Intravitreal steroids in the management of macular oedema

INTRAVITREAL FLUOCINOLONE ACETONIDE IMPLANT FOR RADIATION RETINOPATHY: Report of Preliminary Findings

PURPOSE

To assess the efficacy of a 0.18 mg intravitreal fluocinolone acetonide (FA) implant (Yutiq, EyePoint Pharmaceuticals, Watertown, MA) as a treatment option for patients with radiation retinopathy-related cystoid macular edema.

METHODS

A retrospective review of seven patients treated for uveal melanoma who developed radiation retinopathy-related cystoid macular edema. They were initially treated with intravitreal anti-vascular endothelial growth factor and/or steroid injections and then transitioned to intravitreal FA implant. Primary outcomes include best-corrected visual acuity, central subfield thickness, and number of additional injections.

RESULTS

After FA implant insertion, best-corrected visual acuity and central subfield thickness remained stable in all patients. The variance in best-corrected visual acuity decreased from 75.5 ETDRS letters (range 0-199 letters) to 29.8 (range 1.2-134) after FA implant insertion. Mean central subfield thickness was 384 µ m (range 165-641) and 354 µ m (range 282-493) before and after FA implant insertion, resulting in a 30- µ m mean reduction. The number of intravitreal injections (average 4.9, range 2-10) decreased after intravitreal FA implant insertion with only two patients requiring one additional FA implant (average 0.29, range 0-1) over a mean of 12.1 months (range 0.9-18.5) follow-up.

CONCLUSION

Intravitreal FA implant is an effective treatment for cystoid macular edema radiation retinopathy. The slow release of steroid allows for sustained control of macular edema, which correlated with stable visual acuity and decreased injection burden for patients.

Chronic ocular small vessel disease: An overview of diabetic retinopathy and its relationship with cardiovascular health

Diabetic retinopathy (DR) is a potentially blinding disease originating from small vessel damage in the retina in chronic hyperglycemic states. DR has a complex multi-pathway driven pathogenesis resulting in diabetic macular edema and retinal ischemia, the former being the most common cause of vision impairment in DR. Hypoxia induced cytokines stimulate vascular endothelial growth factor (VEGF) production and subsequent angiogenesis with resultant mechanical retinal damage over time. Anti-VEGF therapy is effective for the treatment of center-involving diabetic macular edema. There is evolving evidence showing the effectiveness of anti-VEGF as both adjuvant and monotherapy in the treatment of proliferative DR, however laser photocoagulation continues to remain the standard of care. DR in large cohort studies has been shown to be an independent risk factor for the development of cardiovascular disease and mortality. In addition, changes in retinal vascular caliber ratios may have implications for risk of macrovascular events with a gender discrepancy towards women.

Radiation retinopathy intricacies and advances in management

Background: Radiation retinopathy is a chronic, progressive, vision-threatening complication from exposure to various radiation sources. While several treatment modalities are available, proper management for this disease is a continuing challenge with no consensus on the most efficacious.Objective: The aim of this article is to provide an updated review of the published literature on the course of the disease, available treatments and their efficacies, frequency of regimen, core issues in patient management, and additional newer treatment modalities, including possible prophylactic approaches.Value: We also highlighted the challenges encountered with managing chronically treated patients through an analysis of a clinical case report on a patient who was treated for several years with different modalities after a diagnosis of radiation retinopathy.

Diabetic Macular Edema Management in Asian Population: Expert Panel Consensus Guidelines

PURPOSE

The aim of this consensus article was to provide comprehensive recommendations in the management of diabetic macular edema (DME) by reviewing recent clinical evidence.

DESIGN

A questionnaire containing 47 questions was developed which encompassed clinical scenarios such as treatment response to anti-vascular endothelial growth factor and steroid, treatment side effects, as well as cost and compliance/reimbursement in the management of DME using a Dephi questionnaire as guide.

METHODS

An expert panel of 12 retinal specialists from Singapore, Malaysia, Philippines, India and Vietnam responded to this questionnaire on two separate occasions. The first round responses were compiled, analyzed and discussed in a round table discussion where a consensus was sought through voting. Consensus was considered achieved, when 9 of the 12 panellists (75%) agreed on a recommendation.

RESULTS

The DME patients were initially profiled based on their response to treatment, and the terms target response, adequate response, nonresponse, and inadequate response were defined. The panellists arrived at a consensus on various aspects of DME treatment such as need for classification of patients before treatment, first-line treatment options, appropriate time to switch between treatment modalities, and steroid-related side effects based on which recommendations were derived, and a treatment algorithm was developed.

CONCLUSIONS

This consensus article provides comprehensive, evidence-based treatment guidelines in the management of DME in Asian population. In addition, it also provides recommendations on other aspects of DME management such as steroid treatment for stable glaucoma patients, management of intraocular pressure rise, and recommendations for cataract development.

