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Aim To validate the diagnostic performance of a custom 96-micro-organism TaqMan PCR card (iCAM) for microbial keratitis (MK) from a single corneal epithelial sample.Methods Patients over the age of 18 referred to Cambridge University Hospital with MK were recruited in this single-site prospective cohort study between September 2021 and January 2023. An ocular-specific, customised microarray card (iCAM) was constructed according to primer and probe nucleotide sequences developed in our department to detect bacteria, viruses, Acanthamoeba and fungi commonly implicated in MK using a single corneal epithelial sample. Part of the corneal epithelial sample was taken for conventional cultures per local protocol, followed by iCAM array. Microbial detection rate and positive predictive value (PPV) were evaluated.Results 38 corneal epithelial samples from 32 patients with MK and 4 control samples from healthy participants were obtained from 36 consecutive patients. A causative microbe was isolated in 15/34 samples (44%) using the iCAM test, compared with 15 by conventional methods (44%). iCAM test processing time varied between 6 and 24 hours compared with up to 7 days for conventional tests. Combined, the microbial detection rate was 65%, with the correlation between methods at 62%. The iCAM test could detect all major micro-organism groups with 56% sensitivity and 60% PPV.Conclusions The iCAM test can detect bacterial, fungal, viral and protozoan organisms using one corneal epithelial sample. The limitations include small patient cohort size and reduced volume of available corneal epithelial sample when shared between the iCAM PCR test and conventional culture methods utilised in the study. A multicentre trial is being planned to validate the clinical impact of using iCAM test on accuracy of diagnosis, early institution of appropriate antimicrobials and clinical outcomes.Trial registration number ISRCTN17422545.

Corneal perforations in eyes with dry eye disease (DED) are difficult to manage due to the interplay of several factors such as the unstable tear film, surface inflammation, and the underlying systemic disease affecting the wound healing process, and the eventual outcome. A careful preoperative examination is required to identify the underlying pathology, and status of ocular surface and adnexa, rule out microbial keratitis, and order appropriate systemic workup in addition to assessing the perforation itself. Several surgical options are available, which include tissue adhesives, multilayered amniotic membrane grafting (AMT), tenon patch graft (TPG), corneal patch graft (CPG), and penetrating keratoplasty (PK). The choice of procedure depends upon the size, location, and configuration of the perforation. In eyes with smaller perforations, tissue adhesives are effective treatment modalities, whereas AMT, TPG, and CPG are viable options in moderate-sized perforations. AMT and TPG are also preferable in cases where the placement of a bandage contact lens may be a challenge. Large perforations require a PK, with additional procedures such as tarsorrhaphy to protect the eyes from the associated epithelial healing issues. Conjunctival flaps are considered in eyes with poor visual potential. The management of the acute condition is carried out in conjunction with measures to improve the tear volume bearing in mind the chances of delayed epithelialization and re-perforation in these cases. Administration of topical and systemic immunosuppression, when indicated, helps improve the outcome. This review aims to facilitate clinicians in instituting a synchronized multifaceted therapy for the successful management of corneal perforations in the setting of DED.

Cataract surgery is one of the most commonly performed ophthalmic surgeries in the world. Dry eye disease (DED) is found to coexist in most patients with cataracts due to the overlapping age groups of both these conditions. Preoperative evaluation for DED is important to improve outcomes. A pre-existing DED affecting the tear film is likely to affect biometry. Moreover, special intraoperative considerations are needed in eyes with DED to reduce complications and improve postoperative outcomes. Dry eye disease (DED) is known to occur following an uneventful cataract surgery or a pre-existing DED is likely to worsen following cataract surgery as well. In these situations, despite a good visual outcome, patient dissatisfaction is common owing to the distressing DED symptoms. This review aims to summarize the preoperative, intraoperative, and postoperative considerations when performing cataract surgery in the presence of a coexisting DED.

