Severity Classification of Limbal Stem Cell Failure Due to Steven Johnson Syndrome in the Light of the Classification Consensus of Limbal Stem Cell Deficiency.

OBJECTIVES: To examine and to understand the limbal stem-cell deficiency (LSCD) because of Steven-Johnson syndrome (SJS) in line with the new classification system for the first time in the literature. METHODS: Medical records of patients with LSCD because of SJS were reviewed retrospectively. In addition to demographic data and ophthalmologic or systemic findings, anterior segment photographs of the patients were reviewed retrospectively. Limbal stem-cell deficiency severity was graded according to the classification published by the Limbal Stem Cell Working Group. RESULTS: Twenty-four eyes of 14 patients with eye involvement secondary to SJS were included in the study. The mean age of the patients was 36.09±16.70 (9-58) years and the female-to-male ratio was 11:3. The anterior segment photographs of the patients were evaluated by two independent masked observers. Limbal stem-cell deficiency severity was graded according to the classification published by Deng et al. Corneal opacity was divided into three stages according to the area of involvement. Corneal opacity was classified as Stage I if the central 5 mm region of the cornea was not affected, as Stage II if the central 5 mm region of the cornea was affected, and as Stage III if the entire corneal surface was affected. Limbal involvement was classified as Stage A if it was below 50%, as Stage B if it was between 50% and 100%, and as Stage C if it was 100%. CONCLUSION: This is the first study in the literature to describe and classify LSCD because of SJS, according to the new LSCD classification. Consistent with the results, LSCD follows a bimodal distribution. Most patients demonstrated severe (Stage III-32.14%) or mild (Stage IA-21.42%) LSCD.

Ocular manifestations of granulomatosis with polyangiitis: report from a tertiary eye care center.

PURPOSE: To report demographic characteristics and ophthalmological manifestations of patients with granulomatosis with polyangiitis (GPA) in a tertiary eye care center in Turkey. METHODS: Medical records of patients with GPA-related ocular manifestations evaluated between 2013 and 2023 were included. Demographic and clinical characteristics of the patients including nature of systemic involvement, ophthalmologic symptoms and signs, laboratory investigations and treatment modality were reviewed. RESULTS: Twelve eyes of 10 patients (5 female/5 male) were included. The mean age was 57.2 ± 12.2 (35-71) years. Five (50%) patients were already diagnosed with GPA. Ocular involvement was the first manifestation of GPA in 3 patients. The remaining 2 patients had simultaneous systemic and ocular symptoms at presentation. Conjunctival hyperemia (9 eyes) and pain (7 eyes) were the most frequent presenting symptoms followed by blurred vision (3 eyes). The frequencies of ocular manifestations were as follows:episcleritis (3 eyes), isolated peripheral ulcerative keratitis (PUK) (3 eyes), scleritis (3 eyes), simultaneous PUK and scleritis (2 eyes) and periorbital mass (1 eye). CONCLUSION: Ophthalmological manifestations can be the initial findings in GPA. Since GPA can affect different structures of the eye, it sometimes might be challenging for ophthalmologists. Therefore, it is crucial for ophthalmologists to be well-informed about GPA-related ocular findings and to have a high index of suspicion for GPA. Although PUK associated with scleritis is highly suggestive for GPA, isolated cases of PUK or scleritis can be seen in GPA. Therefore, it is important to adopt a multidisciplinary approach, consider GPA in differential diagnosis, and benefit from accurate diagnostic tests.

Amniotic Membrane Transplantation for Reconstruction of Ocular Surface Lesion Excisions in Pediatric Population.

PURPOSE: To define the use of human amniotic membrane transplantation (hAMT) for reconstruction of the ocular surface after ocular surface lesion excisions in pediatric population during the last decade in a tertiary eye center. METHODS: A total of 31 patients who underwent hAMT procedure because of the excision of ocular surface lesions between January 2009 and December 2021 were included in this study. The medical data were retrospectively evaluated. RESULTS: The female-to-male ratio was 14/17. The mean age of the patients was 10.1±4.1 (range, 1-18) years. Although a single hAMT was applied to most of the cases (94.4%; 34 eyes), more than one hAMT was applied to 5.6% of cases (2 eyes). The amniotic membrane degradation duration was found to be 21.5±10.8 (range, 13-50) days. CONCLUSIONS: Amniotic membrane is used as a biomaterial in various ocular surface diseases with its anti-inflammatory, antimicrobial, and wound healing properties. Although widely used, there are only a few studies reporting its clinical efficacy in the pediatric age group. It seems to be safe and effective in pediatric age group for ocular surface reconstruction after ocular surface lesion excisions.