Suprachoroidally injected pharmacological agents for the treatment of chorio-retinal diseases: a targeted approach

Delivery of pharmaceuticals to the posterior segment presents challenges that arise from the anatomy and clearance pharmacokinetics of the eye. Systemic and several local administration options [topical, periocular, intravitreal (IVT) and subretinal] are in clinical use, each with a unique benefit to risk profile shaped by factors including the administered agent, frequency of dosing, achievable pharmaceutical concentrations within posterior segment structures versus elsewhere in the eye or the body, invasiveness of the procedure and the inherent challenges with some administration methods. The use of the suprachoroidal space (SCS), which is the region between the sclera and the choroid, is being explored as a potential approach to target pharmacotherapies to the posterior segment via a minimally invasive injection procedure. Preclinical data on agents such as vascular endothelial growth factor inhibitors and triamcinolone acetonide (TA) indicate that administration via suprachoroidal injection results in more posterior distribution of the pharmacologic agent, with higher exposure to the sclera, choroid, retinal pigment epithelium cells and retina, and lesser exposure to the anterior segment, than observed with IVT administration. Based in part on these findings, clinical trials have explored the efficacy and safety of suprachoroidal administration of pharmacologic therapies in conditions affecting the posterior segment. Data on a proprietary formulation of TA administered by suprachoroidal injection show improvement in anatomic and visual outcomes in subjects with noninfectious uveitis, with the potential to mitigate the known risks of cataract and increased intraocular pressure (IOP) associated with the use of intraocular corticosteroids. Suprachoroidal administration appears to be a promising treatment modality and is also in the early stages of investigation for other possible applications, such as injection of antiglaucoma agents into the anterior SCS for long-lasting control of elevated IOP, and as a mode of delivery for gene- or cell-based therapies for retinal disorders.

Acute Bacterial Endophthalmitis Following Dexamethasone Intravitreal Implant: A Case Report

A 54-year-old male presented to our ophthalmology clinic with a diagnosis of the right central retinal vein occlusion with macular edema. The patient was treated with dexamethasone intravitreal implant. Three days after the implant insertion, the patient experienced pain, redness and blurred vision in the same eye. With a provisional diagnosis of acute endophthalmitis, a combination of ceftazidime 2.25 mg/0.1 ml and vancomycin 1 mg/0.1 ml was injected intravitreally. One week after the treatment, endophthalmitis signs and symptoms subsided. This report presents a case of endophthalmitis following dexamethasone intravitreal implant, with a favorable outcome after treatment with intravitreal antibiotic injection without removal of the implant.

Animal models of radiation retinopathy - From teletherapy to brachytherapy

Radiation retinopathy is a serious vision-impairing complication of radiation therapy used to treat ocular tumors. Characterized by retinal vasculopathy and subsequent retinal damage, the first sign of radiation retinopathy is the preferential loss of vascular endothelial cells. Ensuing ischemia leads to retinal degradation and late stage neovascularization. Despite the established disease progression, the pathophysiology and cellular mechanisms contributing to radiation retinopathy remain unclear. Clinical experience and basic research for other retinal vasculopathies, such as diabetic retinopathy and retinopathy of prematurity, can inform our understanding of radiation retinopathy; however, the literature investigating the fundamental mechanisms in radiation retinopathy is limited. Treatment trials have shown modest success but, ultimately, fail to address the cellular events that initiate radiation retinopathy. Animal models of radiation retinopathy could provide means to identify effective therapies. Here, we review the literature for all animal models of radiation retinopathy, summarize anatomical highlights pertaining to animal models, identify additional physiological factors to consider when investigating radiation retinopathy, and explore the use of clinically relevant tests for studying in vivo models of radiation retinopathy. We encourage further investigation into the mechanistic characterization of radiation retinopathy in the hope of discovering novel treatments.

Fluocinolone acetonide for the treatment of diabetic macular edema

INTRODUCTION

Fluocinolone acetonide intravitreal implant is a non-erodible implant approved for the treatment of diabetic macular edema (DME) insufficiently responsive to available therapies. Areas covered: The injectable intravitreal implant releases fluocinolone acetonide at an average rate of 0.2 µg/day for at least 36 months. The two pooled pivotal FAME trials showed that, in patients with DME previously treated with laser photocoagulation, fluocinolone acetonide intravitreal implant was more beneficial than sham injection when looking at the proportion of patients with an improvement from baseline in visual acuity of more than 15 letters at 24 months and at 36 months. Cataract (82%) and intraocular pressure (IOP) elevation (37%) were the most common adverse events. Raised IOP was mostly treated with IOP-lowering medications, with <5% of eyes requiring incisional IOP-lowering surgery. FAME trial program results are confirmed by a series of real-world studies in eyes with chronic/recalcitrant DME. Expert opinion: data indicate that fluocinolone acetonide intravitreal implant is a useful second-line option for the treatment of DME.

Compared antioxidant activity among corticosteroids on cultured retinal pigment epithelial cells

PURPOSE

The aim of this study is to determine if dexamethasone, prednisolone and triamcinolone acetonide (TA), three anti-inflammatory drugs commonly used for ocular treatments, could affect the oxidative status of cultured human cells of the retinal pigment epithelium (RPE) and protect them against oxidative injury.

METHODS

ARPE-19 cells were used as an in vitro model of RPE. Glutathione (GSH) levels were assessed to evaluate the effects of dexamethasone, prednisolone and triamcinolone on cellular antioxidant status. Oxidative stress was induced in ARPE-19 cells by treatment with the oxidizing agent menadione, and the effects of dexamethasone, prednisolone and triamcinolone were evaluated. Release of lactate dehydrogenase (LDH) in the culture medium was used to measure cytotoxicity.