Among the various indications for keratoplasty, failed graft is one of the commonest indications in many published series. It is well known that the major cause of graft failure is endothelial rejection. In the last two decades, there has been a major paradigm shift in the surgical management of corneal diseases, and component keratoplasty has emerged from the concept of replacing the layer that is actually diseased, rather than replacing the full-thickness cornea with the traditional penetrating keratoplasty. This has resulted in improved outcomes and the risk of endothelial rejection has reduced drastically, thus expanding the survival time of the graft. In recent years, reports of graft rejection in component keratoplasty have emerged, with each having a different presentation and responding to a different line of treatment. This review aims to summarize the presentation, diagnosis, and management of graft rejections in component keratoplasty.

Objective: The past few years have seen a rapid advancement in the management of keratoconus (KC). However, there is no prescribed standard of care for the management of KC. This study evaluated the prevailing practice patterns among Indian ophthalmologists in the diagnosis and treatment of KC via an online survey. Methods: This was a survey-based cross-sectional study in which a questionnaire (Supplement 1) was created. Questions pertaining to the practicing experience, setting of practice, and training background were asked in addition to the investigations done and decision making in KC management. Responses were collected via Survey Monkey (Survey Monkey, Palo Alto, California, USA) and statistical analysis performed using R software (4.1.3). Results: The survey was answered by 273 ophthalmologists. Pentacam was the most used topographer (195 users), followed by Orbscan (41 users), Sirius (34 users), and Galilei (3 users). The lowest limit of pachymetry for performing collagen crosslinking (CXL) was 400μ for most practitioners. More than half the respondents (50.55%) did not perform photorefractive keratectomy (PRK) or intracorneal ring segment (ICRS) implantation in a suitable patient. Accelerated 10-minute protocol (9 mW/cm2 for 10 minutes) was the most commonly (54.21%) used for CXL, followed by Dresden protocol (3 mW/cm2 for 30 minutes) (36.63%). When a patient was unsuitable for CXL, 55.31% surgeons advise contact lens (CL) trial, 35.16% surgeons advise keratoplasty, 26.74% surgeons perform stromal augmentation, and 7.69% surgeons advise spectacle correction. Corneal scar was the most common indication (49.45%) for performing keratoplasty. Conclusion: Topography remains the most used diagnostic modality for initial diagnosis. Optical coherence tomography and epithelial mapping are increasingly being used for early diagnosis of KC. Not all ophthalmologists were comfortable performing ICRS or PRK. When patients are unsuitable for CXL, CL trial remains the most frequently advised option followed by keratoplasty.

Keratoconus is the most common corneal ectatic disorder. It is characterized by progressive corneal thinning with resultant irregular astigmatism and myopia. Its prevalence has been estimated at 1:375 to 1:2,000 people globally, with a considerably higher rate in the younger populations. Over the past two decades, there was a paradigm shift in the management of keratoconus. The treatment has expanded significantly from conservative management (e.g., spectacles and contact lenses wear) and penetrating keratoplasty to many other therapeutic and refractive modalities, including corneal cross-linking (with various protocols/techniques), combined CXL-keratorefractive surgeries, intracorneal ring segments, anterior lamellar keratoplasty, and more recently, Bowman’s layer transplantation, stromal keratophakia, and stromal regeneration. Several recent large genome-wide association studies (GWAS) have identified important genetic mutations relevant to keratoconus, facilitating the development of potential gene therapy targeting keratoconus and halting the disease progression. In addition, attempts have been made to leverage the power of artificial intelligence-assisted algorithms in enabling earlier detection and progression prediction in keratoconus. In this review, we provide a comprehensive overview of the current and emerging treatment of keratoconus and propose a treatment algorithm for systematically guiding the management of this common clinical entity.

