Infectious Keratitis Research Articles

Three cases of recalcitrant Paecilomyces keratitis in Southern California within a short period

BackgroundThe aim of this report is to describe the risk factors, clinical course, and characteristics of three cases of Paecilomyces keratitis presenting concurrently within three months in the same location. We used in vivo confocal microscopy and histopathology to corroborate our clinical findings.ObservationsThree eyes of three elderly patients with culture-proven Paecilomyces keratitis were included in this series. These patients resided within a 15-mile radius and presented to a tertiary care eye institute in Southern California between February and April 2022. All three eyes experienced a prolonged, recalcitrant course with recurrence of keratitis in donor corneal tissue despite antifungal therapy and multiple therapeutic penetrating keratoplasties. In vivo confocal microscopy, histopathology, and microbiologic findings corroborated the diagnosis of fungal keratitis with Paecilomyces. With surgical intervention and extensive medical therapy, all three cases resolved after the addition of oral Posaconazole.ConclusionsPaecilomyces is a rare cause of infectious keratitis. Herein we report three similar cases in elderly patients. All had prolonged, recalcitrant infections that required multiple treatment modalities. Our cases, which were supported by in vivo confocal microscopy and histopathology, highlight the importance of timely and aggressive therapy to prevent recurrence.

Association of sodium-glucose cotransporter 2 inhibitors with the incidence of corneal diseases in type 2 diabetes mellitus.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors revealed the protective function on various systemic diseases. This study aimed to determine whether the usage of SGLT2 inhibitors associates with incidences of superficial keratopathy and infectious keratitis in type 2 diabetes mellitus (T2DM) patients. A retrospective cohort study with the usage of National Health Insurance Research Database of Taiwan was conducted. The T2DM patients were divided into the SGLT2 inhibitors and control groups according to the usage of SGLT2 inhibitors or not. The major outcomes were defined as the occurrence of superficial keratopathy and infectious keratitis. There were 766 and 1037 episodes of superficial keratopathy in the SGLT2 inhibitors and control groups and SGLT2 inhibitors group showed a significantly lower incidence of superficial keratopathy than the control group (aHR: 0.721, 95% CI: 0.656-0.791, P < 0.0001). Also, there were 166 and 251 infectious keratitis events in the SGLT2 inhibitors and control groups and patients in the SGLT2 inhibitors group revealed a significantly lower infectious keratitis incidence than those in the control group (aHR: 0.654, 95% CI: 0.537-0.796, P < 0.0001). In addition, the patients that received SGLT2 inhibitors demonstrated lower cumulative incidences of both superficial keratopathy and infectious keratitis compared to the non-SGLT2 inhibitors users (both P < 0.0001). In conclusion, the usage of SGLT2 inhibitors correlates to lower incidence of superficial keratopathy and infectious keratitis in T2DM individuals, which is more significant in patients with persistent SGLT2 inhibitors application.

Cornea on fire: PACK‐CXL in the treatment of infectious keratitis

Infectious keratitis is a severe eye condition that can cause permanent vision loss if not treated promptly. The current standard of care for this condition involves the use of broad‐spectrum topical antibiotic drops. However, researchers have explored photoactivated chromophore for collagen cross‐linking (PACK‐CXL) as a potential treatment option for infectious keratitis. Studies have shown that PACK‐CXL can improve the healing process in bacterial keratitis and prevent corneal melting caused by bacterial enzymatic degradation.When activated by UV light, riboflavin, the photosensitizer used in PACK‐CXL, induces changes in collagen properties, leading to a hardening and strengthening effect on the corneal stroma. However, individuals with corneal ulcers may experience greater penetration of UV light due to the compromised integrity of the cornea, which could cause endothelial cell loss and impair corneal function.The purpose of this presentation is to provide a summary of the evidence on the comparative effectiveness and safety of PACK‐CXL with or without standard therapy versus standard therapy alone for the treatment of bacterial keratitis. The latest randomized controlled trials (RCTs) will be reviewed, and their findings regarding the efficacy and safety of PACK‐CXL in treating infectious keratitis will be discussed, as well as a comparison with standard antibiotic therapy alone. Ultimately, this talk aims to inform evidence‐based recommendations for the treatment of infectious keratitis and provide clinicians with the most up‐to‐date information to make informed treatment decisions.

