Burden of corneal blindness in India

Efficacy of hypertonic saline in treatment of corneal edema: A randomized crossover trial

Background

To determine the efficacy of sodium chloride (NaCl) 5% drops in comparison to 6% ointment and study tear Osmolarity as an objective measure correlating with clinical findings in the treatment of corneal edema.

Methods

This is a prospective, randomized, interventional, open-label, crossover study of 40 eyes of 40 patients with corneal edema due to Bullous keratopathy and Fuchs endothelial dystrophy. Subjects were divided into 2 groups by simple randomization: group A received NaCl 5% drops and group B received NaCl 6% ointment. Both treatments were administered four times daily for seven days. Subsequently, after a 1-week wash-out period, switch over of treatment was done. Central corneal thickness (CCT) and tear osmolarity were primarily efficacy variables.

Results

Baseline parameters were comparable. The median reduction in CCT from baseline (706.7 ± 58.41 μm), at 6 hours with NaCl 5% drops was 23 μm (-27, 74) and that with NaCl6% ointment was 37.5 μm (-7, 85). The reduction in CCT was more with 6% ointment (p = 0.013). The difference in reduction in CCT between two treatments at one week was not statistically significant, although there was a substantial reduction in thickness with each treatment individually. The change in tear osmolarity from the baseline at 2 Hours with both NaCl5% drops and 6% ointment was significant, and it remained so till 6 h. Side-effects such as stickiness, stinginess, blurring, and foreign body sensation were more with 6% eye ointment.

Conclusion

Topical NaCl 6% eye ointment in QID dosage is more effective than NaCl 5% drops in the medical management of corneal edema. In patients symptomatically intolerant to ointment, NaCl 5% eye drops may be prescribed as an effective option.

Clinical perspective and outcome of culture-negative microbial keratitis: A retrospective study

PURPOSE

To study the risk factors, clinical features, and treatment outcomes of patients with culture-negative keratitis (CNK).

METHODS

A retrospective data review of 933 patients with CNK was performed from January 2018 to December 2020. The variables such as the history of injury, visual acuity, slit-lamp findings with measurements of size and depth of ulcer, microbiological evaluation, duct patency, blood glucose levels, and treatment were considered, and clinical outcome was analyzed.

RESULTS

Of the 933 patients with CNK, 763 (81.8%) were medically managed, with a mean treatment duration of 2.08 ± 1.7 weeks. Among them, 622 (66.7%) were both smear and culture-negative, and 311 (33.3%) showed only smear positivity. Smear-positive patients showed a positive correlation with the history of injury. A higher incidence of fungal growth on repeat culture was observed. Surgical interventions were done only in 18.2% of the patients; the rest were treated with topical medications alone.

CONCLUSION

High clinical suspicion, differentiation of causative organisms based on clinical findings, and initiating empirical therapy with broad-spectrum antibiotics and antifungals improve the ultimate prognosis in patients with CNK, even though a standard protocol for empirical medical treatment may differ among institutions and surgeons based on their clinical experience and geographical variations.

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 people improve 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 frame for cornea harvesting, 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 corneal donation.

Analysis of the performance of the CorneAI for iOS in the classification of corneal diseases and cataracts based on journal photographs

CorneAI for iOS is an artificial intelligence (AI) application to classify the condition of the cornea and cataract into nine categories: normal, infectious keratitis, non-infection keratitis, scar, tumor, deposit, acute primary angle closure, lens opacity, and bullous keratopathy. We evaluated its performance to classify multiple conditions of the cornea and cataract of various races in images published in the Cornea journal. The positive predictive value (PPV) of the top classification with the highest predictive score was 0.75, and the PPV for the top three classifications exceeded 0.80. For individual diseases, the highest PPVs were 0.91, 0.73, 0.42, 0.72, 0.77, and 0.55 for infectious keratitis, normal, non-infection keratitis, scar, tumor, and deposit, respectively. CorneAI for iOS achieved an area under the receiver operating characteristic curve of 0.78 (95% confidence interval [CI] 0.5-1.0) for normal, 0.76 (95% CI 0.67-0.85) for infectious keratitis, 0.81 (95% CI 0.64-0.97) for non-infection keratitis, 0.55 (95% CI 0.41-0.69) for scar, 0.62 (95% CI 0.27-0.97) for tumor, and 0.71 (95% CI 0.53-0.89) for deposit. CorneAI performed well in classifying various conditions of the cornea and cataract when used to diagnose journal images, including those with variable imaging conditions, ethnicities, and rare cases.

Safety and Efficacy Profile of Corneas Harvested From Donors of Drowning Victims

PURPOSE

The aim of this study was to analyze the tissue quality and outcomes of corneal transplants from donor corneal tissues harvested from drowning victims.

METHODS

This retrospective study was conducted on corneal tissues harvested from drowning victims between March 2018 and September 2022. Details of the tissue quality and outcomes after keratoplasty were collected from the eye bank and outpatient records.

RESULTS

Thirty-four donor corneas were collected from drowning victims during the study period. The mean age of the donors was 37.1 ± 20.3 years. The mean donor-to-preservation time was 4.9 ± 2.6 hours. The mean endothelial cell density was 3025 ± 271 cells/mm 2 . Twenty donor corneas (58.8%) were used at our institute, 2 were stored in glycerol for future use, and 12 were transported to other transplant centers. The overall utilization was 94.1% (32/34 corneas). Of the 20 corneas used at our institute, 17 were used for optical grafts and 3 for therapeutic indications. Of the 17 optical grafts, 10 were used for optical penetrating keratoplasty, 6 for endothelial keratoplasty, and 1 for anterior lamellar keratoplasty. The most common indication for keratoplasty was regrafting the previously failed grafts (25%). None of the transplanted eyes developed an infection in the immediate postoperative period. Eight eyes had clear grafts after 3 months. Of the 12 tissues transferred to other keratoplasty centers, 10 were used for optical grafts and 2 for therapeutic/tectonic grafts.

CONCLUSIONS

Donor corneas retrieved from drowning victims may be considered safe for transplantation. The postoperative outcomes of the tissues obtained from these donors were satisfactory. Hence, these donor corneas can be optimally used in routine transplantation procedures.

A study on knowledge, attitude, and practice about eye donation among medical students and healthcare professionals at a tertiary hospital in Eastern India

Purpose

To assess and analyze the rate of knowledge, attitude, and practice patterns about eye donation among medical and healthcare professionals in a tertiary care hospital in eastern India.

Methods

This was a cross-sectional, descriptive study conducted on medical students, resident doctors, and nursing and paramedical staff at a tertiary institute in the year 2020. A pretested, structured questionnaire consisting of 28 questions in the three subsections based on knowledge and awareness, attitudes and beliefs, and practice patterns mainly willingness to donate eyes by pledging, was noted. All the responses were individually scored, and the total scores were calculated. Univariate analysis was done to find out the factors that had a positive or negative influence on the knowledge and willingness about eye donation.

Results

Around 270 participants responded to this survey. The majority of the respondents (206, 76.3%) were below 30 years and 64.4% were males. Awareness about eye donation was 95.6% but a willingness to pledge was observed in 51.5% of participants. The total practice score was lower among nonmedicos compared with medicos (3.33 ± 1.22 vs 3.74 ± 0.64), (P < 0.001). On univariate analysis, the Crude Odds Ratio with a 95% confidence interval was 25.787 (5.18-128.33) in the occupational category (P < 0.001).

Conclusion

The study reported an adequate knowledge level among doctors and healthcare workers. The practice pattern among the nursing staff and paramedical workers needs to be improved as they can play a pivotal role in strengthening the hospital corneal retrieval program. They can also be the key messengers during public awareness campaigns for eye donations in our country.

Long-term outcomes of therapeutic corneal transplants performed in a tertiary eye care hospital in South India

Purpose

This study aimed to review the demographics, clinical characteristics, and long-term outcomes of therapeutic penetrating keratoplasty (TPK) performed in a tertiary eye care hospital.

Methods

Case records of 149 therapeutic transplants (135 patients) that were performed during the calendar year 2016 were retrospectively analyzed, and outcomes were measured until 3 years of follow-up. Information on demographics, presentation characteristics, keratoplasty indications, offending microbe, and secondary surgical interventions was studied. The final outcome was classified in terms of therapeutic, anatomical, and functional outcomes.

Results

The median age of the recipients was 55 years with 61% men. The most common indications for TPK were perforated infectious ulcer (45.9%), nonhealing ulcers (29.9%), and graft infections (17.4%). Fungal etiology was noted in 61.2% and bacterial etiology in 17.4% of the eyes. Therapeutic success was achieved in 130 eyes (89%) at the end of 1 month. Anatomical success was achieved in 130 (98.5%) and 88 patients (86.3%) at the end of 1 and 6 months, respectively. At the 6-month time point, 78 patients (76.5%) attained functional success with vision better than light perception. Three-year follow-up data were available for 23.7% of recipients, of which only 12 patients (37.5%) retained a clear graft either after a primary therapeutic or secondary optical keratoplasty.

