Keratoplasty Research Articles

Temporary Conjunctival Flap Plus Medical Treatment Versus Medical Treatment Only for High-Risk Fungal Keratitis: A Randomized Controlled Trial.

The purpose of this study was to evaluate the efficacy of temporary conjunctival flap with topical natamycin and oral voriconazole compared with medical treatment only in reducing the rate of perforation in high-risk fungal keratitis. Sixty-two eyes of 62 patients with severe fungal keratitis were examined; only 54 patients were enrolled and divided randomly into 2 groups. The first group received medical treatment only in the form of topical natamycin 5% together with oral voriconazole 200 mg, while the second group received the same medical treatment plus a temporary conjunctival flap that was removed after 2 weeks. Five patients were lost during the follow-up, and only 49 patients were statistically analyzed. All patients were examined frequently until reepithelialization or the development of perforation. Fifteen perforations were reported, with a higher rate among the medical group (48%) compared with the conjunctival flap group (12.5%), with P value <0.05. A significant delay was noted in reepithelialization time in the medical group compared with the conjunctival flap group (mean time was 21.69 ± 5.41 and 15.36 ± 2.2 days, respectively), with P value = 0.001. Significant improvement in visual acuity was reported over time when comparing baseline versus 3-month visual acuity in the same group using paired t sample test (P value was 0.003 and <0.001 in the first and second group, respectively). Temporary conjunctival flap is associated with a lower perforation rate compared with medical treatment only in severe fungal keratitis, which can provide a cheap and available alternative to therapeutic penetrating keratoplasty.

Outcomes of Photorefractive Keratectomy in Patients Who Underwent Keratoplasty

&amp;lt;i&amp;gt;Purpose&amp;lt;/i&amp;gt;: To assess the efficacy of photorefractive keratectomy (PRK) in patients who underwent corneal transplantation, and to determine the influencing factors. &amp;lt;i&amp;gt;Methods&amp;lt;/i&amp;gt;: The present study was a retrospective chart review research that was conducted at Dhahran Eye Specialist Hospital between 2014 and 2017. &amp;lt;i&amp;gt;Results&amp;lt;/i&amp;gt;: Seventy-nine eyes were included in the study. The mean BCVA showed an improvement of two lines post-PRK as compared to that before PRK (0.73 ± 0.1 and 0.54 ± 0.2, respectively). There was a statistically significant decrease in the cylindrical value postoperatively as compared to that preoperatively (−2.15 ± 1.4 and−3.25 ± 1.8, respectively; p &amp;lt; 0.001). However, there was no statistically significant difference in spherical equivalent and sphere. Three eyes (4%) developed postoperative complications. There was a medium positive correlation between residual stroma and achieved spherical equivalent (SE) (r = 0.305, p = 0.006), as well as between optical zone and postoperative uncorrected visual acuity (r = 0.350, p = 0.001), in addition to post SE (r = 0.307, p = 0.006). However, the depth of ablation showed a medium negative correlation with achieved SE (r = −0.375, p = 0.001). &amp;lt;i&amp;gt;Conclusion&amp;lt;/i&amp;gt;: PRK may be an option for correcting refractive errors in patients who underwent keratoplasty. The optical zone and residual stromal thickness have a positive correlation with the effects of the outcomes, whereas the depth of ablation has a negative correlation with the outcomes.

A surgical alternative of fusiform penetrating keratoplasty for the management of severe infectious keratitis.