The accelerated growth in electronic health records (EHR), Internet-of-Things, mHealth, telemedicine, and artificial intelligence (AI) in the recent years have significantly fuelled the interest and development in big data research. Big data refer to complex datasets that are characterized by the attributes of “5 Vs”—variety, volume, velocity, veracity, and value. Big data analytics research has so far benefitted many fields of medicine, including ophthalmology. The availability of these big data not only allow for comprehensive and timely examinations of the epidemiology, trends, characteristics, outcomes, and prognostic factors of many diseases, but also enable the development of highly accurate AI algorithms in diagnosing a wide range of medical diseases as well as discovering new patterns or associations of diseases that are previously unknown to clinicians and researchers. Within the field of ophthalmology, there is a rapidly expanding pool of large clinical registries, epidemiological studies, omics studies, and biobanks through which big data can be accessed. National corneal transplant registries, genome-wide association studies, national cataract databases, and large ophthalmology-related EHR-based registries (e.g., AAO IRIS Registry) are some of the key resources. In this review, we aim to provide a succinct overview of the availability and clinical applicability of big data in ophthalmology, particularly from the perspective of corneal diseases and cataract, the synergistic potential of big data, AI technologies, internet of things, mHealth, and wearable smart devices, and the potential barriers for realizing the clinical and research potential of big data in this field.

Corneal perforation is a potentially devastating complication that can result from numerous conditions that precipitate corneal melting. It is associated with significant morbidity and prompt intervention is necessary to prevent further complications. Causes include microbial keratitis, ocular surface disease, and autoimmune disorders and trauma. Various management options have been described in the literature to facilitate visual rehabilitation. This rview discusses the treatment options that range from temporising measures such as corneal gluing through to corneal transplantation, with decision making guided by the location, size, and underlying aetiology of the perforation.

Post-keratoplasty infectious keratitis (PKIK) represents a unique clinical entity that often poses significant diagnostic and therapeutic challenges. It carries a high risk of serious complications such as graft rejection and failure, and less commonly endophthalmitis. Topical corticosteroids are often required to reduce the risk of graft rejection but their use in PKIK may act as a double-edged sword, particularly in fungal infection. The increased uptake in lamellar keratoplasty in the recent years has also led to complications such as graft-host interface infectious keratitis (IIK), which is particularly difficult to manage. The reported incidence of PKIK differs considerably across different countries, with a higher incidence observed in developing countries (9.2–11.9%) than developed countries (0.02–7.9%). Common risk factors for PKIK include the use of topical corticosteroids, suture-related problems, ocular surface diseases and previous corneal infection. PKIK after penetrating keratoplasty or (deep) anterior lamellar keratoplasty is most commonly caused by ocular surface commensals, particularly Gramme-positive bacteria, whereas PKIK after endothelial keratoplasty is usually caused by Candida spp. Empirical broad-spectrum antimicrobial treatment is the mainstay of treatment for both PKIK, though surgical interventions are required in medically refractory cases (during the acute phase) and those affected by visually significant scarring (during the late phase). In this paper, we aim to provide a comprehensive overview on PKIK, encompassing the epidemiology, risk factors, causes, management and outcomes, and to propose a treatment algorithm for systematically managing this challenging condition.

Corneal cross-linking (CXL), introduced by Wollensak et al. in 2003, is a minimally invasive procedure to halt the progression of keratoconus. Conventional CXL is recommended in eyes with corneal thickness of at least 400 microns after de-epithelialization to prevent endothelial toxicity. However, most of the keratoconic corneas requiring CXL may not fulfill this preoperative inclusion criterion. Moderate-to-advanced cases are often found to have a pachymetry less than this threshold. There are various modifications to the conventional method to circumvent this issue of CXL thin corneas while avoiding the possible complications. This review is an update on the modifications of conventional CXL for thin corneas.

Adenoid cystic carcinoma (ACC) is a rarely seen malignant epithelial tumor of the eyelids. We present a rare case of primary ACC arising from the tarsal plate of the lower lid that clinically resembled a chalazion. A 66-year-old female presented with a recurring nodule in her left lower lid. She gave history of surgery for chalazion removal from the same site twice earlier. An initial diagnosis of a recurrent chalazion was made, and incision and curettage was done. Light microscopy showed a solid tumor composed predominantly of sheet-like and nested pattern of basaloid to low-columnar cells with intervening fibrovascular septa and lacking an obvious cribriform or tubular architecture. The tumor cells were positive for pan-cytokeratin and CD117 and negative for adipophilin, HMB45, and BerEP4. A diagnosis of solid variant of ACC of the eyelid was made. Wide excision was performed and eyelid defect was reconstructed.