Study of the growth temperature of ocular surface microorganisms in norm and in infectious keratitis

This exploratory study examines the distribution and properties of OS microorganisms isolated under different temperature cultivation conditions in patients with IK and healthy volunteers without ophthalmic pathology. Fifteen participants were divided into two groups. Group 1 (n=10) consisted of patients with signs of unilateral infectious keratitis, while group 2 (n=5) served as the control group. A novel microbiological method was employed to isolate pure cultures of microorganisms. This method involved cultivating microorganisms at two temperature regimes (37 °C and 24 °C) and subsequently identifying them using biochemical, immunological, and physicochemical techniques, including mass spectrometry. Scanning electron microscopy (SEM) with lanthanide staining used as the reference method. The temperature status of the ocular surface was assessed using non-contact infrared thermography. The study demonstrated the presence of psychrotolerant microorganisms on the ocular surface, which exhibited growth at a relatively low temperature of 24 °C. These psychrotolerant microorganisms were found to be isolated from the ocular surface displaying signs of temperature dysregulation. Among such microorganisms are Acinetobacter lwoffii, Achromobacter xylosoxidans, Bacillus licheniformis, Enterococcus faecalis, Klebsiella oxytoca, Klebsiella pneumoniae, Micrococcus luteus, Pseudomonas luteola, Streptococcus spp. When identifying the causative agent of infectious keratitis, it is crucial to consider the divergence of growth temperature of ocular surface microorganisms. The presence of psychrotolerant microorganisms on the ocular surface, which can effectively grow at room temperature, should be taken into account, especially in cases of temperature dysregulation.

Topical blood products modulate the effects of ophthalmic antibiotics against common bacterial pathogens in dogs with infectious keratitis.

Bacterial keratitis is a common and serious condition that often leads to vision impairment and potential loss of the eye if not treated promptly and adequately. Topical blood products are often used concurrently with topical antibiotics, helping to mitigate corneal 'melt' from proteases released on the ocular surface. However, blood products are rich in albumin and could affect the efficacy of antibiotics due to drug-protein binding. In this study, serum and plasma samples were harvested from 10 healthy dogs and 10 healthy horses, obtaining fresh and frozen (1 month at -20°C) aliquots for in vitro experiments. Albumin levels were quantified using species-specific ELISA kits. Thirty bacteria (10 Staphylococcus pseudintermedius, 10 Streptococcus canis, 10 Pseudomonas aeruginosa), isolated from canine patients with infectious keratitis, were each tested with blank plates as well as commercial susceptibility plates (Sensititre™ JOEYE2) to assess the minimal inhibitory concentration (MIC) of 17 different antibiotics in the absence (control) or presence of eight test groups: serum or plasma (fresh or frozen) from canines or equines. Albumin concentrations ranged from 13.8-14.6 mg/mL and 25.9-26.5 mg/mL in canine and equine blood products, respectively. A direct antimicrobial effect was observed mostly with equine vs. canine blood products (specifically serum and to a lesser degree plasma), and mostly for Staphylococcus pseudintermedius isolates. MICs generally increased in the presence of blood products (up to 10.8-fold), although MICs also decreased (down to 0.25-fold) for selected antibiotics and ocular pathogens. Median (range) fold changes in MICs were significantly greater (p = 0.004) with the canine blood products [2 (0.67-8.1)] than the equine blood products [2 (0.5-5)]. In practice, clinicians should consider equine over canine blood products (lesser impact on antimicrobial susceptibility), serum over plasma (greater antimicrobial effects), and administering the blood product ≥15 min following the last antibiotic eyedrop to minimize the amount of albumin-antibiotic binding in tear film.

