On the retinal toxicity of intraocular glucocorticoids

Linking physiology and demographics, non-ocular pathology and pharmaceutical drug use to standard OCT measures of the inner retina: The PPP project

PURPOSE

To assess the associations between physiology and demographics, non-ocular pathology and pharmaceutical drug use against peri-papillary retinal nerve fibre layer thickness (pRNFL T) and other optical coherence tomography (OCT) inner retinal measures in normal, healthy eyes.

METHODS

A retrospective, cross-sectional study of 705 consecutive participants with bilateral normal, healthy optic nerves and maculae. PRNFL Ts, vertical cup/disc ratio (CDR), cup volume and macular ganglion cell layer-inner plexiform layer (GCL-IPL) Ts were extracted from Cirrus OCT scans, then regressed against predictor variables of participants' physiology and demographics (eye laterality, refraction, intraocular pressure [IOP], age, sex, race/ethnicity, etc.) and non-ocular pathology and pharmaceutical drug use according to the World Health Organisation classifications. Associations were assessed for statistical significance (p < 0.05) and clinical significance (|β| > 95% limits of agreement for repeated measures).

RESULTS

A multitude of non-ocular pathology and pharmaceutical drug use were statistically and clinically significantly associated with deviations in standard OCT inner retinal measures, exceeding the magnitude of other factors such as age, IOP and race/ethnicity. Thinner inner retina and larger optic nerve cup measures were linked to use of systemic corticosteroids, sex hormones/modulators, presence of vasomotor/allergic rhinitis and other diseases and drugs (up to -29.3 [-49.88, -8.72] μm pRNFL T, 0.31 [0.07, 0.54] vertical CDR, 0.29 [0.03, 0.54] mm3 cup volume and -10.18 [-16.62, -3.74] μm macular GCL-IPL T; all p < 0.05). Thicker inner retina and smaller optic nerve cup measures were diffusely associated with use of antineoplastic agents, presence of liver or urinary diseases and other diseases and drugs (up to 67.12 [64.92, 69.31] μm pRNFL T, -0.31 [-0.53, -0.09] vertical CDR, -0.06 [-0.11, 0] mm3 cup volume and 28.84 [14.51, 43.17] μm macular GCL-IPL T; all p < 0.05).

CONCLUSION

There are a multitude of systemic diseases and drugs associated with altered OCT inner retinal measures, with magnitudes far exceeding those of other factors such as age, IOP and race/ethnicity. These systemic factors should at least be considered during OCT assessments to ensure precise interpretation of normal versus pathological inner retinal health.

ALTERNATIVE INTRAVITREAL ANTIBIOTICS: A Systematic Review for Consideration in Recalcitrant or Resistant Endophthalmitis

PURPOSE

To organize, categorize, and create a quick reference guide for the use of intravitreal antibiotic alternatives to the standard combination of vancomycin and ceftazidime for the treatment of endophthalmitis.

METHODS

A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. The authors searched for all available information regarding intravitreal antibiotics in the last 21 years. Manuscripts were selected according to relevance, level of information, and the available data regarding intravitreal dose, potential adverse effects, bacterial coverage, and relevant pharmacokinetic information.

RESULTS

The authors included 164 of 1810 manuscripts. The antibiotics were classified according to their class into fluoroquinolones, cephalosporins, glycopeptide and lipopeptide, penicillins and beta-lactams, tetracyclines, and miscellaneous. The authors also included information regarding intravitreal adjuvants for the treatment of endophthalmitis and one ocular antiseptic.

CONCLUSION

The treatment of infectious endophthalmitis is a therapeutic challenge. The current review summarizes the properties of possible intravitreal antibiotic alternatives that should be considered in cases of suboptimal response to initial treatment.