Clinical Approach to Ocular Cicatricial Pemphigoid.

Objectives: To evaluate the demographic data, ocular and systemic findings, clinical management, and outcomes of patients with ocular cicatricial pemphigoid (OCP). Materials and Methods: The medical records of 11 patients diagnosed as having OCP in the ophthalmology department of Ege University between 2008 and 2021 were evaluated retrospectively. Results: The patients' mean follow-up time was 14±5.76 months. All eyes (100%) had conjunctival involvement and 18 (81.81%) had corneal involvement. According to the Tauber staging system, 7 (31.81%), 8 (36.36%), and 7 (31.81%) of the eyes were stage 2, 3, and 4, respectively. The diagnosis was confirmed in 6 (66.66%) of 9 patients who underwent biopsy. Amniotic membrane transplantation was performed in 7 eyes, entropion surgery in 2 eyes, and electrocauterization for trichiasis in 5 eyes. Systemic involvement was observed in 45.45% (5/11) of patients, most commonly oral mucosal involvement (18.18%). Review of medical records showed that alkylating agents, steroids, and dapsone were used in patients treated before 2020. Mycophenolate mofetil was preferred to be used in combination with corticosteroids. Although treatment responses before mycophenolate mofetil usage could not be evaluated well because of loss to follow-up, 4 (66.66%) of 6 patients who received steroid treatment combined with mycophenolate mofetil showed partial or complete clinical remission. No serious side effects and drug withdrawal were observed. Conclusion: OCP is a sight-threatening autoimmune disease that affects older adults. Although positive biopsy results are valuable for diagnosis, negative results do not exclude the diagnosis. The main treatment is systemic immunosuppressives. Disease activity can be suppressed, especially with early initiation of drug therapy. These patients require a multidisciplinary approach. Especially in the presence of isolated ocular findings, ophthalmologists should be able to make the decision to start immunosuppressive treatment, and systemic treatment should not be delayed.

Evaluation of the factors that influence surgical outcome in conjunctival-limbal allograft transplantation.

OBJECTIVE: To evaluate the surgical results and the variables affecting the outcomes in conjunctival-limbal allograft transplantation (CLAL). METHODS: Patients who underwent CLAL for limbal stem cell deficiency (LSCD) between 2007 and 2019 were included in the study. LSCD staging was performed according to the staging system developed by the 'Limbal Stem Cell Working Group'. Stage 1C and higher stage LSCD patients were included in the study. 'Successful surgical outcome' was defined as improvement in LSCD stage at 1 year postoperatively. RESULTS: A total of 19 eyes of 19 LSCD patients were included. The mean age of the patients was 40.21 ± 14.65 (6-65) years, and the male/female ratio was 12/7. CLAL was performed in 9 (47.3%) patients with Stage 2B, 9 (47.3%) patients with Stage 3 and 1 (5.4%) with Stage 1C. LSCD aetiology; chemical injury (12), vernal keratoconjunctivitis (2), aniridia (1), corneal degeneration (1), and unknown (3). Surgery was successful in 52.6% of cases. Surgical success was associated with lower LSCD stage (p = 0.04). Lower grades of chemical injury at presentation and a longer time interval between injury and CLAL were associated with higher surgical success (p = 0.001; p = 0.001). The mean postoperative follow-up time was 50.77 ± 29.46 (6-98) months. CONCLUSIONS: Despite graft rejection and long-term use of immunosuppressants, CLAL is still one of the most preferred techniques in the treatment of bilateral LSCD. Preoperative LSCD stage and degree of chemical burn are important factors affecting the surgical outcome. Also, CLAL surgery should not be rushed and should be performed when inflammation has subsided.

Oxidative Stress Biomarker Levels of Simulated Artificial Body Fluids: Comparative HPLC-PDA and LC-MS/MS Approaches: Significance of Raw PDA and MS/MS Data for Chemometric Discrimination.

