinical cases show the potential of UHR-OCT to help in clinical decision-making and follow-up. Our results and experience indicate that UHR-OCT of the cornea is a promising technique for the use in clinical practice, but can also help to gain novel insight in the physiology and pathophysiology of the human cornea.

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Crosslinking-induced stromal changes resulted in an increase in densitometry, especially in the anterior stroma of the central (0.0 to 2.0 mm) zone. These changes correlated with an increase in retinal straylight but not with the postoperative CDVA values.

PurposeA stromal demarcation line (DL) after corneal cross-linking (CXL) has lately been suggested as a surrogate parameter for the success of CXL. The aim of this study was to investigate the correlation between depth of the central DL 1 month and the change in K values 12 months after CXL.MethodsTreatment-naive subjects with keratoconus were treated using an accelerated CXL protocol [A-CXL(9*10)]. Depth of the DL/relative depth of the DL (DL%) was measured using Visante OCT imaging 1 month postoperatively (OP). Kmax/K2.5 (preOP) and change in Kmax/K2.5 (preOP − 12 months postOP) were assessed using corneal tomography (Pentacam HR, Oculus GmBH).ResultsForty eyes were treated following the A-CXL(9*10). The mean DL depth was 200 ± 99 μm (range 71 to 479)/mean DL% = 42.70 ± 20.00% (range 17–90). There was no statistically significant correlation between stromal depth of the DL and change in Kmax or K2.5, respectively (Spearman rho DL/∆Kmax − 0.14 and DL/∆K2.5 − 0.14). Between DL% and the changes in maximum K values or K2.5, no statistically significant correlation was found as well (Spearman rho DL%/∆Kmax − 0.10 and DL%/∆K2.5 − 0.19). Mean change in Kmax after 12 months was − 0.68 ± 2.26 diopters (D) (median − 0.35 D) and − 0.82 ± 1.6 D (median − 0.65 D) for K2.5 (p = 0.07; p = 0.02).ConclusionsNo statistically significant correlation was found between the stromal central depth of the DL and any outcome parameter for CXL after 12 months. Therefore, the interpretation of the DL as a predictive parameter for the effect of the procedure may not apply.

IMPORTANCE Corneal abrasions are frequent after standard (epithelium-off [epi-off]) corneal collagen cross-linking (CXL) in patients with progressive keratoconus. A new matrix therapy agent (ReGeneraTing Agent [RGTA]) has been developed to promote corneal wound healing. OBJECTIVE To assess the effect of the new type of matrix therapy agent on corneal wound healing after epi-off CXL in patients with keratoconus. DESIGN, SETTING, AND PARTICIPANTS This double-masked randomized clinical trial enrolled 40 patients with keratoconus undergoing epi-off CXL from July 18, 2014, to October 21, 2015, when the last follow-up was completed. The analysis of the intention-to-treat population was performed at the Department of Clinical Pharmacology in cooperation with the Center for Medical Physics and Biomedical Engineering and the Department of Ophthalmology and Optometry of the Medical University of Vienna. INTERVENTIONS Patients were randomized to receive the matrix therapy agent or hyaluronic acid-containing eyedrops, 0.1%, every other day starting immediately after surgery. The size of the corneal defect was measured using ultrahigh-resolution optical coherence tomography (OCT) and slitlamp photography (SLP) with fluorescein staining. MAIN OUTCOMES AND MEASURES Corneal wound healing rate, defined as the size of the defect over time. RESULTS Among the 40 patients undergoing epi-off CXL (31 men; 9 women; mean [SD] age, 31 [10] years), wound healing was significantly faster in the matrix therapy agent group compared with the hyaluronic acid group (4.4 vs 6.1 days; mean difference, 1.7 days; 95% CI, 0.25-3.15 days; P = .008). The defect size was smaller in the matrix therapy agent group than in the hyaluronic acid group as measured with OCT (12.4 vs 23.9 mm 2 ; mean difference, 11.6 mm 2 ; 95% CI, 0.8-23.5 mm 2 ; P = .045) and SLP (11.9 vs 23.5 mm 2 ; mean difference, 11. 6 mm 2 ; 95% CI, 1.3-22.9 mm 2 ; P = .03). A correlation between the defect size measured with OCT and SLP was found (r = 0.89; P < .001). No ocular or serious adverse events occurred. CONCLUSIONS AND RELEVANCE Use of a new matrix therapy agent appears to improve corneal wound healing after CXL in patients with keratoconus. Monitoring of corneal wound healing using ultrahigh-resolution OCT might be an attractive alternative to SLP because OCT provides an objective and 3-dimensional evaluation of the corneal defect. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT02119039