Ocular Delivery of Therapeutic Proteins: A Review

Therapeutic proteins, including monoclonal antibodies, single chain variable fragment (ScFv), crystallizable fragment (Fc), and fragment antigen binding (Fab), have accounted for one-third of all drugs on the world market. In particular, these medicines have been widely used in ocular therapies in the treatment of various diseases, such as age-related macular degeneration, corneal neovascularization, diabetic retinopathy, and retinal vein occlusion. However, the formulation of these biomacromolecules is challenging due to their high molecular weight, complex structure, instability, short half-life, enzymatic degradation, and immunogenicity, which leads to the failure of therapies. Various efforts have been made to overcome the ocular barriers, providing effective delivery of therapeutic proteins, such as altering the protein structure or including it in new delivery systems. These strategies are not only cost-effective and beneficial to patients but have also been shown to allow for fewer drug side effects. In this review, we discuss several factors that affect the design of formulations and the delivery of therapeutic proteins to ocular tissues, such as the use of injectable micro/nanocarriers, hydrogels, implants, iontophoresis, cell-based therapy, and combination techniques. In addition, other approaches are briefly discussed, related to the structural modification of these proteins, improving their bioavailability in the posterior segments of the eye without affecting their stability. Future research should be conducted toward the development of more effective, stable, noninvasive, and cost-effective formulations for the ocular delivery of therapeutic proteins. In addition, more insights into preclinical to clinical translation are needed.

DEVELOPMENT OF PACHYCHOROID PIGMENT EPITHELIOPATHY AND TRANSFORMATION TO CENTRAL SEROUS CHORIORETINOPATHY AFTER INTRAVITREAL DEXAMETHASONE IMPLANTATION

PURPOSE

To report first case of sequential development of pachychoroid pigment epitheliopathy (PPE) and central serous chorioretinopathy (CSC) after repeated intravitreal dexamethasone implantations for diabetic macular edema treatment.

METHODS

We present a case of a 54-year-old man having intravitreal dexamethasone implant for bilateral diabetic macular edema.

RESULTS

We observed development of pachychoroid pigment epitheliopathy, seen as a small pigment epithelial detachment on optical coherence tomography after a fourth dexamethasone implantation. A fifth implantation caused transformation of pachychoroid pigment epitheliopathy to central serous chorioretinopathy.

CONCLUSION

Consecutive administration of dexamethasone implants may have a cumulative effect on retinal pigment epithelium, Bruch membrane, and choroid.

Oral Ursodeoxycholic Acid Crosses the Blood Retinal Barrier in Patients with Retinal Detachment and Protects Against Retinal Degeneration in an Ex Vivo Model

Rhegmatogenous retinal detachment (RD) is a threatening visual condition and a human disease model for retinal degenerations. Despite successful reattachment surgery, vision does not fully recover, due to subretinal fluid accumulation and subsequent photoreceptor cell death, through mechanisms that recapitulate those of retinal degenerative diseases. Hydrophilic bile acids are neuroprotective in animal models, but whether they can be used orally for retinal diseases is unknown. Ursodeoxycholic acid (UDCA) being approved for clinical use (e.g., in cholestasis), we have evaluated the ocular bioavailability of oral UDCA, administered to patients before RD surgery. The level of UDCA in ocular media correlated with the extent of blood retinal barrier disruption, evaluated by the extent of detachment and the albumin concentration in subretinal fluid. UDCA, at levels measured in ocular media, protected photoreceptors from apoptosis and necrosis in rat retinal explants, an ex vivo model of RD. The subretinal fluid from UDCA-treated patients, collected during surgery, significantly protected rat retinal explants from cell death, when compared to subretinal fluid from control patients. Pan-transcriptomic analysis of the retina showed that UDCA upregulated anti-apoptotic, anti-oxidant, and anti-inflammatory genes. Oral UDCA is a potential neuroprotective adjuvant therapy in RD and other retinal degenerative diseases and should be further evaluated in a clinical trial.

Peptidomimetics Therapeutics for Retinal Disease

Ocular disorders originating in the retina can result in a partial or total loss of vision, making drug delivery to the retina of vital importance. However, effectively delivering drugs to the retina remains a challenge for ophthalmologists due to various anatomical and physicochemical barriers in the eye. This review introduces diverse administration routes and the accordant pharmacokinetic profiles of ocular drugs to aid in the development of safe and efficient drug delivery systems to the retina with a focus on peptidomimetics as a growing class of retinal drugs, which have great therapeutic potential and a high degree of specificity. We also discuss the pharmacokinetic profiles of small molecule drugs due to their structural similarity to small peptidomimetics. Lastly, various formulation strategies are suggested to overcome pharmacokinetic hurdles such as solubility, retention time, enzymatic degradation, tissue targeting, and membrane permeability. This knowledge can be used to help design ocular delivery platforms for peptidomimetics, not only for the treatment of various retinal diseases, but also for the selection of potential peptidomimetic drug targets.