Conclusion

Therapeutic keratoplasty is highly effective in eradicating infection and providing anatomical integrity. However, timely intervention can aid in achieving the best functional outcome.

Indications and types of keratoplasties: Trends in the past 10 years (2011-2020) in Eastern India

Purpose

To observe the trends of various types of keratoplasties in different etiologies over a period of 10 years (2011-2020) in a tertiary eye care center of eastern India.

Methods

A retrospective review of patients undergoing keratoplasties from 2011 to 2020 was performed in a tertiary eye care hospital situated in eastern part of India. Apart from demographic data, primary indication for each surgery and type of procedure carried out was recorded. For comparison, data were divided into two time periods: Group I: Jan 2011 to Dec 2015 and Group II: Jan 2016 to Dec 2020.

Results

Over a period of 10 years, a total of 2365 (Group I: 902, Group II: 1463) keratoplasties were performed. The average age of patients was 45.8 ± 19.9 and 46.9 ± 20.9 years in Group I and Group II, respectively. Among all the corneal grafts, 1747 (74%) surgeries were full-thickness. Although optical penetrating keratoplasty (OPK) was most the common indication for full-thickness keratoplasties, Descemet's stripping endothelial keratoplasty (DSEK) remained most performed lamellar keratoplasty. Keratitis, corneal scars, and bullous keratopathies remain to be most common indications in both groups. Number of lamellar keratoplasties increased significantly from Group I to Group II for corneal scars (P = 0.02), bullous keratopathies (P = 0.01), and endothelial dystrophies (P = 0.00).

Conclusion

With change in time, the indication and technique of keratoplasty has witnessed a changing trend from full-thickness keratoplasty to lamellar keratoplasty. There is rise in trend of lamellar keratoplasties over the period.

Evolution of eye banking in India - A review

Corneal blindness ranks third among the causes of blindness worldwide, after cataract and glaucoma. Corneal transplantation offers us a means to address this, and is currently the most commonly performed transplantation procedure worldwide - restoring the gift of sight to many an eye. Eye banks play a very important role in these procedures. India was quick to develop its own eye bank in 1945 soon after the launch of world's first eye bank in 1944. The evolution over the past six decades has been tremendous, placing India on the top, with one of the largest eye-banking system in the world. As of 2023, around 740 members are registered under the Eye Bank Association of India. The highest-ever collection of 71,700 donor eyes was achieved in 2017-2018. The overall tissue utilisation rate ranged between 22 - 28 % for voluntary donations and 50% for hospital-based corneal retrieval programs. Though India has an excellent infrastructure and readiness for corneal transplantation surgery, the need of the hour is to create a strong and independent nodal system. It shall take care of the logistics and factor in technological advances - surgical and otherwise. Public awareness, a national corneal grid, and reducing the red-tape barriers, shall improve availability of grafts nationwide. This review aims to detail the evolution of eye banking in India, to provide a comprehensive understanding, and help the stakeholders focus on the road ahead to attain our targets faster.

Outcomes of manual small incision cataract surgery (MSICS) in eyes with corneal opacity

PURPOSE

To report the outcomes of manual small incision cataract surgery (MSICS) in eyes with corneal opacity.

SETTING

Tertiary care ophthalmic hospital.

DESIGN

Retrospective study.

METHODS

This retrospective study included 286 eyes of 286 patients having cataract with a pre-existing corneal opacity who underwent manual small incision cataract surgery (MSICS) at a tertiary eye institute between January 2020 and January 2022. Data were retrieved from electronic medical records, and we documented demographics, history, detailed anterior and posterior segment examination, cataract grading, pre- and post-operative vision, intra-operative complications and its management, and post-operative course. All these parameters were recorded at the baseline visit, day 1 and at 1 month post-operatively.

RESULTS

Two hundred eighty-six eyes having cataract with a pre-existing corneal opacity which underwent MSICS were evaluated. Corneal opacity was graded as nebular, nebulo-macular, macular and leucomatous types; nebular opacity being the most common. Trauma was the most common cause of opacity followed by infective keratitis. Intra-operative complication rate was 4.89%; which included-7 posterior capsular rent with vitreous disturbance, 2 zonular dialysis, 2 iridodialysis, 2 eyes with aphakia and 1 with Descemet membrane detachment. On follow-up, 6 patients had decentered intraocular lens and 10 had residual cortex. Median logMAR vision improved significantly (p < 0.001) from 1.08 (5/60) pre-operatively to 0.3 (6/12) post-operatively.

CONCLUSION

MSCIS is efficient in providing favorable visual outcomes in patients where corneal opacity makes it difficult for the surgeon to perform a phacoemulsification surgery.

Urgent unmet needs in the care of bacterial keratitis: An evidence-based synthesis

Bacterial corneal infections, or bacterial keratitis (BK), are ophthalmic emergencies that frequently lead to irreversible visual impairment. Though increasingly recognized as a major cause of global blindness, modern paradigms of evidence-based care in BK have remained at a diagnostic and therapeutic impasse for over half a century. Current standards of management - based on the collection of corneal cultures and the application of broad-spectrum topical antibiotics - are beset by important yet widely underrecognized limitations, including approximately 30% of all patients who will develop moderate to severe vision loss in the affected eye. Though recent advances have involved a more clearly defined role for adjunctive topical corticosteroids, and novel therapies such as corneal crosslinking, overall progress to improve patient and population-based outcomes remains incommensurate to the chronic morbidity caused by this disease. Recognizing that the care of BK is guided by the clinical axiom, "time equals vision", this chapter offers an evidence-based synthesis for the clinical management of these infections, underscoring critical unmet needs in disease prevention, diagnosis, and treatment.

Population-based study on the prevalence, clinical characteristics and vision-related quality of life in patients with corneal opacity resulting from infectious keratitis: results from the Corneal Opacity Rural Epidemiological study

AIM

To estimate prevalence and characterise clinical features and vision-related quality of life (VR-QoL) of corneal opacities (COs) resulting from infectious keratitis in a rural North Indian population.

METHODS

The Corneal Opacity Rural Epidemiological study was a cross-sectional study conducted in 25 randomly selected clusters of rural Gurgaon, Haryana, India to determine prevalence of corneal disease across all age groups. During house-to-house visits, sociodemographic details, presence, type and clinical characteristics of corneal disease, laterality and resultant visual impairment (VI) was noted. Subgroup analysis of data was performed to understand the prevalence, clinical characteristics, VR-QoL in patients with CO due to infectious keratitis. VR-QoL scores were compared with healthy controls.

RESULTS

Overall, 65 of 12 113 participants had evidence of infectious keratitis-related CO with a mean age of 63.3 (±14.7 SD) years. Prevalence of infectious keratitis-related CO, including both bilateral (12/65) and unilateral (53/65) cases was 0.54% (95% CI 0.41 to 0.66) seen in a total of 77 eyes of 65 participants. Mean visual acuity was 1.18±0.80 with 30/77 (38.9%) eyes having a presenting visual acuity <3/60. Most of the CO due to infectious keratitis was <3 mm in size (61.03%; 47/77), nebular (42.85%; 33/77) and central (49.35%; 38/77) in location. These participants had significantly higher VR-QoL scores and hence poorer VR-QoL across all three domains of vision function (scores of 28 vs 22, 7.5 vs 5 and 15.5 vs 9, respectively; p<0.0001) when compared with healthy controls.

CONCLUSION

The data from this study give an insight into the burden and clinical characteristics of COs resulting from infectious keratitis. VR-QoL is significantly impaired in patients with CO resulting from infectious keratitis, both in bilateral and unilateral cases.

Modern Technologies in Diagnosis of Fungal Keratitis (Review)

Traumas and infectious diseases of the eye play a leading role in the development of corneal blindness responsible for 1.5-2 million cases of vision loss per year. To date, the issue of reducing the incidence of fungal keratitis is acute and needs to be solved worldwide. Trauma as a risk factor for corneal fungal disease is thought to be prevalent in developing countries due to agricultural involvement, while in developed countries the onset of the disease is predisposed by medical advances such as contact vision correction and modern ophthalmic surgery. Thorough analysis of the pathogenesis gives the possibility to describe the action of fungal enzymes, biofilm formation, and the resistance mechanism, which on the one hand explains the aggressive course of the disease and difficulties in its diagnosis, and on the other hand, it encourages searching for new methods of diagnosis and treatment. The non-specific clinical picture of fungal keratitis, the variety and availability of antibiotics nowadays become an obstacle for rapid detection of this pathology. Low public awareness and late visit to an ophthalmologist are also a barrier to successful combating the increasing incidence of fungal keratitis. Belated diagnosis, increasing resistance of fungi to antibiotics, and lack of registered antifungal ophthalmic drugs justify poor treatment efficacy resulting in decreased visual acuity or vision loss. Existing diagnostic methods need systematization and detailed comparison, identifying the advantages and disadvantages of each. This review considers causative agents and their influence on pathogenesis of the disease, describes difficulties of fungal keratitis diagnosis and possible ways of overcoming these problems using new developments, and also outlines further prospects of research in this direction.