Streptococcus equinus keratitis after small-incision lenticule extraction: A case report and literature review

A 20-year-old male patient underwent small-incision lenticule extraction (SMILE) due to compound myopic astigmatism in both eyes. On the first day after SMILE, the patient was diagnosed with infectious keratitis (IK) caused by Streptococcus equinus. Emergency surgery was performed, and 2.5% vancomycin solution was used to wash the corneal interlamine of both eyes. After surgery, intensive antibiotic treatment and glucocorticoids were administered to reduce haze in the corneal epithelium and prevent corneal scar hyperplasia. IK was controlled in both eyes, and the uncorrected distance visual acuity in both eyes was 20/20.

Contact lens‐related complications

The use of contact lens is very popular and its global market is growing. They have numerous applications, some well‐established and others still not consensual but which have been gaining more and more approval, namely refractive errors, dry eye management, post refractive surgery rehabilitation, persistent epithelial defects, cosmetic approaches and drug delivery systems. Unfortunately, there are some complications caused by their use, some of them sight threatening. The purpose of this presentation is to review these problems and to provide a better understanding of them.The major mechanisms implicated are numerous: trauma, decreased corneal oxygenation, reduced corneal and conjunctival lubrication, allergic and inflammatory responses and infection. However, depending on the complication we are talking about, there are other factors involved, such as contact lens‐related factors (material, design, fit and wearing schedule) and environmental factors (ocular surface condition, external environment, occupational factors, medications and compliance).The symptomatology experienced by patients ranges from hypoesthesia and mild conjunctival hyperemia to photophobia, contact lens intolerance and even decreased visual acuity.Many complications have been described. The most important (most common or most serious) are contact lens discomfort (CLD), dry eye, corneal deepithelialization (CD), sterile infiltrates (SI), corneal neovascularization (CNV), infectious keratitis (IK) and giant papillary conjunctivitis (GPC). Superior epithelial arcuate lesion, contact lens‐related peripheral ulcer, corneal distortion, hypoesthesia, ptosis, pinguecula, corneal edema, allergy aggravation, herpes reactivation and endothelial changes have also been described.CLD is an episodic or persistent adverse ocular sensation related to lens wear with a variable incidence in the literature, ranging from 23% to 94% in different series, being less common with soft lenses. Dry eye plays its role acting as a risk factor for CLD and/or as a consequence of contact lens use. CD manifests as punctate epithelial keratopathy, epithelial abrasions, foreign body tracks, corneal dellen, microcysts, vacuoles, mucin balls and dimple veiling. GPC is one of the most common adverse effects of contact lenses and the papillary reaction of the upper tarsal conjunctiva is the main feature of this entity. CNV is the formation of new vessels basically found in capillaries and venules of the pericorneal plexus, which may progress to the corneal stroma. They are much more associated with soft contact lenses, especially in extended wearers. Of note, contact lens use is one of the most common causes of CNV usually highlighted. SI are the result of an immunological reaction, often do not contain overlying epithelial defect or anterior chamber reaction and may manifest as stromal deep opacities. IK may be caused by bacteria, viruses, fungus or parasites and prompt immediate care and close revaluations to anticipate disastrous outcomes.Conservative measures play a role in almost all complications and their prevention, such as patient education, lubrication, contact lens exchange when applicable and modification of environmental factors. Addressing and learning how to prevent or quickly diagnose all these complications is crucial to prevent serious consequences.

Correlative microscopy (CLEM) of tarsal conjunctival scraping: A new opportunity in the diagnosis of microbial keratitis