RESULTS

Incubation with triamcinolone or prednisolone was not able to revert menadione-induced cytotoxicity and GSH depletion; furthermore, it significantly decreased GSH levels in ARPE-19 cells (nmol of GSH/mg cellular protein: 99.7 ± 0.1 in untreated controls vs. 52.6 ± 5.2 with triamcinolone vs. 77.6 ± 5.2 with prednisolone; p < 0.001). Treatment with dexamethasone protected ARPE-19 cells from cytotoxicity and oxidative damage: lactate dehydrogenase release and GSH depletion were significantly decreased after incubation with this compound (LDHout/LDHtot: 0.221 ± 0.038 with menadione vs. 0.041 ± 0.007 with menadione + dexamethasone; p < 0.001; nmol of GSH/mg cellular protein: 5.7 ± 4.2 with menadione vs. 53.2 ± 6.1 with menadione + dexamethasone, respectively; p < 0.001) and did not induce GSH depletion (nmol of GSH/mg cellular protein: 99.7 ± 0.1 vs. 86.5 ± 8.1 nmol/min/mg prot with dexamethasone; p > 0.05).

CONCLUSIONS

Dexamethasone, besides suppressing intraocular inflammation, may protect human RPE cells from oxidative stress and decrease the oxidation rate of GSH. Triamcinolone and prednisolone, inducing GSH depletion, may contribute to reduce antioxidant capacity of ARPE-19 cells.

Posterior Subtenon's Capsule Triamcinolone Acetonide Injection for the Treatment of Diabetic Macular Edema

PURPOSE

To evaluate and compare the efficacy of posterior subtenon's triamcinolone injections versus grid laser photocoagulation (GLP) combined with posterior subtenon's triamcinolone injection in eyes with diabetic macular edema (DME).

METHODS

In this prospective clinical study, 42 eyes with DME that showed a decrease in visual acuity (VA) were included. The first group consisted of 22 eyes that received a posterior subtenon's injection of 40 mg of triamcinolone acetonide under topical anesthesia. The second group of 20 eyes received macular GLP applied 1 month after subtenon's triamcinolone acetonide (STTA) injection. All patients were evaluated at baseline and 1 day; 1, 2, 4, 6, and 8 weeks; and 3 and 6 months after injection. In some patients, injections were repeated after 3 months. The main outcome measures were VA, central macular thickness (CMT), intraocular pressure, cataract progression, and frequency of complications.

RESULTS

The mean baseline CMT for Group I was 456.85 ± 56.90 μm. The mean baseline CMT for Group II was 455.66 ± 57 μm. In the first group, mean CMTs for second week, 8th week, 12th week, and 6th month were 258.15, 276.50, 280.05, and 433.30 μm, respectively. In the second group, mean CMTs for second week, 8th week, 12th week, and 6th month were 261.42, 272.76, 284.71, and 291.76 μm, respectively. Before treatment, in the first group, the mean best-corrected visual acuity (BCVA) measured using a Snellen chart was 0.19, while the first week, third, and sixth month BCVA means were 0.59, 0.57, and 0.41, respectively. Before treatment, BCVA in the second group was 0.17, while the first week, third, and sixth month means were 0.61, 0.64, and 0.60, respectively. Treatment complications included cataracts in 4 eyes and glaucoma in 1 eye.

CONCLUSION

There is a temporary therapeutic effect of posterior subtenon's triamcinolone injection without laser photocoagulation. GLP improves VA and reduces the risk of recurrent macular edema after posterior STTA injection.

Advances in ophthalmic drug delivery

Various strategies for ocular drug delivery are considered; from basic formulation techniques for improving availability of drugs; viscosity enhancers and mucoadhesives aid drug retention and penetration enhancers promote drug transport into the eye. The use of drug-loaded contact lenses and ocular inserts allows drugs to be better placed where they are needed for more direct delivery. Developments in ocular implants gives a means to overcome the physical barriers that traditionally prevented effective treatment. Implant technologies are under development allowing long-term drug delivery from a single procedure, these devices allow posterior chamber diseases to be effectively treated. Future developments could bring artificial corneas to eliminate the need for donor tissue and one-off implantable drug depots lasting the patient's lifetime.

Treatment of diabetic maculopathy

Diabetic maculopathy is an important cause of severe sight impairment. There has been a significant evolution in its treatment over the past decade and laser treatment is now largely being superseded by intravitreal injections of anti-vascular endothelial growth factor agents or corticosteroids.

Optimization of dexamethasone mixed nanomicellar formulation

The purpose of this study was to develop a clear aqueous mixed nanomicellar formulation (MNF) of dexamethasone utilizing both D-α-tocopherol polyethylene glycol-1000 succinate (Vit E TPGS) and octoxynol-40 (Oc-40). In this study, Vit E TPGS and Oc-40 are independent variables. Formulations were prepared following solvent evaporation method. A three level full-factorial design was applied to optimize the formulation based on entrapment efficiency, size, and polydispersity index (PDI). A specific blend of Vit E TPGS and Oc-40 at a particular wt% ratio (4.5:2.0) produced excellent drug entrapment, loading, small mixed nanomicellar size and narrow PDI. Solubility of DEX in MNF is improved by ~6.3-fold relative to normal aqueous solubility. Critical micellar concentration (CMC) for blend of polymers (4.5:2.0) was found to be lower (0.012 wt%) than the individual polymers (Vit E TPGS (0.025 wt%) and Oc-40 (0.107 wt%)). No significant effect on mixed nanomicellar size and PDI with one-factor or multi-factor interactions was observed. Qualitative (1)H NMR studies confirmed absence of free drug in the outer aqueous MNF medium. MNF appeared to be highly stable. Cytotoxicity studies on rabbit primary corneal epithelial cells did not indicate any toxicity suggesting MNF of dexamethasone is safe and suitable for human topical ocular drops after further in vivo evaluations.

