Mohamed Kamel Soliman

Endogenous endophthalmitis: diagnosis, management, and prognosis

Endogenous endophthalmitis is an ophthalmic emergency that can have severe sight-threatening complications. It is often a diagnostic challenge because it can manifest at any age and is associated with a number of underlying predisposing factors. Microorganisms associated with this condition vary along a broad spectrum. Depending upon the severity of the disease, both medical and surgical interventions may be employed. Due to rarity of the disease, there are no guidelines in literature for optimal management of these patients. In this review, treatment guidelines based on clinical data and microorganism profile have been proposed.

A Peptide Derived from Type 1 Thrombospondin Repeat-Containing Protein WISP-1 Inhibits Corneal and Choroidal Neovascularization

PURPOSE Ocular neovascularization is the primary cause of blindness in a wide range of prevalent ocular diseases including proliferative diabetic retinopathy, exudative age-related macular degeneration, and retinopathy of prematurity, among others. Antiangiogenic therapies are starting to give promising results in these diseases. In the present study the antiangiogenic potential of an 18-mer peptide derived from type 1 thrombospondin repeat-containing protein WISP-1 (wispostatin-1) was analyzed in vitro with human retinal endothelial cell proliferation and migration assays. The peptide was also tested in vivo in the corneal micropocket and the laser-induced choroidal neovascularization (CNV) mouse models. METHODS Human retinal endothelial cells were treated with the WISP-1 peptide and in vitro migration and proliferation assays were performed. Also evaluated was the antiangiogenic effect of this peptide in vivo using the corneal micropocket assay and the laser-induced CNV model. RESULTS Wispostatin-1 derived peptide demonstrated antimigratory and antiproliferative activity in vitro. Wispostatin-1 completely abolished bFGF-induced neovascularization in the corneal micropocket assay. The peptide also demonstrated significant inhibition of laser-induced CNV. CONCLUSIONS An inhibitory effect of Wispostatin-1 on ocular neovascularization was found in vitro and in vivo. The identification of novel and potent endogenous peptide inhibitors provides insight into the pathogenesis of corneal and choroidal neovascularization. The results demonstrate potential for therapeutic application in prevalent ocular disease.

Management of neovascular age-related macular degeneration: current state-of-the-art care for optimizing visual outcomes and therapies in development

Contemporary management of neovascular age-related macular degeneration (AMD) has evolved significantly over the last few years. The goal of treatment is shifting from merely salvaging vision to maintaining a high quality of life. There have been significant breakthroughs in the identification of viable drug targets and gene therapies. Imaging tools with near-histological precision have enhanced our knowledge about pathophysiological mechanisms that play a role in vision loss due to AMD. Visual, social, and vocational rehabilitation are all important treatment goals. In this review, evidence from landmark clinical trials is summarized to elucidate the optimum modern-day management of neovascular AMD. Therapeutic strategies currently under development, such as gene therapy and personalized medicine, are also described.

Diabetic retinopathy: variations in patient therapeutic outcomes and pharmacogenomics.

Diabetes and its microvascular complications in patients poses a significant challenge and constitutes a major health problem. When it comes to manifestations in the eye, each case of diabetic retinopathy (DR) is unique, in terms of the phenotype, genotype, and, more importantly, the therapeutic response. It is therefore important to identify factors that distinguish one patient from another. Personalized therapy in DR is a new trend aimed at achieving maximum therapeutic response in patients by identifying genotypic and phenotypic factors that may result in less than optimal response to conventional therapy, and consequently, lead to poorer outcome. With advances in the identification of these genetic markers, such as gene polymorphisms and human leucocyte antigen associations, as well as development of drugs that can target their effects, the future of personalized medicine in DR is promising. In this comprehensive review, data from various studies have been analyzed to present what has been achieved in the field of pharmacogenomics thus far. An insight into future research is also provided.

