Antioxidant Defense and Pseudoexfoliation Syndrome: An Updated Review.

Oxidative stress (OS) affects the anterior ocular tissues, rendering them susceptible to several eye diseases. On the other hand, protection of the eye from harmful factors is achieved by unique defense mechanisms, including enzymatic and non-enzymatic antioxidants. The imbalance between oxidants and antioxidants could be the cause of pseudoexfoliation syndrome (PEXS), a condition of defective extracellular matrix (ECM) remodeling. A systematic English-language literature review was conducted from May 2022 to June 2022. The main antioxidant enzymes protecting the eye from reactive oxygen species (ROS) are superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), which catalyze the reduction of specific types of ROS. Similarly, non-enzymatic antioxidants such as vitamins A, E and C, carotenoids and glutathione (GSH) are involved in removing ROS from the cells. PEXS is a genetic disease, however, environmental and dietary factors also influence its development. Additionally, many OS products disrupting the ECM remodeling process and modifying the antioxidative defense status could lead to PEXS. This review discusses the antioxidative defense of the eye in association with PEXS, and the intricate link between OS and PEXS. Understanding the pathways of PEXS evolution, and developing new methods to reduce OS, are crucial to control and treat this disease. However, further studies are required to elucidate the molecular pathogenesis of PEXS.

Fibroblast Growth Factor-2 (FGF-2) Expression in Pterygia Using Cell Spot Arrays.

Fibroblast growth factor (FGF) is a main regulator of cell differentiation, cell migration and angiogenesis in normal and abnormal conjunctiva epithelia, but specific mechanisms of its aberrant expression are yet to be investigated. In the present study, we investigated FGF-2 protein expression within several pterygia. Using a liquid-based cytology assay, we obtained cell specimens from pterygia and healthy tissues directly from patients. A combination of immunocytochemistry followed by digital image analysis showed significant overexpression of FGF-2 in all the examined pterygia. In 30/60 (50%) cases there were high levels of staining intensity, whereas in the remaining 30/60 (50%) cases there were moderate levels of expression. FGF-2 levels of the control group were significantly lower in comparison with the pterygia group. There was no significant correlation between FGF-2 levels and either sex or location of the pterygium. FGF-2 levels had a significant correlation with morphological characteristics of the pterygia. More specifically, FGF-2 levels were significantly higher in the pterygia with a fleshy morphology. Interestingly, recurrent lesions demonstrated high expression levels. An overexpression of FGF-2 has been observed frequently in pterygia, where it may play a crucial role in determining the lesion's progression. FGF-2 upregulation correlates with the morphology of pterygia and its tendency to recur. Cell spot analysis based on liquid-based cytology is a simple, yet effective, method for detecting a broad spectrum of protein markers and could be useful in analyzing potential pterygia patient samples.

c-FOS Expression Analysis in Pterygia Cell Spot Arrays.

BACKGROUND/AIM: Mechanisms of c-FOS activation in the onset and progression of pterygia remain under investigation. This study aimed to comparatively analyze c-FOS proto-oncogene expression levels in neoplastic pterygia and normal epithelia. MATERIALS AND METHODS: We used a liquid-based cytology assay on thirty (n=30) pterygia cell populations and normal epithelia (n=10) extracted by a smooth scraping of conjunctiva epithelia. Applying a cell spot-based technique, we constructed five (n=5) slides, each containing eight (n=8) cell spots. A modified immune-cytochemistry (ICC) assay for c-FOS protein was used. Additionally, digital image analysis was implemented to calculate c-FOS immunostaining intensity levels. RESULTS: High staining intensity levels of c-FOS were detected in 12/30 (40%), whereas the rest 18/30 (60%) demonstrated moderate expression. c-FOS levels were statistically significantly higher in the pterygia compared to control tissues (p=0.001). c-FOS levels in the pterygia were not associated with the sex of patients (p=0.678), the presence of recurrent lesion (p=0.390) or the location of the lesion (p=0.158). The levels of c-FOS, however, were marginally significantly affected by the morphology of the pterygia (p=0.005). More precisely, the c-FOS levels were significantly higher in pterygia with a fleshy morphology. CONCLUSION: c-FOS over-expression is observed frequently in pterygia. It seems to be critically involved in the molecular mechanism of the lesion by its over-expression affecting partially their morphological features. Cell spot liquid - based array analysis is an innovative, easy to implement technique for simultaneously evaluating a broad spectrum of molecules in multiple specimens on the same slide.