To describe the surgical procedure of fusiform penetrating keratoplasty (FPK) using multiple trephines of different sizes for treating patients with severe infectious keratitis. Fourteen eyes underwent FPK, and 15 eyes received conventional penetrating keratoplasty (PK) were included in the study. The best-corrected visual acuity (BCVA), refractive outcomes, endothelial cell density, and postoperative complications were recorded. The FPK group was followed for an average of 15.3±2.1mo, whereas the PK group was followed for 16.1±1.9mo. The corneal ulcers were elliptical-shaped in all 14 eyes in the FPK group. The mean BCVA (logMAR, 0.26±0.13) showed no statistically significant differences from that in the PK group (logMAR, 0.21±0.12, P>0.05) at 1y after surgery. But the mean curvature, mean astigmatism, and mean spherical equivalent in the FPK group were lower than those in the PK group (P<0.05). Peripheral anterior synechia was observed in one patient in the FPK group, whereas 6 patients in the PK group. Suture loosening and neovascularization were observed in 4 and 5 eyes in the PK group, respectively. No graft immune rejection or elevation of intraocular pressure was observed in the two groups. For patients with elliptical-shaped corneas or corneal ulcers, FPK can avoid disrupting of corneal limbus, reduce the risk of postoperative complications, and can result in satisfactory visual quality.

A Detailed Analysis of Individuals Having Graft Failure After Corneal Transplantation

ABSTRACT Purpose To describe demographic and clinical characteristics of patients with graft failure after keratoplasty, determine the cause of graft failure and outcomes. Methods The charts of patients between 2008–2013 in the Cornea Service at Wills Eye Hospital with a history of a corneal transplant before the end of 2012 were retrospectively reviewed. Included were patients who had graft failure after corneal transplantation and had at least one year of follow-up after transplantation. Penetrating keratoplasty (PK) and Descemet’s stripping endothelial keratoplasty (DSEK) patients were analyzed separately. Results A total of 186 eyes of 170 patients with graft failure after a PK (156) or DSEK (30) procedures were identified. The baseline characteristics included 100 female and 70 male patients with an age between 0 and 90 years (median 63 years). At the time of surgery, 38% had three or more systemic diseases and 68% were using three or more systemic medicines. Mean follow up time for PK was nearly four times of DSEK. Only 2 DSEK eyes (7%) underwent a 3rd DSEK graft, while 47 (30%) PK eyes underwent a 3rd PK and 15 (10%) PK eyes underwent more than three PK procedures. Conclusions Most DSEK failures occurred in 1st year, while graft failure in PKs is scattered over years. Failure in DSEK is mostly due to graft or surgical risk factors but in PK mostly due to factors in the host. DSEK does not appear to be as affected by the patients’ demographic and clinical characteristics as much as PK.

Impact of Donor, Host, and Surgical Parameters on High Endothelial Cell Density More Than 5 Years after Penetrating Keratoplasty.

To investigate the correlation between postoperative endothelial cell loss (ECL) and donor, host, and surgical parameters, and to assess the clinical impact of maintaining a high endothelial cell density (ECD) of ≥ 1500 cells/mm2 5 years after penetrating keratoplasty (PKP). This retrospective cohort study included 216 eyes with 5 years of follow-up, of which 94 had annual visits, and who underwent normal-risk elective PKP for noninfectious indications by one corneal microsurgeon (B. S.) between 2009 and 2016. Among the 216 eyes, ECL (39.1%) over 5 years postoperative exhibited weak positive correlations with storage solution time (p = 0.024) and postmortem time (p = 0.028), and moderately positively correlations with the preoperative ECD (p < 0.001). The 5-year postoperative ECL differed significantly between in domo-prepared (36.8%) and ex domo donor corneas (46.3%; p = 0.001). In the 94 eyes, no significant differences were found between the two groups for central pupil pachymetry (CCT) and BCVA (p > 0.074). However, CCT increased significantly between 1 and 4 years (p = 0.034) and 1 and 5 years postoperatively (p = 0.012), respectively. BCVA improved significantly at 1 year postoperatively and continued to improve until 2 years postoperatively (p < 0.001). The Lions corneal bank Saar-Lor-Lux achieved a significantly reduced ECL (36.8%) over 5 years compared to ex domo donor corneas (46.3%). A weak positive correlation was found between ECL with the storage solution time and the postmortem time, as well as a moderate positive correlation with the preoperative ECD. Although CCT increased significantly over 5 years, BCVA improved significantly from the first to the second postoperative year and remained stable thereafter.

A bibliometric and citation network analysis of crosslinking.