High-Resolution Imaging of Parafoveal Cones in Different Stages of Diabetic Retinopathy Using Adaptive Optics Fundus Camera

Purpose To assess cone density as a marker of early signs of retinopathy in patients with type II diabetes mellitus. Methods An adaptive optics (AO) retinal camera (rtx1™; Imagine Eyes, Orsay, France) was used to acquire images of parafoveal cones from patients with type II diabetes mellitus with or without retinopathy and from healthy controls with no known systemic or ocular disease. Cone mosaic was captured at 0° and 2°eccentricities along the horizontal and vertical meridians. The density of the parafoveal cones was calculated within 100×100-μm squares located at 500-μm from the foveal center along the orthogonal meridians. Manual corrections of the automated counting were then performed by 2 masked graders. Cone density measurements were evaluated with ANOVA that consisted of one between-subjects factor, stage of retinopathy and the within-subject factors. The ANOVA model included a complex covariance structure to account for correlations between the levels of the within-subject factors. Results Ten healthy participants (20 eyes) and 25 patients (29 eyes) with type II diabetes mellitus were recruited in the study. The mean (± standard deviation [SD]) age of the healthy participants (Control group), patients with diabetes without retinopathy (No DR group), and patients with diabetic retinopathy (DR group) was 55 ± 8, 53 ± 8, and 52 ± 9 years, respectively. The cone density was significantly lower in the moderate nonproliferative diabetic retinopathy (NPDR) and severe NPDR/proliferative DR groups compared to the Control, No DR, and mild NPDR groups (P < 0.05). No correlation was found between cone density and the level of hemoglobin A1c (HbA1c) or the duration of diabetes. Conclusions The extent of photoreceptor loss on AO imaging may correlate positively with severity of DR in patients with type II diabetes mellitus. Photoreceptor loss may be more pronounced among patients with advanced stages of DR due to higher risk of macular edema and its sequelae.

Sirolimus for Retinal and Uveitic Diseases

Chronic inflammation plays an important role in the pathogenesis of ocular diseases such as diabetic retinopathy, uveitis and age-related macular degeneration. Activation and proliferation of naïve T cells may result in pathological changes responsible for significant visual morbidity. Sirolimus (earlier termed rapamycin) is a novel drug that inhibits cellular kinases and, thereby, inhibits T-cell proliferation. Preclinical studies in experimental models have shown promising results with the use of this pharmacological agent in various ocular conditions. Subsequently, early phase I/II studies have provided encouraging safety and efficacy data. This chapter focuses on the mechanisms of action, preclinical study results and data from human clinical trials of sirolimus in human eye diseases. Key highlights from ongoing phase III clinical trials are also provided. Sirolimus, thus, appears to be an important addition to the armamentarium of steroid-sparing therapeutic agents that act on various steps in the inflammatory pathway.

Adaptive Optics Imaging of Retinal Photoreceptors Overlying Lesions in White Dot Syndrome and its Functional Correlation.

PURPOSE To quantify retinal photoreceptor density using adaptive optics (AO) imaging and correlate it with retinal tomography, fundus autofluorescence, and retinal sensitivity overlying lesions in various white dot syndromes (WDS). DESIGN Prospective cross-sectional study. METHODS setting: Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska, USA. STUDY POPULATION Thirty-five lesions of WDS from 12 patients (19 eyes; mean age: 54.4 ± 15.8 years; 9 female) were analyzed. INTERVENTION Macular lesions (≤3 regions of interest/eye), at 2 fixed eccentric loci, were imaged using AO, spectral-domain optical coherence tomography, and fundus autofluorescence. In this study, lesions were defined as active if there was presence of hyperautofluorescence within the lesions. Photoreceptor density was calculated after manual correction and adjustment for axial length. Retinal sensitivity was assessed using microperimetry and correlated with photoreceptor density using Spearman rank correlation test. OUTCOME MEASURES Mean retinal sensitivity and photoreceptor density at the WDS lesions. RESULTS Mean photoreceptor density was 7331 ± 4628 cones/mm(2) overlying 16 active lesions and 6546 ± 3775 cones/mm(2) overlying 19 inactive lesions (P = .896). Mean retinal sensitivity (9.37 ± 5.34 dB) showed modest correlation with photoreceptor density (ρ = 0.42, P = .03). Retinal sensitivity over lesions with intact inner segment-outer segment (IS-OS) junction was 13.35 ± 3.75 dB and 6.33 ± 4.31 dB over lesions with disrupted IS-OS junction (P = .005). CONCLUSIONS AO imaging may allow high-resolution analysis of photoreceptor loss among lesions in WDS. Such microstructural changes may correlate with functional loss.