Intravitreal controlled release of dexamethasone from engineered microparticles of porous silicon dioxide

Dexamethasone is a glucocorticoid that is widely used in the ophthalmic arena. The recent FDA approved dexamethasone implant can provide a three month efficacy but with high rate of drug related cataract and high intraocular pressure (IOP). It seems that higher steroid in aqueous humor and around lens may be associated with these complications based on clinical fact that higher IOP was observed with intravitreal triamcinolone acetonide (TA) than with subtenon TA. We hypothesize that placing a sustained dexamethasone release system near back of the eye through a fine needle can maximize efficacy while mitigate higher rate of IOP rise and cataract. To develop a sustained intravitreal dexamethasone delivery system, porous silicon dioxide (pSiO2) microparticles were fabricated and functionalized with amines as well as carboxyl groups. Dexamethasone was conjugated to pSiO2 through the Steglich Esterification Reaction between hydroxyl of dexamethasone and carboxyl groups on the pSiO2. The drug loading was confirmed by Fourier transform infrared spectroscopy (FTIR) and loading efficiency was quantitated using thermogravimetric analysis (TGA). In vitro release was conducted for three months and dexamethasone was confirmed in the released samples using liquid chromatography-tandem mass spectrometry (LC/MS/MS). A pilot ocular safety and determination of vitreous drug level was performed in rabbit eyes. The drug loading study demonstrated that loading efficiency was from 5.96% to 10.77% depending on the loading reaction time, being higher with longer loading reaction time before reaching saturation around 7 days. In vitro drug release study revealed that dexamethasone release from pSiO2 particles was sustainable for over 90 days and was 80 days longer than free dexamethasone or infiltration-loaded pSiO2 particle formulation in the same setting. Pilot in vivo study demonstrated no sign of ocular adverse reaction in rabbit eyes following a single 3 mg intravitreal injection and free drug level at 2-week was 107.23 ± 10.54 ng/mL that is well above the therapeutic level but only around 20% level of dexamethasone released from OZURDEX(®) (dexamethasone intravitreal implant) in a rabbit eye model. In conclusion, dexamethasone is able to covalently load to the pSiO2 particles and provide sustained drug release for at least 3 months in vitro. Intravitreal injection of these particles were well tolerated in rabbit eyes and free drug level in vitreous at 2-week was well above the therapeutic level.

Short-term safety and efficacy of intravitreal 0.7-mg dexamethasone implants for pseudophakic cystoid macular edema

AIMS

To determine the feasibility, safety, and clinical efficacy of intravitreal 0.7-mg dexamethasone implants (Ozurdex) in patients with refractory cystoid macular edema after uncomplicated cataract surgery.

METHODS AND MATERIALS

In this study, 11 eyes of 11 patients affected by pseudophakic cystoid macular edema refractory to medical treatment were treated with a single intravitreal injection of a dexamethasone implant. Follow-up visits involved Early Treatment Diabetic Retinopathy Study visual acuity testing, optical coherence tomography imaging, and ophthalmoscopic examination.

RESULTS

The follow-up period was six months. The mean duration of cystoid macular edema before treatment with Ozurdex was 7.7 months (range, 6-10 months). The baseline mean best corrected visual acuity (BCVA) was 0.58 ± 0.17 logarithm of the minimum angle of resolution (logMAR). The mean BCVA improved to 0.37 ± 0.16 logMAR (p = 0.008) and 0.20 ± 0.13 logMAR (p = 0.001) after 1 and 3 months, respectively. At the last follow-up visit (6-month follow-up), the mean BCVA was 0.21 ± 0.15 logMAR (p = 0.002). The mean foveal thickness at baseline (513.8 μm, range, 319-720 μm) decreased significantly (308.0 μm; range, 263-423 μm) by the end of the follow-up period (p < 0.0001). Final foveal thickness was significantly correlated with baseline BCVA (r = 0.57, p = 0.002). No ocular or systemic adverse events were observed.

CONCLUSIONS

Short-term results suggest that the intravitreal dexamethasone implant is safe and well tolerated in patients with pseudophakic cystoid macular edema. Treated eyes had revealed a significant improvement in BCVA and decrease in macular thickness by optical coherence tomography.

Dexamethasone intravitreal implant for treatment of patients with persistent diabetic macular edema

PURPOSE

To report the 6-month anatomical and best-corrected visual acuity (BCVA) response after primary intravitreal dexamethasone implantation (Ozurdex®) in patients with refractory diabetic macular edema (DME).

METHODS

Retrospective review of the medical records of 58 patients with decreased visual acuity, due to refractory DME, who underwent a single injection of Ozurdex between November 2010 and January 2012, at the Instituto de Microcirurgia Ocular, Barcelona, Spain.

