ABSTRACT
BACKGROUND: Keratoconus is a bilateral non-inflammatory corneal disease. Collagen cross-linking (CXL) is a new treatment option for the disease that uses ultraviolet A light irradiation and riboflavin administration. The aim of this study is to evaluate the effect of CXL on corneal topographic and refractive values in patients with keratoconus younger than 18 years of age. MATERIALS AND METHODS: For the clinical trial study, 37 patients (64 eyes) younger than 18 years of age with progressive keratoconus were included. Age, sex, family history of keratoconus, and history of allergic disorders and eye rubbing were recorded. Refractive, topographic, and topometric indices were evaluated before and 12 months after the CXL with 3mW for 30 minutes. RESULTS: Mean age (±SD) of the patients was 15.83 ± 1.53 years; 26 (70.3%) of the 37 patients were male. Fourteen (37.8%) had positive family history of keratoconus, 11 (29.7%) had history of allergic disorders, and 15 (40.5%) had positive history of eye rubbing. Of the refractive values, cylinder value decreased significantly from -4.50 ± 0.29 to -4.11 ± 0.28 (P = 0.001). Also, the logarithm of minimal angle of resolution (logMAR) uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) improved significantly 12 months after CXL (P = 0.012 and 0.001, respectively). Maximum keratometry before and after the operation was 53.82 ± 0.72 and 53.33 ± 0.72, respectively (P = 0.018). Differences for simulated K values, the thinnest cornea pachymetry, keratoconus index (KI), index of highest asymmetry (IHA), and index of highest decentration (IHD) before and 12 months after the CXL were statistically significant (P = 0.015, 0.034, <0.001, 0.017, 0.019, and 0.004, respectively). CONCLUSION: CXL improves the refractory, topographic, and topometric indices in patients with keratoconus younger than 18 years of age.
ABSTRACT
BACKGROUND: C4d as a part of complement activation process is a marker for detecting antibody-mediated rejection (ABMR) and its positivity accompanied by positive donor specific antibody (DSA), and morphologic view of humoral rejection has been suggested to detect ABMR since 2003. MATERIALS AND METHODS: 41 specimens of transplanted kidney biopsies gathered from 2006 to 2008 were evaluated for morphological changes on light microscopy, and nephro-pathologist made distinct diagnosis for all of specimens then c4d staining was done for all of them. The association between primary diagnosis without c4d staining and c4d scoring on peritubular capillaries and glomerular capillaries were evaluated to determine whether morphological changes were enough for distinct diagnosis or not. RESULTS: Acute tubular necrosis (ATN) 27%, interstitial fibrosis and tubular atrophy (IF&TA) 17%, and T cell mediated rejection (TCMR) 22% were the commonest diagnosis on light microscopy, and 17% of all biopsies had diffuse positive c4d staining. There was not any report of ABMR in morphological evaluation while c4d positive staining was seen in some specimens (17%). It may result from masking of ABMR by other morphological changes such as TCMR and no specific histologic changes for ABMR on light microscopy. CONCLUSION: We would like to emphasize that c4d staining should be done for all of renal allograft biopsies, and pathologists all over the world should consider the probability of ABMR masked by other morphological changes on light microscopic evaluation.
