Risk of Corneal Transplant Rejection Following COVID-19 Vaccination: A Systematic Review and Meta-analysis.

INTRODUCTION: The COVID-19 pandemic has initiated an unparalleled global vaccination campaign, raising concerns about the vaccine's effects on various health conditions, including the risk of corneal transplant rejection. This systematic review aimed to identify the relationship between COVID-19 vaccination and rejection of corneal transplant, filling a significant gap in the existing medical literature. METHODS: A literature search was performed across multiple databases up to February 12, 2024, to identify studies evaluating the risk of corneal transplant rejection post-COVID-19 vaccination. Eligible studies were original research that reported outcomes of corneal graft rejection following vaccination. Nested Knowledge web software facilitated screening and data extraction. The Newcastle-Ottawa Scale was employed for quality assessment. A meta-analysis was conducted to calculate the aggregated relative risk (RR) utilizing R software version 4.3. RESULTS: Six studies were included in the qualitative synthesis, with four meeting the criteria for meta-analysis. These studies varied in geographic location, surgical techniques, and types of vaccines used. The pooled RR for corneal transplant rejection following COVID-19 vaccination was 0.816 (95% CI 0.178-1.453), indicating no significant risk of rejection. No statistical heterogeneity was observed among the studies (I2 = 0%). CONCLUSIONS: This review and meta-analysis found no significant evidence that COVID-19 vaccination increases the risk of corneal graft rejection. However, the current evidence is insufficient to conclusively determine the vaccine's safety for corneal transplant recipients. These findings underscore the need for additional research to confirm these preliminary results and investigate the long-term effects of COVID-19 vaccination on corneal transplants, aiming to provide evidence-based guidance to healthcare providers and patients.

A single chain variable fragment antibody (Tn 64) cognate to fibronectin type III repeats promotes corneal wound healing by inhibiting fibrosis.

Corneal wound healing requires epithelial reorganization and stromal extracellular matrix (ECM) remodeling, with ECM proteins such as Tenascin C (TnC) regulating and maintaining corneal homeostasis. The N-terminal globular domain and C-terminal fibrinogen-related domains of TnC are separated by epidermal growth factor (EGF)-like repeats, and upto fifteen fibronectin type III domains (Tn fn). Overexpression of Tn fn 1-5 and its splice variants occurs in varied pathologies. We have previously used Tn64 (a single chain variable fragment antibody cognate to Tn fn 1-5) to establish roles of Tn fn 1-5 in fibrotic pathologies such as rheumatoid arthritis and posterior capsular opacification. Here, we show that Tn64 binds to Tn fn repeats 3-5 (which constitute the major site for binding of soluble fibronectin within TnC). Unlike other Tn fn domains, Tn fn 3-5 displays no inhibition of fibronectin matrix assembly. Rather, the Tn fn 3-5 construct is pro-fibrotic and elicits increased expression of fibronectin. We examined corneal epithelial as well as stromal wound healing through Tn64 binding to Tn fn 3-5, using a human corneal epithelial cell (HCEC) line, primary cultures of human corneal fibroblasts (HCFs), and an ex-vivo corneal organ culture model. Tn64 enhanced proliferation and adhesion of corneal epithelial cells, while inhibiting the migration of corneal fibroblasts and myofibroblasts. Tn64 appears to attenuate inflammation through downregulation of TNF-α, prevent corneal fibrosis by limiting fibronectin polymerization, and promote regeneration of corneal epithelia and stroma, suggesting that it could be developed as a therapeutic agent for effective anti-fibrotic corneal wound healing.

Cataract surgery in children using intracameral mydriatic.