RESULTS

At baseline, the mean foveal thickness (FT) was 543.24 ± 156.51 μm. Mean (±SD) values of FT did decrease to 346.82 ± 123.74 μm at month 1 and 341.12 ± 129.64 μm at month 3. Data on the 6-month follow-up showed a mild increase to 420.16 ± 152.15 μm. All of the FT reduction outcomes were statistically significant, with respect to baseline data (p = 0.0001). The baseline BCVA data was 0.66 ± 0.36 logarithm of the minimum angle of resolution (logMAR). The mean BCVA improved to 0.52 ± 0.32 logMAR (p = 0.0001) and 0.44 ± 0.27 logMAR (p = 0.0001) after 1 and 3 months, respectively. At the last visit (6-month follow-up), the mean BCVA increased to 0.51 ± 0.31 logMAR (p = 0.0001).

CONCLUSIONS

In this study, intravitreal treatment with a dexamethasone implant safely reduced DME and improved visual acuity in a difficult-to-treat patient population with long-standing refractory DME.

Combination therapy in diabetic macular oedema and retinal vein occlusion--past and present

This paper summarizes the recent evidence for combined therapies in the intravitreal medical treatment of diabetic macular oedema or macular oedema, secondary to retinal vein occlusion. Since the introduction of anti-inflammatory or anti-VEGF drugs combined with or used alternatively to laser, visual acuity can be stabilized or improved in a significant number of patients. However, there is an ongoing debate regarding the safety, efficiency and economic concerns related to these intravitreal monotherapies because they warrant frequent repetition to maintain the clinical effect. In the literature, the combination of photolasercoagulation, intravitreal steroids or VEGF-inhibitors, or both, shows early compelling evidence that some patients may benefit from less retreatment compared to monotherapy. To provide a conceptual and perspective approach for a first-line combined therapy, this paper also summarizes own results of pilot interventional case series of a 1.5 cc core pars plana vitrectomy and intravitreal substitution with balanced salt solution (BSS), 1.25 mg bevacizumab and 8 mg triamcinolone.

Dexamethasone intravitreal implant for the treatment of noninfectious uveitis

Uveitis can be a sight-threatening eye disease with significant morbidity. Corticosteroids remain the mainstay of treatment of uveitis and provide an effective treatment against ocular inflammation. However, the various modes available for corticosteroid drug delivery can carry significant ocular and systemic side effects which can limit their use in the treatment of uveitis. In an effort to avoid the damage to ocular structures that can ensue with recurrent episodes of ocular inflammation, the side effects associated with systemic steroids, and the need for repeated administration of both topical and locally injected corticosteroids, sustained-release intraocular corticosteroid implants have been developed. The dexamethasone (DEX) drug delivery system (Ozurdex(®); Allergan Inc, Irvine, CA), is a biodegradable intravitreal implant. This implant has been shown to be effective in the treatment of macular edema and noninfectious posterior uveitis and has been approved by the FDA for these entities. This review will highlight the current methods available for corticosteroid delivery to the eye with a particular emphasis on the DEX intravitreal implant and the evidence currently available for its use in noninfectious uveitis.

Development of ocular hypertension and persistent glaucoma after intravitreal injection of triamcinolone

Purpose

This study evaluates intraocular pressure (IOP) elevation secondary to intravitreal injection of triamcinolone acetonide (IVTA) and discusses its management.

Methods

The records of 175 patients who underwent IVTA treatment and regular eye examinations in the period 2003–2006 were reviewed. One hundred and twenty-two of these patients were included in the study, of which 147 eyes that received IVTA (4 mg/0.1 ml) were followed for at least 9 months. Mean IOPs observed after IVTA injection as well as IOP elevations defined as moderate (≥5 mm Hg), important (≥10 mm Hg) and severe (>25 mm Hg) during the follow-up period were evaluated and compared statistically.

Results

Overall, the mean IOPs following IVTA injection were statistically significantly higher than the preinjection IOP (15.8 ± 2.6), after the first hour (17.7 ± 2.9), the first week (18.7 ± 4.1), the first month (19.6 ± 6.2), the second month (19.1 ± 6.1), the third month (18.0 ± 4.1), the sixth month (17.3 ± 4.0), and the ninth month (17.0 ± 2.7), but not after the first day (16.3 ± 7.6). Important IOP elevations were observed mostly in the first (17.7%) and second months (10.2%). In 40 (27.7%) eyes, topical antiglaucomatous therapy was needed and 7 later required surgical intervention to lower the IOP. Of the remaining 33 eyes, topical treatment was continued in 14 (9.5%) because of IOPs ≥20 mm Hg.

Conclusion

The persistence of IOP elevation beyond the IVTA clearance period and the development of intractable secondary glaucoma requiring surgical intervention substantiate the need for careful consideration of IVTA indication and follow-up.

Retinal vein thrombosis: pathogenesis and management

Retinal vein occlusion (RVO) is the most common retinal vascular disease after diabetic retinopathy. Owing to its multifactorial nature, however, management of this condition remains a challenge. Of the two main types of RVO, branch retinal vein occlusion (BRVO) is more prevalent than central retinal vein occlusion (CRVO). Most patients develop the disease at an elderly age, and more than half of them have associated systemic disorders (e.g. hypertension, hyperlipidemia and/or diabetes mellitus). There is no evidence to suggest routine testing for heritable thrombophilias in patients with RVO. The main cause of the visual impairment is macular edema, while neovascularization of the retina and optic disc are the most serious complications leading to vitreous hemorrhage, retinal detachment and neovascular glaucoma. Macular grid laser photocoagulation is an effective treatment for macular edema in patients with BRVO and a visual acuity of 20/40 or less. Other treatment options for reducing the edema are intravitreal steroids, anti-VEGF drugs and vitrectomy. The recently introduced intravitreal application of steroids and anti-VEGF drugs may prove to be a better approach for improving visual acuity. Finally, scatter panretinal laserphotocoagulation can effectively treat neovascularization and its secondary complications.