Dendrimer-Triamcinolone Acetonide Reduces Neuroinflammation, Pathological Angiogenesis, and Neuroretinal Dysfunction in Ischemic Retinopathy

Diabetic retinopathy (DR) is the leading cause of blindness in working-age adults. Severe visual loss in DR is primarily due to proliferative diabetic retinopathy, characterized by pathologic preretinal angiogenesis driven by retinal ischemia. Microglia, the resident immune cells of the retina, have emerged as a potentially important regulator of pathologic retinal angiogenesis. Corticosteroids including triamcinolone acetonide (TA), known for their antiangiogenic effects, are used in treating retinal diseases, but their use is significantly limited by side effects including cataracts and glaucoma. Generation-4 hydroxyl polyamidoamine dendrimer nanoparticles are utilized to deliver TA to activated microglia in the ischemic retina in a mouse model of oxygen-induced retinopathy (OIR). Following intravitreal injection, dendrimer-conjugated TA (D-TA) exhibits selective localization and sustained retention in activated microglia in disease-associated areas of the retina. D-TA, but not free TA, suppresses inflammatory cytokine production, microglial activation, and preretinal neovascularization in OIR. In addition, D-TA, but not free TA, ameliorates OIR-induced neuroretinal and visual dysfunction. These results indicate that activated microglia are a promising therapeutic target for retinal angiogenesis and neuroprotection in ischemic retinal diseases. Furthermore, dendrimer-based targeted therapy and specifically D-TA constitute a promising treatment approach for DR, offering increased and sustained drug efficacy with reduced side effects.

Traditional Chinese medicine is a useful and promising alternative strategy for treatment of Sjogren's syndrome: A review

Primary Sjogren's syndrome (pSS) is a chronic autoimmune disease involving exocrine glands. Current studies have found that the occurrence of the disease is closely related to genetic, environmental and neuroendocrine factors, as well as abnormal activation of T and B lymphocytes. The etiology and pathogenesis of pSS is complex, and there is a lack of specific targeted drugs. Traditional Chinese medicines (TCMs) have been comprehensively investigated for their treatment effects on pSS. Through a systematic review of the literature, we summarized the TCMs used to treat pSS, and find that there are four major ways that TCMs are used, including upregulation of aquaporin proteins, suppression of cell apoptosis, suppression of the abnormal activation of B lymphocytes and suppression of the abnormal activation of T lymphocytes (balancing T helper type [Th]1/Th2 & Th17/Treg and suppressing follicular helper T [Tfh] cells). However, there are not enough data about the active constituents, quality control, pharmacokinetics, toxicity and modern preparations of these TCMs; therefore, more investigations are needed. This paper highlights the importance of TCMs for treating pSS and provides guidance for future investigations.

Temporal Association between Topical Ophthalmic Corticosteroid and the Risk of Central Serous Chorioretinopathy

This retrospective, nationwide, matched cohort study investigated the temporal relationship of central serous chorioretinopathy (CSCR) following topical ophthalmic corticosteroid (TOC) use. Using the Longitudinal Health Insurance Database 2000 (LHID2000), we collected patients diagnosed with CSCR between January 2001 and December 2010 (n  =  2921) and a control group (n  =  17,526). Information for each patient was collected and tracked from the index date until December 2011. TOC users were classified based on (i) the date of the last prescription before diagnosis: current users (≤30 days) and former users (31–182 days and ≥183 days) and (ii) the prescription refill intervals: persistent users (interval ≤90 days) and non-persistent users (interval >90 days). The odds ratio (OR) was estimated from multivariate conditional logistic regression after adjusting for relevant confounders. After adjusting for age, sex, geographic region, index date, previously known comorbidities, the date of last TOC prescription before diagnosis, or prescription refilling intervals, the results revealed that patients were likely to have developed CSCR while using TOCs currently (OR = 30.42, 95% CI = 25.95–35.66, p < 0.001) and persistently (OR = 7.30, 95% CI = 6.13–8.69, p < 0.001) as compared to the controls. Our results indicate that current or persistent TOCs use increases the risk of CSCR. Thus, patients requiring TOCs should be advised of this risk, particularly in current or persistent use conditions.