Purpose: Conventionally, keratoconus (KC) has been considered a noninflammatory corneal ectatic disorder. Recent evidence suggests a possible role of inflammation in the pathogenesis of KC. Hence, we analyzed the levels of inflammatory factors in the tear fluid of Indian KC patients. Methods: Tear fluid samples were collected from age- and sex-matched healthy controls and KC patients (with different grades). The levels of the inflammatory factors in tears were analyzed using cytometric bead array (Human Soluble Protein Flex Set System, BD Biosciences) for levels of interleukin-1α (IL-1α), IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-9, IL-10, IL-12p70, IL-23p40, IL-13, IL-17A, IL-17F, IL-21, interferon-α (IFNα), IFNγ, tumor necrosis factor-α, CCL2/monocyte chemotactic protein-1, CCL4/macrophage inflammatory protein-1β (MIP-1β), MIP-1α, CCL5/RANTES, CXCL10/IP10, ICAM1, CD62E, vascular endothelial growth factor and transforming growth factor β. Results: An increase in Kmax and Kmean, and a decrease in central corneal thickness was observed with increasing grades of KC. Tear analysis showed that most of the tear soluble factors, including cytokines, chemokines, growth factors and cell adhesion molecules were significantly elevated in the KC patients compared to the controls. Conclusion: Our findings suggest that inflammatory factors associated with KC may play a role in its pathogenesis. This opens the potential to explore anti-inflammatory strategies to either halt or delay the progression of KC.

Purpose: The aim of this study was to analyze the effect of postcollagen crosslinking (CXL) haze on the measurement and repeatability of pachymetry and mean keratometry (Km) of four corneal topographers. Materials and Methods: Sixty eyes of sixty patients with progressive keratoconus who had undergone accelerated CXL (ACXL) underwent imaging with a scanning slit imaging device (Orbscan II) and three Scheimpflug imaging devices (Pentacam HR, Sirius, and Galilei). Post-ACXL haze was measured using the densitometry software on the Pentacam HR. Readings of the thinnest corneal thickness (TCT) and Km from three scans of each device were analyzed. Effect of haze on the repeatability of TCT and Km measurements was evaluated using regression models. Repeatability was assessed by coefficient of variation. Results: Corneal densitometry in different zones affected the repeatability of TCT measurement of Orbscan (P < 0.05) significantly but not the repeatability of TCT with Pentacam HR and Sirius (P = 0.03 and 0.05, respectively). Km values were affected by haze when measured with the Pentacam HR (P < 0.05). The repeatability of Km readings for all devices was unaffected by haze. In the anterior 0–2 mm and 2–6 mm zone, TCT (P = 0.43 and 0.45, respectively), Km values (P = 0.4 and 0.6, respectively), repeatability of TCT (P = 0.1 in both zones), and Km (P = 0.5 and 0.1, respectively) with Galilei were found to be the most reliable. Conclusion: Galilei measurements appear to be least affected by post-ACXL haze when compared with other devices. Hence, topography measurements in the presence of haze need to be interpreted with caution.

One of the challenging situations for a cataract surgeon is phacoemulsification in the shallow anterior chamber like cases of phacomorphic glaucoma. Some of the main concerns of operating in a narrow space include endothelial decompensation, descemet's detachment, and posterior capsular rents. High vitreous pressure predisposes to posterior capsular rents owing to a reduced concavity of the posterior capsule and increasing the proximity of phaco-tip to the posterior capsule. We describe a technique of limited vitrectomy in such cases. A small gauge 23-G/25-G trocar cannula is passed transconjunctivally, and the liquefied vitreous is allowed to egress. Vitrectomy is done extraocularly till the vitreous pressure lowers down. This technique helps to debulk the vitreous and decompress the globe in a controlled manner. The resultant posterior displacement of iris-lens diaphragm causes a deepening of the anterior chamber to facilitate phacoemulsification.