Purpose: Research on crosslinking has focused mainly on trying to slow the progression of keratoconus. The objective of this bibliometric analysis is to determine the relationships between the different publications and authors. As well as to identify the different areas of research on crosslinking. Methods: Web of Science (WOS) was the database for the search of publications for the period 1972 to December 2023, using the terms: crosslinking, cross-linking, ocular, vision, visual, cornea, ectasia AND Keratoconus. The analysis of the publication was performed using the CitNetExplorer, VOSviewer and CiteSpace software. Results: 7161 publications and 59415 citation networks were found. The year with the most publications is 2021, a total of 571 (7.97%) publications and 135 citation networks. The most cited publication was "Riboflavin/ultraviolet-a-induced collagen crosslinking for the treatment of keratoconus" published by Wollensak et al. in 2003, with a citation index of 1780. Using the Clustering function, five groups were found that cover the main research areas in this field: keratoconus, corneal transplantation, cataracts, corneal inflammation and axial growth. Conclusion: The treatment of keratoconus continues to be the topic of interest in this area of research. However, in recent years there has been an increase in research on how crosslinking helps to slow down axial growth.

Complications After Pediatric Penetrating Keratoplasty: An IRIS Registry Study.

To describe the frequency of postoperative complications in children undergoing penetrating keratoplasty (PK). This retrospective cohort study included pediatric patients (aged 0-18 years) in the Intelligent Research in Sight (IRIS) Registry who underwent primary PK between January 2013 and December 2020. Patients were identified using Current Procedure Terminology codes. Postoperative complications were identified using International Classification of Diseases Revision 9 and 10 codes and categorized as complications affecting the anterior segment (epithelial defect, infectious keratitis, neurotrophic keratitis, and glaucoma) or posterior segment (vitreous hemorrhage, retinal detachment, choroid detachment, choroidal hemorrhage, endophthalmitis, epiretinal membrane, and proliferative vitreoretinopathy). Of the 544 pediatric patients undergoing PK, 259 (47.6%) experienced postoperative complications. Anterior segment complications (n = 222, 40.8%) were more common than posterior segment complications (n = 96, 17.6%). The most common anterior complication was infectious keratitis (n = 163, 30.0%) with a median onset time of 275 days (IQR 50-560 days) after surgery. Vitreous hemorrhage (n = 52, 9.6%) and retinal detachment (n = 48, 8.8%) were the most common posterior segment complications. Infectious keratitis was the most common postoperative complication in children undergoing PK. More complications occurred in the anterior segment (70%) of the eye as compared with the posterior segment (30%). These findings demonstrate the challenges associated with pediatric PK and may help guide postoperative monitoring and management.

Outcomes of sutured scleral-fixated intraocular lens implantation combined with penetrating keratoplasty

BackgroundThe purpose of the study was to assess visual outcomes, complications, intraocular lens (IOL) stability, and corneal status after sutured scleral-fixated intraocular lens implantation combined with penetrating keratoplasty (PKP).MethodsThis retrospective single-arm cohort study included patients who underwent PKP and sutured scleral-fixated intraocular lens implantation between 2013 and 2018 at the Dhahran Eye Specialty Hospital. The eyes were examined postoperatively at 1, 3, 6, 12, and 24 months. Corneal status, complications, and IOL status were also evaluated periodically, and the number of eyes with a BCVA of > 20/200 was recorded.ResultsTwenty-two eyes from 22 patients were included. The median duration of follow-up was 3 (IQR 1.8; 4.4) years. Reasons for surgery were traumatic globe rupture (six eyes, 27.3%), bullous keratopathy (nine eyes, 40.1%), failed previous graft (five eyes, 22.7%), and corneal scarring (two eyes, 9.1%). Twelve (54.5%) eyes showed a BCVA of > 20/200 (non-blind) at 12 months after surgery and only five (22.7%) before surgery. Twelve months after surgery, 13 patients showed an improvement in BCVA in two lines (59.1%), seven remained the same (31.8%), and 2 deteriorated (9.1%). The indication for surgery (p = 0.2) and the stability of the sutured-scleral fixated IOL (p = 0.8) were not associated with an improvement in BCVA at the final follow-up. The corneal graft remained clear in nine eyes (40.9%) at a median duration of 3 years. The overall average survival period for all corneal grafts was 42.9 months.ConclusionsThe combination of sutured scleral-fixated intraocular lens implants and PKP is an effective intervention for preserving visual acuity in patients with complex cases. However, the risk of graft failure and then need for repeat transplantation should be taken into consideration.