Les œdèmes maculaires

L’œdème maculaire est une augmentation de volume de la macula, zone centrale de la rétine, responsable de l’acuité visuelle. Des symptômes visuels handicapent la vie de millions de patients atteints d’œdème maculaire secondaire à une maladie chronique et parfois aiguë de la rétine. Les protéines qui neutralisent la voie du facteur de croissance de l’endothélium vasculaire (VEGF) ou les glucocorticoïdes, au prix d’injections intraoculaires répétées pendant des années, limitent les symptômes visuels. Mieux comprendre pourquoi et comment l’œdème se forme et comment les molécules thérapeutiques exercent un effet anti-œdémateux permettra de mieux prévenir la survenue de cette complication rétinienne handicapante et cécitante.

The emerging role of paraptosis in tumor cell biology: Perspectives for cancer prevention and therapy with natural compounds

Standard anti-cancer therapies promote tumor growth suppression mainly via induction of apoptosis. However, in most cases cancer cells acquire the ability to escape apoptotic cell death, thus becoming resistant to current treatments. In this setting, the interest in alternative cell death modes has recently increased. Paraptosis is a new form of programmed cell death displaying endoplasmic reticulum (ER) and/or mitochondria dilation, generally due to proteostasis disruption or redox and ion homeostasis alteration. Recent studies have highlighted that several natural compounds can trigger paraptosis in different tumor cell lines. Here, we review the molecular mechanisms underlying paraptotic cell death, as well as the natural products inducing this kind of cell death program. A better understanding of paraptosis should facilitate the development of new therapeutic strategies for cancer prevention and treatment.

Recent advances in slow and sustained drug release for retina drug delivery

INTRODUCTION

Striking recent advance has occurred in the field of medical retina, greatly because intraocular drugs have been developed, enhancing their clinical efficacy while avoiding systemic side-effects. However, the burden of repeated intraocular administration makes limits the optimal efficacy of treatments, prompting the development of new drugs with prolonged half-life or of sustained drug delivery systems.

AREAS COVERED

In this review, we describe the various drugs and drug delivery systems that have reached the clinical stage and those that are in clinical development and we discuss the limitations to clinical translation.

EXPERT OPINION

Substantial fundamental work is still required to build guidelines on optimal animal models for ocular pharmacokinetics and safety studies depending on the target disease site and the on the type of therapeutic compounds. The effects of a drug administered as a bolus at high concentration in the vitreous might differ from those resulting from the sustained release of a lower concentration, and no delivery platform can be simply adapted to any drug. For the treatment of retinal diseases, development of therapeutic compounds should integrate from its early conception, the combination of an active drug with a specific drug delivery system, administered by a specific route.

Mental stress as consequence and cause of vision loss: the dawn of psychosomatic ophthalmology for preventive and personalized medicine

The loss of vision after damage to the retina, optic nerve, or brain has often grave consequences in everyday life such as problems with recognizing faces, reading, or mobility. Because vision loss is considered to be irreversible and often progressive, patients experience continuous mental stress due to worries, anxiety, or fear with secondary consequences such as depression and social isolation. While prolonged mental stress is clearly a consequence of vision loss, it may also aggravate the situation. In fact, continuous stress and elevated cortisol levels negatively impact the eye and brain due to autonomous nervous system (sympathetic) imbalance and vascular dysregulation; hence stress may also be one of the major causes of visual system diseases such as glaucoma and optic neuropathy. Although stress is a known risk factor, its causal role in the development or progression of certain visual system disorders is not widely appreciated. This review of the literature discusses the relationship of stress and ophthalmological diseases. We conclude that stress is both consequence and cause of vision loss. This creates a vicious cycle of a downward spiral, in which initial vision loss creates stress which further accelerates vision loss, creating even more stress and so forth. This new psychosomatic perspective has several implications for clinical practice. Firstly, stress reduction and relaxation techniques (e.g., meditation, autogenic training, stress management training, and psychotherapy to learn to cope) should be recommended not only as complementary to traditional treatments of vision loss but possibly as preventive means to reduce progression of vision loss. Secondly, doctors should try their best to inculcate positivity and optimism in their patients while giving them the information the patients are entitled to, especially regarding the important value of stress reduction. In this way, the vicious cycle could be interrupted. More clinical studies are now needed to confirm the causal role of stress in different low vision diseases to evaluate the efficacy of different anti-stress therapies for preventing progression and improving vision recovery and restoration in randomized trials as a foundation of psychosomatic ophthalmology.

