Cerium oxide nanoparticles as promising ophthalmic therapeutics for the treatment of retinal diseases

Nanotechnology offers exciting new approaches for biology and medicine. In recent years, nanoparticles, particularly those of the rare metal cerium, are showing potential for a wide range of applications in medicine. Cerium oxide nanoparticles or nanoceria are antioxidants and possess catalytic activities that mimic those of super oxide dismutase and catalase, thereby protecting cells from oxidative stress. The retina is highly susceptible to oxidative stress because of its high oxygen consumption and high metabolic activity associated with exposure to light. Many retinal diseases progress through oxidative stress as a result of a chronic or acute rise in reactive oxygen species. Diseases of the retina are the leading causes of blindness throughout the world. Although some treatments may delay or slow the development of retinal diseases, there are no cures for most forms of blinding diseases. In this review is summarized evidence that cerium oxide nanoparticles can function as catalytic antioxidants in vivo in rodent models of age-related macular degeneration and inherited retinal degeneration and may represent a novel therapeutic strategy for the treatment of human eye diseases. This may shift current research and clinical practice towards the use of nanoceria, alone or in combination with other therapeutics.

Ocular damage secondary to lights and lasers: How to avoid and treat if necessary

An armamentarium of the latest light and laser technologies are used by physicians of different disciplines to address a variety of aesthetic challenges in the periocular region and throughout the body. If improperly used, these modalities can inflict serious ocular injury on the patient, support personnel, and operator. It is paramount that providers involved in operating these technologies be knowledgeable about the physical and clinically relevant properties of the unit being used. This involves training in the proper utilization, appropriate treatment parameters, and safety measure for each. Selection of the appropriate eye protection is particularly important for both the patient and the personnel. It is also imperative for the laser operator to understand the range of potential ocular complications associated with the cosmetic use of lasers and lights, to recognize the signs and symptoms associated with ocular damage, and to provide efficient first aid measures should damage ensue. Possible ocular complications related to the cosmetic use of lasers and lights range from mild eyelid swelling and erythema to potentially blinding macular injury. Ocular injury may also be inflicted by the improper selection or placement of eye protection. A complete ophthalmologic evaluation and timely management of potential complications is mandated when there is any concern for ocular injury.

Blue light induced retinal oxidative stress: Implications for macular degeneration

A number of studies have shown that oxidative stress can be harmful for the retina. The real causal circumstances that lead to degenerative diseases like age related macular degeneration remain obscure. Whether light induced radical stress is a direct interaction of light with photoreceptors or a secondary mechanism within the pigment epithelium or choroid is in discussion. Among the molecular mechanisms involved are production of reactive oxygen species (ROS), secondary lipid peroxidation, protein oxidation and DNA-damage. The initial trigger to write this review was first a recent finding of our group that the photoreceptor outer segments produce great amounts of ROS and second the detection of ectopic enzymes of the respiratory chain localized there - in addition to the hitherto known ROS sources like the visual pigments with their intermediates and the photoreceptor mitochondria harbouring the respiratory chain.

Pseudopemphigoid as caused by topical drugs and pemphigus disease

Pseudopemphigoid can cause a chronic cicatricial conjunctivitis that is clinically identical to the manifestations seen in mucous membrane pemphigoid, a disorder with a common clinical phenotype and multiple autoimmune links. For the purpose of this review, we will describe pseudopemphigoid as caused by topical drugs, the most common etiology with ocular manifestations, and as caused by the pemphigus disease, a more rare etiology. Specifically, we will discuss the ophthalmological features of drug-induced cicatricial conjunctivitis, pemphigus vulgaris, and paraneoplastic pemphigus. Other etiologies of pseudopemphigoid exist that will not be described in this review including autoimmune or inflammatory conditions such as lichen planus, sarcoidosis, granulomatosis with polyangiitis (Wegener’s granulomatosis), erythema multiforme (minor, major, and Stevens-Johnson syndrome), bullous pemphigoid, skin-dominated linear IgA bullous dermatosis, and skin-dominated epidermolysis bullosa acquisita. Prompt diagnosis of the underlying etiology in pseudopemphigoid is paramount to the patient’s outcome as certain diseases are associated with a more severe clinical course, increased ocular involvement, and differential response to treatment. A complete history and ocular examination may find early cicatricial changes in the conjunctiva that are important to note and evaluate to avoid progression to more severe disease manifestations. When such cicatricial changes are noted, proper diagnostic techniques are needed to help elucidate a diagnosis. Lastly, collaboration between ophthalmologists and subspecialists such as dermatologists, pathologists, immunologists, and others involved in the care of the patient is needed to ensure optimal management of disease.