Macular function after intravitreal triamcinolone acetonide injection for diabetic macular oedema

PURPOSE

We aimed to evaluate the effect of intravitreal triamcinolone acetonide (IVTA) on macular function in patients with diabetic macular oedema (DMO).

METHODS

Eleven eyes in 11 patients with DMO were enrolled. In each eye, at baseline and at 30 days after IVTA injection, logMAR visual acuity (VA), macular sensitivity, fixation stability and fixation location by MP-1 microperimetry and optical coherence tomography (OCT) foveal thickness were assessed.

RESULTS

Thirty days after IVTA injection, eyes with DMO showed a significant (p<0.001) reduction in foveal thickness and significant (p<0.01) increases in logMAR VA and MP-1 retinal sensitivity (p<0.001). There was also significant (p=0.046) improvement in fixation location and some improvement in fixation stability, although the latter was not significant (p=0.08).

CONCLUSIONS

In eyes with DMO, short-term improvement in retinal sensitivity and fixation properties can be achieved by IVTA injection.

Intraocular lens as a drug delivery system for dexamethasone

PURPOSE

To evaluate the effect of an intraocular lens (IOL) coated with dexamethasone on postoperative inflammation after cataract surgery.

METHODS

Clear lens extraction was performed bilaterally in eight 8-week-old rabbits. An uncoated silicone IOL (CeeOn; AMO, Santa Ana, CA, USA) was implanted in one randomly selected eye. In the other eye, the same silicone IOL model was implanted but was coated with dexamethasone. Aqueous humour was obtained preoperatively and on days 1, 3, 7, 14 and 28 postoperatively. Three inflammatory parameters were measured and compared between the eyes: prostaglandin E2 (PGE2), white blood cell (WBC) count and protein content. The animals were killed on day 28 postoperatively.

RESULTS

PGE2 levels measured on days 1, 3 and 7 were significantly lower in eyes with a coated IOL compared to eyes with an uncoated IOL (p < 0.01). The WBC count was significantly lower in eyes with a coated IOL on days 1 (p < 0.01) and 3 (p < 0.05). There was significantly less protein in eyes with a coated IOL on days 1 and 3 (p < 0.01).

CONCLUSION

Coating a silicone IOL with dexamethasone significantly reduced postoperative inflammation after clear lens extraction in rabbits.

Non-infectious pediatric uveitis: an update on immunomodulatory management

Pediatric non-infectious uveitis remains a rare but potentially sight-threatening group of diseases. However, early screening and treatment can improve outcomes. No single agent has proven to be efficacious in all cases. A wide variety of long-term immunomodulatory treatments are available; these agents differ in both their potency and side effect profiles. Corticosteroids remain an extremely valuable form of treatment in the short-term management of uveitis. Other major groups of immunomodulatory treatments include the calcineurin inhibitors and antimetabolites such as methotrexate, which is frequently used as the first-line agent. The biologics, including anti-tumor necrosis factor agents and interferons, are newer and potentially very useful therapies although side effects limit their use. Successful outcomes may be achieved with appropriate immunosuppressant therapy given early in the disease, although clinical trials are required to define the true efficacy of this strategy.

Diabetic macular edema

A variety of treatment options are available for the treatment of diabetic macular edema. They include laser photocoagulation, anti-VEGF drugs, intravitreal steroids, and vitrectomy with or without release of vitreoretinal traction. A full understanding of the physiological mechanisms of these treatment modalities allows sensible combination of treatment options. Retinal photocoagulation has repeatedly been shown to improve retinal oxygenation, as does vitrectomy. Oxygen naturally reduces VEGF production and thereby decreases leakage of plasma proteins from capillaries into the tissue. In addition, vitrectomy allows faster clearance of cytokines, such as VEGF, from the retina into the vitreous cavity. The VEGF-lowering effect of photocoagulation and vitrectomy can be augmented with anti-VEGF drugs and corticosteroids reduce the effect of VEGF on capillary permeability. Starling's law explains vasogenic edema, which is controlled by osmotic and hydrostatic gradients between vessel and tissue. It explains how VEGF-induced vascular permeability causes plasma protein to leak into the tissue interstitial space, thus decreasing the osmotic pressure gradient between vessel and tissue, resulting in water accumulation, i.e. edema. This is reversed by reducing VEGF production, which is achieved with laser treatment; or by removing VEGF with antibodies or vitrectomy; or by reducing the permeability effect with steroids. At the same time, Starling's law takes into account hemodynamic changes that affect the hydrostatic gradient. High arterial blood pressure and hypoxic vasodilatation increase the hydrostatic pressure in the microcirculation, which increases water flux from vessel to tissue and induce edema. Treatment of arterial hypertension or reversal of retinal hypoxia with laser reverses this pathophysiology and reduces edema. Newton's third law explains, that vitreoretinal traction decreases hydrostatic tissue pressure in the retina, increases the pressure gradient between vessel and tissue, and stimulates water fluxes from vessel into tissue, leading to edema. Release of vitreoretinal traction reverses this mechanism and reduces edema.