PURPOSE: To study the pupil dynamics with premixed intracameral anesthetic mydriatic combination of phenylephrine (0.31%), tropicamide (0.02%), and lidocaine (1%) in pediatric cataract surgery. METHODS: Consecutive children aged ≤12 years planned for cataract surgery were recruited. A commercially available premixed combination of phenylephrine (0.31%), tropicamide (0.02%), and lidocaine (1%) was injected at the beginning of surgery without any topical/infusion drugs for mydriasis. Pupil sizes at various points of surgery were studied. RESULTS: We recruited 75 patients with a mean age of 24.3 ± 33.4 months (range: 1 month-11 years). Adequate mydriasis with a single injection was achieved in 93.5% (n = 73 eyes of 70 patients) without additional pharmacotherapy or intervention. The mean pupillary diameter increased from 1.8 ± 0.79 to 6.1 ± 1.4 mm after injection (mean change of 4.2 ± 1.25 mm from baseline). The mean variability in pupillary diameter was 0.73 ± 1.3 mm. In five eyes, good dilatation was not possible even after repeat injection. CONCLUSION: Fixed-dose premixed intracameral injection is effective in pupil dilatation. It alleviates the need for any topical dilators or additional intraoperative supplementation for pediatric cataract surgery.

Use of discarded corneo-scleral rims to create cornea-like tissue.

BACKGROUND: Corneal disease is a major cause of blindness. Transplantation of cadaver-derived corneas (keratoplasty) is still the current therapy of choice; however, the global shortage of donor corneas continues to drive a search for alternatives. To this end, biosynthetic corneal substitutes have recently begun to gain importance. Here, we present a novel method for the generation of a cornea-like tissue (CLT), using corneo-scleral rims discarded after keratoplasty. METHODS AND RESULTS: Type I collagen was polymerized within the corneo-scleral rim, which functioned as a 'host' mould, directing the 'guest' collagen to polymerize into disc-shaped cornea-like material (CLM), displaying the shape, curvature, thickness, and transparency of normal cornea. This polymerization of collagen appears to derive from some morphogenetic influence exerted by the corneo-scleral rim. Once the CLM had formed naturally, we used collagen crosslinking to fortify it, and then introduced cells to generate a stratified epithelial layer to create cornea-like tissue (CLT) displaying characteristics of native cornea. Through the excision and reuse of rims, each rim turned out to be useful for the generation of multiple cornea-shaped CLTs. CONCLUSIONS: The approach effectively helps to shorten the gap between demand and supply of CLMs/CLTs for transplantation. We are exploring the surgical transplantation of this CLT into animal eyes, as keratoprostheses, as a precursor to future applications involving human eyes. It is possible to use either the CLM or CLT, for patients with varying corneal blinding diseases.

Diabetes is affecting everyone everywhere.

The article titled "Accessibility and Utilization of Healthcare Services Among Diabetic Patients: Is Diabetes a Poor Man's Ailment?" gave insights into a pandemic systemic disease known as diabetes mellitus. This modern-era pandemic affects everyone, regardless of their financial background. As a result, diabetes is not a systemic disease which just involves people of low socioeconomic status.

Clinical outcomes of corneal neurotization using sural nerve graft in neurotrophic keratopathy.

OBJECTIVE: To evaluate the efficacy of corneal neurotisation using sural nerve graft coaptation of the contralateral supratrochlear nerve in unilateral neurotrophic keratopathy and corneal anesthesia. Corneal neuralization has emerged as a potential option in the treatment of neurotropic keratopathy, however not free from the predicament. We evaluated the long-term outcome of corneal neurotisation in the treatment of unresponsive unilateral neurotropic keratopathy using surgical variations to mimic and expedient the surgical procedure. METHODS: A Prospective interventional study involving patients with unilateral neurotrophic keratopathy (NK) who did not respond to medical measures was conducted. The study parameters evaluated were best-corrected visual acuity improvement, ocular surface evaluation parameters [tear break-up time (TBUT), Schirmer's 1, and ocular surface staining scores (corneal and conjunctival staining)], central corneal sensation (Cochet Bonnet esthesiometer), sub-basal nerve fiber length (SBNFL), and sub-basal nerve fiber density (SBNFD) determined by central confocal microscopy at recruitment and during follow-up at 1-month, 3-month, 6-month, 9-month and 12-month respectively, following corneal neurotization. RESULTS: Eleven eyes of 11 patients with unilateral neurotrophic keratopathy (NK) who underwent corneal neurotisation were studied. The mean follow-up was 10.09±2.31months (range, 6-12). Mean best corrected visual acuity in log MAR at baseline, 1.35±0.52 improved significantly to 1.06±0.76 (P = 0.012) at 3 months and continued to 0.55±0.60 (P = 0.027) at 12 months. There was a significant reduction in NK grade severity and improvement in the ocular surface as early as 1 month, and central corneal sensations (P = 0.024) as soon as 3 months. Mean corneal SBNF improved from 3.12±1.84 mm/mm2 to 4.49±1.88 at 1 month (P = 0.008), 13.31±3.61 mm/mm2 (P = 0.028) at 12 months. Mean central corneal SBNFD evident at 6 months was 1.83±2.54no/mm2 (P = 0.018) and 4.90±3.12no/mm2 (P = 0.028) at 12 months. CONCLUSION: This study substantiates the routine practice of corneal neurotisation by simplifying the intricacies observed during the procedure.

