Cornea最新文献

Purpose: The purpose of this study was to delineate the concurrence of limbal stem cell deficiency (LSCD) and neurotrophic keratopathy in patients with ocular graft-vs-host disease (oGVHD).

Methods: Medical records of patients with oGVHD were reviewed. Parameters collected included corneal sensitivity measured by using a noncontact esthesiometer, corneal fluorescein staining score (National Eye Institute grading scale), tear volume (Schirmer I test), and subbasal nerve density and limbal structure assessed by in vivo confocal microscopy.

Results: Twenty-eight patients (mean age: 60.8 ± 10.4 years) with oGVHD were included; 50% (n = 14) had partial LSCD (P-LSCD), and 32% (n = 9) had complete LSCD (C-LSCD). Patients with C-LSCD showed significantly reduced total nerve density and branch nerve density compared with those with P-LSCD ( P < 0.02, P < 0.04) and no LSCD ( P < 0.01, P = 0.02). Dendritic cell density was significantly higher in the C-LSCD group compared with the no LSCD group ( P < 0.05). Corneal sensitivity was significantly reduced in patients with C-LSCD compared with those with P-LSCD ( P = 0.01) and no LSCD ( P < 0.02). Patients with C-LCSD had higher corneal fluorescein staining scores than patients with P-LSCD ( P < 0.01) and no LSCD ( P = 0.02).

Conclusions: This study highlights a significant concurrence of LSCD and neurotrophic keratopathy in patients with oGVHD, underscoring the link between inflammation, neurodegeneration, and loss of stem cell function.

Purpose: To assess the accuracy of various Pentacam indices in distinguishing keratoconus (KC) in pediatric patients with high astigmatism and to establish appropriate cutoff values.

Methods: This prospective multicenter cross-sectional study included 312 eyes from 167 patients aged 6 to 18 years (mean age, 13.1 ± 3.2 years) evaluated with Oculus Pentacam HR. Patients were categorized into 4 groups: KC, forme fruste keratoconus, astigmatism greater than 2 diopters (Cyl2D), and control. A subgroup of Cyl2D comprised patients with astigmatism greater than 4 diopters (Cyl4D). Twenty-three Pentacam indices were analyzed, and receiver operating characteristic curves determined optimal cutoff points, sensitivity, and specificity.

Results: The best indices for distinguishing KC from Cyl2D were high-order aberration root mean square of the anterior corneal surface (area under the receiver operating characteristic curve 0.987), Belin/Ambrosio enhanced ectasia total derivation (0.971), index of vertical asymmetry (0.971), average pachymetric progression index (0.962), maximum Ambrosio relational thickness (0.960), posterior elevation (0.952), and anterior elevation (0.948). The accuracy of these indices was highest in the control group and lowest in the Cyl4D group. Area under the receiver operating characteristic curve was significantly lower for fruste keratoconus than KC. Optimal cutoff values were higher for astigmatic patients than for those with no refractive error.

Conclusions: Most indices effectively distinguished between KC and normal pediatric patients. For individuals with high astigmatism, we suggest focusing on specific indices such as high-order aberration root mean square, Belin/Ambrosio enhanced ectasia total derivation value, maximum Ambrosio relational thickness, average pachymetric progression index, and index of vertical asymmetry. Optimal cutoff points for these patients were higher than those for nonastigmatic children and differed from adult populations.

Purpose: To explore the morphological characteristics of corneal endothelial cells in eyes with Down syndrome.

Methods: We conducted a comparative analysis of corneal endothelial cell density, coefficient of variation, hexagonal cell appearance rate, and corneal thickness using specular microscopy. Our study included 21 eyes of 11 patients with Down syndrome and 37 eyes of 19 control subjects.

Results: In all eyes with Down syndrome, corneal endothelial cell density exceeded 2000 cells/mm 2 , and no abnormalities in cell morphology or significant differences from the control group were observed across all parameters.

Conclusions: The structure and function of corneal endothelial cells in eyes with Down syndrome were within the normal range, even in the presence of chromosomal abnormalities of 21-trisomy in somatic cells.

Purpose: To investigate current practice patterns among corneal specialists performing Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK).

Methods: An online questionnaire was distributed via the Canadian Ophthalmological Society and Kera-net (Cornea Society listserv) for the period from March to May 2025. The survey collected data on demographics, clinical practice, and intra/postoperative management strategies related to DSAEK and DMEK, including use of perioperative assistive techniques, tamponade strategies, postoperative positioning, and follow-up protocols.

Results: There were 70 respondents. All performed DSAEK while 82.9% performed DMEK. Most had over 5-year experience with DSAEK (85.7%) and DMEK (77.6%). Donor tissue marking was common (82.5% for DMEK; 72.9% for DSAEK), as were peripheral iridotomy/iridectomy (70.2% for DMEK; 37.1% for DSAEK), and intra/postoperative dilation (45.6% for DMEK; 61.4% for DSAEK). Intraoperative anterior segment optical coherence tomography was used by 15.8% (DMEK) and 12.9% (DSAEK) of respondents. Sulfur hexafluoride (SF6) gas is the preferred tamponade agent for routine DMEK (55.2%) but less so for DSAEK (7.1%). Intraoperative tamponade was more frequent in DSAEK (90.0%) than DMEK (67.2%). Full/near-full air/gas fills were left in 42.9% of routine DSAEK and 50.0% of DMEK. Same-day postoperative review was performed by 74.1% (DMEK) and 67.2% (DSAEK). Many surgeons discharged routine cases from corneal services by postoperative year 1 (53.4% for DMEK; 51.4% for DSAEK).

Conclusions: This study sheds insights into the current endothelial keratoplasty practices among corneal specialists. Further research is needed to examine how these technique variations correlate with clinical outcomes.