Cranial neuropathies in sarcoidosis

Sarcoidosis is a multisystem, chronic inflammatory disease that is characterized by the development of non-caseating granulomas in multiple body tissues and organ systems. Neurological complications of systemic sarcoidosis include peripheral and cranial neuropathies, myopathies, seizures, gait dysfunction, and cognitive decline. Because sarcoidosis has a predilection to involve the basilar meninges, cranial neuropathy is the most prevalent neurological deficit seen when the nervous system is involved. Sarcoidosis cranial neuropathy may occur at different stages of the disease and even as the initial clinical manifestation of central nervous system involvement. Attributing a cranial neuropathy to sarcoidosis can be challenging, particularly in the setting of normal imaging studies. In this review, cranial neuropathies in sarcoidosis are discussed in detail.

Improving refractive outcomes in cataract surgery: A global perspective

This review summarises the current evidence base and provides guidelines for obtaining good refractive outcomes following cataract surgery. Important background information is also provided. In summary, the requirements are: (1) standardisation of biometry equipment used for axial length and keratometry measurement and the use of optical or immersion ultrasound biometry; (2) sutureless cataract surgery with “in the bag” intraocular lens (IOL) placement; (3) an appropriate 3^rd, 4^th or 5^th Generation IOL power formula should be used; (4) IOL formula constants must be optimized; (5) under certain conditions, the refractive outcome of the 2^nd eye can be improved based on the refractive error of the first eye; and (6) results should be audited for refinement and to ensure that standards are met.

Systematic review of macular ganglion cell complex analysis using spectral domain optical coherence tomography for glaucoma assessment

AIM: To review the use of spectral domain optical coherence tomography (SD-OCT) for macular retinal ganglion cells (RGC) and ganglion cell complex (GCC) measurement in glaucoma assessment, specifically for early detection and detection of disease progression.

METHODS: A systematic review was performed by searching PubMed, Medline, and Web of Science for articles published in English through July 2014 describing the various macular SD-OCT scanning strategies developed for glaucoma assessment. The review focused on papers evaluating the use of macular RGC/GCC SD-OCT to detect early glaucoma and its progression. The search included keywords corresponding to the index test (macular ganglion cell/RGC/GCC/Spectral domain OCT), the target condition (glaucoma), and diagnostic performance. The RGC/GCC SD-OCT scanning strategies used to assess glaucoma of most commonly used SD-OCT instruments were described and compared. These included the Cirrus high definition-OCT (Carl Zeiss Meditec, Inc., Dublin, CA, United States), RTVue (Optovue, Inc., Fremont, CA, United States), Spectralis (Heidelberg Engineering, Heidelberg, Germany) and the 3D OCT 2000 (Topcon Corporation, Tokyo, Japan). Studies focusing on the ability of RGC/GCC SD-OCT to detect early glaucomatous damage and on the correlation between glaucomatous progression and RGC/GCC measurement by SD-OCT were reviewed.

RESULTS: According to the literature, macular RGC/GCC SD-OCT has high diagnostic power of preperimetric glaucoma, reliable discrimination ability to differentiate between healthy eyes and glaucomatous eyes, with good correlation with visual filed damage. The current data suggests that it may serve as a sensitive detection tool for glaucomatous structural progression even with mild functional progression as the rate of change of RGC/GCC thickness was found to be significantly higher in progressing than in stable eyes. Glaucoma assessment with RGC/GCC SD-OCT was comparable with and sometimes better than circumpapillary retinal nerve fiber layer thickness measurement.

CONCLUSION: An increasing body of evidence supports using macular RGC/GCC thickness as an indicator for early glaucoma. This might be a useful tool for monitoring disease progression.