Automatic Diagnosis of Infectious Keratitis Based on Slit Lamp Images Analysis

Infectious keratitis (IK) is a common ophthalmic emergency that requires prompt and accurate treatment. This study aimed to propose a deep learning (DL) system based on slit lamp images to automatically screen and diagnose infectious keratitis. This study established a dataset of 2757 slit lamp images from 744 patients, including normal cornea, viral keratitis (VK), fungal keratitis (FK), and bacterial keratitis (BK). Six different DL algorithms were developed and evaluated for the classification of infectious keratitis. Among all the models, the EffecientNetV2-M showed the best classification ability, with an accuracy of 0.735, a recall of 0.680, and a specificity of 0.904, which was also superior to two ophthalmologists. The area under the receiver operating characteristics curve (AUC) of the EffecientNetV2-M was 0.85; correspondingly, 1.00 for normal cornea, 0.87 for VK, 0.87 for FK, and 0.64 for BK. The findings suggested that the proposed DL system could perform well in the classification of normal corneas and different types of infectious keratitis, based on slit lamp images. This study proves the potential of the DL model to help ophthalmologists to identify infectious keratitis and improve the accuracy and efficiency of diagnosis.

Incidence, Clinical Profile, and Management of Keratitis Caused by Uncommon Species of Pseudomonas at a Tertiary Eye Care Center

PURPOSE

The purpose of this study was to study the incidence, demographic features, clinical course, profiling, and management of uncommon species of Pseudomonas keratitis (other than Pseudomonas aeruginosa ) at a tertiary eye care center.

METHODS

Thirty cases of culture-proven uncommon species of Pseudomonas keratitis between January 2017 and December 2021 were retrospectively studied. The incidence, demographic and clinical profile, predisposing factors, microbial results, treatment, and visual outcomes were analyzed. We evaluated the risk factors for poor treatment outcomes.

RESULTS

Among bacterial keratitis cases, uncommon species of Pseudomonas keratitis occurred at a rate of 2.2%. The mean age at presentation was 51.37 years, and the most common predisposing factor was corneal trauma (36.7%). The mean best corrected visual acuity (BCVA) [in log of minimum angle of resolution (logMAR)] at presentation was 1.99, and the mean ulcer size was 5.75 mm. On culture, 56.7% of the cases were identified as Pseudomonas putida , 26.7% as Pseudomonas stutzeri , 10% as Pseudomonas mendocina, and 3.3% each of Pseudomonas oryzihabitans and Pseudomonas alcaligenes . We recorded good treatment responses in 66.7% of cases with the medical therapy of a combination of broad-spectrum antibiotics, whereas 33.3% of cases required surgical intervention. The risk factors for poor clinical outcome were older age, ocular trauma, previous ocular surgeries, poor BCVA at presentation, large ulcer size, delayed treatment, hypopyon, and early complications such as perforation, limbal involvement, and total ulcer.

CONCLUSIONS

Uncommon species of pseudomonas keratitis was more closely related to predisposing factors such as corneal trauma and other factors such as previous ocular surgeries, older age, large ulcers, longer duration of treatment, early surgical intervention in complicated cases, and poor visual outcome.

Risk Factors for Descemet Membrane Endothelial Keratoplasty Rejection: Current Perspectives- Systematic Review

Descemet membrane endothelial keratoplasty (DMEK) is a corneal endothelial transplantation procedure with selective removal of a patient's defective Descemet membrane and endothelium. It is replaced with a healthy donor Descemet membrane and endothelium without a stromal component. Corneal graft rejection can be at the level of epithelium, stroma as well endothelium. DMEK graft rejection is relatively less common than rejection with DSAEK or penetrating keratoplasty, and a good outcome may be achieved with prompt management. The clinical picture of DMEK rejection is usually similar to endothelial rejection in Descemet Stripping Endothelial Keratoplasty (DSEK/DSAEK), which generally manifests as pain, redness, reduction in visual acuity, stromal edema, endothelial rejection line, keratic precipitates at the back of the cornea and corneal neovascularization. However, more subtle forms of rejection or immune reactions are more common in DMEK compared to DSAEK eyes. Early clinical diagnosis, prompt intervention, and meticulous management safeguard visual acuity and graft survival in these cases. Intensive topical steroids form the mainstay in the management of DMEK rejection. Sometimes, oral or intravenous steroids or other systemic immunomodulators may be required. DMEK graft failure can be primary or secondary, and failure usually requires a second procedure in the form of repeat DMEK or DSEK or penetrating keratoplasty (PKP). A detailed literature search was performed using search engines such as Google Scholar, PubMed, and Google books, and a comprehensive review on DMEK rejection was found to be lacking. This review is a comprehensive update on the risk factors, pathophysiology, primary and secondary graft failure, recent advances in diagnosis, prevention of rejection, and updates in the management of DMEK rejection. The review also discusses the differential diagnosis of DMEK failure and rejection, prognosis, and future perspectives considering DMEK failure and rejection.

Qualitative and Quantitative Evaluation of Donor Corneal Tissue by Slit Lamp and Specular Microscopy

Background In India, donor eye collection and promotion of eye banking are insufficient to meet the needs. By adequately evaluating donor corneas, eye banks can maximize the number of viable corneas for transplantation. This study evaluated donor corneal tissue based on age, lens status, and cause of death by their morphology and endothelial cell count via slit lamp and specular microscopy. Methods We conducted a prospective observational study of all eye bank donor corneas indicated for eye donation at a tertiary hospital and research center in Western Maharashtra between September 2019 to December 2021. We evaluated the corneoscleral discs by slit-lamp microscopy specular microscopy. We analyzed donor corneas quantitatively and qualitatively and graded them accordingly. We also collected blood samples for serological testing and the donor's behavioral and family medical histories. Results We collected 94 eyes from 47 donors; the mean age of the donor population was 48.2 years, and most donors were aged 41 to 80 years. Thirty-one donors (65.96%) were male, and 16 were female (34.04%. For preservation, we used Cornisol (Aurolab, Madurai, India) in 36 cases (77%) and McCarey-Kaufman medium in 11 cases (23%). We found a mean endothelial cell density (ECD) of 2214.40/mm2, with hexagonality of 53.05%, and a coefficient of variation of 38.01. Further, we observed that ECD and hexagonality of cells in phakic donors were significantly greater than that of pseudophakic (PP) donors. Moreover, ECD and hexagonality significantly decreased in donors with the chronic disease compared to those who had a sudden, unexpected death. Conclusion Corneal grafts from younger donors, phakic donors, and donors who experienced an acute cause of death were qualitatively and quantitatively significantly better than those of older donors, PP donors, and donors who experienced sudden, unexpected death. Therefore, eye bank specular examination can improve tissue utilization and transplantation success. Therefore, we strongly recommend that eye bank personnel evaluate their donor tissue with a specular microscope to enhance the quality of eye care.

Emerging antimicrobial resistance and need for antimicrobial stewardship for ocular infections in India: A narrative review

Patients with ocular infections are at increased risk of vision impairment and may require immediate medical care to preserve their vision. Management of ocular bacterial infections has evolved in recent years and includes a pragmatic selection of broad-spectrum antibiotics based on the causative bacteria. Nevertheless, the treatment of bacterial ocular infections is increasingly becoming a challenge, as the causative bacterium acquires resistance to antibiotics through intrinsic and acquired methods. From an Indian perspective, along with the challenges of antibiotic resistance, there are other factors such as lack of knowledge on epidemiology, and lack of data on local susceptibility patterns of ocular pathogens that have significant impact on the management of ocular infections. This narrative review summarizes the available knowledge on prescribing antibiotics for five common ocular infections in India. It further highlights the significance of the understanding of antimicrobial susceptibility patterns across India as a cornerstone to promote rational use of ocular antibiotics. This review indicates that large-scale antimicrobial resistance surveillance studies can facilitate the synchronization of ophthalmic antimicrobial prescription policies with local antibiotic resistance patterns. Further, establishment of an antimicrobial stewardship program in ophthalmology can potentially increase the efficacy of diagnostic tools, and implement earlier adoption of effective antibiotics. Overall, this review provides consolidated information and key considerations for treatment decision-making of common ocular infections in India.