Safety of intraoperative autologous plasma incubation of corneal grafts for reducing endothelial cell loss: a pilot study.

Corneal endothelial cell loss contributes to transplant failure. Autologous plasma products (APP) activate salvaging pathways that can prevent oxidative stress perioperatively. This study aimed to evaluate the safety of intraoperative incubation of full-thickness corneal grafts in platelet-rich plasma (aPRP) and plasma rich in growth factors (PRGF-Endoret) in mitigating postoperative corneal endothelial cell loss (ECL). Pilot study including patients undergoing penetrating keratoplasty (PK) for various indications between June 2021 and December 2022. Patients were randomly assigned to receive either aPRP or PRGF-Endoret incubation, while those who declined intervention served as the control group. Demographic and clinical data were collected, including preoperative and postoperative endothelial cell count, intraocular pressure, pachymetry, and adverse reactions. Thirty individuals who underwent PK completed follow-up: eight from the aPRP group, 10 from the PRGF-Endoret group, and 12 from the control group. No adverse events related to APP treatment were recorded. In the first and third postoperative months, the APP group had significantly lower ECL percentages (37% vs. 25%, p = 0.02, and 44% vs. 33%, p = 0.02, respectively); this trend was maintained in the sixth month. When stratified, the PRGF-Endoret group showed significant differences in ECL reduction compared to controls at both time points (p = 0.03 and p = 0.05, respectively). The aPRP group showed a similar statistically significant outcome exclusively on the third postoperative month (p = 0.04). APP tended to reduce corneal edema faster than controls. Hexagonality was significantly better in the APP groups in the first and third months, particularly in the PRGF-Endoret group (p < 0.005). Preoperative incubation with APP is safe and promotes better endothelial cell quality and quantity in the early postoperative period following PK. These findings suggest a potential clinical benefit in enhancing graft outcomes and warrant further investigation.

Immunophenotypical Characterization of Limbal Mesenchymal Stromal Cell Subsets during In Vitro Expansion.

Limbal mesenchymal stromal cells (LMSCs) reside in the limbal niche, supporting corneal integrity and facilitating regeneration. While mesenchymal stem/stromal cells (MSCs) are used in regenerative therapies, there is limited knowledge about LMSC subpopulations and their characteristics. This study characterized human LMSC subpopulations through the flow cytometric assessment of fifteen cell surface markers, including MSC, wound healing, immune regulation, ASC, endothelial, and differentiation markers. Primary LMSCs were established from remnant human corneal transplant specimens and passaged eight times to observe changes during subculture. The results showed the consistent expression of typical MSC markers and distinct subpopulations with the passage-dependent expression of wound healing, immune regulation, and differentiation markers. High CD166 and CD248 expressions indicated a crucial role in ocular surface repair. CD29 expression suggested an immunoregulatory role. Comparable pigment-epithelial-derived factor (PEDF) expression supported anti-inflammatory and anti-angiogenic roles. Sustained CD201 expression indicated maintained differentiation capability, while VEGFR2 expression suggested potential endothelial differentiation. LMSCs showed higher VEGF expression than fibroblasts and endothelial cells, suggesting a potential contribution to ocular surface regeneration through the modulation of angiogenesis and inflammation. These findings highlight the heterogeneity and multipotent potential of LMSC subpopulations during in vitro expansion, informing the development of standardized protocols for regenerative therapies and improving treatments for ocular surface disorders.

A New Technique of Sterile Polyethylene Instrument Cover as Temporary Corneal Patch to Reconstruct Anterior Chamber in Penetrating Keratoplasty Combined with Intraocular Surgery.