Emerging roles of oxidative stress in the pathogenesis of pseudoexfoliation syndrome (Review).

Pseudoexfoliation syndrome (PEXS) is a systemic disease caused by defects in the extracellular matrix (ECM) remodelling process leading to the chronic deposition of extracellular, fibrillary, white flaky pseudoexfoliation material (PEXM) throughout the body. Specifically, PEXM deposits on the lens capsule cause open-angle glaucoma, cataracts and blindness in patients with PEXS. Several gene single nucleotide polymorphisms are linked to the development of PEXS in humans, including lysyl oxidase-like 1 gene, clusterin and fibulin-5. The exact reason for the PEXM generation and its resulting pathogenesis is not well understood. However, defective ECM remodelling and oxidative stress (OS) have been hypothesized as significant events leading to the PEXM. Specifically, the link between OS and PEXS has been well studied, although the investigation is still ongoing. The present review explored recent advances in various aspects of PEXS and the involvement of OS in the eye for PEXS development.

Aqueous Humour Ofloxacin Concentration after Topical Instillation in Patients with Dry Eye Disease.

Background and Objectives: A prospective, randomized clinical trial was conducted to evaluate the concentration of ofloxacin in the aqueous humour (AqH) of patients suffering from dry eye disease (DED) after topical instillation. Materials and Methods: Ninety-one (91) cataract patients scheduled for phacoemulsification were categorized into three groups according to DED severity. Group I (n = 17) was comprised of subjects without DED, patients in group II (n = 37) were evaluated as having non-severe DED, while group III (n = 37) consisted of patients suffering from severe DED. Preoperatively, patients received 4 drops of 0.3% of ofloxacin at 15 min intervals. One hour after the last instillation, aqueous samples were collected intraoperatively. Results: The median AqH concentration of ofloxacin in group I was 199.9 ng/mL (range 92.2−442.8 ng/mL), while in group II it was 530.5 ng/mL (range 283.7−1004.9 ng/mL), and 719.2 ng/mL (range 358.0−1512.4 ng/mL) in Group III, p < 0.001 (Kruskal-Wallis tests). Pairwise tests (two-tailed with Bonferroni corrections) between groups resulted in a p-value of 0.001 when group II was compared to group I and group III was compared to group I, and a p-value of 0.020 when group II was compared to group III. The severity of DED, across groups I, II, and III, and the levels of ofloxacin revealed a strong positive correlation (r = 0.639, p < 0.001). Conclusions: Ofloxacin concentration in the AqH after topical drop instillation may be affected by the degree of ocular surface inflammation in patients suffering from DED.

Nanotechnology-based formulations to amplify intraocular bioavailability.

Conventional drug delivery formulations, such as eye drops and ointments, are mainly administered by topical instillation. The topical delivery of ophthalmic drugs is a challenging endeavor despite the eye is easily accessible. Unique and complex barriers, serving as protection against extrinsic harmful factors, hamper therapeutic intraocular drug concentrations. Bioavailability for deeper ocular tissues of the anterior segment of the eye is exceptionally low. As the bioavailability of the active substance is the major hurdle to overcome, dosing is increased, so the side effects do. Both provoke patient poor compliance, confining the desired therapeutic outcome. The incidence and severity of adverse reactions amplify evenly in the case of chronic treatments. Current research focuses on the development of innovative delivery strategies to address low ocular bioavailability and provide safe and convenient dosing schemes. The main objective of this review is to explore and present the latest developments in ocular drug delivery formulations for the treatment of the pathology of the anterior segment of the eye. Nanotechnology-based formulations, that is, organic nanoparticles (liposomes, niosomes/discosomes, dendrimers, nanoemulsions, nanosuspensions, nanoparticles/nanospheres) and inorganic nanoparticles, nanoparticle-laden therapeutic contact lenses, in situ gelling systems, and ocular inserts, are summarized and presented accordingly.

Kyrieleis Arteriolitis Associated with Acute Retinal Necrosis due to Herpes Simplex Virus Type 1 Secondary to Herpetic Encephalitis.