HPLC-PDA, LC-MS/MS methods were developed for simultaneous determination of a group of oxidative stress biomarkers (OSBs); 2dA, 2dC, 2dU, 3NLT, 5HMU and 8OHdG in 10 simulated artificial body fluids. O-phosphoric acid and methanol composed mobile phases A and B for gradient elution in HPLC-PDA using ODS-2 column. Linearity obtained for 1.0×10-6-1.0×10-4M range. LODs were 1.73×10-6, 1.19×10-6, 2.59×10-6, 1.40×10-6, 2.21×10-6 and 4.07×10-6M for 2dU, 8OHdG, 2dA, 2dC, 5HMU and 3NLT, respectively. LOQs were 5.29×10-6, 4.02×10-6, 6.82×10-6, 4.02×10-6, 6.82×10-6 and 9.92×10-6M. About 10 mM aqueous ammonium acetate solution and methanol containing 0.1% (v/v) formic acid composed mobile phases A and B for gradient elution in LC-MS/MS. Linearity obtained for 1.0×10-8-1.0×10-6M range. LODs were 2.88×10-10, 1.01×10-8, 3.38×10-9, 1.36×10-7, 1.81×10-7 and 1.40×10-8M for 2dU, 8OHdG, 2dA, 2dC, 5HMU and 3NLT, respectively. LOQs were 9.37×10-10, 3.22×10-8, 1.91×10-8, 4.53×10-7, 5.90×10-7 and 2.18×10-8M. Both methods were validated using ICH Q2(R1) guideline. Specificity, linearity, range, accuracy, precision, reproducibility, LOD, LOQ and recovery were achieved. Chemometric analysis was performed on raw PDA and MS data to check their significance for discrimination of OSBs. Sets of single and triple quadrupole fragmentations were evaluated for principle component analysis. Chosen number of PCs successfully distinguished OSBs of interest.

Evaluation of Limbal Stem Cell Transplant Success in Ocular Chemical Injury.

OBJECTIVES: We evaluated limbal stem cell transplant success in limbal stem cell deficiency due to chemical injury at a tertiary eye care center in Turkey with a novel system for describing limbal stem cell deficiency, as developed by the Limbal Stem Cell Working Group. MATERIALS AND METHODS: Medical records of 80 eyes of 80 patients after limbal stem cell transplant for limbal stem cell deficiency secondary to chemical injury were included, with patients grouped according to surgical procedure, ie, limbal autograft, limbal allograft, and cultivated limbal epithelial cell transplant. Surgical success was defined as improvement in postoperative year 1 of limbal stem cell deficiency stage. RESULTS: Patients' mean age was 37.9 ± 15.7 years (range, 4-71 years). Male/female ratio was 2.4. Forty-five patients (56.3%) were injured with alkaline substance, and 16 (20%) with acid substance. Mean follow-up time was 60.3 ± 30.6 months (range, 6-118.6 months). Limbal autograft, allograft, and cultivated limbal epithelial cell transplants were performed in 58 (72.5%), 12 (15%), and 10 (12.5%) eyes, respectively. Intervals between injury and surgery in limbal autograft, limbal allograft, and cultivated limbal epithelial cell transplants were 43.3 ± 94.1 months (range, 0.5-592 months), 14.5 ± 10.6 months (range, 2.4-32.5 months), and 122.8 ± 158.9 months (range, 21.1-504 months),respectively (P = .02); and surgical success rates in each group were 65.5%, 41.7%, and 90%, respectively (P = .03). Overall surgical success rate was 65%. CONCLUSIONS: Accurate determination of the limbal stem cell deficiency stage is crucial for proper evaluation of surgical success. Surgery type and interval between injury and surgery were the most important factors associated with higher surgical success rates. Despite the limited number of patients in the subgroups, the results were remarkable to emphasize the significance of a novel limbal stem cell deficiency scoring system.

Correction of high astigmatism with toric intraocular lens in eyes with corneal transplant.