Purpose: To determine peripheral corneal endothelial cell density (ECD) changes with age compared with central ECD changes.

Methods: Seventy-five phakic subjects with normal corneas were stratified prospectively into 3 age groups (20-39, 40-59, and 60-79 years, n = 25/group). Specular microscopic images were captured of the central, mid-peripheral, and peripheral cornea (3, 4, and 4.5 mm from the center, with 6, 4, and 2 targets, respective to the diameter). ECD was graded by 2 image analysts from a reading center at all locations with adjudication if ECD differed between the 2 graders >5%.

Results: Central, mid-peripheral, and peripheral mean ECD decreased significantly with age. Central mean ECD decreased by 83 cells/mm 2 per decade ( P = 0.008). Mid-peripheral to peripheral mean ECD decreased by 86, 92, and 83 cells/mm 2 at 3, 4, and 4.5 mm from the center, respectively, per decade increase in age ( P = 0.003, 0.002, and 0.006, respectively). Estimated mean ECD differences by location for all participants showed an increase in ECD at 3 mm compared with the center and 4.5 mm (ECD greater by 91 and 102 cells/mm 2 , P 's < 0.001, respectively), as well as ECD at 4 mm compared with the center and 4.5 mm (ECD greater by 80 and 91 cells/mm 2 , P = 0.003 and <0.001, respectively).

Conclusions: Central, mid-peripheral, and peripheral corneal ECD decreases significantly with age. There appears to be higher ECDs at 3 mm and 4 mm from the center, varying with age. These normative data could be useful in evaluating peripheral endothelial changes longitudinally in endothelial disease and surgery.

Purpose: The objective of this study is to enhance the efficiency and expediency of the corneal recipient selection process from extensive recipient lists by developing an interactive program that simulates the authorized operator with an artificial intelligence-based algorithm.

Methods: Taking into account the characteristics of real patients, 1000 distinct artificial corneal recipient candidates, each with 21 features, were generated as the recipient data set, and 50 distinct artificial donors, each with 5 features, were generated as the donor data set. Operators ranked the 20 most suitable corneal recipient candidates for each donor. These ranking lists, with the respective data sets, were employed during the training and inference stages of the multilayer perceptron used in machine learning. At the end of the training process, the top 20 recipient candidates identified by the operators for each donor were then compared with the top 20 recipient candidates identified by the system.

Results: The initial 11 candidates selected by the operator are endorsed by the system with a probability of at least 78%, whereas the initial 13 candidates selected by the operator are endorsed by the system with a probability of at least 67%. On average, the system identifies 17 out of 20 candidates, which corresponds to approximately 85% of all possible candidates.

Conclusions: This study has resulted in the development of an interactive program that simulates the operator. This adaptable system, which does not impose specific selection criteria, can be trained in various eye banks worldwide and has the potential for extensive use.

Purpose: This study analyzed the contamination rate of autologous serum (AS) eye drops in 2 different eye dropper bottles (glass bottles with a filter-free rubber tip vs. plastic bottles with a one-way-valve) and evaluated patient preference regarding bottle type.

Methods: In this prospective, comparative, nonrandomized study, 17 patients with severe dry eye disease administered AS eye drops using the standard glass eye dropper bottle and the plastic eye dropper bottle. Patients recorded the date/time of start and end of use. The tip of the eye dropper bottle was cultivated on a chocolate agar plate and the residual content of the bottle in a thioglycolate medium. Patients also filled in a questionnaire regarding bottle preference. The main outcome was microbial contamination of the eye dropper bottle.

Results: In total, 229 glass and 104 plastic eye dropper bottles were analyzed for microbial contamination. The average duration of use was 3.8 days for glass and 4.1 days for plastic bottles. Tip contamination rates increased proportionally with duration of use and were comparable for both bottle types. Content contamination for glass bottles reached 50% after 2.5 days. For plastic bottles, the content of only 1/104 was contaminated. None of the patients developed clinical symptoms or complications related to bacterial contamination. Overall, 80% of patients preferred the glass bottle.

Conclusions: Plastic bottles with a filter system preventing backflow of eye drops from the bottle tip, successfully prevented the microbial contamination of AS content inside the bottle over an extended period. Bottle tips were contaminated similarly in both types of bottles.

Purpose: To characterize Acanthamoeba isolates from patients with Acanthamoeba keratitis (AK) at the subgenotypic level, and to determine the distribution of genotypes and subgenotypes associated with clinical infections.

Methods: Corneal scrapings from clinically diagnosed patients with AK were subjected to molecular genotyping. DNA was extracted and amplified using PCR targeting the 18S ribosomal RNA gene. Sequencing data were analyzed, and phylogenetic trees were constructed using MEGA X software to determine species, genotypes, and subgenotypes.

Results: Eight species of Acanthamoeba were identified: Acanthamoeba castellanii (38%), Acanthamoeba culbertsoni (25%), Acanthamoeba polyphaga (13%), Acanthamoeba hatchetti (6%), Acanthamoeba triangularis (6%), Acanthamoeba jacobsi (6%), Acanthamoeba healyi (3%), and Acanthamoeba spp. (3%). Genotypic analysis revealed 4 major genotypes: T4 (72%), T10 (19%), T12 (3%), and T15 (6%). The predominant T4 genotype was further classified into 5 subgenotypes: T4A, T4B, T4C, T4D, and T4F.

Conclusions: This study highlights the genetic diversity of Acanthamoeba in AK cases, with a predominance of the T4 genotype and its subgenotypes. Subgenotypic classification provides enhanced resolution in molecular epidemiology and may contribute to understanding pathogenicity and clinical outcomes in AK.