We report the case of a 52-year-old woman who presented to the emergency department with acute retinal necrosis in her left eye secondary to herpes simplex virus type 1 encephalitis for which she had been hospitalized four months before. Treatment with intravitreal foscarnet and intravenous acyclovir was promptly commenced followed by the addition of oral prednisolone. PCR analysis of aqueous humor detected HSV type 1 DNA. The condition responded to therapy with partial resolution of intraocular inflammation and improvement of visual acuity, but the presence of Kyrieleis plaques was observed two weeks after the initiation of treatment, when five intravitreal foscarnet injections had been administered. The patient was switched to oral therapy with valacyclovir, and 10 weeks after commencing treatment, the patient's left eye was free of inflammation, having achieved a BCVA of 20/20. Oral steroid treatment was gradually tapered off, and the patient was instructed to remain on prophylactic antiviral therapy. Kyrieleis arteriolitis is an uncommon finding in the context of acute retinal necrosis. As far as we are aware, we report the first case of Kyrieleis arteriolitis in acute retinal necrosis secondary to viral encephalitis and the second one presenting Kyrieleis plaques in acute retinal necrosis caused by herpes simplex virus type 1. Prior reports of cases of Kyrieleis arteriolitis in acute retinal necrosis are also presented.

Vascular Endothelial Growth Factor Expression Patterns in non- Human Papillomavirus - Related Pterygia: An Experimental Study on Cell Spot Arrays Digital Analysis.

PURPOSE: The role of angiogenic factors -such as vascular endothelial growth factor (VEGF) - in the development and progression of pterygia lesions remains under investigation. In the current study, we analyzed VEGF protein expression in a series of pterygia and normal conjunctiva epithelia. METHODS: Using a liquid-based cytology assay, thirty (n = 30) cell specimens were obtained by applying a smooth scraping on conjunctiva epithelia and fixed accordingly. None of them had a history of Human Papillomavirus (HPV) infection. Similarly, the same process was applied also in normal conjunctiva epithelia (n = 10; control group). We constructed five (n = 5) slides each containing eight (n = 8) cell spots. An immunocytochemistry (ICC) assay was implemented. Digital image analysis was also performed for evaluating objectively the corresponding immunostaining intensity levels. RESULTS: All the examined pterygia cell samples over-expressed the marker. High staining intensity levels were detected in 15/30 (50%), whereas the rest 15/30 (50%) demonstrated moderate expression. Overall VEGF expression was statistically significantly higher in pterygia compared to normal conjunctiva epithelia (p=.0001). Concerning the other parameters, VEGF protein expression did not associate with the gender of the patients (p = 0.518), the presence of a recurrent lesion (p = 0.311), the anatomical location (p = 0.191) or with their morphology (p = 0.316). Interestingly, the recurrent lesions demonstrated the highest levels of VEGF expression. CONCLUSIONS: VEGF overexpression is a frequent event in pterygia playing a potentially central molecular role in the progression of the lesion. Cell spot array analysis -based on liquid cytology- seems to be an innovative, easy-to-use technique for analyzing a broad variety of molecules in multiple specimens on the same slide by applying different ICC assays.

Pseudoexfoliation syndrome: The critical role of the extracellular matrix in pathogenesis and treatment.

Pseudoexfoliation syndrome (PEXS) is an age-related condition manifesting mainly in ocular tissues. PEXS is manifested through excess aggregation of fibrillary extracellular material at the anterior part of the eye that consists of a plethora of biomolecules, such as different proteoglycans (PGs) and glycosaminoglycans. PEXS is often linked to increased intraocular pressure, and can also lead to pseudoexfoliation glaucoma with very poor prognosis. Various stimuli are known to affect PEXS, including oxidation stress (OS), UV radiation and osmotic pressure. OS, is prominently involved on the progression of the syndrome as it promotes fibrogenesis, possibly via the induction of transforming growth factor-ß (TGF-ß) and other biomolecular effectors. In addition, PEXS initiation is tightly connected with the dysregulation of extracellular matrix (ECM) homeostasis since aberrant expression of ECM molecules is linked to both the accumulation and low degradation of pseudoexfoliation material. This article aims at uncovering the crucial role of various ECM effectors such as lysyl oxidase-like proteins, matrix metalloproteinases, and TGF-ß1, as well as the biochemical pathways involved in the development and the progression of the PEXS.

TWO-YEAR RESULTS OF INTRAVITREAL INJECTIONS OF AFLIBERCEPT IN COATS DISEASE: A CASE REPORT.