Updates in uveitic macular edema

Macular edema is one of the most common vision-threatening complications of uveitis noted in one third of patients with uveitis. The release of a number of inflammatory mediators induces retinal vascular hyperpermeability leading to uveitic macular edema (UME) which most commonly is of cystoid shape. Fluorescein angiography and non-invasive spectral-domain optical coherence tomography are standard procedures for diagnosis and follow-up of UME with some innovations such as scanning laser ophthalmoscope retro-mode imaging. Effective management of UME requires thorough understanding of the individual case. Proper control of intraocular inflammation is mandatory before targeting macular edema itself. Mainstay of treatment is immunosuppressive therapy with various drug delivery routes including topical, local subconjunctival, peribulbar and sub-Tenon’s, intravitreal and systemic. Clinical trials with biologics are under way to study the efficacy of these agents in suppressing intraocular inflammation and resolution of UME. Visual prognosis in UME depends on numerous factors. Younger age and better visual acuity at baseline are associated with more favorable visual outcome in most studies

Advances in retinal imaging modalities: Challenges and opportunities

Imaging in ophthalmology is playing an increasingly important role not only in screening, but also in monitoring and assessing response to treatment in an objective manner. Technical advances in various modes of imaging acquisition provide more detailed images. These can be combined and reviewed on one screen in the place of acquisition or sent for a remote assessment. Moreover, the machines are more user-friendly, which reduces the need for highly skilled technicians. In this article the authors describe currently available and experimental ophthalmic imaging modalities and their impact on clinical practice.

Ocular renin-angiotensin system with special reference in the anterior part of the eye

The renin-angiotensin system (RAS) regulates blood pressure (BP) homeostasis, systemic fluid volume and electrolyte balance. The RAS cascade includes over twenty peptidases, close to twenty angiotensin peptides and at least six receptors. Out of these, angiotensin II, angiotensin converting enzyme 1 and angiotensin II type 1 receptor (AngII-ACE1-AT1R) together with angiotensin (1-7), angiotensin converting enzyme 2 and Mas receptor (Ang(1-7)-ACE2-MasR) are regarded as the main components of RAS. In addition to circulating RAS, local RA-system exists in various organs. Local RA-systems are regarded as tissue-specific regulatory systems accounting for local effects and long term changes in different organs. Many of the central components such as the two main axes of RAS: AngII-ACE1-AT1R and Ang(1-7)-ACE2-MasR, have been identified in the human eye. Furthermore, it has been shown that systemic antihypertensive RAS- inhibiting medications lower intraocular pressure (IOP). These findings suggest the crucial role of RAS not only in the regulation of BP but also in the regulation of IOP, and RAS potentially plays a role in the development of glaucoma and antiglaucomatous drugs.

Traumatic cataracts in children: Visual outcome

AIM: To review results of traumatic cataracts in children.

METHODS: Only those pediatric patients who fitted in the definite inclusion criteria were considered for study enrollment. They were further examined for any kind of co-morbidities because of trauma, operated upon for traumatic cataracts with intraocular lens implantation. Amblyopia if present was treated. All were re-examined at the culmination of six-week postoperative period. According to the Birmingham Eye Trauma Terminology System the traumatic cataract cases were divided into group 1 (open globe) and group 2 (closed globe), and then determinants of visual acuity were compared.

RESULTS: There were 544 eyes in group 1 and 127 eyes in group 2 in our study of 671 eyes with pediatric traumatic cataracts. Visual acuity at the end of 6 wk after surgery in the operated eye was > 6/60 in 450 (82.7%) and ≥ 6/12 in 215 (39.4%) eyes in the open globe group and > 20/200 in 127 (81.8%) and ≥ 6/12 in 36 (28.4%) eyes in the closed globe group (P = 0.143), and the difference between the groups was not significant in children. Overall, 402 (39.4%) eyes gained ≥ 6/60 and > 5/12 in 238 (35.4%) cases. Surgical treatment caused a significant difference in visual outcome (P = 0.000). When we compared achieved visual outcome with ocular trauma score predicted vision, no significant difference was found.

CONCLUSION: Traumatic cataracts in children may have better outcome and ocular trauma score is a useful predictive method for the ocular trauma in children.