Dendrimer as a momentous tool in tissue engineering and regenerative medicine

Dendrimers have been comprehensively used for cargo delivery, nucleic acid delivery (genes, miRNA/siRNAs), delivery of macromolecules, and other various biomedical applications. Dendrimers are highly versatile in function and can be engineered as multifunctional biomacromolecules by modifying the surface for fulfilling different applications. Dendrimers are being used for crosslinking of existing synthetic and natural polymeric scaffolds to regulate their binding efficiency, stiffness, biocompatibility, transfection, and many other properties to mimic the in vivo extracellular matrix in tissue engineering and regenerative medicine (TERM). Dendritic inter-cellular linkers can enhance the linkages between cells and result in scaffold-independent tissue constructs. Effectively engineered dendrimers are the ideal molecules for delivering bioactive molecules such as cytokines, chemokines, growth factors, etc., and other metabolites for efficaciously regulating cell behavior. Dendrimeric nanostructures have shown tremendous results in various TERM fields like stem cells survival, osteogenesis, increased crosslinking for eye and corneal repair, and proliferation in cartilage. This review highlights the role and various aspects of dendritic polymers for TERM in general and with respect to specific tissues. This review also covers novel explorations and insights into the use of dendrimers in TERM, focusing on the developments in the past decade and perspective of the future.

Streptococcus pneumoniae exerts oxidative stress, subverts antioxidant signaling and autophagy in human corneal epithelial cells that is alleviated by tert-Butylhydroquinone

Streptococcus pneumoniae is one of the leading causes of bacterial keratitis in the developing world and globally. In the current study, we have determined oxidative stress as pathogenesis of S. pneumoniae infection in corneal tissues and human corneal epithelial cells (HCEC) and explored host immune response of HCEC towards S. pneumoniae. We also determined whether treatment with tert-Butylhydroquinone (tBHQ), a Nrf2 inducer, could alleviate oxidative stress and reduce bacterial cytotoxicity in these cells. Oxidative stress was determined in corneal tissues of patients and HCEC by immunohistochemistry and immunofluorescence analysis, respectively. The expression of antioxidant genes, cytokines and antimicrobial peptides was determined by quantitative PCR. Infection of HCEC by S. pneumoniae was determined by colony-forming units. The autophagy and cell death were determined by fluorescence microscopy. The phosphorylation of signaling proteins was evaluated by immunoblot analysis. S. pneumoniae induced oxidative stress during corneal infections and inhibited antioxidant signaling pathways and immune responses like autophagy. tBHQ aided in restoring Nrf2 activation, reduced reactive oxygen species generation and prevented cytotoxicity and cell death in S. pneumoniae-infected HCEC. tBHQ also induced autophagy in a Nrf2-dependent manner and reduced bacterial survival in HCEC. Increased expression of antimicrobial peptides by tBHQ might have contributed to a reduction of bacterial load and cytotoxicity, as exemplified in LL-37 depleted corneal epithelial cells exposed to S. pneumoniae compared to control siRNA-transfected cells. tBHQ mediates alleviation of oxidative stress induced by S. pneumoniae by activating Nrf2-mediated antioxidant signaling in corneal epithelial cells. tBHQ also enhances expression of antimicrobial peptides in corneal cells and aids in inhibition of bacterial survival and cytotoxicity of HCEC.

Cyclodextrin Stabilized Freeze-Dried Silica/Chitosan Nanoparticles for Improved Terconazole Ocular Bioavailability

This research assesses the beneficial effects of loading terconazole, a poorly water-soluble antifungal drug in silica/chitosan nanoparticles (SCNs) for ocular delivery. Nanoparticles were fabricated by the simple mixing of tetraethyl ortho silicate (TEOS) and chitosan HCl as sources of silica and nitrogen, respectively, along with alcoholic drug solution in different concentrations. Freeze-dried nanoparticles were fabricated using cyclodextrins as cryoprotectants. SCNs were assessed for their particle size, PDI, yield, drug loading and in vitro release studies. A 2³.3¹ full factorial experimental design was constructed to optimize the prepared SCNs. DSC, XRD, FTIR, in addition to morphological scanning were performed on the optimized nanoparticles followed by an investigation of their pharmacokinetic parameters after topical ocular application in male Albino rabbits. The results reveal that increasing the water content in the preparations causes an increase in the yield and size of nanoparticles. On the other hand, increasing the TEOS content in the preparations, caused a decrease in the yield and size of nanoparticles. The optimized formulation possessed excellent mucoadhesive properties with potential safety concerning the investigated rabbit eye tissues. The higher C_max and AUC_0–24 values coupled with a longer t_max value compared to the drug suspension in the rabbits’ eyes indicated the potential of SCNs as promising ocular carriers for poorly water-soluble drugs, such as terconazole.

Comparing the effectiveness of different postoperative counseling methods for post-keratoplasty patients

PURPOSE

To compare various counseling methods for improving patient education, compliance, and administration of eye drops prescribed for post-optical keratoplasty patients and assess the most efficient counseling method.

METHODS

A prospective, questionnaire-based pilot study was conducted among 60 post-optical keratoplasty patients who were randomly assigned into three groups for postoperative eye drop counseling, namely group 1 (video counseling), group 2 (chart counseling), and group 3 (verbal counseling at Cornea department). The questionnaire was answered by the patients/attendants applying the eye drops on the first 3 consecutive visits. McNemar-Bowker test was used to compare responses in each group and the Kruskal-Wallis test was used to compare responses among the three groups. The Institutional Ethics Committee of Aravind Eye Hospital, Tirunelveli (Registration number ECR 816/Inst/Tn/2016) approved this study.

RESULTS

Results demonstrated improvement in various categories assessed regarding drop administration in all three groups, which assessed patients' knowledge, attitude, and hygiene. Although all three groups showed improvements during subsequent follow-up visits, the video-counseling method was found to be an effective means of communication.

CONCLUSION

Our study emphasizes that the nonverbal and noncontact means of communication by video demonstration would be an effective way of counseling. It can be considered in the present scenario of the pandemic as well.

Utilization rate of corneal tissue obtained from donors over 75 years of age in Western India for keratoplasty

Purpose:

To examine the utilization patterns of cornea procured from diseased individuals ≥75 years of age at an eye bank in western India.

Methods:

In this retrospective study, data from 1,217 eyes of 653 donors with age ≥75 years were reviewed from October 2008 to December 2019. Donor age, lens status, endothelial cell count (ECD), utilization of the tissue for transplantation or non-clinical purposes (e.g., research, training/discarded), and causes of non-utilization were noted.

Results:

The mean age of the donors was 80.9 ± 4.6 years and the tissue utilization rate was 36.5% (445 out of 1,217 eyes). The eyes used for keratoplasty procedures had a lower donor age (79.6 ± 5.7 vs. 81.5 ± 5.1; P < 0.001), a higher endothelial cell count (2493 ± 531 vs. 2034 ± 581; P < 0.001), and were more often phakic (61% vs. 36.6%) compared to the unused group. A multivariable logistic regression analysis showed that the likelihood of tissue utilization for keratoplasty was 13% higher with every 100-cell increment in donor ECD (odds ratio [OR] = 1.13, 95% CI = 1.10–1.16, P < 0.001) and 33% lower with having a pseudophakic status in the donor eye (OR = 0.67, 95% CI = 0.52–0.87, P = 0.03). Age was not a significant determinant of tissue utilization when used in the same multivariable model.

Conclusion:

More than one-third of the eyes (36.5%) can be utilized even when the donors are above 75 years of age. Eyes that were more likely to be utilized for keratoplasty were phakic and had a significantly higher ECD; age was not a determinant in tissue utilization.

Successful culture of Acanthamoeba remains a key towards diagnosis of unusual clinical presentation of keratitis: A first case report from chhattisgarh

A fifty-nine-year-old female with corneal ulcer with a history of trauma in the past having clinical presentation of fungal keratitis visited the Ophthalmology outpatient department with a history of redness, watering, pain and white discoloration of the right eye cornea for two months. Sample was cultured on non-nutrient agar medium and revealed Acanthamoeba. Patient was managed with Chlorhexidine eye drop and keratoplasty.