Pharmacological management of intra-operative miosis during cataract surgery.

Cataract surgery requires a well-dilated and stable pupil for a good outcome. Unexpected pupillary constriction during surgery increases the risk of complication. This problem is more pronounced in children. There are now pharmacological interventions that help tackle this unforeseen happening. Our review discusses the simple and quick options available to a cataract surgeon when faced with this dilemma. As cataract surgical techniques continue to improvise and get faster, an adequate pupil size is of paramount importance. Various topical and intra-cameral drugs are used in combination to achieve mydriasis. Despite good pre-operative dilation, the pupil can be quite unpredictable during surgery. Intra-operative miosis limits the field of surgery and increases the risk of complications. For example, if the pupil size decreases from 7 mm to 6 mm, this 1 mm change in pupil diameter will lead to a decrease of 10.2 mm2 in the area of surgical field. Making a good capsulorhexis with a small pupil can be a challenge, even for an experienced surgeon. Repeated touching of the iris increases the risk of fibrinous complications. Removal of cataract and the cortical matter becomes increasingly difficult. Intra-ocular lens implantation in the bag also requires adequate dilation. When dealing with challenging cases like lens subluxation, pseudo-exfoliation, and zonular dehiscence, a small pupil further increases the risk and adversely affects the surgical outcome. Hence, achieving and maintaining adequate mydriasis throughout surgery is essential. This review highlights the risk factors for small pupils during surgery and current management strategies.

Role of swept-source anterior segment optical coherence tomography in imaging pediatric cataract.

Purpose: To determine the morphology of pediatric cataracts and assess the status of the anterior and posterior capsules preoperatively on swept-source anterior segment optical coherence tomography (ASOCT) and compare the findings to those of intraoperative examination. Secondly, we aimed to obtain biometric measurements on ASOCT and compare them to those obtained on A-scan/optical methods. Methods: This was a prospective and observational study carried out at a tertiary care referral institute. ASOCT scans for anterior segment were obtained preoperatively for all patients, aged <8 years, scheduled for paediatric cataract surgery. The morphology of the lens and capsule and biometry were performed on ASOCT and the same were assessed intraoperatively. The main outcome measures were comparison of ASOCT findings to intraoperative findings. Results: The study included 33 eyes of 29 patients (range 3 months-8 years). The morphological characterization of cataract on ASOCT was accurate in 31/33 (94%) cases. ASOCT accurately identified fibrosis and rupture of the anterior and posterior capsules in 32/33 (97%) cases each. In 30% of eyes, ASOCT gave additional information preoperatively compared to the slit lamp. Intraclass correlation coefficient (ICC) calculation revealed a good agreement between the keratometry values obtained on ASOCT and those obtained preoperatively with a handheld/optical keratometer (ICC = 0.86, P = 0.001). Conclusion: ASOCT is a valuable tool that could provide complete preoperative information of the lens and capsule in pediatric cataract cases. In children as young as 3 months of age, intraoperative risks and surprises could be diminished. The keratometric readings are highly dependent on patient cooperation but show good agreement with the handheld/optical keratometer readings.