Topical biological agents targeting cytokines for the treatment of dry eye disease

Because inflammation plays a key role in the pathogenesis of dry eye disease and Sjögren’s syndrome, topical anti-inflammatory agents such as corticosteroids and cyclosporine A have been used to treat inflammation of the ocular surface and lacrimal gland. Systemic biological agents that target specific immune molecules or cells such as tumor necrosis factor (TNF)-α, interferone-α, interleukin (IL)-1, IL-6, or B cells have been used in an attempt to treat Sjögren’s syndrome. However, the efficacy of systemic biological agents, other than B-cell targeting agents, has not yet been confirmed in Sjögren’s syndrome. Several studies have recently evaluated the efficacy of topical administration of biological agents targeting cytokines in the treatment of dry eye disease. Topical blockade of IL-1 by using IL-1 receptor antagonist could ameliorate clinical signs and inflammation of experimental dry eye. Using a mouse model of desiccating stress-induced dry eye, we have demonstrated that topical application of a TNF-α blocking agent, infliximab, could improve tear production and ocular surface irregularity, decrease inflammatory cytokines and Th-1 CD4+ cells on the ocular surface, and increase goblet cell density in the conjunctiva. Although controversy still remains, the use of topical biological agents targeting inflammatory cytokines may be a promising therapy for human dry eye disease.

Binocular disturbance after glaucoma drainage device implantation

Binocular vision disturbance is a well-described complication of glaucoma drainage device (GDD) implantation. The pathophysiology is not well-understood, but may involve bulk effects from the implant and surrounding bleb, as well as modulation of muscle function due to surgical trauma and post-operative inflammation, resulting in a combined resection/posterior fixation effect. Retrospective studies have found the risks of motility disorder and diplopia vary widely, estimated to be 56%-86% and 57%-75%, respectively. More recently, cross-sectional studies and prospective trials estimate post-GDD incidence to be approximately 1%-44%, with the incidence in newer generation of implants designed to limit bleb size likely lower at 1%-5%. Suggested methods of management strategies include prismatic spectacles, monocular occlusion, extreme monovision, and strabismus surgery.

Glaucoma and Alzheimer's disease: Their clinical similarity and future therapeutic strategies for glaucoma

Glaucoma refers to a group of diseases characterized by optic neuropathies that are commonly associated with degeneration of the retinal ganglion cells. Although intraocular pressure (IOP) is the only proven treatable factor, several studies indicate that other factors are involved in the pathogenesis of glaucoma. Since normal tension glaucoma (NTG) is the most common glaucoma at least in Japan and South Korea, development of new therapeutic strategies for glaucoma, besides reduction of IOP, is crucial. The clinical characteristics and mechanisms underlying neuronal degeneration in Alzheimer’s disease, a progressive neurodegenerative disease, are similar to those of glaucoma. Impaired cerebral blood flow (CBF) is common to both these diseases; therefore, improving CBF may be considered a new treatment for glaucoma, especially for NTG. In addition, targeting the formation and aggravation pathway for amyloid-β and administration of apolipoprotein E-containing lipoproteins may be potential strategies for glaucoma treatment.

Human ciliary muscle cell responses to kinins: Activation of ERK1/2 and pro-matrix metalloproteinases secretion

AIM

To study activation of extracellular signal-regulated kinase-1/2 (ERK1/2) and pro-matrix metalloproteinases (pro-MMPs) secretion from isolated primary human ciliary muscle (h-CM) cells in response to bradykinin (BK) and other agonists.

METHODS

Serum-starved h-CM cells were challenged with vehicle, BK agonists or antagonists. Cell lysates were evaluated for phosphorylated ERK1/2 using homogeneous time-resolved fluorescence technology based on a sandwich immunoassay. Rabbit polyclonal anti-pro-MMP antibodies were used to measure pro-MMPs using immunoblot analysis.

RESULTS

A 10 min incubation time using 5 × 10⁴ h-CM cells/well was optimum condition for studying stimulation of ERK1/2 phosphorylation. BK (100 nmol/L) caused a 1.86 ± 0.26 fold (n = 3) increase in ERK1/2 phosphorylation above baseline. BK analogs, Met-Lys-BK and RMP-7 (100 nmol/L), also stimulated ERK1/2 phosphorylation by 1.57 ± 0.04 and 1.55 ± 0.09 fold, respectively. However, Des-Arg⁹-Bradykinin, a B₁ receptor-selective agonist (0.1-1 μmol/L), was essentially inactive. HOE-140 or WIN-64338 (B₂-antagonists) appreciably blocked phosphorylation of ERK1/2 induced by various BK agonists. Pre-treatment of cells with a prostaglandin (PG) synthase inhibitor (bromfenac; 1 μmol/L) failed to alter kinin-induced ERK1/2 activation. BK and a non-peptide BK agonist (FR-190997) (10 nmol/L-1 μmol/L) also enhanced pro-MMPs secretion (pro-MMP-1 > pro-MMP-3 > pro-MMP-2; 1.45-1.75-fold over baseline) from h-CM cells.

