Role of artificial intelligence, machine learning and deep learning models in corneal disorders - A narrative review

In the last decade, artificial intelligence (AI) has significantly impacted ophthalmology, particularly in managing corneal diseases, a major reversible cause of blindness. This review explores AI's transformative role in the corneal subspecialty, which has adopted advanced technology for superior clinical judgment, early diagnosis, and personalized therapy. While AI's role in anterior segment diseases is less documented compared to glaucoma and retinal pathologies, this review highlights its integration into corneal diagnostics through imaging techniques like slit-lamp biomicroscopy, anterior segment optical coherence tomography (AS-OCT), and in vivo confocal biomicroscopy. AI has been pivotal in refining decision-making and prognosis for conditions such as keratoconus, infectious keratitis, and dystrophies. Multi-disease deep learning neural networks (MDDNs) have shown diagnostic ability in classifying corneal diseases using AS-OCT images, achieving notable metrics like an AUC of 0.910. AI's progress over two decades has significantly improved the accuracy of diagnosing conditions like keratoconus and microbial keratitis. For instance, AI has achieved a 90.7% accuracy rate in classifying bacterial and fungal keratitis and an AUC of 0.910 in differentiating various corneal diseases. Convolutional neural networks (CNNs) have enhanced the analysis of color-coded corneal maps, yielding up to 99.3% diagnostic accuracy for keratoconus. Deep learning algorithms have also shown robust performance in detecting fungal hyphae on in vivo confocal microscopy, with precise quantification of hyphal density. AI models combining tomography scans and visual acuity have demonstrated up to 97% accuracy in keratoconus staging according to the Amsler-Krumeich classification. However, the review acknowledges the limitations of current AI models, including their reliance on binary classification, which may not capture the complexity of real-world clinical presentations with multiple coexisting disorders. Challenges also include dependency on data quality, diverse imaging protocols, and integrating multimodal images for a generalized AI diagnosis. The need for interpretability in AI models is emphasized to foster trust and applicability in clinical settings. Looking ahead, AI has the potential to unravel the intricate mechanisms behind corneal pathologies, reduce healthcare's carbon footprint, and revolutionize diagnostic and management paradigms. Ethical and regulatory considerations will accompany AI's clinical adoption, marking an era where AI not only assists but augments ophthalmic care.

Successful Management of Pythium insidiosum Keratitis Masquerading as Dematiaceous Fungal Keratitis in an Immunosuppressed Asian Male

PURPOSE

To describe the first case of Pythium insidiosum keratitis masquerading as dematiaceous fungal keratitis in a seropositive male.

CASE SUMMARY

A 44-year-old seropositive male previously treated for acute retinal necrosis presented with pain and defective vision in the right eye following a mud injury 5 days back. Presenting visual acuity was hand movements close to the face. Ocular examination revealed a 7 × 7 mm dense, greyish-white mid stromal infiltrate with pigmentation and few tentacles. The clinical diagnosis suggested fungal keratitis. Corneal scraping on 10% KOH and Gram stain revealed slender, aseptate hyaline hyphae. Before culture results, the patient was treated with topical 5% natamycin and 1% voriconazole, but the infiltrate progressed. Culture on 5% sheep blood agar revealed white fluffy, submerged, shiny, and appressed colonies, and Pythium insidiosum was confirmed by zoospore formation. The patient was further managed with topical linezolid 0.2% hourly, azithromycin 1% hourly, and adjuvant drugs.

CONCLUSION

This is an uncommon presentation of Pythium keratitis masquerading as dematiaceous fungal keratitis in an immunocompromised male.

