Purpose: To present 1-year data comparing the efficacy of the combination of CXL and INTACS vs CXL only in the treatment of keratoconus. Methods: The chart records of 25 eyes of 19 patients with keratoconus treated with CXL and INTACS between January 2011 and May 2013 were retrospectively reviewed. The outcomes of this combined procedure were compared with the outcomes of 143 eyes of 109 patients treated by CXL only. The following parameters were studied and outcomes were evaluated at 12 months postoperatively: uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), keratometry (Max K and Average K), and spherical equivalent. Results: Uncorrected visual acuity at 12 months following CXL+INTACS was significantly better than CXL only, in terms of lines gained. Uncorrected vision in the CXL+INTACS group improved by 1.7 lines more than in the CXL only group (p = 0.024). While the CXL+INTACS group, on average, gained 0.08 lines more than the CXL only group at 12 months postoperatively, this difference was not statistically significant (p = 0.1). The maximum keratometric value was significantly reduced by both CXL only and CXL+INTACS; however, there was, on average, a 2.45D greater flattening of K_MAX in the CXL+INTACS group when compared with the CXL only group (p = 0.00003). Conclusion: Both groups (CXL only and CXL+INTACS) demonstrated significant improvements in UCVA, BSCVA, and keratometry. However, there were statistically significant greater improvements in UCVA lines gained, keratometry, and spherical equivalent in the CXL+INTACS group compared with the CXL only group.

Aim: Evaluation of the changes in deformation amplitude (DA) ratio, integrated radius (IR), stress–strain index (SSI), and stiffness parameter at first applanation (SP-A1) obtained by the corneal visualization Scheimpflug technology (Corvis ST) and this is before and after different laser vision correction (LVC) procedures. Methods: An interventional study that is prospective, randomized, and comparative. Individuals having a maximum astigmatism of −3.00 D and a maximum [(mean refractive spherical equivalent (MRSE)] of −7.00 D. Using the Corvis ST, measurements were made of the DA ratio, IR, SSI, and SPA1 prior to and following three distinct LVC procedures: Photorefractive keratectomy (PRK; group I), laser assisted in situ keratomileusis (LASIK; group II), and Femto-LASIK (Femto-laser assisted in situ keratomileusis; group III). Results: Comparison between pre- and posttreatment showed significant increase in the DA ratio and IR with no significant change in SSI in group I. While in group II and III showed significant increase in DA ratio, IR and significant decrease in SSI. The SP-A1 change was significantly decreased in all three groups. Conclusion: The response of the corneal biomechanical to the three surgical procedures varied differently and the significant change was in the IR and SP-A1, where the SSI and DA ratio was nonsignificant. The results of LASIK and PRK showed the highest and lowest reductions in total corneal stiffness, respectively, while Femto-LASIK stayed in between.

The purpose of this paper is to describe a case of keratoconus with high hyperopia, a condition typically associated with high myopia. This case led to the diagnosis of nanophthalmos and possibly Leber's congenital amaurosis.

Purpose: In vitro assessment of the photo-oxidative effects induced by conventional cross-linking (CXL) and accelerated cross-linking (ACXL) at 5.4 J/cm² energy dose (fluence). Methods: A total of 20 eye-bank human corneas were treated with different epithelium-off (EPI-OFF) CXL UV-A protocols: five EPI-OFF at 3 mW/5.4 J/cm² for 30 minutes (Dresden protocol), five at 15 mW/5.4 J/cm² for 12 minutes pulsed light (Siena ACXL protocol), and five at 30 mW/5.4 J/cm² pulsed light for 6 minutes. Five corneas were used as control group. Semi-thin and ultrathin sections were examined by a Philips transmission electron microscope at the Department of Human Pathology of Siena University. Histology overview included Bowman's lamina thickness measurement, CXL depth, collagen fibers density, and CXL-induced photo-oxidative damage. Results: The study provides descriptive histological evidences of in vitro corneal changes induced by ACXL, identifying the differences between treatment depths based on different UV-A power settings and exposure times. The higher UV-A power with the shorter exposure time induced a lower photo-oxidative CXL penetration, while the longer exposure time increased CXL treatment photo-oxidative depth. Increased fiber density induced by higher UV-A power was observed only in the anterior 50 µm of corneal stroma in all cases. Conclusion: Cross-linking photo-oxidative damage is fluence-dependent. Keeping a constant fluence, the longer exposure time increased the treatment depth due to more oxygen diffusion, while the higher UV-A power with shorter exposure time without increasing the fluence resulted in reduced treatment depth due to less oxygen diffusion. The higher reduction of collagen fibrils distance in the anterior 50 µm stroma appears to be independent from UV-A power and exposure time.