OBJECTIVES: To evaluate the results of toric intraocular lens (IOL) implantation during cataract surgery in eyes with high regular astigmatism associated with prior penetrating keratoplasty (PK). METHODS: A retrospective data analysis of patients with prior PK, who underwent uncomplicated cataract surgery with hydrophobic toric single piece IOL (EyeCryl Toric®, Biotech Vision Care, Luzern, Switzerland). RESULTS: A total of 18 eyes of 18 patients were included in the study. The mean age was 53.4 ± 12.4 (25-70) years. The mean follow-up period was 15.5 (4-24) months. The mean best corrected visual acuity (BCVA) significantly increased from 1.36 ± 1.0 logMAR to 0.31 ± 0.17 logMAR (p < .001) pre- and post-operative 4 weeks, respectively. There was no significant change in mean BCVA during follow-up; mean BCVA was 0.32 ± 0.17 logMAR at the last visit. The mean pre-operative topographic astigmatism was 6.52 ± 1.80 diopters (D). The mean manifest refraction astigmatism was decreased from 6.55 ± 1.62 D to 2.80 ± 1.43 D (p˂0.001). The mean Surgically induced astigmatism (SIA) was 3.74 ± 0.77 D according to vector analysis. There was no patient with graft rejection or failure, the mean endothelial cell loss rate was 12.75 ± 3.76% (7-17%). There was no patient requiring IOL reposition. CONCLUSIONS: Toric IOL implantation during cataract surgery provides an option to correct astigmatism in post-PK eyes with high regular astigmatism. When appropriate patients are selected it is a safe method to achieve significant improvements in visual acuity and astigmatism.

Clinical Characteristics and Severity Distribution of Tertiary Eye Center Attendance by Ocular Chemical Injury Patients.

OBJECTIVES: To report demographic characteristics, types and grades of injury, regional distribution of injury severity, clinical findings, and long-term results of acute ocular chemical burns. METHODS: Medical records of patients with chemical burns between 2010 and 2020 who were admitted to Ege University less than 72 hr after the injury were reviewed. Age, gender, cause of the burn, injury severity, initial and final best-corrected visual acuity, surgical intervention, and complications were recorded. The injury severity was graded according to Dua classification. RESULTS: A total of 104 patients (137 eyes) were included. The mean age was 42.69±17.39 (7-90) years with a male-to-female ratio of 86:18. The most common causes were home (32.6%) and industrial accidents (45.1%). The causative agent percentages for alkaline, acid, and neutral were 49.0%, 35.5%, and 5.7%, respectively. The percentages of eyes in each grade (1-6) were 16.0%, 16.0%, 15.3%, 16.7%, 17.5%, and 18.2%, respectively. Complications mostly occurred in eyes with grade 2 or higher injuries (83.7%). The relationship between injury grade and limbal stem-cell deficiency was statistically significant (P<0.001). Surgery was mostly needed in grade 4 or higher injuries (44 eyes). CONCLUSION: The severity of the burn is one of the most important prognostic factors in chemical burns. It is important to determine the spreading of the regional injury severity beside the global one to predict complication risk of the injuries. In the present study, the injury distribution was homogeneous in all grades. Limbal stem-cell deficiency development took place mostly in grade 5 and 6 burns as expected.

Ten Years of Pediatric Ocular Chemical Burn Experience in a Tertiary Eye Care Center in Turkey.

OBJECTIVES: To report 10 years of pediatric ocular chemical burn experience in a tertiary eye care center in Turkey. METHODS: Thirty-three patients aged 18 years and younger who presented with ocular chemical burn between 2011 and 2021 were enrolled. Demographic data and clinical characteristics of patients were reviewed. Limbal stem cell deficiency (LSCD) stage was assessed according to LSCD working group's staging system. The initial and final best-corrected visual acuities were recorded. RESULTS: The mean age was 10.4±5.5 (0.25-18) years with an F/M ratio of 12/21. Eleven (33.3%) of the patients were injured with acid and 5 (15.1%) with alkaline. The most common causative agent was nail polish remover (n=7, 21.2%), followed by cologne (n=5, 15.1%) and hand sanitizer (n=4, 12.1%). The severity of burn was ≥grade 4 in 20 patients (60.6%). Chemical injury resulted in LSCD in 18 patients (54.5%). Surgery was performed (LSCD ≥Stage 2 B) in 13 patients (39.3%); limbal stem cell transplantation (LSCT) (n=11), staged amniotic membrane transplantation, and symblepharon release (n=2). Penetrating keratoplasty after LSCT was performed in three of 11 patients. The mean follow-up time was 31.9±28.6 months (6-102.33) after the surgery. CONCLUSIONS: In pediatric population, accurate diagnosis and management of ocular chemical burns are challenging. Although the severity of burn and consequently LSCD rate seems to be high in children, comparative studies in a larger population are still needed.