Aims/Purpose: To evaluate the efficacy of correlated Scanning Electron Microscopy (SEM)/Optical Microscopy (OM) analysis of conjunctival scrapings in diagnosing infectious keratitis with prior negative culture tests or ineffective broad‐spectrum antibiotic therapy.Methods: 102 eyes of 87 patients (45M, 42F) affected by keratitis were evaluated by cytological examination of scrapings of the superior tarsal conjunctiva in OM (Nikon Eclipse 50i) and SEM (JEOL), after 72 h of wash‐out. Inclusion criteria: age &gt; 18 years, corneal epithelial defects from suspected infection, ineffectiveness of previous broad‐spectrum antimicrobial therapy or negative conjunctival swab. Exclusion criteria: ocular surgery &lt;3 months, immunosuppression, allergic keratitis, severe dry eye, ocular herpes, ulcer &gt;3 mm, anterior chamber involvement. Identification of inflammatory infiltrate (OM) and microorganisms (SEM) was performed by two independent operators with the same devices and methodology. Weekly clinical control with new conjunctival scraping for OM and SEM after cycles of therapy were carried out.Results: Pathogenic microorganisms were detected in 94/102 eyes: Acanthamoeba (22), Candida (18), Mycoplasma (15), Mycobacteria (13), Chlamydia (12), Micrococci (11), Pseudomonas (6), Cocci (6), Aspergillus (5), Fusarium (2); in 14 cases 2 or more different forms coexisted; in 2 cases a subsequent PCR test revealed the presence of HSV‐1; 3 cases showed signs of severe dry eye; other 3 marked eosinophilia. Operator agreement: 99%. The specific treatment for the germs detected determined in all cases clinical and microbiological resolution in 14–49 days (mean 27.6 ± 2.4).Conclusions: CLEM put in evidence the correlation between phlogistic cells and pathogens, allowing the diagnosis and the treatment of different forms of infectious keratitis and other pathological conditions. The interpretation and repeatability, however, require appropriate training and dedicated equipment.

Corneal sensory nerve function: An overview

Somatosensory innervation of the cornea is provided by the peripheral axons of a small number of primary sensory neurons located in the ophthalmic region of the trigeminal ganglion. Corneal sensory nerve fibres are heterogeneous and may express different neurotransmitters and ion channels involved in transduction and coding of the stimuli acting on the tissue. Based on their activation by one or several types of physical and chemical stimuli, corneal nerve fibres are classified as polymodal nociceptors, mechanonociceptors and cold thermoreceptors. Impulse activity originated at corneal sensory nerves reaches second‐order neurons located at the lower brainstem, from where sensory information travels to the contralateral posterior thalamus and, then, to the brain cortex.After processing, the activation of the different classes of corneal neurons results in different sensations that depend on the type of primary sensory neuron initially activated by the stimulus, although pain is the main sensation elicited by corneal stimulation. Sensations originated at the cornea are explored by esthesiometry, allowing to quantify the threshold, intensity and quality of the evoked sensations. Sensitivity of the ocular surface is reduced with age and altered by several pathological processes that affect sensory innervation, either ocular (such as allergic keratoconjunctivitis, infectious keratitis, eye surgery, hereditary corneal dystrophies, dry eye, etc.) or systemic diseases, such as diabetes and peripheral neuropathies.A prominent feature of ocular nociceptors is their sensitization by the inflammatory mediators released after noxious stimulation or tissue injury, while cold thermoreceptor activity is inhibited by inflammatory substances. Both the spontaneous and the stimulus‐evoked activity increases in sensitized nociceptors, which causes sustained pain and hyperalgesia. After corneal sensory nerves damage (produced as a consequence of an ocular or systemic disease, or by accidental or surgical injury), part of sensory nerves degenerates leading to reduced sensitivity to natural stimulation in the affected area. At the same time, axons start to regenerate and to recover the ability to transduce and encode the stimulus. During this regeneration process, cold thermoreceptor and nociceptor nerves may become hyperexcitable due to changes in their expression/activity of ion channels, which give rise to dryness sensation and ocular neuropathic pain.(Supported by PID2020‐115934RB‐I00 from DOI: MCIN/AEI/10.13039/50110001103, and CIPROM/2021/48 from the Generalitat Valenciana, Spain)

Neuroinflammation: The missing link between pain and immunity

The density of corneal nerves in the cornea is the highest of the entire body. Most ocular surface diseases/injuries affect corneal neurons and are followed by a process named neurogenic inflammation, which eventually leads to pain, activation and recruitment of leukocytes and neoangiogenesis. On the other hand, leukocytes affect nerve physiology by secreting pro‐inflammatory cytokines and neuropeptides. The clinical outcome of the neuroinflammatory process is two‐faced. While immune activation is beneficial to prevent/control infections and ensure prompt wound healing, a prolonged and/or excessive neuroinflammatory response can have catastrophic consequences on corneal integrity and vision, or induce chronic pain. Clearly, a better understanding of these complex processes can have a deep impact on the treatment of highly prevalent ocular disorders, such as dry eye or infectious keratitis.