Socio-Ecological determinants of myopia in rural school students in North India: Results from a nurse-led program.

Socio-ecological determinants of high myopia incidence among school students largely remain unexplored, especially in developing countries. A cross-sectional study was conducted in rural schools in North India to assess the relationship between these determinants and myopia among adolescent students. A public health nurse used a pre-tested questionnaire (demographics, family ocular status, and screen time) and Snellen's chart for testing visual acuity, and referred suspected cases for cycloplegic refraction assessment. Among the total of 955 students, the median (range) age was 14 (13-15) years. The prevalence of myopia was 5.03% (95% confidence interval [CI]: 4.99-5.07). Myopia was found to be associated with computer usage at school (P = 0.058), malnutrition (P = 0.001), and familial myopia (P = 0.079) in the bivariate analysis. Significant predictors of myopia in the regression model were females (odd ratio [OR]: 6.29; 95% CI: 2.69-14.72), higher maternal age (OR: 1.09; 95% CI: 1-1.17), and reading distance <20 cm (OR: 1.98; 95% CI: 1.01-3.87).

Ophthalmic Manifestations of the Monkeypox Virus: A Systematic Review and Meta-Analysis.

BACKGROUND: The accurate estimation of the prevalence of mpox-induced ophthalmic lesions will enable health departments to allocate resources more effectively during the ongoing mpox pandemic. The aim of this meta-analysis was to estimate the global prevalence of ophthalmic manifestations in mpox patients. METHODS: A systematic search was carried out in seven databases-Pub Med, Scopus, Web of Science, EMBASE, ProQuest, EBSCOHost, and Cochrane-for studies published on or before 12 December 2022. The pooled prevalence of ophthalmic manifestations was estimated by the random effects model. Risk of bias assessment of the studies and sub-group analysis to explain heterogeneity were undertaken. RESULTS: Overall, 12 studies were included, with 3239 confirmed mpox cases, among which 755 patients reported ophthalmic manifestations. The pooled prevalence of ophthalmic manifestations was 9% (95% confidence interval (CI), 3-24). Studies from Europe reported a very low prevalence of ocular manifestations of 0.98% (95% CI 0.14-2.31), compared to studies from Africa with a substantially higher prevalence of 27.22% (95% CI 13.69-43.26). CONCLUSIONS: A wide variation in the prevalence of ocular manifestations among mpox patients was observed globally. Healthcare workers involved in mpox-endemic African countries should be aware of ocular manifestations for early detection and management.

Perception of college-going girls towards corneal donation in North India: A latent class analysis study.

Purpose: To assess the perception of college-going girls toward corneal donation in Northern India. Methods: An online survey with a pre-structured, pre-validated questionnaire was conducted on 1721 college-going girls in Northern India. The knowledge and attitude scores were regressed, and latent class analysis was carried out. Results: The average of scores for all participants was computed individually for the knowledge questions and the attitude questions, and based on this score, total participants were divided into two groups: Better corneal donation behaviors (BCDB) and poor corneal donation behaviors. The binomial logistic regression model of knowledge domain for predicting BCDB, age of the participant, their awareness about corneal donation, and willingness to discuss eye donation among family members were found significant. Similarly, for the attitude domain, awareness about corneal donation, knowledge about hours within which ideal eye donation needs to be undertaken, and knowledge about eye donation during coronavirus disease 2019 (COVID-19) pandemic were found to be significant. Latent class analysis identified one subset of participants having poorer knowledge and attitude scores and that they were more from a rural background, were having more than first order as birth order, were belonging to SC/ST classes, had illiterate or secondary education of father and mother, and were living in rented houses. Conclusion: The findings of the study significantly contribute to devising a mechanism to improve knowledge and influencing the attitude about eye donation among the youth, especially young women, who can act as counselors and motivators for the masses as well as their own families, in the generations to come.