Comparison of Culture-Positive and -Negative Microbial Keratitis

Objectives: To evaluate and compare the risk factors, presenting features, and outcomes of patients with culture-positive and culture-negative microbial keratitis (MK) who presented to a tertiary referral center. Materials and Methods: We conducted a retrospective review of the medical records of 314 patients who were diagnosed with MK in our clinic between 2012 and 2019. Results: Among 314 patients, 142 had positive cultures (45.2%). The mean ages of the culture-positive and -negative patients at the time of diagnosis were 51.39±21.31 (range, 14-90) years and 56.68±21.34 (7-94) years, respectively (p=0.028). The mean best corrected visual acuity (BCVA) of the culture-positive and -negative patients were1.74±1.25 (0-3.1) LogMAR and 1.91±1.23 (0-3.1) LogMAR prior to treatment and increased to 1.21±1.30 (0-3.1) LogMAR and 1.27± 1.29 (0-3.1) LogMAR at last visit, respectively. There was no statistically significant difference between culture-positive and -negative patients' BCVA levels at presentation or last visit. Ninety-two patients (64.7%) were infected with bacteria and 50 patients (35.2%) with fungi. The most common pathogen was Pseudomonas aeruginosa (18.3%), followed by Streptococcus pneumoniae (11.2%) and Fusarium spp. (11.2%). Keratitis foci were either centrally or paracentrally located in 105 eyes (73.9%) of culture-positive patients and 149 eyes (86.6%) of culture-negative patients. Multiple foci were present mostly in culture-positive patients (p=0.001). There was no significant difference between the culture-positive and -negative groups in terms of hypopyon presence (p=0.364). The proportion of contact lens (CL) wearers was 33% (n=47) among culturepositive MK patients and 13.3% (n=23) among culture-negative MK patients, respectively (p<0.001). Culture positivity was found to be significantly higher in keratitis associated with CL use (p=0.0001). Conclusion: Microbiological analysis and culture evaluation are important steps in order to manage proper treatment in microbial keratitis. Prognosis mostly depends on the infectivity of the microbiological agent.

Graft Failure and Repeat Penetrating Keratoplasty.

OBJECTIVES: In this study, we report the indications and outcomes of repeat penetrating keratoplasty and the reasons for graft failure. MATERIALS AND METHODS: We performed a retrospective data analysis of patients who had undergone 2 or more penetrating keratoplasties for the same eye between 1991 and 2016. RESULTS: Among 1613 penetrating keratoplasties, 149 regrafts of 105 eyes were reviewed. The mean follow-up time after repeat penetrating keratoplasty was 3.2 ± 3.9 (range, 3 months to 17 years) years. The mean number of penetrating keratoplasties was 2.25 ± 0.69 per eye (range, 2-6). The most common primary indication for repeat penetrating keratoplasty was bullous keratopathy (31.4%), which was followed by corneal dystrophy (20.0%). The mean follow-up time was 8.05 ± 5.03 years (range, 8 mo to 24.75 y). At the last follow-up, 62 eyes (59%) had clear grafts and the mean best-corrected visual acuity was 1.26 ± 0.99 (range, 0-3) logMAR. Endothelial failure, especially late endothelial failure (36.9%), and glaucoma-related endothelial failure (18.8%) were the most common reasons for failed grafts. Allograft rejection (17.4%) and graft infection (14.1%) constituted the next most frequent causes. CONCLUSIONS: Graft failure is a common indication among penetrating keratoplasties. Primary indications and reasons for failed grafts affect long-term outcomes. Therefore, a better understanding of the indications for risk, leading causes of failed grafts, and complications could help to determine effective preventive measures.

Effect of polyethylene cover on the treatment of exposure keratopathy in ICU.

BACKGROUND: Exposure keratopathy may lead to serious complications such as microbial keratitis, corneal perforation, and visual impairment if not treated. AIM: To compare the effect of carbomer eye drops when used alone and in combination with polyethylene covers in the healing of exposure keratopathy. METHODS: A single blind randomized-controlled trial (RCT) in two intensive care units (ICUs) was carried out in a university hospital in Western Turkey between September 2011 and December 2012. The control group received only carbomer, eye drops while the intervention group received both carbomer eye drops and polyethylene covers. The primary outcome was the decrease or absence of corneal damage, which refers to healing. Corneal damage was followed up with a fluorescein dye test (decrease/absence of the corneal staining) by the same ophthalmologist for 10 days. RESULTS: A total of 43 corneas in 24 patients were studied. Corneal epithelial defects decreased in the intervention group by day 2 and progressed or remained unchanged in the control group every day (P = .001). Patient characteristics did not affect the grade ranges of corneal staining in the groups except for level of consciousness. CONCLUSION: Carbomer eye drops, when used in combination with polyethylene covers, were effective in managing exposure keratopathy. RELEVANCE TO CLINICAL PRACTICE: Corneal damage and further ocular complications can be reduced with the utilization of polyethylene covers in nursing care and treatment.