The global incidence and prevalence of Acanthamoeba keratitis

Aims/Purpose: To assess the global incidence and prevalence of Acanthamoeba keratitis (AK).Methods: The review protocol was prospectively registered in PROSPERO (CRD42022363243) and the Cochrane Handbook was followed in the conduction of the analysis. The study included male and female participants worldwide (&gt;15 years old). PubMed, Scopus, Web of Science, EMBASE, and CINHAL were the sources of data. The incidence of AK was determined by calculating the number of cases per centre per year, while the prevalence was evaluated for the entire population and the entire population of patients with non‐viral infectious keratitis. Based on the population prospects of the United Nations, actual and provisional estimates of the global epidemiological burden of AK, covering a period of up to 50 years, were provided.Results: A total of 134 articles were included in the analysis. The analysis revealed a median incidence of 2.42 (95% CI: 1.67, 3.8) new cases of AK per centre per year, without any statistically significant difference among the continents (p = 0.1411). The percentage of AK cases within the total number of MK cases was found to be 1.62% (95% CI: 1.51, 1.74). Using a random effect model, the prevalence of AK in relation to the entire population was estimated to be 0.0003% (95% CI: 0.0001; 0.0006). The projected increase in the total and provisional numbers of AK cases indicates a rise of 20.4% (2003 AK cases) in 2053 and 24.8% (2076 AK cases) in 2073, compared to the baseline of 2023 (1663 AK cases).Conclusions: Although rare, AK is a significant condition that is projected to increase in prevalence by up to 24% over the next 50 years.

A nanotechnology‐based solution for epi‐on corneal cross‐linking

Keratoconus (KC) is a bilateral progressive corneal ectasia resulting in irregular astigmatism and loss of visual function, in youth and children. Corneal cross‐linking (CXL) is the standard treatment to halt the progression of KC. The conventional protocol consists of removal of the corneal epithelium (epi‐off), followed by soaking of riboflavin and then irradiation with UVA light, leading to stiffening of the cornea. However, postoperative ocular adverse events related to epithelial removal, such as infectious keratitis and delayed visual recovery, have been described. Some alternative methodologies have been tested but pain, no control on corneal permeability, and high investment for set‐up acquisition are drawbacks. Accordingly, the treatment of KC is at an extremely exciting stage, and research on delivering riboflavin into the cornea without removing the epithelium is underway.To address this clinical unmet need, we developed an advanced solution consisting of nanoparticle‐modified commercial soft contact lenses. Safety conditions were determined using ex vivo porcine eyes. The efficacy of our solution on corneal epithelial permeability to riboflavin was tested using in vivo rat eyes. Our nanotechnology‐based solution allows high spatial and temporal precision control of epithelial permeability to riboflavin. We aim to validate this innovative strategy as an epithelium‐on (epi‐on) protocol for the effective treatment of KC, with obvious advantages in terms of safety, patient comfort, and recovery time. Furthermore, our strategy is compatible with current equipment and riboflavin solutions, allowing to capitalize clinicians' expertise and the resources already existing in private clinics and public health services.This project was financially supported by Foundation for Science and Technology (FCT, Portugal): Exploratory Research Project EXPL/BIA‐BQM/0042/2021, Strategic Projects UIDB/04539/2020, UIDP/04539/2020, and UID/NEU/04539/2019; and by COMPETE‐FEDER (POCI‐01‐0145‐FEDER‐007440).