CONCLUSION

These collective data suggest that B₂ kinin receptors initiate signaling in h-CM cells by a relatively rapid mechanism (within minutes) involving ERK1/2 activation which in turn regulates MMPs production (within hours). The latter process does not involve PGs.

Pathogenesis, prevention, diagnosis and management of retinal vein occlusion

Retinal vein occlusion (RVO) is the second vascular retinal cause of visual loss and defined by the occlusion of a retinal vein. It is divided into branch retinal vein occlusion or central retinal vein occlusion, depending on the location of occlusion. RVO has severe medical, financial and social implications on the patients. The diagnosis of the disease is easier nowadays with the use of spectral domain optical coherence tomography and fluorescein angiography. The treatment options for RVO have changed dramatically over the past few years with the introduction of the intravitreal injections of dexamethasone (Ozurdex), bevacizumab (Avastin), ranibizumab (Lucentis) and aflibercept (EYLEA), along with the panretinal laser photocoagulation, abandoning former treatment modalities and surgical solution. This manuscript is a review of current literature about RVO with emphasize on the pathophysiology, risk factors and prevention, diagnosis and sub-group categorization and treatments including medical and surgical. Since no official guidelines are available for the treatment of RVO patients, and considering the latest developments in the treatment options, and the variety of follow-up and treatment modalities, this manuscript aims to provide tools and knowledge to guide the physician in treating RVO patients, based on the latest publications from the literature and on several of the patients characteristics.

Predictors of visual outcome in traumatic cataract

Traumatic cataract resulting from open- or closed-globe ocular trauma is one of the most common causes of blindness. Visual outcome is unpredictable because this is not determined solely by the lens. There is a lack of a standard classification, investigations, and treatment guidelines related to the outcome, with considerable debate regarding predictive models. We review the predictors of visual outcome following surgical treatment of traumatic cataracts, which may act as a guide to clinicians.

Ablative laser assisted topical delivery of antifibrotics in the management of cicatricial ectropion

A variety of surgical techniques have traditionally been used to manage cicatricial ectropion. These techniques primarily aim at vertical lengthening of the anterior lamella and include a variety of skin flaps and grafts. Alternative techniques such as dermal filler injection to support the eyelid margin may also be used in the management of select patients with cicatricial ectropion. The application of different types of laser for scar revision throughout the body has rapidly evolved; similar mechanisms, principles and treatment rationale can be applied to the use of lasers in the management of cicatricial ectropion. Additionally, ablative lasers, such as Carbon Dioxide and Erbium:yttrium-aluminum-garnet lasers, may be used in the transdermal delivery of antifibrotic agents, such as interferon gamma, interferon alpha, vitamin D, triamcinolone and 5-fluorouracil, resulting in efficient target tissue penetration, limitation of systemic drug toxicity and decreased degradation. Although the combination of ablative fractional resurfacing and topical antifibrotic agents is a new treatment modality, there is a great potential for its efficient utility in the management of periocular scarring and cicatricial ectropion. The introduction of these innovative therapeutic modalities offers ophthalmologists a greater range of possible effective treatments to address periocular scar tissue and the resultant cicatricial ectropion.

Choroidal neovascularization secondary to pathological myopia

Myopic choroidal neovascularization (mCNV), one of the complications of pathological myopia, is also one of the leading causes of visual impairment worldwide. The socioeconomic impact of mCNV in Asian countries is particularly significant due to the rising incidence of pathological myopia. There have been major advances in the treatment of mCNV in the past few years. Previous treatment modalities, such as thermal laser photocoagulation and photodynamic therapy, aimed to prevent vision loss; however, newer modalities such as intravitreal anti-vascular endothelial growth factor (VEGF) agents have been shown to successfully restore vision in many patients. Challenges remain as long term safety and efficacy of anti-VEGF agents are unknown. This article aims to provide a review of the literature of the epidemiology, progression, clinical course and treatment modalities as well as areas of future developments related to myopic CNV.