Navigating diagnostic and therapeutic challenges in ocular manifestations of Hansen's disease and trachoma: A narrative review

Neglected tropical diseases (NTDs) encompass a group of approximately 20 diseases prevalent in tropical and subtropical regions, closely associated with poverty, affecting over a billion people in low-income countries. This manuscript aims to explore the ocular manifestations and burden of two significant NTDs, namely Hansen's disease and trachoma while addressing gaps in understanding and management. Hansen's disease, caused by Mycobacterium leprae , has a long history and presents with diverse neurological and ocular manifestations. Despite the availability of treatment, ocular complications persist, leading to significant visual impairment in some cases. The manuscript emphasizes the importance of early diagnosis, regular ophthalmic examinations, and follow-ups to prevent and control ocular complications, reducing the burden of visual impairment and blindness. Trachoma, caused by Chlamydia trachomatis , remains the leading infectious cause of blindness in underdeveloped and remote areas. The manuscript highlights the clinical diagnosis and implementation of the World Health Organization's (WHO's) SAFE (surgery, antibiotics, facial hygiene, and environmental sanitation) strategy to prevent transmission and associated blindness. However, challenges in health surveillance tools and underreporting of trachoma cases are addressed, emphasizing the need for improved strategies to combat the disease effectively. Through a comprehensive review of the ocular manifestations and management of Hansen's disease and trachoma, this manuscript contributes to the existing knowledge base and enhances a deeper understanding of these NTDs. Addressing gaps in understanding and management emphasizes the importance of implementing WHO's strategies and collaborative efforts to achieve the global goal of reducing the burden of NTDs and improving community health and well-being. The manuscript underscores the significance of early intervention, preventive measures, and technological advancements, providing valuable insights for policymakers, healthcare professionals, and researchers working in the field of NTDs.

Current Concepts and Recent Updates of Optical Biometry- A Comprehensive Review

One of the most recent advancements in the field of cataract surgery is optical biometry. With the advent of optical biometry ocular measurements are now simpler, quicker, and more precise. The devices have made intraocular lens (IOL) power calculations easier in difficult situations too, such as in cases with extremes of axial lengths, silicone filled eyes, cataract surgery in post-keratoplasty eyes, post Laser-Assisted in Situ Keratomileusis (LASIK) eyes, etc. The gold standard for IOL power calculation in the present day is by the use of optical biometry devices. The anatomical measurements by these devices are highly precise and because of these measurements and the incorporation of various IOL power calculation formulas the optical biometry devices give the accurate power and the post-operative visual outcome is highly satisfactory among the patients. The growing use of these devices has made cataract the most commonly performed refractive surgical procedure nowadays. In the current scenario, optical biometry has widespread acceptance in almost all countries and has many advantages over ultrasound or immersion biometry. Cataract surgeons can obtain easy and reliable measurements from these devices. Refractive surprises have also decreased considerably with their use. This article will comprehensively review the principles of the various optical biometry devices, the parameters used in each of the devices, the advantages and disadvantages, and add more like what all this article will add.

Corset suture: A novel technique of overlay appositional continuous sutures with air tamponade for management of large acute corneal hydrops

Management of large acute corneal hydrops (ACH) has always been a challenge. Various medical and surgical management options have been used, such as topical steroids, cycloplegics, antiglaucoma medications, antibiotics, Descemet's membrane reposition, and pre-Descematic sutures, for the management of acute hydrops, but have shown limited benefit. We hereby describe a novel technique of appositional continuous overlay sutures along with air tamponade for surgical management of corneal edema following large ACH. In this technique, the epithelium is scraped to visualize the stromal cleft, and then corneal marking is done to locate the suture placement site. Next, a continuous overlay, 10-0 nylon suture is passed in a crisscross fashion, just like the laces of a corset. A small paracentesis is made to lower the intraocular pressure. Stromal fluid is milked out using two iris spatulas, simultaneous suture tension adjustment is done, and the knot is secured. Appropriate anterior chamber tamponade is achieved using air, paracentesis is hydrated, and a bandage contact lens is applied. We noted complete resolution of corneal edema within 2 weeks of the procedure, with significant improvement in visual acuity.