Modulating neuroinflammation to restore vision

Corneal inflammation is a common feature in most diseases of the eye, including rare eye diseases. Specifically, it has a key role in dry eye, infectious keratitis and after surgery. While the immune system was originally considered the master generator of the inflammatory response, the role of the nervous system (both central and peripheral) in regulating immune activation has finally emerged. Specifically, the role of neurotransmitters and neruopeptides in exacerbating, or modulating, the inflammatory response has been described. These recents findings have shed light on novel mechanisms which can be exploited therapeutically for the treatment of blinding ocular diseases, such as aniridia, graft versus host disease, or corneal burns.

Direct Applications of Non-Thermal Atmospheric Pressure Plasma: An Emerging Therapeutic Era in Ophthalmology.

This article explores the burgeoning role of cold atmospheric plasma (CAP) in ophthalmology. The versatile nature of CAP has transformed various facets of eye care, offering novel possibilities across different clinical domains. From sterilizing surgical instruments without compromising their integrity to effectively managing challenging corneal diseases like microbial keratitis and fungal infections, CAP has shown promising results. Moreover, its potential role in promoting corneal wound healing, facilitating corneal transplants, and enhancing outcomes in cataract surgeries deserves attention. The low-tension plasma blade (ie, the Fugo blade™, Medisurg Ltd. Norristown, PA), a controlled and precise form of CAP, has emerged as a game-changer in delicate eye surgeries. Its unmatched precision, minimal tissue damage, and surgeon-friendly nature have revolutionized ophthalmic procedures, including ptosis correction, dry eye treatment, and conjunctival cyst ablation. Despite conflicting findings on the efficacy of this technology in certain aspects, the extensive body of research on CAP underscores its potential for wider ophthalmic integration. Further investigation, including human trials, is crucial for understanding the in vivo safety profile of CAP for ophthalmic applications and optimizing its use, potentially revolutionizing ocular disease management and improving patient outcomes.

Comparative study between topical insulin, autologous serum, and honey-based eye drops as adjunctive treatment in resistant corneal ulcer

Background Resistant keratitis is a difficult situation faced every day in ophthalmology clinics. Resistance to healing may be attributed to many factors. Many adjunctive agents are widely used in a trial to accelerate healing and to prevent resistance to eliminate the chance of development of disabling complications. Purpose The aim of this study was to compare the effectiveness of topical insulin, autologous serum, and honey-based eye drops as adjunctive therapies in resistant corneal ulcers. Patients and methods This prospective study investigated 45 eyes of infected keratitis not responding to culture-based medical treatment for 2 weeks. The eyes were divided into three groups each of 15 eyes. The insulin group was treated with topical insulin drops, the serum group with autologous serum drops, and the honey group with honey-based drops. Culture-based medical treatment was also continued in the three groups till complete healing was achieved. The results of the three groups were compared regarding the time needed for healing and best-corrected visual acuity outcome. Results Best-corrected visual acuity improved by one or more lines in 11 (73.33%) cases in the insulin group, in 10 (66.67%) cases in the serum group, and in nine (60%) cases in the honey group, with no statistically significant difference (χ 2=1.525, P=0.822). Healing occurred in 14–28 days in 12 (80%) cases in the insulin group, in 13 (86.67%) cases in the serum group, and in 10 (66.67%) cases in the honey group, with no statistically significant difference (χ 2=1.8, P=0.407). The remaining cases in each group required amniotic membrane transplantation due to thinning. Conclusion The effects of topical insulin, autologous serum, and honey-based eye drops, when used as adjunctive methods added to the culture-based medical therapy in the management of resistant corneal ulcers, were comparable. Autologous serum gave slightly higher effect than topical insulin and honey-based eye drops but the difference was statistically insignificant.

Herpes simplex keratitis: an epidemiologic study

Background Recurrent keratitis due to herpes simplex virus (HSV) infection is called herpes simplex keratitis. Aim of the work The aim of the study was to assess the incidence of herpes simplex keratitis to total infectious keratitis, risk factors, and complications of different presentations of herpes simplex keratitis. Patients and methods This prospective and observational clinical study was carried out at the cornea unit of the Tanta University Ophthalmology Hospital on 100 patients who suffered from herpes simplex keratitis during 1 year from the first of January 2021 to the end of December 2021. Results The incidence of HSK was 100, 5.12% cases of total cases of keratitis (1950) who attended the Ophthalmology Outpatient Clinic. The incidence of HSK peaks in middle age from 20- to 60 years, younger patients tend to have more recurrences and complications leading to a greater reduction of vision. Conclusion Recurrences of the disease are the major cause of ocular morbidity. HSV stromal keratitis is found to occur more commonly in recurrences than other types. Earlier diagnosis through increased suspicion in patients with risk factors and rapid diagnostic techniques improve outcomes for HSK patients.