Bilateral papillitis and unilateral focal chorioretinitis as the presenting features of syphilis

BackgroundSyphilis is a multisystem bacterial infection caused by Treponema pallidum. The incidence of infection in the United States has risen by more than 75% since the year 2000, when it was at a low of 2.1 per 100,000 people. Ocular involvement may occur in any stage of infection and may present in a variety of ways, with posterior uveitis being the most common manifestation. We report a case of ocular syphilis infection with an unusual presentation of bilateral non-granulomatous panuveitis with papillitis and unilateral focal chorioretinitis.FindingsThis is a retrospective case report with literature review. A 39-year-old Caucasian female presented with a 2-week history of bilateral ocular flashes and left eye pain. Dilated fundus examination revealed mild optic disc edema in both eyes, the right eye more than the left. In the left eye, there was an area of retinal elevation and whitening involving the peripheral retina. Fluorescein angiography, B-scan ultrasonography, and ocular coherence tomography were performed, and laboratory tests were ordered based on the clinical presentation. After rapid plasma reagin (RPR) and fluorescent treponemal antibody absorption (FTA-Abs) were positive, syphilitic uveitis was confirmed, and the patient was admitted for a 14-day course of high-dose intravenous penicillin G.ConclusionsThe first signs and symptoms of syphilis may be ocular, which can lead to a diagnostic challenge. A high index of suspicion is the key for early diagnosis of ocular syphilis. Prompt treatment with intravenous penicillin G is highly effective in resolving the infection.

Sustained-release fluocinolone acetonide intravitreal insert for macular edema: clinical pharmacology and safety evaluation

Introduction: Inflammation plays a key role in the pathological processes leading to macular edema. Sustained release, low-dose intraocular corticosteroid delivery devices provide long-term anti-inflammatory therapy. Recently, a novel fluocinolone acetonide intravitreal insert (FAi, Iluvien), has been introduced with promising long-term results in the treatment of macular edema. Areas covered: An extensive review of the literature in the English language was performed to provide comprehensive information on the pharmacological properties of FAi and its safety and efficacy data from various multi-center randomized clinical trials. Expert opinion: The FAc, Retisert is a sustained-release device that is surgically implanted in the vitreous and has been approved by the US FDA for the treatment of non-infectious intermediate, posterior or panuveitis. FAi was developed after FAc and is an intravitreal corticosteroid delivery system that allows controlled release of therapeutic levels of fluocinolone acetonide (FA). Initial efficacy and safety data suggest that this delivery system maintains clinical effectiveness for up to 3 years after a single delivery of the device. This second-generation fluocinolone delivery device has shown superior safety results in clinical trials compared to the previous version of the higher dose FAc (0.59 mg). Sustained delivery preparations may help to reduce the treatment burden and its associated risks by decreasing the frequency of intravitreal injections. However, much needs to be learnt from additional clinical trials, post-marketing surveillance and results of extension studies. Concerns of intravitreal corticosteroids, such as cataract and increase in intraocular pressure, remain major challenges for this therapeutic strategy.

SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY EVALUATION OF RETINAL STRUCTURE IN PATIENTS WITH SUSACS SYNDROME.

Purpose: To report spectral-domain optical coherence tomography (SD-OCT) features in patients diagnosed with Susacs syndrome. Methods: Clinical report of two cases. Results: Spectral-domain optical coherence tomography was performed in two patients diagnosed with Susacs syndrome. Both the patients had normal macular perfusion on fluorescein angiography (FA). However, SD-OCT revealed bilateral, temporal macular atrophy with disorganization and thinning of the retinal layers. The outer plexiform layer showed nodularity and waviness suggestive of ischemic swelling of the bipolar cells. Conclusion: Retinal structural changes in Susacs syndrome have not been described earlier. Spectral-domain optical coherence tomography may be more sensitive than fluorescein angiography in detecting microstructural retinal alterations in various layers, especially in apparently perfused retina. These findings may provide an insight into the pathogenesis of Susacs syndrome.