Breaking-Down Barriers: Proposal of Using Cellulose Biosynthesis Inhibitors and Cellulase Enzyme as a Novel Treatment Modality for Vision Threatening Pythium Insidiosum Keratitis

Pythium insidiosum, an Oomycete, causes severe keratitis that endangers vision. Its clinical, morphological, and microbiological characteristics are often indistinguishable from those of fungal keratitis, earning it the moniker "parafungus". Distinctive clinical hallmarks that set it apart from other forms of keratitis include radial keratoneuritis, tentacles, marginal infiltration, and a propensity for rapid limbal spread. The therapeutic approach to Pythium keratitis (PK) has long been a subject of debate, and topical and systemic antifungals and antibacterials have been tried with limited success. Approximately 80% of these eyes undergo therapeutic keratoplasty to salvage the eye. Hence, there is a need to innovate for alternative and better medical therapy to safeguard these eyes. The resistance of Pythium to standard antifungal treatments can be attributed to the absence of ergosterol in its cell wall. Cell walls of plants and algae have cellulose as an essential constituent. Cellulose imparts strength and structure and acts as the "skeleton" of the plant. Fungal and animal cell walls typically lack cellulose. The cellular architecture of Pythium shares a similarity with plant and algal cells through the incorporation of cellulose within its cell wall structure. Inhibitors targeting cellulose biosynthesis (CBI), such as Indaziflam, Isoxaben, and Quinoxyphen, serve as critical tools for elucidating the pathways of cellulose synthesis. Furthermore, the enzymatic action of cellulase is instrumental for the extraction of proteins and DNA. To circumvent this issue, we hypothesize that CBI's and cellulase enzymes can act on the Pythium cell wall and may effectively treat PK. The available literature supporting the hypothesis and proof of concept has also been discussed. We have also discussed these drugs' molecular mechanism of action on the Pythium cell wall. We also aim to propose how these drugs can be procured and used as a potential medical management option for this devastating entity.

Management of symblepharon with Gore-tex as a novel treatment option for ocular chemical burns

PURPOSE

To assess the clinical outcomes of symblepharon release in patients with ocular surface chemical injury using Gore-Tex as a novel treatment option.

METHODS

This was a retrospective analysis of 23 eyes of 22 chemical injury patients done during a period of January 2014 to December 2021 at a tertiary eye care centre in South India. All patients underwent symblepharon lysis along with Gore-Tex application over the sclera with minimum 1 year follow up. The patients were assessed for demographic details, visual acuity, intraocular pressure, anterior and posterior segment details, photographic documentation, preoperative diagnosis, previous surgical details in recurrent cases, surgical procedures, final visual acuity, surgical outcomes, and complications. The clinical outcomes were assessed and outcomes were defined as success, partial success, or failure.

RESULTS

The median age was 17 years (IQR, 12-39 years). Among them 10 eyes with symblepharon had grade 3 length, 12 eyes grade 3 width and 12 eyes had grade 3 loss of palisades of Vogt. The success was achieved in 52.2% of the patients; partial success in 34.8% and 13.3% had failure. The mean duration of recurrence was 6.75 ± 3.6 months. Failure was noted in young patients with mean age 9.75years and with grade 3c symblepharon. There was no sight threatening complications noted.

CONCLUSION

The study showed very good results with Gore-Tex as a novel treatment option for chemical injury patient with symblepharon formation. It can be easily employed to prevent the symblepharon recurrence of various ocular surface disorders.

Novel trocar assisted intraocular lens and capsular bag complex fixation

PURPOSE

To describe the innovative technique of trocar-assisted intraocular lens (IOL) and capsular bag complex fixation.

METHODS

In this technique, initial pupil dilatation is achieved either with intracameral adrenaline or with the help of iris hooks. Automated anterior vitrectomy is performed in cases with vitreous prolapse. A 25 G trocar cannula is placed at the limbus through a paracentesis opposite the zonular dialysis area. The cannula lumen act as a guide to pass the double-arm polypropylene suture attached to the needle. This prevents any inadvertent corneal injury and acts as a perpendicular tract to pass the needle through IOL capsular bag complex.