PURPOSE: To report long-term results of treatment with intravitreal injections of aflibercept in a newly diagnosed case of Coats disease. METHODS: An 18-year-old man presented to the retina clinic of our hospital complaining of blurred vision in the right eye for the past 3 months. His past medical and ocular history were unremarkable. The best-corrected visual acuity was 20/200 in the right eye and 20/20 in the left eye. Fundoscopy in the right eye revealed extensive macular edema with a circinate ring of hard exudates in the posterior pole temporally to the macula. Optical coherence tomography demonstrated macular edema with subretinal fluid. Peripheral telangiectasias and light bulb aneurysms in the inferior temporal arcade as well as in the nasal far periphery were found in the right eye in fluorescein angiography, confirming the diagnosis of stage 2B Coats disease. The left eye was normal. RESULTS: The original therapeutic strategy proposed was antivascular endothelial growth factor injections in the right eye, followed by laser photocoagulation. However, the patient did not consent to laser treatment and was treated with aflibercept monotherapy with 8 monthly intravitreal injections of aflibercept, followed by 6 injections every 2 months for a total of 14 injections over a period of 2 years. The best-corrected visual acuity in the right eye improved to 20/25 while optical coherence tomography imaging revealed significant decrease in retinal thickness with resolution of macular edema, and fluorescein angiography demonstrated prominent regression of aneurysms and leakage. CONCLUSION: To the best of our knowledge, this is the first case treated with aflibercept monotherapy, suggesting the significant role of vascular endothelial growth factor in vascular permeability in Coats and supporting the rationale that antivascular endothelial growth factors are a valuable therapeutic option for Coats disease.

Short-term effect of non-preserved cationic oil-in-water ophthalmic emulsion on tear meniscus parameters of healthy individuals in a prospective, controlled pilot study.

Background: This study investigated the effect of instilling a single drop of non-preserved cationic oil-in- water ophthalmic emulsion (Cationorm®) on the lower (LTM) and upper tear meniscus (UTM) parameters of normal eyes. Methods: In this prospective, single-center, non-randomized, controlled pilot study, optical coherence tomography was used to estimate the UTM and LTM height, depth, and cross-sectional area in participants without a history of dry eye disease. In the right eye (study eye), we instilled one drop of Cationorm® in the lower conjunctival sac. Scans of the tear menisci were acquired at baseline, before the instillation, and at 5, 15, and 30 min thereafter. Control scans of the left eye (control eye) were obtained at the same timepoints. The tear meniscus parameters of the study eye were compared with the control eye at each timepoint. Results: Twenty subjects (11 male and 9 female; mean [standard deviation] of age: 37.8 [10.9] years) were included in the study. Compared to the control eye, instillation of a single drop of Cationorm® resulted in significantly higher LTM parameter values and a higher UTM cross-sectional area up to 30 min after instillation (all P < 0.05). The UTM height and depth were significantly greater in the study eye than in the control eye up to 5 min (P < 0.001 and 0.007, respectively) and 15-min (P = 0.045, and 0.002, respectively) after Cationorm® instillation. In the study eye, Cationorm® resulted in a significant increase in LTM parameter values up to 30 min post-instillation (all P < 0.001). The UTM height was significantly greater up to 15 min post-instillation than at baseline. The UTM depth and area increased significantly from baseline to 5 min after instillation (P = 0.043, and 0.002, respectively). Conclusions: Cationorm® seems to have a prolonged residence time on the ocular surface of healthy subjects as indicated by LTM parameters and to a lesser extent by UTM parameters.

Effect of Intravitreal Injection of Aflibercept on Cardiovascular Risk Parameters in Patients with Neovascular Age-Related Macular Degeneration.

OBJECTIVE: Systemic administration of anti-Vascular Endothelial Growth Factors (anti- VEGFs) has been associated with severe cardiovascular adverse events in oncologic patients. The purpose of this pilot study is to evaluate the short-term effect of a single intravitreal injection of aflibercept on biomarkers related to increased risk of cardiovascular disease. PATIENTS AND METHODS: Forty-seven treatment naïve patients with neovascular age-related macular degeneration in one eye were enrolled in the study. The patients underwent treatment with one intravitreal injection of aflibercept in the affected eye. Laboratory biomarkers of cardiovascular disease were evaluated before the first intravitreal injection of aflibercept and at 7 and 30 days after aflibercept administration. More precisely, we evaluated the levels of homocysteine, total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and Creactive protein. RESULTS: There was not any statistically significant change in the levels of the evaluated parameters up to one month after the first intravitreal injection of aflibercept. CONCLUSION: According to our study, the administration of a single dose of aflibercept in eyes with neovascular age-related macular degeneration does not seem to affect the evaluated biomarkers that are related to cardiovascular disease.