Glucocorticoid receptor signaling in the eye

Glucocorticoids (GCs) are essential steroid hormones that regulate numerous metabolic and homeostatic functions in almost all physiological systems. Synthetic glucocorticoids are among the most commonly prescribed drugs for the treatment of various conditions including autoimmune, allergic and inflammatory diseases. Glucocorticoids are mainly used for their potent anti-inflammatory and immunosuppressive activities mediated through signal transduction by their nuclear receptor, the glucocorticoid receptor (GR). Emerging evidence showing that diverse physiological and therapeutic actions of glucocorticoids are tissue-, cell-, and sex-specific, suggests more complex actions of glucocorticoids than previously anticipated. While several synthetic glucocorticoids are widely used in the ophthalmology clinic for the treatment of several ocular diseases, little is yet known about the mechanism of glucocorticoid signaling in different layers of the eye. GR has been shown to be expressed in different cell types of the eye such as cornea, lens, and retina, suggesting an important role of GR signaling in the physiology of these ocular tissues. In this review, we provide an update on the recent findings from in vitro and in vivo studies reported in the last 5 years that aim at understanding the role of GR signaling specifically in the eye. Advances in studying the physiological effects of glucocorticoids in the eye are vital for the elaboration of optimized and targeted GC therapies with potent anti-inflammatory potential while minimizing adverse effects.

Distribution of fluorescein sodium and triamcinolone acetonide in the simulated liquefied and vitrectomized Vitreous Model with simulated eye movements

Intravitreal administration is the method of choice for drug delivery to the posterior segment of the eye with special emphasis on the vitreous body and its surrounding retinal vasculature. In order to gain a better understanding of the underlying distribution processes, an in vitro model simulating the vitreous body (Vitreous Model, VM) and a system simulating the impact of movement on the VM (Eye Movement System, EyeMoS) was previously developed. In the study reported here, these systems were modified in regard to a standardized injection procedure, the diversity of simulated eye movements, extended periods of investigation, the opportunity to simulate the state after vitrectomy and in considering the physiological temperature. Fluorescein sodium (FS) and triamcinolone acetonide (TA) were used as (model) drugs to examine the drug distribution within the VM. Vitrectomy was simulated by replacing half the volume of the polyacrylamide gel that was used as vitreous substitute with the clinically used Siluron® 5000 whereas for a simulated liquefaction half the volume of the gel was replaced by buffer. A simulated liquefaction caused a 12-fold faster distribution of FS compared to the simulated juvenile VM, which was most likely caused by convective forces and mass transfer. Also, the injection technique (injection into the gel or into the buffer compartment) influenced the resulting distribution pattern. Without any liquefaction, the previously described initial injection channel occurred with both (model) drugs and, in the case of TA, remained almost unchanged during the investigation period of 72h. Simulating vitrectomized eyes, TA did not spread uniformly, but either remained in the depot or strongly sedimented within the VM suggesting that a homogenous distribution of a TA suspension is highly unlikely in vitrectomized eyes. High variabilities were observed with ex vivo animal eyes, demonstrating the limited benefit of explanted tissues for such distribution studies. The combination of the modified VM and EyeMoS seems a valuable tool for characterizing intravitreal dosage forms in a reproducible simulation of diversified eye movements and a partially liquefied or vitrectomized vitreous body.