RESULTS

We performed this technique in 9 cases with an excellent outcome with a minimum of 3 months of follow-up. All patients had well-centred IOL. There was no incidence of corneal injury, Descemet membrane detachment, iris trauma, IOL tilt, decentration, dislocation, vitreous prolapse or retinal detachment. All patients achieved excellent visual acuity ranging from 6/12-6/6 postoperatively.

CONCLUSION

The novel trocar-assisted IOL bag complex fixation technique is very effective and allows smooth IOL fixation in technically challenging cases with IOL subluxation. The trocar acts as a guide to prevent injury to the surrounding tissue, and IOL fixation is achieved with minimal manipulations in the anterior chamber. It also prevents the need for IOL explantation in these cases.

Leveraging ChatGPT for ophthalmic education: A critical appraisal

In recent years, the advent of artificial intelligence (AI) has transformed many sectors, including medical education. This editorial critically appraises the integration of ChatGPT, a state-of-the-art AI language model, into ophthalmic education, focusing on its potential, limitations, and ethical considerations. The application of ChatGPT in teaching and training ophthalmologists presents an innovative method to offer real-time, customized learning experiences. Through a systematic analysis of both experimental and clinical data, this editorial examines how ChatGPT enhances engagement, understanding, and retention of complex ophthalmological concepts. The study also evaluates the efficacy of ChatGPT in simulating patient interactions and clinical scenarios, which can foster improved diagnostic and interpersonal skills. Despite the promising advantages, concerns regarding reliability, lack of personal touch, and potential biases in the AI-generated content are scrutinized. Ethical considerations concerning data privacy and potential misuse are also explored. The findings underline the need for carefully designed integration, continuous evaluation, and adherence to ethical guidelines to maximize benefits while mitigating risks. By shedding light on these multifaceted aspects, this paper contributes to the ongoing discourse on the incorporation of AI in medical education, offering valuable insights and guidance for educators, practitioners, and policymakers aiming to leverage modern technology for enhancing ophthalmic education.

Subconjunctival dexamethasone-assisted conjunctival autograft harvesting versus normal saline during pterygium surgery - A randomized clinical trial

PURPOSE

To evaluate the effect of subconjunctival dexamethasone compared to normal saline on conjunctival autograft harvesting in patients undergoing pterygium surgery.

METHODS

Fifty-two eyes of 52 patients who underwent pterygium excision combined with autologous conjunctival graft (CAG) using releasable suture were included in this prospective interventional study. The patients were randomized into two groups of 26 patients each. Group A consisted of patients in whom CAG was harvested using subconjunctival 0.5 ml of 0.4% dexamethasone sodium phosphate and in group B patients, normal saline was used. The patients were assessed for postoperative pain, foreign body sensation, and watering as the subjective signs of inflammation and conjunctival inflammation and lid edema as the objective signs of inflammation at 12 and 24 h postsurgery.

RESULTS

The mean age of group A and B patients was 47.69 + 13.09 and 46.00 + 10.76 years, respectively. The male:female ratio was 1.6:1 in group A and 1.1:1 in group B. The mean surgical time in group A was 243.96 ± 52.13 s and in group B was 258.08 ± 43.99 s. Postoperative pain, foreign body sensation, and watering were significantly lower in group A patients than in group B patients at both 12 and 24 h postoperatively (group A: 4.65 ± 1.33, 4.88 ± 1.73, and 3.85 ± 1.43, respectively, at 12 h; 1.89 ± 1.03, 1.69 ± 1.09, and 1.69 ± 0.97, respectively, at 24 h and group B: 6.42 ± 0.95, 6.65 ± 0.98, and 6.27 ± 1.40, respectively, at 12 h; 3.27 ± 1.43, 3.12 ± 1.25, 2.58 ± 1.14, respectively, at 24 h) ( P < 0.001). Conjunctival inflammation was significantly lower in group A at 12 h ( P < 0.05) and 24 h ( P < 0.05) after surgery compared to group B. Lid edema failed to show any significant ( P = 0.17) difference with respect to severity in both the groups at 12 and 24 h ( P = 0.699).