Choroidal Thickness Evaluation in a Transfusion-Dependent Beta-Thalassemia Greek Population.

PURPOSE: To evaluate choroidal thickness in a group of beta-thalassemia patients as assessed by enhanced depth imaging optical coherence tomography. PATIENTS AND METHODS: This single-center, observational study involved transfusion-dependent beta-thalassemia (TD-ß-thal) patients and healthy controls. One eye of each participant was included in the study. Submacular and peripapillary choroidal thickness, as well as central macular thickness and retinal nerve fiber layer thickness, were evaluated. RESULTS: Thirty-eight TD-ß-thal patients (mean age 42 ± 10.7 years) and 22 healthy controls (mean age 40.3 ± 10.2 years) were included in the study. Subfoveal choroidal thickness was 297.4 ± 74.5 µm in the patient group and 358.4 ± 71.4 µm in the control group (p=0.003). Overall, in the submacular area, the choroid was found to be significantly thinner in the beta-thalassemia population compared to controls in all evaluated points, except for the spot located 1500 µm nasally to the fovea (p=0.093). In the peripapillary area, choroidal thickness was also significantly lower in the thalassemic population compared to the controls (nasal p=0.033, temporal p=0.01, superior p=0.01), except for the inferior quadrant (p= 0.191). We did not observe statistically significant differences in the retinal nerve fiber layer thickness and the central macular thickness between the two groups (p=0.658 and p=0.276, respectively). No correlations with hemoglobin, serum ferritin or iron levels emerged. Patients with the intermediate subtype appeared to have significantly thinner choroids than the ones with thalassemia major. CONCLUSION: Our findings suggest that choroidal thickness in the submacular and peripapillary area is significantly reduced in thalassemic patients, compared to healthy individuals. Choroidal thinning in beta-thalassemia possibly reflects the effect of chronic anemia and underlying hemodynamic changes on choroidal tissue.

Effect of intravitreal injection of aflibercept on blood coagulation parameters in patients with age-related macular degeneration.

PURPOSE: Treatment with intravitreal injections of anti-vascular endothelial growth factor agents has been associated with an increased risk of arterial thromboembolic events. The aim of the present pilot study was to assess the effect of a single intravitreal injection of aflibercept on coagulation. METHODS: Treatment-naïve patients with age-related macular degeneration (n = 47), who were scheduled to undergo treatment with intravitreal injections of aflibercept, were enrolled. None of the included patients received any anticoagulation therapy or had a history of a recent arterial thromboembolic event. Blood samples were collected before the first intravitreal injection, and at 7 and 30 days after aflibercept administration. We evaluated coagulation parameters, such as platelet count and plasma fibrinogen and D-dimer levels; functional clotting parameters, such as prothrombin time, international normalized ratio, and activated partial thromboplastin time; and anticoagulant parameters, such as the levels of Proteins S and C. RESULTS: The levels of all of the evaluated biomarkers were within the normal range at baseline and at both the time points throughout the study. No statistically significant changes were observed in any of the measured parameters at 1 week and 1 month after aflibercept administration. CONCLUSION: A single intravitreal injection of aflibercept in treatment-naïve patients with exudative age-related macular degeneration has no statistically significant effect on blood coagulation parameters for up to 1 month after aflibercept administration. Our results also provide an explorative statistical data, and further studies are required to evaluate any significant clinical effects of aflibercept on blood coagulation parameters. CLINICALTRIALSGOV ID: NCT03509623.

Comparison of intraocular pressure using Goldmann applanation tonometry versus non-contact tonometry in eyes with high-viscosity silicone oil.