Tissue Adhesives for the Management of Corneal Perforations and Challenging Corneal Conditions.

Corneal perforations are ophthalmological emergencies which can have serious and detrimental consequences, if not managed timely and appropriately. These are a significant cause of ocular morbidity and can result in decreased vision, blindness, and even loss of the eye. Corneal perforations can be managed using a range of treatment approaches, including temporary solutions such as the application of corneal glue and bandage contact lens, as well as definitive treatment such as corneal transplantation. Tissue glues/adhesives were developed as substitutes for sutures in ophthalmic surgery. Unlike sutures, these glues are associated with shorter overall surgical times and reduced inflammation, thus improving postoperative comfort without compromising wound strength. The available tissue adhesives can be broadly classified into two types: synthetic (eg, cyanoacrylate derivatives) and biological (eg, fibrin glue). Cyanoacrylate glue is chiefly used as a corneal patch to manage acute corneal perforations and improve visual outcomes. Fibrin glue can be used instead of cyanoacrylate glue in many conditions with the benefits of reduced conjunctival and corneal inflammation and reaction. Apart from this, each type of adhesive is distinct in terms of its benefits as well as limitations and is accordingly used for different indications. The present review focuses on the two main types of tissue adhesives, their applications in the management of corneal perforations, the associated complications, safety and efficacy data related to their use available in the literature and the need for newer adhesives in this field.

Axial myopia, a protective factor for diabetic retinopathy-role of vascular endothelial growth factor.

Long axial length is one of the ocular protective factors in development of diabetic retinopathy (DR). In this study we examined the effect of axial length (AL) on aqueous humor vascular endothelial growth factor (VEGF) levels in patients with diabetes mellitus with or without DR. Forty-eight eyes of 48 participants were divided into three groups of 16 each. Group A consisted of non-diabetic patients, Group B had diabetic patients without DR, and Group C had diabetic patients with treatment-naive non-proliferative DR (NPDR). The groups were further subdivided based on axial lengths i.e., AL ≤ 23.30 mm (A1, B1, C1) and AL > 23.30 mm (A2, B2, C2). Undiluted aqueous humor was obtained during cataract surgery to measure the VEGF levels. We observed significant decrease in VEGF concentration in patients with AL ≥ 23.30 mm as compared with AL ≤ 23.30 mm in non-diabetic as well as diabetic patients. As the eye elongates, there is less secretion of VEGF in non-diabetics as well in diabetics with or without DR. Our findings strengthened the concept that an increase in AL leads to less VEGF in diabetic eyes, thus leading to less severe DR changes.

Association of screen time, quality of sleep and dry eye in college-going women of Northern India.

PURPOSE: To evaluate the association of daily screen time and quality of sleep with the prevalence of dry eye among college-going women. METHODS: This study was a cross-sectional, comparative questionnaire-based study of 547 college-going women in northern India. A 10-item Mini Sleep Questionnaire was used to check the quality of sleep, and the Standard Patient Evaluation of Eye Dryness (SPEED) scale was used to examine the prevalence of dry eye among college-going women. RESULTS: Multinomial logistic regression showed a significant association between dry eye with daily screen time spent (P < 0.05) and the quality of sleep (P < 0.05) among college-going girls. Using Latent Class Analysis, two latent classes were selected based on the Bayesian Information Criteria. It was found that the majority population falls in class two and was having Severe Sleep-Wake difficulty. It was seen that the participants in class two belonged to the age bracket of 18-21 years, were from stream Humanities, education of father and mother equal to graduation, father working only, belonging to the nuclear family, having one sibling, hailing from the urban locality, spending more than 6 h daily on-screen, a majority of them using mobile phones, not using eye lubricants, and reported an increase in screen time during COVID-19. CONCLUSION: Dry eye and sleep quality are essential global health issues, and coupled with increased screen time, may pose a challenge in the present era. Preventive strategies need to be incorporated in school and college curriculums to promote physical, social, and psychological well-being and quality of life.