CONCLUSION

Subconjunctival dexamethasone decreased patient discomfort following pterygium surgery. The dexamethasone group had reduced conjunctival inflammatory signs without any notable complications.

Pediatric corneal transplantation: techniques, challenges, and outcomes

Pediatric corneal transplant is a highly demanding and technically challenging procedure for the cornea surgeon in today's era. These cases pose unique challenges in clinical and surgical management. The indications of pediatric corneal transplant can be therapeutic, tectonic, optical, and cosmetic. Pediatric patients undergoing corneal transplants are at a high risk of graft infection, failure, rejection, dehiscence, and amblyopia due to young age, robust immune system, increased incidence of trauma, and compliance issues. The other factors contributing to graft failure can be allograft rejection, secondary glaucoma, corneal vascularization, multiple surgeries, vitreous prolapse, and lack of treatment compliance. A successful corneal transplant in children depends on meticulous preoperative evaluation, uneventful surgery, the expertise of a corneal surgeon, and regular and timely postoperative follow-up. Therapeutic and optical penetrating keratoplasty are the most commonly performed transplants in children. However, with the advancements in surgical technique and management protocol, the current focus has shifted toward lamellar keratoplasty. Lamellar keratoplasty offers early visual recovery and potentially fewer complications. Visual rehabilitation through corneal transplant in otherwise blind eyes can be a boon for the children. Recently, keratoprostheses have been promising in children with multiple graft failures. The current review gives insights into epidemiology, etiology, indications, clinical characteristics, investigations, management options, recent advances, and the future of pediatric corneal transplants. As surgical techniques continue to grow and comprehension of pediatric corneal transplants is improving, we can safeguard these eyes with the best possible anatomical and functional outcomes.

Molecular and epigenetic mechanisms governing ocular surface squamous neoplasia: opportunities for diagnostics

INTRODUCTION

Ocular surface squamous neoplasia (OSSN) is the most common ocular malignancy; the pathophysiology is influenced by molecular, genetic, and epigenetic mechanisms. The incidence of OSSN is associated with the anatomy and physiology of the ocular surface, limbal stem cell configuration, limbal vulnerability, cancer stem cells, dysplasia, neoplasia, angiogenesis, invasion, and metastasis. The key etiological factors involved are human papillomavirus (HPV), human immunodeficiency virus (HIV), immunosuppression, p53 tumor suppressor gene, hypovitaminosis A, and failure of Deoxyribonucleic acid (DNA) repair mechanisms.

AREAS COVERED

This special report is a focussed attempt to understand the molecular mechanism, genetic and epigenetic mechanism, and diagnostic modalities for OSSN.

EXPERT OPINION

While these mechanisms contribute to genome instability, promoter-specific hypermethylation might facilitate and promote tumor formation by silencing tumor suppressor genes. OSSN understanding has improved with increased literature available on various genetic, molecular, and epigenetic mechanisms, although the exact genetic and epigenetic mechanisms still need to be elucidated. It is important to note that the molecular mechanisms of OSSN can vary among individuals, and further research is required to elucidate the underlying processes fully. Understanding these mechanisms is crucial for the development of targeted therapies and improved management of OSSN.