A Review of the Role of Intravitreal Corticosteroids as an Adjuvant to Antibiotics in Infectious Endophthalmitis

Infectious endophthalmitis is an important cause of vision loss worldwide. This entity most often occurs as a complication of intraocular surgery especially following cataract surgery or intravitreal injection. Endophthalmitis is regarded as a serious complication following ocular surgery and the final visual outcome is fundamentally contingent on timely recognition and intervention. Intravitreal and oral antibiotics in combination with pars plana vitrectomy or vitreous aspiration remain the mainstay in the management of endophthalmitis. However, significant inflammation may persist even after sterilization of the intraocular cavities with appropriate antibiotics resulting in failure of treatment. This forms the basis for the use of intravitreal corticosteroids as an adjuvant to antibiotics in the management of infectious endophthalmitis. In the index manuscript, we review the existing literature to determine the role of intravitreal corticosteroids as an adjuvant to antibiotics in treating infectious endophthalmitis, and discuss their beneficial effects and controversial concerns.

Long-term efficacy and safety of intravitreal dexamethasone implant for the treatment of diabetic macular edema

PURPOSE

To evaluate the long-term efficacy and safety of the dexamethasone intravitreal implant Ozurdex® in the treatment of diabetic macular edema (DME).

METHODS

This was a retrospective noncomparative study. A total of 23 patients with DME followed for at least 12 months were included. All patients were treated with at least 2 Ozurdex® injections for the treatment of DME. Best-corrected visual acuity, central retinal thickness, intraocular pressure (IOP), and cataract progression were recorded over 12 months.

RESULTS

From baseline, the mean decrease in central retinal thickness was 315.9 µm at the 12th month and the mean best-corrected visual acuity improvement from baseline was 8.7 letters. Ozurdex® is administered via the extended release system Novadur®. Its efficacy extends beyond 4 months with a single injection and permits allows good stabilization until the 12th month, with 2.13 injections during this period. An increase in IOP was observed in 13.1% of patients and all were managed using topical IOP-lowering medications. No glaucoma or cataract surgery was necessary, and no endophthalmitis was reported.

CONCLUSIONS

In real-life clinical practice, Ozurdex® has anatomical and functional effectiveness for the treatment of DME. Side effects were rare and manageable in our practice.

RISK OF RHEGMATOGENOUS RETINAL DETACHMENT WITH CENTRAL SEROUS CHORIORETINOPATHY

PURPOSE

To investigate the risk of rhegmatogenous retinal detachment (RRD) after central serous chorioretinopathy (CSCR).

METHODS

The study included 2,830 patients with CSCR and 16,980 control patients matched using a propensity score for age, sex, and comorbidities including status after cataract operation, blunt trauma, myopia, diabetes mellitus, hypertension, and hyperlipidemia from January 2001 through December 2010 from the Taiwan Longitudinal Health Insurance Database 2000. Information of each patient was collected until December 2011. Cox proportional hazard regression analysis was used to obtain the adjusted hazard ratio for RRD. The RRD-free survival rate was calculated using Kaplan-Meier analysis.

RESULTS

Thirty-five patients with CSCR (1.24%) and 27 controls (0.16%) had RRD (P < 0.0001) during follow-up, resulting in a significantly higher risk of RRD in the patients with CSCR (incidence rate ratio = 7.83, 95% confidence interval = 4.74-12.93). After adjustment for potential confounders, the adjusted hazard ratio for developing RRD was increased 7.85 times in the cohort of total sample (adjusted hazard ratio = 7.85, 95% confidence interval = 4.75-12.97).

CONCLUSION

It was found that CSCR increased the risk of RRD even after adjustment for age, sex, and comorbidities including status after cataract operation, blunt trauma, myopia, diabetes mellitus, hypertension, and hyperlipidemia.

Sustained-release steroids for the treatment of diabetic macular edema

Glucocorticoids have been used for decades in the treatment of ocular disorders via topical, periocular, and more recently intravitreal routes. However, their exact mechanisms of action on ocular tissues remain imperfectly understood. Fortunately, two recently approved intravitreal sustained-release drug delivery systems have opened new perspectives for these very potent drugs. To date, among other retinal conditions, their label includes diabetic macular edema, for which a long-lasting therapeutic effect has been demonstrated both morphologically and functionally in several randomized clinical trials. The rate of ocular complications of intravitreal sustained-release steroids, mainly cataract formation and intraocular pressure elevation, is higher than with anti-vascular endothelial growth factor agents. Yet, a better understanding of the mechanisms underlying these adverse effects and the search for the minimal efficient dose should help optimize their therapeutic window.

