Inflammatory and genomic interactions within keratoconus susceptible patients: a nationwide registered case-control study.

PURPOSE: This study aimed to investigate the association between variants in the interleukin (IL)-1 gene cluster and susceptibility to keratoconus (KC) in an Iranian population. METHODS: In the case group, there were 188 KC patients diagnosed by clinical findings and corneal tomography. The control group included all 205 healthy controls with no personal or family history of eye-related, metabolic, or immune system-related disease. Using the standard salting out extraction procedure, genomic DNA was isolated from peripheral blood leukocytes. The genotypes were determined by applying agarose gel electrophoresis for the IL-1RN 86 bp VNTR and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for rs16944 and rs1143634. RESULTS: The results showed a significant association between the IL-1ß rs1143634 (rs1143634 T allele, P = 0.008) and IL-1RN 86 bp VNTR polymorphisms (LL and LS genotype, P = 0.048 and 0.012 respectively) and susceptibility to KC in the Iranian population. The genotype distributions of rs1143634 (P = 0.004) and rs2234663 (P = 0.042) significantly differed between case and control groups, with certain genotypes demonstrating a protective effect against KC. Logistic regression analysis revealed a protective effect of the IL-1RN L allele [odds ratio (OR) = 0.367, 95% confidence interval (CI): 0.240-0.562; P = 0.000] and certain haplotypes (OR = 0.628, 95% CI: 0.447-0.884; P = 0.007) against KC. However, no significant association was found for the IL-1ß rs16944 polymorphism. CONCLUSION: This study provides evidence for an association between variants in the IL-1 gene cluster and susceptibility to KC in an Iranian population. Further research on larger and more diverse populations is warranted to validate these findings and explore the underlying mechanisms involved.

Main issues in deep anterior lamellar keratoplasty: A systematic narrative review.

Deep anterior lamellar keratoplasty (DALK) has emerged as a transformative approach in managing corneal pathologies, notably keratoconus (KC), providing a viable alternative to penetrating keratoplasty (PK). This systematic review explores the intricacies of DALK, comparing its preoperative, intraoperative, and postoperative considerations with PK. Extensive literature searches revealed a wealth of data regarding DALK's advantages and challenges, with an emphasis on graft survival, visual outcomes, and complications. In the preoperative phase, DALK showcases its versatility, catering to a wide spectrum of patients, including those with KC and ocular surface disorders. Intraoperatively, it offers innovative techniques to address emphysema, bubble formation, and Descemet's membrane perforation, all while maintaining a strong focus on patient-centered outcomes. Postoperatively, DALK's lower rejection rates and decreased complications underscore its potential superiority over PK, although unique challenges such as graft failure from nonimmunologic factors demand vigilant management. This comprehensive review not only serves as a valuable resource for ophthalmic surgeons but also sheds light on the evolving landscape of corneal transplantation, highlighting DALK's role as a transformative force in the field.

Biomechanical changes in keratoconus after customized stromal augmentation.

PURPOSE: To verify corneal biomechanical changes, poststromal augmentation using myopic small-incision lenticule extraction's (SMILEs) lenticules in advanced keratoconus (KCN) through Corvis ST (Oculus, Wetzlar, Germany). MATERIALS AND METHODS: A clinical trial enrolled 22 advanced KCN patients. We implanted lenticules exceeding 100 µ according to a nomogram and evaluated biomechanical factors through Corvis ST at 3-, 6-, and 24-month postimplantation. We examined parameters during the first applanation (A1), second applanation (A2), highest concavity (HC)/max concavity events, and Vinciguerra screening parameters, as recently established criteria derived from the ideal blend of diverse biomechanical and ocular factors and formulated through the application of logistic regression. Regression analyses explored relationships with age, mean keratometry value, thickness, sphere, cylinder, and best-corrected visual acuity. RESULTS: Patients were well matched for age, intraocular pressure, and central corneal thickness (CCT). The mean spherical equivalent decreased from -13.48 ± 2.86 Diopters (D) to -8.59 ± 2.17 D (P < 0.007), and mean keratometry decreased from 54.68 ± 2.77 D to 51.95 ± 2.21 D (P < 0.006). Significant increases were observed in HC time (HCT), Radius-central curvature radius at the HC state-, peak distance (PD) during HC state, CCT, first applanation time, and stiffness parameter (A1T and SP-A1), whereas HC deformation amplitude, maximum deformation amplitude ratio at 2 mm, Corvis Biomechanical Index (CBI), integrated radius (IR), second applanation deformation amplitude (A2DA), first applanation velocity and deflection amplitude (A1V and A1DeflA) significantly decreased postlenticule implantation. Multivariable regression revealed age positively correlated with SP-A1 (P = 0.003) and negatively with HC delta Arc length (P = 0.007). Mean K positively correlated with CCT (P = 0.05) and negatively with CBI (P = 0.032). Best-corrected visual acuity positively correlated with HCT (P = 0.044), and the cylinder positively correlated with PD (P = 0.05) and CCT (P = 0.05) whereas negatively with IR (P = 0.025). CONCLUSIONS: Stromal augmentation using myopic SMILE lenticules induces significant corneal biomechanical changes in KCN.

Light scattering in intraocular lenses explanted 15 to 40 years after surgery.

The optical quality of intraocular lenses (IOLs) of different materials that have been implanted from 16 to 44 years in human eyes was studied. The IOLs were explanted due to other causes than loss of transparency. The scattered light from the IOLs was assessed in two angular regimes by using dark field images (for wide angles) and the optical integration method (for narrower angles). No evident differences were found in the scattering intensities processed from the dark images. The explanted lenses presented slightly increased amounts of straylight between 1 and 5.1° when compared to a reference new unused lens.