Infectious Keratitis: An Update on Role of Epigenetics

Epigenetic mechanisms modulate gene expression and function without altering the base sequence of DNA. These reversible, heritable, and environment-influenced mechanisms generate various cell types during development and orchestrate the cellular responses to external stimuli by regulating the expression of genome. Also, the epigenetic modifications influence common pathological and physiological responses including inflammation, ischemia, neoplasia, aging and neurodegeneration etc. In recent past, the field of epigenetics has gained momentum and become an increasingly important area of biomedical research As far as eye is concerned, epigenetic mechanisms may play an important role in many complex diseases such as corneal dystrophy, cataract, glaucoma, diabetic retinopathy, ocular neoplasia, uveitis, and age-related macular degeneration. Focusing on the epigenetic mechanisms in ocular diseases may provide new understanding and insights into the pathogenesis of complex eye diseases and thus can aid in the development of novel treatments for these diseases. In the present review, we summarize the clinical perspective of infectious keratitis, role of epigenetics in infectious keratitis, therapeutic potential of epigenetic modifiers and the future perspective.

Recent Perspectives in the Management of Fungal Keratitis

Mycotic keratitis is common in warm, humid regions with a varying profile of pathogenic fungi according to geographical origin, socioeconomic status, and climatic condition. Clinical diagnosis can be challenging in difficult cases and those refractory to treatment. Fungal hyphae on microscopic examination and culture isolation have been the gold standard in the laboratory diagnosis of fungal keratitis. A culture isolate of the aetiological fungus is essential to perform antifungal susceptibility testing. As the culture isolation of fungi is time-consuming, causing delays in the initiation of treatment, newer investigative modalities such as in vivo confocal microscopy and molecular diagnostic methods have recently gained popularity. Molecular diagnostic techniques now help to obtain a rapid diagnosis of fungal keratitis. Genomic approaches are based on detecting amplicons of ribosomal RNA genes, with internal transcribed spacers being increasingly adopted. Metagenomic deep sequencing allows for rapid and accurate diagnosis without the need to wait for the fungus to grow. This is also helpful in identifying new emerging strains of fungi causing mycotic keratitis. A custom-tear proteomic approach will probably play an important diagnostic role in future in the management of mycotic keratitis. Positive repeat cultures are being suggested as an important gauge indicative of a poor prognosis. Positive repeat fungal cultures help to modify a treatment regimen by increasing its frequency, providing the addition of another topical and oral antifungal agent along with close follow-up for perforation and identifying need for early therapeutic keratoplasty. The role of collagen crosslinking in the treatment of fungal keratitis is not convincingly established. Rapid detection by multiplex PCR and antifungal susceptibility testing of the pathogenic fungi, adopted into a routine management protocol of fungal keratitis, will help to improve treatment outcome. Early therapy is essential in minimizing damage to the corneal tissue, thereby providing a better outcome. The role of conventional therapy with polyenes, systemic and targeted therapy of antifungal agents, newer azoles and echinocandins in fungal keratitis has been widely studied in recent times. Combination therapy can be more efficacious in comparison to monotherapy. Given the diversity of fungal aetiology, the emergence of new corneal pathogenic fungi with varying drug susceptibilities, increasing the drug resistance to antifungal agents in some genera and species, it is perhaps time to adopt recent molecular methods for precise identification and incorporate antifungal susceptibility testing as a routine.

Development and Validation of a Model to Predict Anterior Segment Vision-Threatening Eye Disease Using Primary Care Clinical Notes

PURPOSE

The purpose of this study was to develop a decision-support tool to predict anterior segment vision-threatening disease (asVTD) to aid primary care physicians (PCPs) with patient triage and referral.

METHODS

The University of Michigan electronic health record data between January 1, 2016, and May 31, 2019, were obtained from patients presenting to a PCP with anterior eye symptoms and then saw an ophthalmologist within 30 days. asVTD included diagnosis of corneal ulcer, iridocyclitis, hyphema, anterior scleritis, or scleritis with corneal involvement by an ophthalmologist. Elastic net logistic regression with 10-fold cross-validation was used for prediction modeling of asVTD. Predictors evaluated included patient demographics and PCP notes processed using clinical natural language processing software (clinspacy).

RESULTS

Two thousand nine hundred forty-two patients met the inclusion criteria, of which 133 patients (4.5%) had asVTD. The age was significantly lower among those with asVTD versus those without (median = 42 vs. 53 yrs, P < 0.001). Sex (P = 0.8) and race (P = 0.9) were not significantly different between groups. The final prediction model had an area under the curve of 0.72 (95% confidence interval 0.67-0.77). At a threshold achieving a sensitivity of 90%, the specificity was 30%, the positive predictive value was 5.8%, and the negative predictive value was 99%.

CONCLUSIONS

The use of the prediction model increased the positive predictive value for asVTD compared with referral based on prevalence probabilities (17 patients vs. 22 patients needing to be evaluated to identify 1 case of asVTD). A prediction algorithm has potential to improve triage and initial management decision-making for PCPs because it performs better than probabilities in the absence of such a tool.

Genipin in an Ex Vivo Corneal Model of Bacterial and Fungal Keratitis

Purpose

To determine whether genipin (a natural crosslinker) could reduce the colonization and proliferation of bacteria and fungi in an ex vivo model of corneal infection.

Methods

This study, using an ex vivo model of bacterial and fungal keratitis, investigated the antimicrobial efficacy of genipin crosslinking. Excised corneoscleral buttons were wounded by scalpel incision and subsequently infected with Staphylococcus aureus, Pseudomonas aeruginosa, or Candida albicans. After inoculation, corneas were treated with genipin for 24 hours at 37°C. Histologic examinations were carried out, and the number of viable colony-forming units (CFU)/cornea was determined.

Results

Genipin exerts bactericidal action against S. aureus and P. aeruginosa, as well as fungicidal action against C. albicans and significantly reduced the CFU compared to contralateral eyes that received saline treatment (P < 0.05).

Conclusions

These data identify genipin as a novel ocular antimicrobial agent that has the potential to be incorporated into the therapeutic armamentarium against microbial keratitis.

Translational Relevance

This study provided evidence for the antimicrobial and antifungal properties of genipin as an alternative crosslinker that could be used in the management of infectious keratitis.

Awareness on Eye Donation in the North-eastern State of Tripura, India - The Tripura Eye Survey

Purpose: To determine the awareness on eye donation and willingness to pledge eyes for donation among the population aged ≥40 years in the northeastern state of Tripura, India. Methods: A population-based cross-sectional study was carried out among 2,500 participants. The investigators conducted a detailed interview on awareness of eye donation and willingness to pledge eyes for donation. 'Awareness' was defined as having heard about eye donation. Those who reported awareness of eye donation were asked a question on willingness to pledge their eyes. Results: A total of 2,440/2,500 (97.6%) participants responded to the questionnaire. Among these, 1,216 (49.8%) participants were men, and 859 (35.2%) had no education. The mean age of the participants was 54.7 years (standard deviation:12.1 years). Overall, 61.4% (95% CI:59.5-63.4; n = 1,499) reported awareness of eye donation; of those only 3.8% (95% CI:2.9-4.9; n = 57) were willing to pledge their eyes for donation. On multivariable analyses, the odds of awareness were higher among those who had school education (OR:2.12; 95% CI: 1.73-2.56) or higher education (OR:11.79; 95% CI:7.35-18.93). Deformity associated with eye donation (n = 327;76.9%) followed by religious reasons (n = 63; 14.8%) and a belief that those who donate eye are 'born blind in the next birth' (n = 23; 5.4%) were the main reasons for lack of willingness to pledge their eyes for donation. Conclusions: Although the awareness regarding eye donation was satisfactory, there was lack of willingness to pledge eyes for donation. There is a need for focussed information, education, and communication campaigns to encourage eye donation in Tripura.

Impact of COVID-19 Pandemic on Infectious Keratitis Outcomes: A Retrospective Multicenter Study in Tertiary Eye Hospitals of South India

PURPOSE

The purpose of this study was to report the adverse effects of the COVID-19 pandemic on the clinical outcomes of infectious keratitis in South India.

METHODS

Two hundred fifty-eight patients presented with infectious keratitis at 6 tertiary care centers when strict travel restrictions were in place from March 24 to May 31, 2020. Case records were collected retrospectively and analyzed for demographics, type of initial treatment, length of delay in presentation, microbiological diagnosis, clinical course, and final treatment outcome.

RESULTS

The mean age of the patients was 49.2 years, with most of them (61.2%) being male. Forty-one patients (15.9%) did not receive any treatment for at least a week after the onset of symptoms. One hundred eight patients (41.9%) presented with severe ulcer (32 had a frank perforation). Resolution of the infection was achieved only in 103 patients (45.6%). A total of 90 patients (39.8%) with ulcers had a perforation, yet only 29 patients (32.2%) could receive keratoplasty because of the unavailability of donor tissues. At the end of 6-month follow-up, 47 patients had anatomical failure (loss of globe) and 12 additional patients had functional failure (total permanent vision loss).