Age-related macular degeneration treatment in the era of molecular medicine

Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in the developed world. The quality of life of both patients and families is impacted by this prevalent disease. Previously, macular degeneration had no known effective treatment. Today, vitamins for non-exudative AMD and intravitreal injection of medications for its exudative form are primary forms of current treatment. Modern advances in molecular science give rise to new possibilities of disease management. In the year 2003 the sequencing of the entire human genome was completed. Since that time, genes such as complement factor H, high-temperature requirement factor A1, and age-relateed maculopathy susceptibility 2 have been discovered and associated with a higher risk of AMD. A patient’s genetic make-up may dictate the effectiveness of current or future therapeutic options. In addition, utilizing genetic data and incorporating it into new treatments (such as viral vectors) may lead to longer-lasting (or permanent) VEGF blockade and specific targeting of complement related genes. There have also been considerable advances in stem cell directed treatment of AMD. Retinal pigment epithelial (RPE) cells can be derived from human embryonic stem cells, induced pluripotent stem cells, or adult human RPE stem cells. Utilizing animal models of RPE and retinal degeneration, stem cell-derived RPE cells have been successfully implanted into the subretinal space. They have been injected as a cell mass or as a pre-prepared monolayer on a thin membrane. Visual recovery has been demonstrated in a retinal dystrophic rat model. Preliminary data on 2 human subjects also demonstrates possible early visual benefit from transplantation of stem cell-derived RPE. As more data is published, and as differentiation and implantation techniques are optimized, the stabilization and possible improvement of vision in individuals with non-exudative macular becomes a real possibility. We conclude that the technologic advances that continue to unfold in both genetic and stem cell research offer optimism in the future treatment of AMD.

Anticataractogenic effect of hesperidin in galactose-induced cataractogenesis in Wistar rats

AIM: To explore the anticataractogenic potential of hesperidin, a flavanone, in galactose-induced cataractogenesis.

METHODS: In this study, cataract was induced by administering galactose enriched food in a set of rats. Effect of different dosages of hesperidin (25, 50 and 75 mg/kg body weight) were administered simultaneously with galactose in prevention of cataract was determined in another set. In both sets of animals, the levels of peroxidation, oxidants (NO and OH), antioxidants (enzymatic: Superoxide dismutase, catalase, glutathione S-transferase, GPx and non-enzymatic: Reduced glutathione, vitamin E), aldose reductase and sorbitol were determined in the eye lens. In addition, glucose and lipid peroxidation levels were also tested in serum. The quantitative changes in lens inducible nitric oxide synthase (iNOS) and its expression were also determined using Western blot and real-time polymerase chain reaction analyses.

RESULTS: Galactose enriched food produced cataract in both the eye lens as a sequel to elevated serum glucose. Simultaneous administration of hesperidin not only reduced serum glucose but also prevented cataract development, through reduced levels of reactive oxygen species (NO and OH) and iNOS expression as well as elevated enzymic and non-enzymic antioxidants were observed in the eye lens.

CONCLUSION: These results indicate the preventive effect of hesperidin against cataract in hyperglycemic rats.

State of the art management of diabetic macular edema

Macular edema following diabetic retinopathy is one of the ocular complications associated with diabetes, and it is the leading cause of visual loss in the active young and middle aged population in developed countries. While all patients with diabetes particularly those with diabetic retinopathy are at increased risk of developing eye complications, early detection and timely intervention may prevent or delay loss of visual acuity. Systemic management of diabetes through combined control of blood sugar, hypertension, and hyperlipidemia has remained the most effective method to prevent diabetic retinopathy and its progression. Development of diabetic retinopathy and related complications require, surgical and medical interventions including photocoagulation, vitrectomy, and intravitral drug injection to preserve vision. Considering recently most popular treatment of diabetic macular edema (DME) including intravitreal anti-vascular endothelial growth factor (VEGF) agents, several issues such as ideal regimen, duration of treatment, combination therapy and long -term safety have remained unanswered yet and deserve further investigations. In this review, all the articles that had investigated such treatment modalities for DME as well as pharmacokinetic, efficacy, safety, dose and frequency of intravitreal pharmacologic agents and also the effect of macular ischemia, initial macular thickness and optical coherence tomographic patterns of DME on the final outcomes of treatment with Intravitreal drugs are reviewed. In summary, literature searches reveal that almost all studies that have been published up to now provide some evidence that support the use of intravitreal anti-VEGF agents for treatment of either naïve or persistent DME in short and long term up to two years.