Indications and Outcomes of Repeat Keratoplasty for Graft Failure at a Tertiary Eye Care Center in Nepal.

Graft failure is a common complication following keratoplasty requiring repeat keratoplasty (re-KP). To determine the indications and outcome of repeat keratoplasty at a tertiary eye care centre in Nepal. This was a retrospective study of 78 patients who underwent re-KP for graft failure in Tilganga Institute of Ophthalmology from Jan 2015 to Dec 2020. Indications for the primary keratoplasty, causes of graft failure and outcomes of re-KP in terms of vision acuity, graft clarity and secondary glaucoma were evaluated. Cases of regraft with less than one-year follow-up period were excluded. A total of 78 re-KPs had been performed in 78 patients during the study period. Seventy eyes had undergone single corneal regraft and 8 eyes had undergone multiple (second or third) regraft surgery. Most common indication of primary keratoplasty was infectious keratitis (n=36; 46.2%). On follow up, 36 eyes (46.2%) were clear at the last visit, of which 31 eyes were single regraft cases and 5 were of multiple regraft cases. Most common cause of graft failure was graft infection (n=34; 43.6%) followed by corneal scarring (n=12; 15.4%). Of 42 eyes with failed regrafts, recurrence of the preoperative infection was commonest cause (n=15, 35.7%) followed by secondary glaucoma (n=11; 26.2%). Of 36 eyes with clear regraft, only 4 eyes (11.11%) achieved best corrected vision of ≥6/18 and remaining 32 eyes had BCVA <6/18 due to associated cataract, secondary glaucoma and high astigmatism. The most common cause for re-KP includes graft infection followed by secondary glaucoma. Outcomes of corneal regrafts in the form of graft clarity and visual acuity are suboptimal.

Frequency and visual outcomes of herpes simplex keratitis in a Kuwaiti tertiary referral center.

Herpes simplex virus (HSV), a cause of many ocular pathologies, may affect the corneal epithelium, stroma, or endothelium, with the epithelium as the most frequently affected location. We aimed to determine the frequency and visual outcomes of HSV keratitis over a 1-year period at Farwaniya Hospital, Kuwait. This prospective observational case series included patients diagnosed with HSV keratitis who presented to the outpatient or eye casualty department between September 2022 and September 2023. Full history, demographic profile, detailed ocular and slit-lamp examinations, and visual acuity assessments were recorded prior to and after treatment. Baseline corneal sensation was assessed in the four corneal quadrants using the cotton wisp test. Of the 227 patients who presented with infectious keratitis, 72 (31.7%) were diagnosed with HSV keratitis. The mean (SD) age was 45.86 (16.06) years, and 48 (66.7%) patients were male. The subtypes of HSV keratitis were endotheliitis in 27 (37.5%) patients, dendritic ulcer in 22 (30.6%), stromal keratitis with ulceration in 9 (12.5%) and without ulceration in 8 (11.1%), and geographic ulcer in 6 (8.3%). The mean baseline best-corrected distance visual acuity (BCDVA) differed significantly between the HSV keratitis subtypes (P < 0.001). Most patients (n = 70, 97.2%) had unilateral eye involvement, were treated within 1 - 2 weeks, and demonstrated improved BCDVA. Despite the improvement in BCDVA in all HSV keratitis subtypes, a significant difference in the median BCDVA remained after treatment (P < 0.001). Pairwise comparisons revealed a significantly better BCDVA after treatment in eyes with dendritic epithelial ulcers than in eyes with HSV stromal keratitis with ulceration (P = 0.003) or geographic epithelial ulcers (P = 0.005). After treatment, corneal haze and neovascularization were detected in 54 (75.0%) and 24 (33.3%) patients, respectively. We detected a substantial frequency of HSV keratitis in one of the governorates of Kuwait, with endotheliitis as the most common manifestation. Timely standard treatment interventions based on valid guidelines resulted in BCDVA improvement in all subtypes of HSV keratitis in our series, indicating the importance of early treatment. However, the BCDVA in eyes with dendritic epithelial ulcers remained substantially better than that in eyes with geographic epithelial ulcers or HSV stromal keratitis with ulceration, signifying the effect of the initial HSV keratitis subtype on visual outcomes. To our knowledge, this is the first study to highlight the frequency of HSV keratitis in a Kuwaiti hospital, and larger-scale research in this region is needed to further understand and manage the condition.