Efficacy and Safety of Intravitreal Dexamethasone Implant in Patients with Diabetic Macular Edema

Purpose: To evaluate the efficacy and safety of intravitreal implant of dexamethasone (Ozurdex®) in diabetic macular edema (DME). Methods: This was a retrospective multicenter noncomparative study. Seventy-eight patients with DME followed for at least 6 months were included (P1.5 Network). Best-corrected visual acuity (BCVA), central retinal thickness (CRT), intraocular pressure (IOP) and cataract progression were studied at baseline and then at 1, 2, 4 and 6 months. Results: The mean CRT decrease from baseline was 145.2 µm at 6 months. The mean BCVA improvement from baseline was 6.7 at 6 months. An increase in IOP was observed for 11.7% of patients, and all patients were managed by topical treatment. No glaucoma or cataract surgery was necessary, and no endophthalmitis was reported. Conclusions: One injection of Ozurdex has an anatomical and functional effectiveness for the treatment of DME. Side effects were rare and manageable in our practice.

On the use of an appropriate TdT-mediated dUTP-biotin nick end labeling assay to identify apoptotic cells

Apoptosis is an essential cellular mechanism involved in many processes such as embryogenesis, metamorphosis, and tissue homeostasis. DNA fragmentation is one of the key markers of this form of cell death. DNA fragmentation is executed by endogenous endonucleases such as caspase-activated DNase (CAD) in caspase-dependent apoptosis. The TUNEL (TdT-mediated dUTP-biotin nick end labeling) technique is the most widely used method to identify apoptotic cells in a tissue or culture and to assess drug toxicity. It is based on the detection of 3'-OH termini that are labeled with dUTP by the terminal deoxynucleotidyl transferase. Although the test is very reliable and sensitive in caspase-dependent apoptosis, it is completely useless when cell death is mediated by pathways involving DNA degradation that generates 3'-P ends as in the LEI/L-DNase II pathway. Here, we propose a modification in the TUNEL protocol consisting of a dephosphorylation step prior to the TUNEL labeling. This allows the detection of both types of DNA breaks induced during apoptosis caspase-dependent and independent pathways, avoiding underestimating the cell death induced by the treatment of interest.

Long-term outcomes of triamcinolone acetonide-assisted anterior vitrectomy during complicated cataract surgery with vitreous loss

PURPOSE

To report the long-term outcomes of triamcinolone acetonide-assisted anterior vitrectomy during complicated cataract surgery with vitreous loss.

SETTING

Tel Aviv Medical Center, Tel Aviv, Israel.

DESIGN

Case series.

METHODS

Consecutive patients who had triamcinolone acetonide-assisted anterior vitrectomy for complicated cataract surgery with vitreous loss between January 2010 and January 2012 were studied. The main outcome measures were the results of the ocular examination and spectral-domain optical coherence tomography of the macula at the last follow-up visit 12 months or more postoperatively. The ocular examination included corrected distance visual acuity (CDVA), intraocular pressure (IOP), and anterior segment and fundus biomicroscopy.

RESULTS

The study included 15 patients (15 eyes) with a mean age of 71 years (range 50 to 92 years). The mean follow-up was 21 months (range 12 to 29 months). At the last follow-up, the mean CDVA was statistically significantly better than preoperatively (0.24 logMAR ± 0.31 [SD] versus 0.89 ± 0.81 logMAR) (P=.0033); all patients had improved CDVA over the preoperative values. Except for 1 patient with a macular scar, all the patients had a CDVA between 20/40 and 20/20. At last follow-up, 1 patient required 2 IOP-lowering medications that had been used preoperatively as well. The mean IOP was 15.3 ± 2.4 mm Hg. There were no cases of residual vitreous strands in the anterior chamber, inflammatory reactions, triamcinolone acetonide crystals, retinal breaks, retinal detachment, or pseudophakic cystoid macular edema.

CONCLUSION

Triamcinolone acetonide-assisted anterior vitrectomy during complicated cataract surgery with vitreous loss was safe and effective.

Safety of intravitreal triamcinolone acetonide: an electrophysiologic and histopathological study in rabbits

AIM

To evaluate the retinal safety of various doses of intravitreal triamcinolone acetonide (TA) in rabbits.