Complications such as explosive choroidal hemorrhage, residual cortex, and capsule rupture often occur during intraocular surgery combined with penetrating keratoplasty (PKP) due to poor maintenance of the anterior chamber. To address these challenges, we have innovatively utilized a sterile polyethylene instrument cover to temporarily reconstruct the anterior chamber. In this report, we describe a technique where a 'temporary corneal patch' was created from a sterile instrument cover, using a trephine to ensure a diameter approximately 1-2 mm wider than the corneal bed or perforation. This patch was then sutured into the host corneal bed or the perforation with 10-0 nylon sutures during intraocular surgery combined with PKP. Each case was evaluated for surgical efficacy and complications. We successfully applied this technique in three cases of combined corneal transplantation surgery. In two cases, PKP, phacoemulsification, and intraocular lens implantation were successfully performed. In the third case, PKP, vitrectomy, and other intraocular procedures were performed. No intraoperative or postoperative complications were observed. The use of a sterile polyethylene material as a temporary corneal patch for anterior chamber reconstruction represents a safe, effective, and cost-efficient approach for intraocular surgery combined with PKP or posterior segment surgery as a keratoprosthesis.

Suitability and Early Clinical Outcomes of Corneal Donor Tissue in the 76–80-Year-Old Age Group

Purpose: There is a significant global shortage of corneal donor tissue suitable for keratoplasty. One simple strategy for addressing this shortage is to increase the upper age limit for acceptable tissue over the current customary upper limit of age 75. We describe a pilot study completed at one eye bank procuring, processing, and distributing keratoplasty tissue from donors aged 76 to 80 years. Methods: This is a retrospective case series of donor tissues aged 76 to 80 years in comparison with donor tissues aged 71 to 75 years. Standard tissue parameters were evaluated for all tissues, including tissue suitability, mean endothelial cell density (ECD), death-to-procurement time, and cause of death. For the older tissues, clinical outcomes through 3 months were obtained from each surgeon, including intraoperative and postoperative complications. Results: Corneal tissues from donors aged 76 to 80 years had a similar suitability rate (57%) when compared with donors aged 71 to 75 years (59%) (P = 0.635). Both groups had comparable ECDs (P = 0.097). Early clinical outcomes of corneal grafts from donors older than 76 years were favorable, with no early graft failure or significant concerns for clinical safety or efficacy. Conclusions: Our findings suggest that corneal tissues aged 76 to 80 years can be safely and efficiently transplanted in the United States. While additional study is needed, our results strengthen the case that expanding the upper age limit for donor age has the potential to help meet the global shortage for suitable keratoplasty tissue.

In Situ-Forming, Bioorthogonally Cross-linked, Nanocluster-Reinforced Hydrogel for the Regeneration of Corneal Defects.

Corneal defects can lead to stromal scarring and vision loss, which is currently only treatable with a cadaveric corneal transplant. Although in situ-forming hydrogels have been shown to foster regeneration of the cornea in the setting of stromal defects, the cross-linking, biomechanical, and compositional parameters that optimize healing have not yet been established. This, Corneal defects are also almost universally inflamed, and their rapid closure without fibrosis are critical to preserving vision. Here, an in situ forming, bioorthogonally cross-linked, nanocluster (NC)-reinforced collagen and hyaluronic acid hydrogel (NCColHA hydrogel) with enhanced structural integrity and both pro-regenerative and anti-inflammatory effects was developed and tested within a corneal defect model in vivo. The NCs serve as bioorthogonal nanocross-linkers, providing higher cross-linking density than polymer-based alternatives. The NCs also serve as delivery vehicles for prednisolone (PRD) and the hepatocyte growth factor (HGF). NCColHA hydrogels rapidly gel within a few minutes upon administration and exhibit robust rheological properties, excellent transparency, and negligible swelling/deswelling behavior. The hydrogel's biocompatibility and capacity to support cell growth were assessed using primary human corneal epithelial cells. Re-epithelialization on the NCColHA hydrogel was clearly observed in rabbit eyes, both ex vivo and in vivo, with expression of normal epithelial biomarkers, including CD44, CK12, CK14, α-SMA, Tuj-1, and ZO-1, and stratified, multilayered morphology. The applied hydrogel maintained its structural integrity for at least 14 days and remodeled into a transparent stroma by 56 days.