Outcome of Optical Keratoplasty for Corneal Scar due to Infective Keratitis.

Corneal opacity is an important cause of blindness in developing countries. This study analyzes optical keratoplasty performed for corneal opacity due to infective keratitis. This is a retrospective study of all consecutive cases of optical keratoplasty performed between 2011 and 2014 (four-year period) for healed infective keratitis. Cases with less than two months' followup were excluded during outcome evaluation. Comparison was made between keratoplasty for Microbial and Viral (herpetic) Scar. Ninety-three eyes of 93 patients were enrolled. Fifty-nine (63.4%) were male. Average age of patients was 38.9±19.5 years. Average donor endothelial cell count was 2713±434.5 cells/mm2. Fifty-four (58%) corneal scars were due to microbial keratitis and others were herpetic. Eighty-five (91.4%) had undergone penetrating keratoplasty. Eighty-eight (94.6%) cases were included for outcome analysis. Average follow-up duration was 37±27.5 months. Fifty-two (59%) had clear graft at their last visit. Twenty-three (26.1%) grafts had endothelial failure and 13 (14.7%) grafts failed due to late onset keratitis. Twenty-five (28.4%) had vision of ≥6/18. Rejection occurred in 24(27.2%) and glaucoma in 11(12.5%). Post-operatively viral keratitis in the graft occurred significantly more inViral Scar Group (38.6%, n=15) than in Microbial Scar Group (5.5%, n=3). But there was no significant difference in graft clarity, rejection, vision and secondary glaucoma between the two Groups. Outcome of keratoplasty for post-infectious scars was found fairly satisfactory. Although occurrence of viral keratitis was higher in case of keratoplasty done for Viral Scars, the final result was similar to that of microbial scar.

Bacterial and fungal isolates from 107 cases of ulcerative keratitis in Japanese Thoroughbred racehorses (2017–2021)

Infectious ulcerative keratitis is a common disease in racehorses. To improve treatment outcomes, this study aimed to assess the antimicrobial susceptibilities of bacterial and fungal isolates obtained from the cornea of Japanese Thoroughbred racehorses with equine infectious ulcerative keratitis. Bacterial and fungal cultures were performed for 166 corneal swabs from 107 cases. A disc diffusion test and minimum inhibitory concentration test were also performed to assess antimicrobial susceptibility of the bacterial and fungal isolates, respectively. Bacterial and/or fungal isolates were obtained from 85.0% (91/107) of the cases. Staphylococcus was primarily isolated from bacterial isolates, including methicillin-resistant Staphylococcus aureus (MRSA), Aerococcus, Streptococcus, Acinetobacter, and Pseudomonas. Aspergillus was primarily isolated from filamentous fungi, and Debaryomyces species was primarily identified in yeast-like fungi. Ofloxacin resistance was observed in 100% (12/12), 15.9% (7/44), and 25.0% (3/12) of MRSA, Staphylococcus, and Streptococcus isolates, respectively. The prevalence of quinolone-resistant Staphylococci and Streptococci has increased in the past two decades. All Aspergillus isolates were susceptible to voriconazole, whereas other filamentous fungi, including Fusarium, were less susceptible to voriconazole. Further studies are required to determine effective treatments for antimicrobial-resistant isolates.