Treatment of cystoid macular edema with the new-generation NSAID nepafenac 0.1%

Purpose:

To describe the use of nepafenac 0.1% for cystoid macular edema (CME).

Methods:

This was a multicenter retrospective review of 22 CME cases (20 patients) treated with nepafenac 0.1% (six with concomitant prednisolone acetate 1%) from December 2005 to April 2008: three acute pseudophakic CME cases, 13 chronic/recalcitrant pseudophakic CME cases, and six cases of uveitic CME. Pre- and post-treatment retinal thickness and visual acuity were reported.

Results:

Following treatment for six weeks to six months, six eyes with uveitic CME showed a mean retinal thickness improvement of 227 ± 168.1 μm; mean best-corrected visual acuity (BCVA) improvement was 0.36 ± 0.20 logMAR. All three cases of acute pseudophakic CME improved after four to 10 weeks of nepafenac, with a mean improvement in retinal thickness of 134 ± 111.0 μm. BCVA improved in two patients (0.16 and 0.22 logMAR) but not in the third due to underlying retinal pigment epithelium changes. Thirteen eyes with chronic/recalcitrant pseudophakic CME demonstrated a mean improvement in retinal thickness of 178 ± 128.7 μm after nepafenac and mean BCVA improvement of 0.33 ± 0.19 logMAR.

Conclusion:

The positive outcomes of these 22 eyes strongly suggest that nepafenac 0.1% is a promising drug for the treatment of CME. Additional study under randomized controlled conditions is warranted.

Management of ocular inflammation and pain following cataract surgery: focus on bromfenac ophthalmic solution

Recently, several new ophthalmic NSAID products have been introduced for commercial use in the United States. The purpose of this review is to briefly overview the ophthalmic NSAIDs currently in use and to discuss the management of postoperative ocular inflammation and pain following cataract surgery with a particular focus on bromfenac ophthalmic solution 0.09%. Bromfenac ophthalmic solution 0.09% is indicated for the reduction of ocular pain and inflammation following cataract surgery. Studies have shown that bromfenac ophthalmic solution 0.09% has equivalent efficacy to the other topical NSAIDs in reducing postsurgical inflammation and controlling pain. The unique chemical structure of bromfenac makes it both a potent inhibitor of the COX-2 enzyme and a highly lipophilic molecule that rapidly penetrates to produce early and sustained drug levels in all ocular tissues. Clinically, these pharmacokinetic features are manifested in a rapid reduction of postsurgical inflammation and pain with bid dosing. Bromfenac ophthalmic solution 0.09% is a versatile agent and is effective when used as either monotherapy or as an adjunct therapy to steroids.

Effects of repeated injection of intravitreal triamcinolone on macular oedema in central retinal vein occlusion

PURPOSE

To investigate the effectiveness of repeated injections of intravitreal triamcinolone acetonide (IVTA) in the treatment of macular oedema caused by central retinal vein occlusion (CRVO).

METHODS

Seventeen pseudophakic or aphakic eyes of 17 patients (10 male, seven female) with macular oedema caused by CRVO received a repeat injection of 4 mg IVTA, 16 weeks after the first injection of the same dose. The examination included measurements of best-corrected visual acuity (BCVA) for distance and central foveal thickness (CFT) by optical coherence tomography (OCT), preoperatively and 1, 2, 3 and 4 months postoperatively. The values were compared by paired-t test. Side-effects were monitored.

RESULTS

BCVA and CFT were not significantly different before initial and repeat injections. Transient improvements of BCVA and CFT were achieved after both injections. At the end of follow-up, BCVA and CFT were significantly different compared to pre-injection values in the same group (P = 0.032, 0.049 in the initial-injection group and P = 0.001, 0.008 in the repeat-injection group, respectively). However, compared to the initial injection, BCVA measurements were significantly worse at each time-point (P = 0.043, 0.011, 0.010 and 0.012, respectively) after the repeat injection, as were CFT at 1, 2 and 3 months post-injection (P = 0.040, 0.015 and 0.025, respectively). The achieved maximum mean intraocular pressures were 20.00 [standard deviation (SD) 2.06] mmHg and 18.56 (SD 3.65) mmHg after the first and repeat injections, respectively. These values were not significantly different (P = 0.467). No other significant adverse events were noted during the study.

CONCLUSION

A repeat injection of 4 mg IVTA may not be as effective as an initial injection for the treatment of macular oedema caused by CRVO.

Acute glaucoma secondary to angle obstruction by triamcinolone crystals

PURPOSE

To present a case of acute glaucoma secondary to massive transit of triamcinolone acetonide into the anterior chamber in a pseudophakic, vitrectomized eye following intravitreal injection for treatment of cystoid macular edema.

SETTING

Manchester Royal Eye Hospital.

METHOD

Case study.

CONCLUSION

In vitrectomized eyes with open posterior capsule receiving high dose intravitreal triamcinolone, it is prudent to perform pressure check within a week of injection.