CONCLUSIONS

Delay in presentation and acute shortage of donor corneal tissues for emergency keratoplasty because of the COVID-19 pandemic had a grave impact, resulting in irreversible blindness in a significant number of patients.

Demographic and clinical profile, surgical outcome, and quality of life in patients who underwent bilateral lamellar corneal grafts

Purpose:

Lamellar corneal grafts have revolutionized the management of corneal blindness by replacing only the disease specific corneal layers. To the best of our knowledge, there is no study in literature describing the outcomes of bilateral lamellar keratoplasty in the Indian population. The aim of this work was to study the demographic profile, surgical outcomes, and quality of life in patients who underwent bilateral lamellar keratoplasty and to assess the correlation between these three.

Methods:

An observational cross-sectional study was conducted on 47 patients who underwent bilateral deep anterior lamellar keratoplasty (DALK) (n = 31) or descemet stripping automated endothelial keratoplasty (DSAEK) (n = 16) with a minimum follow-up of 6 months after the second surgery. Demographic parameters were collected by interview, surgical outcomes by clinical examination, and quality of life by a questionnaire.

Results:

A total of 47 patients were evaluated, women 42.56%, (n = 20) and men 57.44% (n = 27) with 38.3% being in 18–30 years age group and 23.4% above 60 years; 17.02% patients had a good socioeconomic status (score >60) and 61.70% had poorer socioeconomic status (score <50). Quality of life score (VR-QoL) was ≥50 in 82.9% patients and ≥70 in 14.89%. No significant association existed between VR-QoL scores and demographic factors. However, statistically significant association existed between VR-QoL and age of patient (P < 0.05), postoperative vision (P ≤ 0.05), and contrast sensitivity (P ≤ 0.01).

Conclusion:

Bilateral lamellar corneal grafts provide satisfactory visual outcomes compatible with day-to-day functioning. VR-QoL has a direct correlation to the age, visual acuity, contrast sensitivity, and inverse correlation with lenticule thickness in DSAEK and residual bed thickness in DALK.

Preventing corneal blindness caused by keratitis using artificial intelligence

Keratitis is the main cause of corneal blindness worldwide. Most vision loss caused by keratitis can be avoidable via early detection and treatment. The diagnosis of keratitis often requires skilled ophthalmologists. However, the world is short of ophthalmologists, especially in resource-limited settings, making the early diagnosis of keratitis challenging. Here, we develop a deep learning system for the automated classification of keratitis, other cornea abnormalities, and normal cornea based on 6,567 slit-lamp images. Our system exhibits remarkable performance in cornea images captured by the different types of digital slit lamp cameras and a smartphone with the super macro mode (all AUCs>0.96). The comparable sensitivity and specificity in keratitis detection are observed between the system and experienced cornea specialists. Our system has the potential to be applied to both digital slit lamp cameras and smartphones to promote the early diagnosis and treatment of keratitis, preventing the corneal blindness caused by keratitis.

Phosphodiesterase Type 5 Inhibitors and Visual Side Effects: A Narrative Review

Phosphodiesterase type 5 inhibitors such as sildenafil citrate and tadalafil are well known for the treatment of erectile dysfunction. However, their use in the presence of pulmonary hypertension can cause ophthalmologic side effects, including non-arteritic optic ischemic neuropathy, chorioretinopathy, glaucoma, and optic atrophy. The present review aimed to identify these visual side effects and provide recommendations. We identified articles published from January 2000 to March 2019 on diseases arising from the management of sexual dysfunction in urology or pulmonary hypertension in pneumonia that could cause pathologic alterations in eye structure based on a literature search of the MEDLINE electronic database using keywords for the most common adverse effects and different kinds of phosphodiesterase 5 inhibitors. After applying the exclusion criteria, we selected 36 of the 77 articles initially identified to write the narrative review and added 20 additional articles to completely describe the pathological entities. Phosphodiesterase type 5 inhibitors can cause side effects in the eye including ocular surface abnormalities, increased intraocular pressure and glaucoma, uveitis, non-arteritic ischemic neuropathy, chorioretinopathy, retinal occlusion, and visual field changes. There is an increased need for well-performed studies to better understand these side effects, which are common due to the wide use of sildenafil.

Enhanced in vivo antifungal activity of novel cell penetrating peptide natamycin conjugate for efficient fungal keratitis management

Natamycin is the only FDA approved drug that is used as a first line of treatment for fungal keratitis caused by filamentous fungi, however natamycin is known for poor corneal penetration. Cell penetrating peptides (CPPs) are emerging nanocarriers for the enhanced delivery of various macromolecules owing to their distinct cellular translocation ability. In the present study, tissue penetration ability and antifungal efficacy of CPP (Tat₂) conjugated natamycin has been investigated and compared with natamycin alone in vivo. Results show that Tat₂natamycin exhibits five- fold higher ocular penetration than natamycin alone when given topically. Complete resolution of fungal keratitis in 44% of the animals in Tat₂natamycin treated group as compared to only 13% of the animals in natamycin treated group further highlights its increased antifungal efficacy. Hence, this conjugate is a promising antifungal molecule with enhanced ocular penetration as well as antifungal efficacy against selected fungal species.

Clinical and Microbiological Profile of Bacterial and Fungal Suspected Corneal Ulcer at University of Gondar Tertiary Eye Care and Training Centre, Northwest Ethiopia

Background. A corneal ulcer is a major cause of monocular blindness in developing countries, including Ethiopia. Its etiology varies based on its geographical location and climatic conditions. Therefore, the main objective of this research was to assess the clinical and microbiological profile of suspected bacterial and fungal corneal ulcers at the Tertiary Eye Care and Training Centre at Gondar University. Methods. A cross-sectional hospital-based study of corneal ulcer cases was performed from February to October 2019. Sociodemographic and clinical data were collected using a standardized questionnaire. Corneal scrapings were used to classify bacterial and fungal pathogens. The specimens were inoculated on BHI media and sub-cultured on culture media for the separate cultivation of bacteria and fungi. Biochemical tests have been carried out to classify bacteria. Following CLSI, the antimicrobial resistance pattern of bacterial isolates was carried out. Wet mounting, Lactophenol cotton blue staining, and colony characteristics on SDA were used to classify fungal species. The data were analyzed with version 20 of the SPSS. Results. A total of 30 suspected bacterial and fungal keratitis patients have been enrolled in this study. The visual acuity presented in 90% of the affected eyes was in the category of blindness (<3/60). In 71% of the cases, clinically presumed risk factors were identified. Trauma was the most common risk factor found in 46% of cases, followed by keratitis exposure (13%). Of the corneal scrape tests, 76.6% were positive for bacteria and fungi. Fungi were identified in 53.3% of corneal ulcers followed by 33.3% of bacterial growth. The commonest fungi and bacteria isolated were Aspergillus species (69%) and S. aureus, respectively. The prevalence of Methicillin-resistant S. aureus (MRSA) was 2 (40%). The identified Pseudomonas species were susceptible to Gentamicin and Ciprofloxacin but resistant to Ceftriaxone. Conclusion. The primary microbial agents for corneal ulcers were fungi, and trauma was the most significant risk factor associated with corneal ulcers. To avoid chronic ocular morbidity and blindness, early identification of the etiologic agent and the provision of adequate management are recommended.

Role of teleophthalmology to manage anterior segment conditions in vision centres of south India: EyeSmart study-I

Purpose:

To study the role of teleophthalmology (TO) in the diagnosis and treatment of anterior segment conditions (including adnexal conditions) in rural areas.

Methods:

This is a pilot study of 5,604 patients, who visited primary vision centres (VCs) for 1 week from 1-7 September 2018. The patients were examined by a vision technician (VT) to identify those who may need teleconsultation. The centres were located in 16 districts of four Indian states of Andhra Pradesh, Telangana, Odisha, and Karnataka. The demographic profile, along with the role of teleconsultation was reviewed.

Results:

Teleconsultation was advised in 6.9% of the patients, out of which 59.6% were referred to a higher level of care, and 40.4% were treated directly at the VC. Teleconsultations were higher among males (7.0% as compared to 6.6% in females), though not statistically significant (P = 0.55). Teleconsultation was higher in the older population, that is, 60 years and above (14.5%); those with severe visual impairment (VI) (21%) and blindness (31.1%); and in the states of Telangana (11%) and Andhra Pradesh (6.3%). It was noted that 45% of the patients who underwent teleconsultation had pathologies related to ocular surface, cornea and lid, and adnexa-related conditions.

Conclusion:

Teleconsultation has a significant role in the management of anterior segment conditions in bridging the gap between the patients and ophthalmologists in rural India. TO can also play an important role in the diagnosis and management of anterior segment, lid, and adnexa-related pathologies.