BACKGROUND: To compare intraocular pressure (IOP) measurements using Goldmann applanation tonometer (GAT) and air tonometer (non-contact tonometry [NT]) in vitrectomized eyes with high-viscosity silicone oil tamponade, as well as in normal eyes. PATIENTS AND METHODS: In this prospective comparative study, 32 eyes with silicone oil tamponade of high viscosity (5700 CS) and 32 normal fellow eyes were included. IOP was measured by GAT and air tonometer 30 ± 12 days after vitrectomy, while measurements of central corneal thickness (CCT) were also obtained. RESULTS: In eyes with silicone oil, IOP was 20.09 ± 4.91 mmHg and 16.75 ± 3.86 mmHg using contact tonometer and air tonometer, respectively (p < 0.0001). In normal eyes, IOP was 16.41 ± 2.15 mmHg and 16.31 ± 2.49 mmHg using the same tonometry techniques and this difference was not statistically significant (p = 0.598). In addition, no significant correlation was detected between IOP measurements using both techniques and age, gender, CCT, and type of lens. CONCLUSIONS: It seems that GAT overestimates IOP in eyes with high-viscosity silicone oil compared with NT, while both IOP measurement techniques in normal eyes provide similar values. Further assessment of available IOP measurement methods could possibly establish the most accurate technique for IOP estimation in vitrectomized eyes with silicone oil tamponade.

Effect of a single session of micropulse laser trabeculoplasty on corneal endothelial parameters.

BACKGROUND: To evaluate the effect of a single session of micropulse laser trabeculoplasty on the cornea in eyes with primary open-angle glaucoma and pseudoexfoliation glaucoma. METHODS: This single-centre, prospective, case series enrolled patients with primary open-angle and pseudoexfoliation glaucoma under treatment with glaucoma agents that required additional intraocular pressure reduction. Eyes underwent 360 degrees treatment with 532 nm micropulse laser trabeculoplasty. Central corneal thickness, endothelial cell count, hexagonal cell ratio and co-efficient of variation of endothelial cells were measured before micropulse laser trabeculoplasty and at one, three and six months after treatment. RESULTS: Twenty eyes of 20 patients (mean age 67.6 ± 8.0 years) with primary open-angle glaucoma and 18 eyes of 18 patients (mean age 71.44 ± 6.43 years) with pseudoexfoliation glaucoma were included in the study. Treatment with micropulse laser trabeculoplasty resulted in statistically significantly lower intraocular pressure compared to baseline in both primary open-angle and pseudoexfoliation glaucoma eyes (p < 0.0001 at both comparisons). Central corneal thickness, endothelial cell count, hexagonal cell ratio and co-efficient of variation of the endothelial cell size showed no significant change between baseline and six months after micropulse laser trabeculoplasty in both primary open-angle and pseudoexfoliation glaucoma eyes. CONCLUSION: A single session of micropulse laser trabeculoplasty did not affect central corneal thickness and corneal endothelium parameters in eyes with primary open-angle and pseudoexfoliation glaucoma.

Late-Onset Bilateral Choroidal Metastases from Clear Cell Renal Cell Carcinoma.

AIM: To present a case of clear cell renal cell carcinoma with late-onset bilateral choroidal metastases. Case Report. A 57-year-old male patient in the Oncology Clinic complained of reduced vision in the right eye (OD) for 7 days. The patient, who was under immunotherapy with nivolumab, had been diagnosed with clear cell renal cell carcinoma in the left kidney 15 years ago that recurred in the right kidney before 2 years. Metastases in the brain, lungs, and bones had also been diagnosed. On ophthalmological examination, the visual acuity was 20/50 OD and 20/20 in the left eye (OS). Dilated fundus examination in OD revealed a single raised oval-shaped yellowish choroidal nodule infratemporally with macular involvement. A similar lesion, sparing the macula, was observed in OS. Fundus autofluorescence revealed diffuse punctate hyperautofluorescence on the lesions. Serous macular detachment was also observed in OD. A standardized A-scan ultrasound demonstrated an irregular structure of the lesions with moderate to high internal reflectivity. Based on the history and clinical and echographic characteristics, the diagnosis of bilateral choroidal metastases from renal cell carcinoma was set. CONCLUSION: Choroidal metastases from the primary renal tumor are extremely rare. The time interval between primary malignancy and choroidal metastasis is reported to be 12-96 months. Bilateral choroidal metastases have been described in 9 cases. We describe a rare case where bilateral choroidal metastases were diagnosed 15 years after the initial diagnosis of clear cell renal cell carcinoma.

Bacteriology and Antimicrobial Susceptibility Patterns of Childhood Acute Bacterial Conjunctivitis in Western Greece.