Multi-parametric evaluation of autologous cultivated Limbal epithelial cell transplantation outcomes of Limbal stem cell deficiency due to chemical burn.

BACKGROUND: The sparsity of established tools for the grading of limbal stem cell deficiency hinder objective assessments of the clinical outcome of cultivated limbal epithelial cell transplantation. To advance towards the development of standards for the comparison of the outcomes of these bio-surgical protocols we have now applied a battery of recognized objective and patient-declared subjective outcome criteria to the autologous modality of cultivated limbal epithelial cell transplantation. METHODS: The prospective study involved ten patients (M/F = 9/1; mean age = 42.1 years) displaying overt unilateral limbal stem cell deficiency complying with the inclusion criteria described in Methods. Limbal biopsies were obtained from the contralateral eye and their outgrowths after 2-week cultures were transplanted on the affected eye after pannus resection. Outcomes were followed up for 12 months. The objective tests were scores for best-corrected visual acuity (BCVA); using the LogMAR scale, a multiparametric ocular surface score (OSS), and the Schirmer's test. Subjective scores were based on patient answers to a) perception of visual improvement/pain; b) the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ 25); and c) the 12-item Ocular Surface Disease Index Questionnaire (OSDI). All procedures were performed under good manufacture practices using solely xeno-free reagents. In all cases, a single biopsy was divided into two pieces and they were expanded in order to prevent outgrowth failure. In 5 patients, both biopsies generated healthy culture sheet. In those cases the lesser outgrowth were used for immune-histological characterization. RESULTS: The experimental parallel outgrowth samples showed a similar percent of p63α+ cells. PreOp and 12-month PostOp BCVAs and OSSs were, respectively, 1.15 ± 0.70; 0.21 ± 0.13 and 7.40 ± 2.01; 2,30 ± 1.30, (p < 0.05). Patient's responses to all three question sets except ocular pain were consistent with significant improvement (p < 0.05). CONCLUSION: Objective clinical metrics demonstrate that in patients with limbal stem cell deficiency, cultivated limbal epithelial cell transplantation improves vision and ocular surface health and subjective visual perceptions.

Chronically retained feathery chestnut-burr spine-related corneal injury: clinical features and outcome.

PURPOSE: To establish the clinical features and outcomes of patients with chronically retained, feathery chestnut-burr spine-related corneal injury. METHODS: The data of the patients who presented with chestnut-burr-related corneal injury between 2010 and 2018 were retrospectively evaluated. Nineteen eyes of 19 patients, with chronically retained corneal intrastromal feathery chestnut-burr spines, were included. RESULTS: The mean age of the patients (11 male and 8 female) was 29.8 ± 19.9 years. Best-corrected visual acuity was 0.13 ± 0.23 logMAR at initial examination and increased to 0.0 ± 0.0 logMAR at last visit. Chestnut-burr spines were located in the peripheral cornea in 14 eyes (73.7%) and in the central cornea in 5 eyes (26.3%). Localized corneal edema surrounding the chestnut-burr spines were detected in all eyes. No eyes were Seidel positive. Three eyes (15.8%) had low-grade anterior chamber reaction. None of the patients had epithelial ulceration or any sign of infection at initial presentation. In order to control acute localized inflammation, all patients were put on topical steroid (loteprednol etabonate). The mean duration of topical steroid treatment was 3.8 ± 1.8 (range 2-7) months. During the follow-up period, inflammation was controlled and no sign of reinflammation occurred. CONCLUSION: Acute inflammation in intrastromal chestnut-burr spines can be well controlled with easy tapering of topical steroids. However, as the reinflammation possibility cannot be excluded, long-term follow-up of these patients is mandatory.

Treatment-Resistant Bacterial Keratitis: Challenges and Solutions.

