Cornea最新文献

Purpose: The purpose of this study was to assess whether omission of dextran from corneal organ culture medium alters the outcome of Descemet membrane endothelial keratoplasty.

Methods: Participation in this single-center, multisurgeon, prospective, randomized, comparative clinical trial was offered to patients scheduled for Descemet membrane endothelial keratoplasty between April 2020 and May 2022. Patients received grafts from corneas deswollen in organ culture medium-containing 6% dextran T-500 or from corneas that were not deswollen. Corrected distance visual acuity (CDVA), graft detachment, central corneal thickness (CCT), and corneal endothelial cell counts were measured at different time points up to 12 months postoperatively.

Results: Grafts stored with dextran were transplanted in 92 patients, and grafts stored without dextran were transplanted in 102 patients. Mean donor age and endothelial cell counts did not differ significantly between both groups. Mean (±SD) postmortem time in hours was 23.9 ± 11.8 in grafts that were deswollen and 28.2 ± 13.8 in grafts that were not deswollen ( P = 0.02). The groups did not show any significant difference at baseline regarding sex, CDVA, or CCT. In the group with dextran, patients had a mean age of 72.5 ± 9.9 years versus 69.5 ± 8.7 in the group without dextran ( P = 0.03). CDVA improved and CCT decreased significantly in both groups. No differences were detected between the groups regarding CDVA, CCT, endothelial cell counts, or rebubbling rates.

Conclusions: This study did not detect any evidence that the omission of dextran from organ culture medium negatively affects the outcomes of Descemet membrane endothelial keratoplasty.

Purpose: To determine whether corneal backscatter, pachymetric indices, and ectasia indices derived from Scheimpflug tomography can identify Fuchs endothelial corneal dystrophy (FECD) corneas with abnormal tomography, the relationships between these parameters and tomographic edema in FECD, and if these parameters help predict improvement in central corneal thickness (CCT) after Descemet membrane endothelial keratoplasty (DMEK).

Methods: Tomography maps of 132 eyes of 80 subjects with FECD were analyzed to determine how backscatter, pachymetric, and ectasia parameters compared with the instrument's normative database and if any predicted tomographic edema. Tomography maps from a separate group undergoing DMEK were split into derivation (48 eyes of 39 subjects) and validation (45 eyes of 41 subjects) subgroups to derive a predictive model of improvement in CCT after DMEK. Backscatter, pachymetric, and ectasia parameters were incorporated to determine if the model could be enhanced.

Results: Among all ectasia, pachymetric, and backscatter parameters, at best only 65% of FECD corneas with definite tomographic edema could be identified based on the instrument's normative database. Among all parameters individually, the highest sensitivity for detecting tomographic edema was 77%. Anterior and mid-corneal backscatter featured in a model predicting improvement in CCT after DMEK with high performance in derivation (R 2 = 0.79; 95% confidence interval, 0.65-0.87) and validation (R 2 = 0.72; 95% confidence interval, 0.52-0.83) subgroups.

Conclusions: The Scheimpflug camera software program could not reliably detect abnormal tomography in FECD from corneal backscatter, pachymetric indices, or ectasia indices. Corneal backscatter contributes to, but does not enhance, a predictive model of improvement in CCT after DMEK.

Purpose: The cataract surgery dissatisfaction rate is 20% to 35% due to ocular surface discomfort. We investigate the ocular surface discomfort after surgical failure as a consequence of age-related parainflammation. We also aim to prevent it by immune-modulating prophylactic management.

Methods: Monocentric clinical trial realized in a teaching hospital. Prospective, randomized, open-label, unmasked clinical trial. One hundred patients diagnosed with cataracts underwent phacoemulsification surgery. Groups A (<65 years; n = 25) and B (>75 years; n = 25) received surgery only. Groups C and D (both >75 years and both n = 25) used cyclosporine A 0.1% cationic emulsion (CE) eye drops or CE lubricating eye drops (both twice daily), respectively, for 30 days before surgery. Patients were followed up 90 days after surgery. The primary outcome was postoperative ocular surface failure; secondary outcomes examined the influence of prophylactic cyclosporine A 0.1% CE therapy on ocular surface outcomes.

Results: Group B demonstrated greater severity regarding ocular surface signs and symptoms throughout the study period, versus all other groups. Signs/symptoms were typically lower in Group A. Group C achieved significant reductions in conjunctival Symptom Assessment in Dry Eye values ( P < 0.05), conjunctival hyperemia severity ( P < 0.01), and meibomian gland dysfunction ( P < 0.001) at Day 45, versus Group B, and tear break-up time was increased ( P < 0.001). Ocular surface inflammatory marker transcription (HLADR, intercellular adhesion molecule 1 [ICAM-1], and interleukin 6 [IL-6]) was significantly downregulated in Group C, versus Group B, at 90 days ( P < 0.05).

Conclusions: Cataract surgery induced ocular surface system failure with a clinically significant persistent inflammatory status (InflammAging) in patients older than 75 years. Prophylactic cyclosporine A 0.1% CE eye drops were associated with improved ocular surface homeostasis and reductions in inflammatory markers.

Purpose: To evaluate the efficacy and safety of sterile corneal allograft ring segments implantation for the treatment of keratoconus by analyzing long-term visual, refractive, and tomographic clinical outcomes.