A Comprehensive Review of Donor Corneal Preservation Strategies.

Successful corneal transplantation relies on the viability of the corneal endothelium. Although various preservation systems have been developed in the field of eye banking, long-term storage of the corneal endothelium poses challenges and is costly. Optisol-GS in the past has been the most commonly used solution for intermediate-term corneal storage in the United States. However, disruptions in the availability of Optisol-GS, caused by rising costs and supply shortages, have necessitated alternative methods of corneal preservation. Previously described preservation methods include hypothermia (2-8°C) for short-term storage (7-14 days), organ culture (28-37°C) for intermediate storage (4-7 weeks), and cryopreservation for longer-term storage. In this review, we examine standard practice and alternative methods for corneal storage.

Patch Transplant in Corneal Perforations: Time, Method, and Cause.

We present demographic data and clinical features of corneal perforations repaired with patch grafts prepared from residual donor corneal rims. For this retrospective study, we evaluated patients who underwent corneal perforation repair with corneal or corneoscleral patch grafts. We recorded demographic data, as well as perforation cause, examination notes, tissue type-size used, follow-up time, and additional surgeries. Anterior segment photographs were also evaluated. Transplanted tissues were prepared from residual donor corneas used in penetrating keratoplasty and were manually adjusted to the precise size of the wound. Fifteen patients were enrolled in the study. Mean age of the patients was 64.9 ± 19.7 years (range, 15-81 years) with a female-to-male ratio of 0.85. The causes of perforation were grouped as inflammation, infection, and trauma. The main indications were inflammation (n = 7; 46.7%) and infection (n = 6; 40%), followed by trauma (n = 2; 13.3%). All patients demonstrated preservation of globe integrity during the follow-up time; however, 1 patient's eye required regrafting with limbal conjunctival excision due to melting and leakage. Three eyes required permanent tarsorrhaphy to control progressive exposure keratopathy, and 2 eyes underwent penetrating keratoplasty to cure scar-related corneal opacity. Patch grafts are effective surgical interventions to assure and maintain globe integrity in corneal perforations. The main advantage seems to be that patch grafting allows special preparations for wound architecture. Moreover, in clinics performing keratoplasty, these patch tissues are readily available.

Examining Medical Students' and Professionals' Perspectives on Eye Donation and Corneal Transplantation.

Background Corneal blindness affects millions across India. Corneal transplantation is the primary treatment; however, there is a severe shortage of donor corneas.This study aimed to assess awareness, knowledge, and attitudes towards corneal donation among medical students and professionals, identify barriers to donation, and explore popular information sources for promoting awareness about corneal transplants and eye donation. Methods Using a validated, self-administered questionnaire, this cross-sectional study surveyed 350 medical undergraduates, postgraduates, and doctors. Data collection occurred over a period of three months via Google Forms (Mountain View, CA: Google LLC). The questionnaire assessed knowledge about corneal donation criteria, willingness to donate corneas, factors influencing donation decisions, and sources of awareness about corneal transplants. Ethical clearance was obtained, and data was analyzed using SPSS version 20.0 (Armonk, NY: IBM Corp.). Results Regarding donor eligibility, 269 (76.9%) knew that anyone regardless of age can donate, 270 (77.1%) knew that donation occurs postmortem, 269 (68.3%) knew the time limit for cornea collection, only 133 (38%)knew medical conditions impacting donor eligibility, and 250 (71.4%) knew only corneal tissue is retrieved. A large number, 333 (95.1%), are aware of the functions of eye banks. Of the participants, 228 (65.1%)were willing to donate their corneas. Popular reasons for donations included helping blind peopleimprove their quality of life and the nobility of the act. The main barriers include a lack of awareness, a desire to preserve the body, health issues, and ethical concerns during extraction. The most preferred sources of information are social media, health workers/eye camps, TV advertisements, and celebrity endorsements. Overall, doctors and postgraduates demonstrated superior knowledge in most areas compared to undergraduates, and ophthalmologists showed higher knowledge in specific domains (like age limits, factors affecting the eligibility of eye donors, time framefor corneaharvesting, and the identification of certain diseases and conditions barring donation) than non-ophthalmologists. Conclusion Our research uncovered knowledge deficits regarding corneal donation criteria and procedures mainly among undergraduate students. The findings highlight the importance of impactful educational initiatives that utilize preferred communication channels. These efforts should address myths and misconceptions, analyze vital motivating factors, overcome barriers, and understand cultural perspectives influencing the overall attitude towards cornealdonation.