Retinal emboli

Retinal emboli are opacities identified in retinal arterioles and are often incidental findings on ophthalmic examination. They are generally composed of cholesterol, platelet-fibrin, or calcium and are thought to arise from carotid arteries, coronary arteries, or cardiac valves. In the general population, the estimated prevalence is 0.2% to 1.3%, and the estimated incidence is 0.9% to 2.9%. The transient nature of retinal emboli likely explains the variations between and within these reported figures. The strongest risk factor for retinal emboli is smoking, which has been reported consistently across many studies. Other likely risk factors include older age, hypertension, male sex, total cholesterol, coronary artery disease, and history of coronary artery bypass grafting. The presence of multiple risk factors, as is common in many patients, confers a higher risk for retinal emboli. Several studies suggest that retinal emboli predict an increase in stroke-related, all-cause, and possibly cardiovascular mortality. Due to these sequelae, patients often undergo further workup, most commonly carotid ultrasonography. However, given the low prevalence of significant carotid disease in patients with retinal emboli, further workup, such as carotid ultrasound, should be reserved for those with risk factors for carotid disease. All patients would benefit from medical optimization and coordinated care with the primary care physician.

Pharmacologic vitreolysis: New strategy for treatment of anomalous vitreo-macular adhesion

Persistent anomalous vitreo-macular adhesion (VMA) is a well-known factor, associated with a variety of sight threatening diseases - including macular hole, vitreo-macular traction syndrome, cystoid and diabetic macular edema, exudative age- related macular degeneration, myopic traction maculopathy and others. With the advent of optical coherence tomography our understanding of these pathologies and the ability of their early diagnosis has gone much far in the past two decades. The release of macular traction has been of exclusive surgical capability. Notwithstanding good results, vitrectomy is hampered by the inability of complete vitreo-retinal separation (i.e., smooth, bare internal limiting membrane), compulsory postoperative positioning in macular hole cases, surgical complications, and high costs. With aim to offer less invasive and safe treatment modality for anomalous VMA, investigators have made enormous progress in the past decade. Leading among the studied nonsurgical measures is the intravitreal application of pharmacologic agents for the induction of vitreo-retinal separation and vitreous liquefaction, a method termed pharmacologic vitreolysis. Several vitreolytic agents have been studied to date, the most potent among them proved to be plasmin. Recently, ocriplasmin (formerly known as microplasmin) - a more stable than plasmin recombinant product, proved to be safe and efficient in releasing VMA in large studies, and consequently received FDA approval. It’s role in clinical practice is now in the process of being determined. This paper aims to review and summarize the current knowledge and status of investigation on this new approach for the treatment of VMA.

Evaluation of laser in situ keratomileusis for myopic correction performed under thin flaps

AIM: To evaluate the efficacy and safety of laser-assisted subepithelial keratectomy (LASIK) for myopic correction done under thin flaps (120 μm) and compare with results obtained under thick flaps (150 μm).

METHODS: The study included 150 myopic eyes of 75 patients without previous refractive surgery who underwent LASIK prospectively. Two microkeratome heads (90 and 130) were used to create a flap with thickness of 120 μm and 150 μm, respectively. Thin flap group (120 μm) included 75 eyes while thick flap group included 75 eyes. Follow-up period was 12 mo. Efficacy, safety, and stability were evaluated and compared between the two groups.

RESULTS: In 150 eyes, the mean preoperative spherical equivalent refraction was -8.65 ± 2.6 D, mean sphere was -4.4 ± 3.5 D, and mean cylinder was -1.0 ± 1.3 D. The amount of ablation was significantly larger in the thin flap (88.5 ± 32.21 μm) group than in the thick flap group (64 ± 28.13 μm). Percentage of safety was higher in the thin flap group (94.8%) than in the thick flap group (91.7%). There were no intraoperative complications, especially flap-related problems. Subjective symptoms of dry eye occurred in 20.7% and 33.3% of eyes in the thin and thick flap groups, respectively.

CONCLUSION: Thin-flap LASIK is effective and safe in correcting myopic defects. It achieves better visual results, rapid visual recovery, and stable postoperative refraction than LASIK with thick flaps.