Acute bacterial conjunctivitis is a common, highly contagious infection in children and is usually treated empirically with broad spectrum topical antibiotics. In the current study we investigated bacteriology and antibiotic susceptibility patterns in childhood acute bacterial conjunctivitis in Western Greece. We conducted a retrospective analysis of presumed acute bacterial conjunctivitis cases in ''Karamandaneio'' Pediatric General Hospital of Patras, Western Greece, between February 1, 2013 and January 31, 2018. Specimens from the lower conjunctiva fornix were isolated from 191 cases and outcomes were analyzed to identify the pathogenic bacteria of acute bacterial conjunctivitis and their corresponding antibiotic susceptibility patterns. Patients were divided into 3 groups; Group A included neonates under 28 days of life, Group B children from 1 month to 2 years and Group C from 2 years to 14 years. Results revealed that Staphylococcus spp., Haemophilus spp. and Streptococcus spp. were the most prevalent pathogens. No significant differences in isolated pathogens were found between the age groups. Antibiotic resistance rates were higher against ampicillin, ceftriaxone, ceftazidime and sulfamethoxazole. Resistance rates to Ciprofloxacin were low while none of the evaluated isolates were resistant to vancomycin. We concluded that predominant pathogens of childhood acute bacterial conjunctivitis in Western Greece were Staphylococcus spp., Haemophilus spp. and Streptococcus spp. Continuous surveillance, focused in distinct geographic areas, is encouraged to prepare more precise protocols of empirical treatment.

Expression and Localization of Glycosaminoglycans/Proteoglycan in Pterygium: An Immunohistochemical Study.

Pterygium is a triangle-shaped fibrovascular hyperplasia of the bulbar conjunctiva on the cornea. The purpose of this study was to analyze Proteoglycans (PGs) by Immunohistochemistry (IHC) in pterygium tissues and to compare the results with normal conjunctiva. Twenty-four patients (14 males) undergoing primary pterygium excision and 17 healthy individuals (10 males), undergoing extracapsular cataract surgery, were included. Pterygium tissues and normal conjunctiva tissues were surgically removed. The tissue sections were fixed in 2% paraformaldehyde and incubated with monoclonal antibodies against PGs anti-mouse IgG. Immunohistochemical study showed stronger expression of keratan sulfate in the stroma of the pterygium compared to normal conjunctiva. An increased expression of heparan sulfate was observed in the epithelial layer and around the pterygium vessels. On the other hand, dermatan sulfate showed an increased expression and localization not only in the sub-epithelial area of the pterygium and normal conjunctiva, yet throughout the stroma of the pterygium. The differences in the expression and localization of the studied extracellular matrix proteoglycans in the pterygium tissue compared to normal conjunctiva may explain the tissue hyperplasia, structure, and the functional properties in pterygium.

Micropulse laser trabeculoplasty on pseuodexfoliation glaucoma patients under topical prostaglandin analogue monotherapy: 1-year results.

PURPOSE: To evaluate the effectiveness of a single session of micropulse laser trabeculoplasty (MLT) to lower intraocular pressure (IOP) in patients with pseudoexfoliation glaucoma (PEXG). METHODS: In this single-center, one-arm, prospective study patients with PEXG under prostaglandine analogue monotherapy with inadequate IOP control were treated with 360° 532-nm MLT. Patients were evaluated at 1 day, 1 month, 3 months, 6 months, and 12 months post-MLT while they were treated with the same drug regimen as pre-MLT. Mean IOP reduction and percentage of IOP change during the follow-up were calculated. Cases that required any further intervention, like additional hypotensive medication, laser or surgical therapy, throughout the study period were considered failures and removed from the study. RESULTS: Twenty-seven eyes (27 patients, 17 male) were included in the study. The age of the patients was 72.37 ± 6.29 years and the baseline IOP was 20.41 ± 1.87 mmHg. Treatment with MLT resulted in significantly lower IOP at 1, 3, 6, and 12 months after MLT compared to baseline (p < 0.0001 for all comparisons). By the end of the study, 52.17% of the PEXG eyes demonstrated a ≥ 20% IOP reduction compared to baseline. Four eyes (14.81%) did not respond to MLT (three eyes at 3 months and one eye at 6 months after trabeculoplasty) and were considered failures since they required additional intervention. CONCLUSIONS: Micropulse laser trabeculoplasty appears to be an effective method to lower IOP in patients with PEXG up to 12 month of follow-up period. TRIAL REGISTRATION: The study is registered on www.ClinicalTrials.gov with registration number NCT03483402.