Methods: This prospective study included 62 eyes of 49 patients with keratoconus who underwent corneal allograft ring segments implantation at Istanbul Medipol University Faculty of Medicine between February 2020 and August 2022. Surgical outcomes using the Istanbul nomogram were evaluated in patients preoperatively and postoperatively at 1 month, 6 months, 1 year, and 3 years. Outcomes measured were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent (SE), spherical refraction (SR), cylindrical refraction (CR), topographic keratometric values, and corneal thickness at the thinnest point.

Results: Preoperative mean UDVA and CDVA (LogMAR) were 0.96 ± 0.50 and 0.72 ± 0.47, respectively, and increased to 0.41 ± 0.34 and 0.22 ± 0.19 at the last visit ( P < 0.001). There was a significant decrease in SE, SR, and keratometric values postoperatively ( P < 0.001). There was no difference in CR and thinnest corneal thickness values ( P = 0.333 and 0.154, respectively). The stromal and epithelial thicknesses measured by anterior segment optical coherence tomography were stabilized at 6 months and 1 year, respectively. No major complications or side effects were observed intraoperatively or postoperatively.

Conclusions: This study demonstrated that sterile corneal allograft ring segments implantation is a safe and feasible treatment for keratoconus, yielding notable long-term visual outcomes with minimal implant-related complications.

Purpose: To report a successfully managed case of idiopathic Fusarium sclerouveitis in a healthy patient with no identifiable risk factors.

Methods: We describe a case of a 79-year-old man who presented with right-sided eye, facial, and head pain. Initial examination revealed temporal scleral thinning, inflammation, and anterior chamber cell/flare. Cultures were positive for Fusarium species.

Results: The patient was treated with sub-Tenon amphotericin, intrascleral voriconazole, surgical debridement, Rose Bengal photodynamic therapy, systemic voriconazole and posaconazole, and topical natamycin. The infection resolved and the patient's visual acuity improved to 20/40.

Conclusions: Fusarium sclerouveitis can occur without clear risk factors. This case highlights the importance of an aggressive, multimodal treatment approach for successful management.

Purpose: To investigate the effectiveness of mitochondrial-targeted antioxidant mitoquinone (MitoQ) and nontargeted antioxidant idebenone (Idb) in alleviating mitochondrial dysfunction in corneal endothelial cells (CEnCs).

Methods: In vitro experiments were conducted using immortalized normal human corneal endothelial cells (HCEnC-21T; SVN1-67F) and Fuchs endothelial corneal dystrophy (FECD) cells (SVF5-54F; SVF3-76M). Cells were pretreated with MitoQ or Idb and then exposed to menadione (MN) with simultaneous antioxidant treatment. Mitochondrial parameters were evaluated through adenosine triphosphate viability assays, JC-1 staining for mitochondrial membrane potential, and Tom-20 antibody staining for fragmentation, with analysis performed using ImageJ software. HCEnC-21T cells were additionally exposed to ultraviolet-A (25 J/cm 2 ) to assess drug effects under physiological stress. Mitochondrial fragmentation in FECD specimens was analyzed pre- and post-treatment with the drugs. Statistical analysis was conducted using 1-/2-way analysis of variance with post-hoc Tukey test.

Results: MitoQ and Idb enhanced cell viability and mitochondrial membrane potential in both normal and FECD cells under MN-induced stress. Idb reduced MN-induced mitochondrial fragmentation by 32% more than MitoQ in HCEnC-21T cells and by 13% more in SVF5-54F cells. Under ultraviolet-A stress, Idb and MitoQ improved mitochondrial function by 31% and 25%, respectively, with MitoQ increasing mitochondrial function by 42% in FECD specimens.

Conclusions: Differential responses in mitochondrial dysfunction across cell lines highlight disease heterogeneity. MitoQ and Idb protected CEnCs from oxidative stress and improved mitochondrial bioenergetics, suggesting that mitochondrial-targeted antioxidants could be considered for mitochondrial dysfunction in CEnCs.

Purpose: The study was performed to evaluate and optimize a novel technique to close stellate corneal lacerations in a wet laboratory environment.

Materials and methods: Twenty-one ex vivo porcine eyes with standardized, experimentally created stellate corneal lacerations were assigned to one of three surgical repair techniques. In Group 1 (n = 9), lacerations were closed with simple interrupted sutures only. In Group 2 (n = 7), a large-radius central purse string was used in addition to simple interrupted sutures. In Group 3 (n = 5), a small-radius central purse string was used in addition to simple interrupted sutures. Wound stability was assessed by determining the intraocular pressure (IOP) at which wound leak occurred.

Results: Group 3 eyes demonstrated a mean wound leak IOP of 56.1 mm Hg (range 32-90.3) compared with groups 1 and 2, which demonstrated mean wound leak IOPs of 6.4 mm Hg (range 1.9-19) and 13.3 mm Hg (range 2.8-31), respectively. These differences were highly statistically significant ( P  < 0.002 and P  < 0.015, respectively, compared with Group 3).

Discussion: The use of a small-radius internal purse-string suture, when combined with simple interrupted sutures, produced a highly effective watertight closure in experimentally created stellate corneal lacerations, significantly outperforming approaches using only interrupted sutures or a large-radius purse string. The use of a small-radius purse-string suture should be considered for clinical use in the repair of stellate corneal lacerations.