Exploratory Use of Fluorescent SmartProbes for the Rapid Detection of Microbial Isolates Causing Corneal Ulcer

PURPOSE

To explore the use of optical SmartProbes for the rapid evaluation of corneal scrapes from patients with suspected microbial keratitis, as a clinical alternative to Gram stain.

DESIGN

Experimental study with evaluation of a diagnostic technology.

METHODS

Corneal scrapes were collected from 267 patients presenting with microbial keratitis at a referral cornea clinic in South India. Corneal scrapes were flooded with SmartProbes (BAC One or BAC Two) and evaluated by fluorescence microscopy (without the need for sample washing or further processing). The SmartProbe-labeled samples were scored as bacteria/fungi/none (BAC One) or gram-negative bacteria/none (BAC Two) and compared to Gram stain results.

RESULTS

Compared to Gram stain, BAC One demonstrated sensitivity and specificity of 80.0% and 87.5%, respectively, positive and negative predictive values (PPV, NPV) of 93.8% and 65.1%, and an accuracy of 82.2. BAC Two demonstrated sensitivity and specificity of 93.3% and 84.8%, respectively, an NPV of 99.2%, and an accuracy of 85.6%. When the corresponding culture results were compared to the Gram stain result, the sensitivity and specificity were 73.4% and 70.7%, the PPV and NPVs were 86.5% and 51.0%, and overall accuracy was 72.6.

CONCLUSIONS

Fluorescent SmartProbes offer a comparative method to Gram stain for delineating gram-positive or gram-negative bacteria or fungi within corneal scrapes. We demonstrate equivalent or higher sensitivity, specificity, PPV and NPVs, and accuracy than culture to Gram stain. Our approach has scope for point-of-care clinical application to aid in the diagnosis of microbial keratitis.

Use of 'U-shaped tool for follow up of corneal ulcer cases in the COVID-19 pandemic

To describe a smartphone-based telemedicine tool for monitoring of corneal ulcer size during the corona pandemic, a simple "U"-shaped tool was constructed using three Schirmer's strips that were provided to the patients with small to medium-sized corneal ulcers. The patient and the attendant were trained to use this simple U-shaped tool at home and send digital images to the treating ophthalmologist, to monitor the course of the ulcer. The tool was used in five eyes of five patients with active microbial keratitis. Patients were followed up regularly with the use of telemedicine facility every 48 h for an average duration of 7.6 days (range 6-9 days). In all the five eyes, assessment of the serial images with U-shaped tool showed decrease in size of corneal ulcer, which corroborated with subjective improvement in symptoms. Hence, the novel "'U'-shaped tool" may provide an effective measure in following-up of corneal ulcer patients in times of the COVID-19 pandemic, obviating frequent hospital visits and risk of contracting COVID.

Antimicrobial peptides in human corneal tissue of patients with fungal keratitis

BACKGROUND

Fungal keratitis (FK) is the leading cause of unilateral blindness in the developing world. Antimicrobial peptides (AMPs) have been shown to play an important role on human ocular surface (OS) during bacterial, viral and protozoan infections. In this study, our aim was to profile a spectrum of AMPs in corneal tissue from patients with FK during the active pase of infection and after healing.

METHODS

OS samples were collected from patients at presentation by impression cytology and scraping. Corneal button specimens were collected from patients undergoing therapeutic penetrating keratoplasty for management of severe FK or healed keratitis. Gene expression of human beta-defensin (HBD)-1, -2, -3 and -9, S100A7, and LL-37 was determined by quantitative real-time PCR.

RESULTS

Messenger RNA expression (mRNA) for all AMPs was shown to be significantly upregulated in FK samples. The levels of HBD-1 and -2 mRNA were found to be elevated in 18/20 FK samples. Whereas mRNA for HBD-3 and S100A7 was upregulated in 11/20 and HBD9 was increased in 15/20 FK samples. LL-37 mRNA showed moderate upregulation in 7/20 FK samples compared with controls. In healed scar samples, mRNA of all AMPs was found to be low and matching the levels in controls.

CONCLUSION

AMP expression is a consistent feature of FK, but not all AMPs are equally expressed. HBD-1 and -2 are most consistently expressed and LL-37 the least, suggesting some specificity of AMP expression related to FK. These results will help to identify HBD sequence templates for designing FK-specific peptides to test for therapeutic potential.

Dry eye disease in children and adolescents in India

PURPOSE

To describe the etiological causes and clinical profile of dry eye disease (DED) among children and adolescents seeking eye care in India.

METHODS

This was a cross-sectional study of 1023 new patients (≤21 years of age) diagnosed with DED presenting between 2010 and 2018 to a multi-tier ophthalmology hospital network. Children and adolescents with both symptoms and signs of dry eyes were considered as subjects. The data entry and retrieval were done using an electronic medical record system and analyzed using appropriate statistical tests.

RESULTS

The mean age of the patients was 15.2 ± 5.6 years and 76% were in their early and late adolescence. Overall, the main etiologies responsible for DED in children and adolescents were Meibomian gland dysfunction (MGD) in 49% of cases, Stevens-Johnson Syndrome (SJS) in 33% and Vitamin A deficiency (VAD) in 9%. Aqueous deficiency dry eye (ADDE) because of SJS and VAD accounted for most of the cases in infancy (92%), toddlerhood (96%), early childhood (76%) and middle childhood (68%). While Meibomian gland dysfunction (MGD) related evaporative dry eye (EDE) was the leading cause of DED in early (51%) and late adolescence (66%). Severe visual impairment and blindness was significantly greater in eyes with ADDE as compared to those with EDE (p < 0.0001), 81% of which were affected by SJS.

CONCLUSION

The causes of and visual morbidity due to DED varied significantly in different age-groups. Most of the visual morbidity in children and adolescents was limited to eyes with ADDE due to SJS.

Peripheral Blood As a Source of Stem Cells for Regenerative Medicine: Emphasis Towards Corneal Epithelial Reconstruction-An In Vitro Study

BACKGROUND

Mesenchymal stem cell-based treatments are now emerging as a therapy for corneal epithelial damage. Although bone marrow, adipose tissue and umbilical cord blood are the main sources of mesenchymal stem cells (MSCs), other tissues like the peripheral blood also harbor mesenchymal-like stem cells called peripheral blood-derived mononuclear cells (PBMNCs). These blood derived stem cells gained a lot of attention due to its minimally invasive collection and ease of isolation. In this study, the feasibility of using PBMNCs as an alternative cell source to corneal limbal stem cells envisaging corneal epithelial regeneration was evaluated.

METHODS

Rabbit PBMNCs were isolated using density gradient centrifugation and was evaluated for mesenchymal cell properties including stemness. PBMNCs were differentiated to corneal epithelial lineage using rabbit limbal explant conditioned media and was evaluated by immuno-cytochemistry and gene expression analysis. Further, the differentiated PBMNCs were engineered into a cell sheet using an in-house developed thermo-responsive polymer.

RESULTS

These blood derived cells were demonstrated to have similar properties to mesenchymal stem cells. Corneal epithelial lineage commitment of PBMNCs was confirmed by the positive expression of CK3/12 marker thereby demonstrating the aptness as an alternative to limbal stem cells. These differentiated cells effectively generated an in vitro cell sheet that was then demonstrated for cell sheet transfer on an ex vivo excised rabbit eye.

CONCLUSION

PBMNCs as an alternative autologous cell source for limbal stem cells is envisaged as an effective therapeutic strategy for corneal surface reconstruction especially for patients with bilateral limbal stem cell deficiency.

Mechanical Stability of Cryopreserved Split-Thickness Tectonic Corneal Grafts

PURPOSE

To evaluate the influence of cryopreservation on the pressure-strain relationship of microkeratome dissected anterior stromal grafts (ASGs).

METHODS

Partial thickness ASGs were created from 7 pairs of human corneas and randomized to immediate grafting or grafting after 3 months of cryopreservation at -80°C into a whole globe ex vivo corneal perforation model. High frequency ultrasound speckle tracking was used to calculate the cross-sectional axial and lateral strains in each graft at increasing intraocular pressure (IOP) from 5 to 30 mm Hg. The mean axial and lateral strains were compared between the paired groups.

RESULTS

The mean axial and lateral strains were not significantly different between the cryopreserved and noncryopreserved ASGs. The mean lateral strains at 30 mm Hg in the noncryopreserved and cryopreserved grafts were 2.4% ± 2.1% and 1.4% ± 0.7% (P = 0.294), respectively. The mean axial strains at 30 mm Hg in the noncryopreserved and cryopreserved grafts were -7.8% ± 3.3% and -5.5% ± 3.0% (P = 0.198), respectively. A linear pressure-strain relationship was found for all grafts at physiologic IOP.