Endophthalmitis Rates and Types of Treatments After Intraocular Procedures

Long-term trend analyses of overall endophthalmitis rates and treatment patterns are scarce. It is also unknown if the deviation from the recommendations of the Endophthalmitis Vitrectomy Study toward decreased utilization of vitrectomy is associated with different vision outcomes. To determine whether the rate of endophthalmitis after intraocular procedures or the primary treatment (prompt vitrectomy vs tap and inject) for endophthalmitis has changed over the past 20 years. This cohort study examined data for cohorts created by querying for different intraocular procedures, including intravitreal injections and surgeries for cataract removal, glaucoma, retinal conditions, and corneal transplants from 2000 to 2022. The data source was a US administrative medical claims database comprising commercial and Medicare Advantage insurance plans. Any intraocular procedure with at least 6 months of data available before and 6 weeks after the procedure was eligible. Exclusion criteria consisted of any previous diagnosis of endophthalmitis or another intraocular procedure during the follow-up period. The main outcomes were rate of postprocedure endophthalmitis and relative rate of prompt vitrectomy (vs tap and inject) as the primary method of treatment. Among 2 124 964 patients, the mean (SD) age was 71.4 (10.2) years; 1 230 320 were female and 894 414 male. Over 22 years, 5 827 809 intraocular procedures were analyzed with 4305 cases of endophthalmitis found for an overall endophthalmitis rate of 0.07%. The yearly rate of endophthalmitis varied but generally declined from a high of 7 cases per 3502 procedures (0.20%) in 2000 to a low of 163 cases per 332 159 procedures (0.05%) in 2022. The percentage of cases treated with prompt vitrectomy also varied but generally declined over time with a high of 17 of 35 (48.6%) in 2003 and a low of 60 of 515 (11.6%) in 2021. Multivariable analysis of the endophthalmitis incidence rate ratio (IRR) showed a per-year decrease of 2.7% (IRR, 0.97; 95% CI, 0.97-0.98; P < .001) over the study period. A similar analysis also showed that the incidence rate of prompt surgical treatment decreased by 3.8% per year throughout the study period (IRR, 0.96; 95% CI, 0.95-0.97; P < .001). This study found that the incidence of endophthalmitis following intraocular procedures appears to have decreased substantially over the past 20 years while prompt vitrectomy is being used less frequently as primary treatment than in the past.

Outcomes of keratoplasty in a cohort of Pythium insidiosum keratitis cases at a tertiary eye care center in India.

To assess outcomes of keratoplasty performed in patients diagnosed with keratitis caused by Pythium insidiosum (PI). Retrospective review. Preoperative, intra operative and post operative data of patients diagnosed with PI keratitis and who underwent keratoplasty for their condition from January 2020 to December 2021 were collected from the central patient database of a tertiary eye care hospital in India. The data were analyzed for anatomic success, elimination of infection, graft survival, incidence of repeat keratoplasty, final visual acuity and varied complications. In total, 16 eyes underwent penetrating keratoplasty for PI keratitis during the study period. Mean time to keratoplasty from onset of symptoms was 31.3 days and mean graft size was 10.4 mm. Nine out of the 16 cases had recurrence of infection following surgery, seven of which required a repeat keratoplasty for elimination of infection. Mean graft size for repeat keratoplasty performed in recurrent cases was 11.7 mm. Globe was successfully salvaged in 14 out of 16 patients (87.5 %). Three grafts remained clear at 6-month follow up while 11 grafts failed. Mean improvement in uncorrected visual acuity from 2.32 to 2.04 logMAR was observed at last follow up. Endo-exudates, graft infiltration, graft dehiscence, secondary glaucoma and retinal detachment were the various complications noted after keratoplasty. PI keratitis is a tenacious and potentially blinding condition. Keratoplasty remains the choice of treatment in this condition, however recurrence of disease and graft failure are common. Large sized grafts, meticulous per-operative removal of infection, adjuvant cryotherapy, and intraoperative and post operative use of antibiotics can help in improving outcome of keratoplasty in these patients.