METHODS

Thirty New Zealand albino rabbits were divided into five groups (six animals each). In group 1 (control group), each animal received a single intravitreal injection of 0.1mL phosphate buffered saline. In groups 2, 3, 4 and 5, each rabbit received a single intravitreal injection of 4, 8, 16 and 32mg of TA, respectively. Each dose was contained in 0.1mL phosphate buffered saline. Clinical ocular examinations were performed before the injection and on the 1st, 3rd, 10th and 17th post-injection days. A standard dark adapted electroretinogram (ERG) was obtained before injection and on the 3rd, 10th and 17th post-injection days. After 17d, animals were sacrificed and their eyes prepared for pathological examination.

RESULTS

By monitoring ERG as a functional index for the retina, intravitreal injection of 4mg TA showed no significant ERG changes. At doses of 8, 16 and 32, hyper-abnormal responses in a- and b- waves of ERG were detected on the 3rd post-injection day. These changes gradually returned back to normal limits after 17d. Histopathological examination of the retina of all animals showed no pathological changes.

CONCLUSION

High doses of intravitreal TA seemed to have enhancing effects on the retinal function with gradual return to normal limits with no pathological changes detected in examined eyes.

Eye

The Eye chapter of the 3rd edition of Haschek and Rousseaux’s Handbook of Toxicologic Pathology brings a comprehensive description of pathological processes affecting the ocular tissues in the most commonly used laboratory animals and their correlations with human diseases of interest in toxicology. Also presented are detailed descriptions of the structure and function of the different ocular tissues, the most advanced techniques applied in the toxicological evaluation of the eye, useful animal models of human disease, and known mechanisms of ocular toxicity. The introductory sections of the chapter also feature such essential topics as ocular embryology, an overview of clinical ophthalmic evaluation, and eye-specific techniques of tissue processing.

Long-term follow-up of inflammatory cystoid macular edema

PURPOSE

To determine the long-term functional and anatomical outcome of idiopathic uveitic cystoid macular edema (UCME).

METHODS

A longitudinal retrospective study was undertaken of the medical records of patients with UCME. All individuals were examined in the uveitis Service at the Moorfields Eye Hospital. The main outcome measures were change in visual acuity and anatomical outcome of UCME at diverse time points.

RESULTS

A total of 109 eyes (92 patients) with UCME were included in the analysis. Mean follow-up was 60 ± 45 months (median, 48 months). Mean logarithm of the minimum angle of resolution visual acuity 1 month after the intervention improved significantly (P < 0.001) by 0.21 ± 0.27 and maintained at similar levels throughout the follow-up period. Visual acuity at the final follow-up improved in 75 eyes (69%), was deteriorated in 21 eyes (19%), and remained unchanged in 13 eyes (12%). Younger age and better visual acuity at baseline were associated with more favorable visual outcome (P < 0.001). Optical coherence tomography documentation of improvement or total resolution of UCME was observed in 84 eyes (77%) at the final follow-up.

CONCLUSION

Cystoid macular edema is a major complication in uveitis. Current management provides satisfactory long-term results for the majority of those individuals. Visual acuity 1 month after the intervention is usually indicative of the final functional outcome.

[Retinal drug targets]

Retinal effects of systemically administered drugs are rare due to the hematoretinal barriers that protect the retina from circulating active principles. However, some compounds may have direct or indirect toxic effects on the retina through direct interaction with a specific receptor or due to their accumulation within pigment of uveal cells. In the latter case, toxicity is dose-dependent and may be observed years after cessation of medication, as observed with antimalarial drugs. Anti-infective and anti-inflammatory agents, particularly glucocorticoids, are currently injected peri- or intraocularly. The mechanisms and the exact toxicity of glucocorticoids on the retina remain poorly understood. More recently, anti-VEGF has been specifically developed for the treatment of retinal diseases. However, the long-term blockade of VEGF on normal retinal physiology should be determined taking into account VEGF and VEGF receptors expression in the normal and pathologic retina. Whilst enormous advances are made in the treatment of retinal diseases, basic research is still required to define more accurately the molecular targets of drugs to improve their benefits and reduce their potential side effects.