CONCLUSIONS

ASGs cryopreserved at -80°C maintain their IOP-strain relationship compared with noncryopreserved ASGs at physiologic pressures, supporting the potential use of cryopreserved human corneal stroma for patch grafting procedures.

Outcome of Sclerokeratoplasty in Devastating Sclerocorneal Infections

Purpose:

To assess the achievement of anatomical integrity after primary tectonic sclerokeratoplasty procedure and outcome after subsequent secondary procedures to manage devastating corneoscleral infection threatening the structural integrity of the eyeball.

Methods:

This prospective interventional study comprised 60 patients with severe devastating corneoscleral pathology of infective origin with varying degrees of scleral involvement who underwent tectonic sclerokeratoplasty. They were grouped into three groups according to the involvement of scleral quadrants, i.e., Group A with only one quadrant, Group B with two quadrants, and Group C with more than two quadrants. The demographics, clinical features, microbiological status, postoperative complications, need for secondary procedures, and tectonic outcome in terms of anatomical success were analyzed in all three groups during follow-up between 2 and 5 years.

Results:

The donor graft size in Groups A, B, and C was 9.5–10.5, 11–12, and 12.5–14 mm, respectively. Globe integrity after primary procedure was noted in all patients of Group A, 76% of Group B, and 38% of Group C. Reinfection was observed in 19 cases of Groups B and C, from which 5 Group C patients were eviscerated and 14 underwent regrafting. Postoperative complications (suture related, rejection, graft failure, and secondary glaucoma) were encountered more frequently in Group C patients. Secondary procedures (cataract/posterior segment surgery, secondary intraocular lens, and trabeculectomy) were required more in Groups B and C. After regrafting, 7 eyes were salvaged and 7 (3 in Group B and 4 in Group C) resulted in phthisis bulbi. Thus, tectonic outcome was achieved in 80% of cases.

Conclusions:

Sclerokeratoplasty is an effective tectonic treatment for restoring the globe anatomy in severe corneoscleral infection. Outcome depends on involvement of scleral quadrants, graft size, and severity of disease. Subsequent regrafting procedures are required to overcome reinfection of the primary graft.

Indications and prognosis for keratoplasty in eyes with severe visual impairment and blindness due to corneal disease in India

PURPOSE

To describe the indications and prognosis for keratoplasty in eyes with severe visual impairment and blindness due to corneal diseases in India.

METHODS

This hospital-based cross-sectional study included 1 057 215 new patients presenting to a multitier ophthalmology network from 2016 to 2018. All patients with a central corneal pathology and best corrected visual acuity of less than 20/200 in the affected eye(s) were identified as cases and grouped according to laterality. The main outcome measure was the prognosis for keratoplasty, based on the surgical indication.

RESULTS

A total of 28 824 (2.73%) patients were identified with severe visual impairment or blindness due to corneal diseases; of which, 22 582 (78.3%) had unilateral and 6242 (21.7%) had bilateral affliction. Overall, 85% of the corneal pathologies were due to avoidable causes, which accounted for 97% and 63% of the unilateral and bilateral cases, respectively (p<0.0001). The most common aetiologies were microbial keratitis (27.2%) and corneal opacification (25.5%) in unilateral cases; and corneal opacification (38.2%) and ectasias (14.5%) in bilateral cases. Overall, 60.1% of affected eyes carried a fair to poor prognosis for keratoplasty. However, while in unilateral cases only 29.9% of eyes carried good to excellent prognosis for keratoplasty, in bilateral cases, 58% of eyes carried good to excellent prognosis for keratoplasty (p<0.0001).

CONCLUSIONS

The indications and prognosis for keratoplasty varied greatly based on whether the affliction was unilateral or bilateral. Most of the eyes affected by corneal visual impairment or blindness, however, carried an unfavourable prognosis for keratoplasty.

In Vitro Culture of Human Corneal Endothelium on Non-Mulberry Silk Fibroin Films for Tissue Regeneration

Purpose

The purpose of this study was to determine if non-mulberry varieties of silk are suitable for the culture of corneal endothelium (CE).

Methods

Aqueous silk fibroin derived from Philosamia ricini (PR), Antheraea assamensis (AA), and Bombyx mori (BM) were cast as approximately 15 µm films with and without pores on which human CE cells were cultured. Tensile strength, elasticity, transmittance in visible range, and degradation properties of the films were characterised. Adhesion of CE to the silk films was quantified using MTT assay in addition to quantifying the number and area of focal adhesions using paxillin. Expression of CE markers was determined at the gene and protein levels using PCR and immunostaining, respectively. Barrier integrity of the cultured cells was measured as permeability to FITC dextran (10 kDa) in the presence or absence of thrombin.

Results

The films exhibited robust tensile strength, >95% transmittance and a refractive index comparable to the native cornea. BM degraded significantly faster when compared to PR and AA. A comparison between the three varieties of silk showed that significantly more cells were adhered to PR and AA than to BM. This was also reflected in the expression of stable focal adhesions on PR and AA, thus enabling the formation of intact monolayers of cells on these varieties unlike on BM. Treatment with thrombin significantly increased cellular permeability to dextran.

Conclusions

Our data shows that PR and AA varieties sufficiently support the growth and function of CE cells. This could be attributed to the presence of natural cell binding motifs (RGD) in these varieties.

Translational Relevance

Development of a suitable carrier for engineering the CE to address a major clinical requirement of healthy donor tissues for transplantation.

Highly specific Electrochemical Sensing of Pseudomonas aeruginosa in patients suffering from corneal ulcers: A comparative study

Pseudomonas aeruginosa is the most common pathogenic gram-negative bacteria causing corneal ulcers globally. In severe cases, often after trauma and eye injury, corneal destruction progresses rapidly and may be completed within 24–48 h causing blindness. In our preliminary work, we have established an ultrasensitive polyaniline (PANI)/gold nanoparticles (Au NPs)/indium tin oxide (ITO) modified sensor for rapid detection of pyocyanin (PYO) in P. aeruginosa infections with a linear range from 238 μM to 1.9 μM and a detection limit of 500 nM. In the present study, we evaluated the efficiency of the established modified electrochemical sensor in the diagnosis of P. aeruginosa in 50 samples collected from patients suffering from corneal ulcers. The obtained results were compared with the results gained by the screen-printed electrode, conventional techniques, automated identification method, and the amplification of the 16 s rRNA gene by PCR as a gold standard test for P. aeruginosa identification. We have found that the electrochemical detection of PYO by square wave voltammetry technique using PANI/Au NPs modified ITO electrode was the only technique showing 100% agreement with the molecular method in sensitivity, specificity, positive and negative predictive values when compared with the SPE, conventional and automated methods.

Rose Bengal Photodynamic Antimicrobial Therapy for Patients With Progressive Infectious Keratitis: A Pilot Clinical Study

PURPOSE

To report clinical outcomes of rose bengal photodynamic antimicrobial therapy (RB-PDAT) as an adjunct treatment for severe, progressive infectious keratitis.

DESIGN

Consecutive interventional case series.

METHODS

Patients with progressive infectious keratitis unresponsive to standard medical therapy underwent RB-PDAT at the Bascom Palmer Eye Institute from January 2016 through March 2018. RB-PDAT was performed by applying a solution of rose bengal (0.1% or 0.2% RB in balanced salt solution) to the de-epithelialized cornea for 30 minutes, followed by irradiation with a 6 mW/cm² custom-made green LED source for 15 minutes (5.4 J/cm²).

RESULTS

The current study included 18 patients (7 male and 11 female) ranging from 17 to 83 years old. Acanthamoeba was the most frequent microbe (10/17; 59%), followed by Fusarium spp. (4/17; 24%), Pseudomonas aeruginosa (2/17; 12%), and Curvularia spp. (1/17; 6%); 1 patient had no confirmed microbiologic diagnosis. Main clinical risk factor for keratitis included contact lens wear (79%). The average area of epithelial defect prior to first RB-PDAT was 32 ± 27 mm² and average stromal depth hyperreflectivity measured with anterior segment optical coherence tomography was 269 ± 75 μm. Successful RB-PDAT (avoidance of therapeutic keratoplasty) was achieved in 72% of the cases, with an average time to clinical resolution (decreased pain and inflammation with re-epithelialization and infiltrate resolution) of 46.9 ± 26.4 days after RB-PDAT. Time of follow-up after RB-PDAT was 13.3 ± 5.7 months.

CONCLUSION

RB-PDAT can be considered as an adjunct therapy for cases of severe, progressive infectious keratitis before performing a therapeutic keratoplasty.