Bacterial keratitis is an important ophthalmic emergency and one of the most common causes of corneal blindness. The main causes of treatment resistance in bacterial keratitis are failure to eliminate predisposing factors, misdiagnosis and mistreatment. At first, exogenous, local and systemic predisposing factors that disturbing ocular surface must be eliminated to improve corneal ulcers and to prevent recurrences. Smears and scrapings for staining and culture are indispensable diagnostic tools for cases of sight-threatening keratitis (centrally located, multifocal, characterized by melting, painful). Main treatment agents in bacterial keratitis treatment are topical antibiotics. Until the results of culture antibiograms reach the ophthalmologist, empirical antibiotic selections based on direct microscopic examination and gram stain findings are the most appropriate initial treatment approach currently. S. aureus and coagulase-negative staphylococci (CoNS), the most common gram-positive agents, have resistance rates of more than 30% for fluoroquinolone and methicillin. Multidrug resistance rates are similarly high in these microorganisms. P. aeruginosa is the most common gram-negative micro-organism, in case of multidrug-resistant isolates, both functional and anatomical prognosis of the eyes are very poor. In cases of sight-threatening and resistant keratitis, antibiotic susceptibility testing containing imipenem, colistin, and linezolid is seeming to be an important requirement. Despite its efficiency limited to superficial cases, a nonpharmaceutical anti-infective treatment option such as corneal crosslinking for bacterial keratitis is an emerging hope, while antibiotic resistance increases.

Contact Lens-Associated Microbial Keratitis in a Tertiary Eye Care Center in Turkey.

OBJECTIVES: To evaluate the risk factors, causative microorganisms, and presenting features of infection in patients with contact lens-associated microbial keratitis (CLAMK) admitted to a tertiary referral center in Turkey. METHODS: A retrospective review of the medical records of 62 patients who were diagnosed as CLAMK in our clinic between 2012 and 2018 was conducted. RESULTS: The mean age of the patients (22 men and 40 women) at the time of diagnosis was 24.5±8.3 years (range, 16-48). The mean best-corrected visual acuity (BCVA) was 0.7±0.9 log of minimal angle of resolution (logMAR) (0-3) before treatment and increased to 0.1±0.1 logMAR (0-0.4) at the end of the follow-up. All patients, except one using rigid gas-permeable CL, were frequent replacement soft CL users. Thirty-one (50%) patients declared overnight wear, and 37 (58.9%) patients declared showering or swimming in CLs regularly. Cultures of either corneal scrapings or CL materials were positive in 40 (64.5%) eyes, 12 (19.4%) of which had mixed infections. Thirteen strains of microorganisms were demonstrated, among which there were seven (53.8%) gram-negative bacteria, one (7.7%) gram-positive bacteria, four (30.7%) fungi, and Acanthamoeba (7.7%). The most common pathogen was Pseudomonas aeruginosa, followed by Serratia marcescens and Stenotrophomonas maltophilia. According to culture results, P. aeruginosa infections were associated with significantly worse BCVA. Keratitis foci were either centrally or paracentrally located in 39 (62.9%) eyes, and 16 eyes (25.8%) presented with hypopyon. CONCLUSION: Along with growing number of CL users, CLAMK constitutes an important problem with possibly worse visual outcomes. Thus, in addition to meticulous treatment, management of risk factors and behavioral modifications is crucial.

The Utility of Colistin in Multiple Drug-Resistant Pseudomonas aeruginosa Bacterial Keratitis in a Kaposi's Sarcoma Patient

A 71-year-old male patient presented with decreased visual acuity, redness, and discharge in his right eye for 5 days. He had undergone evisceration of his left eye several years earlier. Before presentation, he had received chemotherapeutic agents for Kaposi's sarcoma of the scalp. Slit-lamp examination revealed severe hypopyon and an extensive corneal ulcer with surrounding infiltrate, which extended to the deep stroma. Microbiological evaluation identified the causative agent to be multiple drug-resistant Pseudomonas aeruginosa. Based on culture and susceptibility results, the patient was started on topical colistin 0.19% instilled hourly. Complete resolution of keratitis with residual corneal scarring was observed. In recent years, there has been an increase in drug resistance in P. aeruginosa keratitis. The lack of new antimicrobial agents against these resistant strains has led clinicians to reconsider colistin, which is an old drug. In this report, we aimed to stress the utility of colistin in multiple drug-resistant P. aeruginosa bacterial keratitis in a Kaposi's sarcoma patient.