Understanding barriers, recommended solutions, and future prospects for the diagnosis and management of Pythium insidiosum keratitis

Pythium insidiosum keratitis (PIK) is a devastating corneal infection resulting in blindness in a large number of cases. Clinically and morphologically, it closely mimics fungal keratitis, and hence is also labeled as "parafungus." Although many clinical studies have documented evidence regarding the virulence of microorganism, and anatomical and functional outcomes, it remains a clinical challenge and diagnostic dilemma for most clinicians. Till today, PIK is being diagnosed and treated with certainty at only limited centers across the globe. But the question is why this is so? Taking this as the research question, this section on current ophthalmology aims to highlight the understanding of barriers to diagnosing and treating PIK, the suggestions to improve diagnosis and treatment, and the future prospects.

An Innate Host Defense Protein β2-Microglobulin Keeps a Check on α-Synuclein amyloid Assembly: Implications in Parkinson's Disease

Amyloid formation due to protein misfolding has gained significant attention due to its association with neurodegenerative diseases. α-Synuclein (α-syn) is one such protein that undergoes a profound conformational switch to form higher order cross-β-sheet structures, resulting in amyloid formation, which is linked to the pathophysiology of Parkinson's disease (PD). The present status of research on α-syn aggregation and PD reveals that the disease progression may be linked with many other diseases, such as kidney-related disorders. Unraveling the link between PD and non-neurological diseases may help in early detection and a better understanding of PD progression. Herein, we investigated the modulation of α-syn in the presence of β2-microglobulin (β2m), a structural protein associated with dialysis-related amyloidosis. We took a multi-disciplinary approach to establish that β2m mitigates amyloid formation by α-syn. Our fluorescence, microscopy and toxicity data demonstrated that sub-stoichiometric ratio of β2m drives α-syn into off-pathway non-toxic aggregates incompetent of transforming into amyloids. Using AlphaFold2 and all-atom MD simulation, we showed that the β-strand segments (β1 and β2) of α-synuclein, which frequently engage in interactions within amyloid fibrils, interact with the last β-strand at the C-terminal of β2m. The outcome of this study will unravel the yet unknown potential linkage of PD with kidney-related disorders. Insights from the cross-talk between two amyloidogenic proteins will lead to early diagnosis and new therapeutic approaches for treating Parkinson's disease. Finally, disruption of the nucleation process of α-syn amyloids by targeting the β1-β2 region will constitute a potential therapeutic approach for inhibiting amyloid formation.

Impact of Covid-19 on Pediatric Ophthalmology Care: Lessons Learned

The COVID-19 pandemic came with many new challenges that forced personal and professional lifestyle modifications. Medical facilities were in scarcity against this new unknown enemy and were challenged with the overloaded patient flow, scarcity of healthcare staff, and evolving treatment modalities with a better understanding of the virus each day. Ophthalmology as a "branch of medicine" suffered challenges initially because of a lack of guidelines for patient management, close working distance during routine examinations, and halt of major surgeries, including cataracts. Pediatric ophthalmology had major implications, as reduced outpatient visits would mean deeper amblyopia, and changed lifestyles, including online classes and home refinement, predisposing children to myopia, digital eye strain, and worsening of strabismus. COVID-19 also unveiled underlying accommodation and convergence anomalies that predisposed pediatric and adolescent patients to an increased prevalence of headache and acute onset esotropia. Teleophthalmology and other innovative solutions, including the use of prism glasses, safe slit-lamp shields, alternative ways of school screening with the use of photoscreeners, performing retinoscopy only when needed, and using autorefractors were among the few guidelines or modifications adopted which helped in the efficient and safe management of pediatric patients. Many pediatric ophthalmologists also suffered in terms of financial constraints due to loss of salary or even closure of private practices. School screening and retinopathy of prematurity screening suffered a great setback and costed a lot of vision years, data of which remains under-reported. Important implications and learnings from the pandemic to mitigate future similar situations include using teleophthalmology and virtual platforms for the triage of patients, managing non-emergency conditions without physical consultations, and utilizing home-based vision assessment techniques customized for different age groups. Though this pandemic had a lot of negative implications, the innovations, modifications, and other important learnings helped pediatric ophthalmologists in navigating safely.