Utility of a Model to Predict Endothelial Cell Density of Donor Corneas to Determine Suitability for Transplantation.

In Germany, approximately one-third of the harvested donor corneas are not suitable for transplantation, mostly due to insufficient endothelial cell density (ECD). The ECD can only be reliably determined after harvesting and processing of the cornea. Our group has previously developed a predictive model for corneal ECD: \( {Predicted\, ECD} = 2919-6^{\ast}\;{age}\; [{years}]-189\; [{if\, male}]\\ -7^{\ast}\;{death-to-explantation\, interval\,} [{hours}]\\ - 378\; [{if\, pseudophakic}] \;{cells/mm}^2 \). A total of 2.999 consecutive donor corneas harvested between 2017 and 2021 from the Eye Bank of Rhineland-Palatinate in Mainz, Germany, were included. An actual ECD of >2000cells/mm2 was defined as the cutoff value. To evaluate the clinical utility of the prognostic model as a screening instrument for transplant eligibility in an independent cohort, we performed a decision curve analysis. The median predicted ECD was 2061cells/mm2 (interquartile range [IQR] = 1834 to 2221), whereas the median actual ECD was 2377cells/mm2 (IQR = 1907 to 2624). There was a positive correlation between predicted and actual ECD (correlation coefficient = 0.411; P < 0.01). Our predictive model for ECD is a strong predictor for an actual ECD greater than 2000 (odds ratio = 1.374, 95% confidence interval [CI]) per 100 cells; P < 0.001, area under the curve [AUC] of 0.73). Decision curve analysis showed that the predictive model yielded a positive net benefit in clinical settings. Decision curve analysis demonstrated a positive net benefit of the ECD predictive model in clinical settings with limited eye bank resources. In possible scenarios where a choice between corneal grafts is required, or in countries with limited eye bank infrastructure and staff, the initial estimate of ECD from the formula may be beneficial.

Potential of an Amphiphilic Artificial Corneal Endothelial Layer as a Replacement Option for Damaged Corneal Endothelium.

Bullous keratopathy, a condition severely impacting vision and potentially leading to corneal blindness, necessitates corneal transplantation. However, the shortage of donor corneas and complex surgical procedures drive the exploration of tissue-engineered corneal endothelial layers. This study develops a transparent, amphiphilic, and cell-free membrane for corneal endothelial replacement. The membrane, securely attached to the posterior surface of the cornea, is created by mixing hydroxyethyl methacrylate (HEMA) and ethylene glycol dimethylacrylate (EGDMA) in a 10:1 ratio. A 50µL volume is used to obtain a 60µm hydrophobic membrane on both sides, with one side treated with a polyvinylpyrrolidone (PVP) solution. The resulting membrane is transparent, foldable, biocompatible, amphiphilic, and easily handled. When exposed to 20% sulfur hexafluoride (SF6), the hydrophilic side of the membrane adheres tightly to the corneal Descemet's membrane, preventing water absorption into the corneal stroma, and thus treating bullous keratopathy. Histological test confirms its effectiveness, showing normal corneal structure and low inflammation when implanted in rabbits for up to 100 d. This study showcases the potential of this membrane as a viable option for corneal endothelial replacement, offering a novel approach to address donor tissue scarcity in corneal transplantation.