Physiology of vitreous surgery

Vitreous surgery has various physiological and clinical consequences, both beneficial and harmful. Vitrectomy reduces the risk of retinal neovascularization, while increasing the risk of iris neovascularization, reduces macular edema and stimulates cataract formation. These clinical consequences may be understood with the help of classical laws of physics and physiology. The laws of Fick, Stokes-Einstein and Hagen-Poiseuille state that molecular transport by diffusion or convection is inversely related to the viscosity of the medium. When the vitreous gel is replaced with less viscous saline, the transport of all molecules, including oxygen and cytokines, is facilitated. Oxygen transport to ischemic retinal areas is improved, as is clearance of VEGF and other cytokines from these areas, thus reducing edema and neovascularization. At the same time, oxygen is transported faster down a concentration gradient from the anterior to the posterior segment, while VEGF moves in the opposite direction, making the anterior segment less oxygenated and with more VEGF, stimulating iris neovascularization. Silicone oil is the exception that proves the rule: it is more viscous than vitreous humour, re-establishes the transport barrier to oxygen and VEGF, and reduces the risk for iris neovascularization in the vitrectomized-lentectomized eye. Modern vitreous surgery involves a variety of treatment options in addition to vitrectomy itself, such as photocoagulation, anti-VEGF drugs, intravitreal steroids and release of vitreoretinal traction. A full understanding of these treatment modalities allows sensible combination of treatment options. Retinal photocoagulation has repeatedly been shown to improve retinal oxygenation, as does vitrectomy. Oxygen naturally reduces VEGF production and improves retinal hemodynamics. The VEGF-lowering effect of photocoagulation and vitrectomy can be augmented with anti-VEGF drugs and the permeability effect of VEGF reduced with corticosteroids. Starling's law explains vasogenic edema, which is controlled by osmotic and hydrostatic gradients between vessel and tissue. It explains the effect of VEGF-induced vascular permeability changes on plasma protein leakage and the osmotic gradient between vessel and tissue. At the same time, it takes into account hemodynamic changes that affect the hydrostatic gradient. This includes the influence of arterial blood pressure, and the effect oxygen (laser treatment) has in constricting retinal arterioles, increasing their resistance, and thus reducing the hydrostatic pressure in the microcirculation. Reduced capillary hydrostatic pressure and increased osmotic gradient reduce water fluxes from vessel to tissue and reduce edema. Finally, Newton's third law explains that vitreoretinal traction decreases hydrostatic tissue pressure in the retina, increases the pressure gradient between vessel and tissue, and stimulates water fluxes from vessel into tissue, leading to edema.

Comparative therapy evaluation of intravitreal bevacizumab and triamcinolone acetonide on persistent diffuse diabetic macular edema

PURPOSE

To compare the effect of an intravitreal injection of bevacizumab, an anti-vascular endothelial growth factor (VEGF) antibody, with that of triamcinolone acetonide, a corticosteroid for reduction of diabetic macular edema (DME).

DESIGN

Prospective, comparative interventional case series.

METHODS

Twenty-eight eyes of 14 patients with bilateral DME participated in this study. In each patient, one eye received an intravitreal injection of 4 mg triamcinolone acetonide and the other eye received 1.25 mg bevacizumab. The clinical course of best-corrected visual acuity (VA) with a logarithm of the minimum angle of resolution chart and averaged foveal thickness using optical coherence tomography was monitored for up to 24 weeks after the injection.

RESULTS

Before the injection, foveal thickness and VA were 522.3 +/- 91.3 microm and 0.64 +/- 0.28 microm in the triamcinolone-injected eye, and 527.6 +/- 78.8 microm and 0.61 +/- 0.18 microm in the bevacizumab-injected eye, respectively; there was no significant difference between the eyes. One week after the injection, both eyes showed significant regression of macular edema. The triamcinolone-injected eye (342.6 +/- 85.5 microm and 0.33 +/- 0.21 microm) showed significantly better results than the bevacizumab-injected eye (397.6 +/- 103.0 microm and 0.37 +/- 0.17 microm). However, both eyes showed the recurrence of macular edema with time, even at 24 weeks. Triamcinolone (410.4 +/- 82.4 microm and 0.47 +/- 0.25 microm) kept better results than bevacizumab (501.6 +/- 92.5 microm and 0.61 +/- 0.17 microm).

CONCLUSIONS

With the generally used concentration, intravitreal injection of triamcinolone acetonide showed better results in reducing DME and in the improvement of VA than that of bevacizumab, suggesting that the pathogenesis of DME is not only attributable to VEGF-dependency, but is also attributable to other mechanisms suppressed by corticosteroid.

Intracameral triamcinolone acetonide to control postoperative inflammation following cataract surgery with phacoemulsification

PURPOSE

To explore the efficacy, safety and tolerability of 1 mg intracameral triamcinolone acetonide (TA) in controlling ocular inflammation in patients undergoing cataract surgery.

METHODS

Sixty eyes of 60 patients undergoing cataract extraction with phacoemulsification at the Department of Ophthalmology, Baskent University School of Medicine were randomized into two groups. After surgery, eyes in group A were injected with 1 mg/0.1 ml TA into the anterior chamber, but eyes in group B were not. Postoperatively; in group B, topical prednisolone acetate 1% eyedrops were administered six times per day for 7 days, then four times per day for 15 days, to control postoperative inflammation. In group A, topical corticosteroids were not used. To evaluate the efficacy of intracameral TA, anterior chamber cells, anterior chamber flare and conjunctival hyperaemia were measured on postoperative days 1, 7 and 30 by slit-lamp biomicroscopy. The safety of intracameral TA was evaluated by visual acuity measurements, intraocular pressure values and fundus examination. Tolerance variables were assessed by the degree of burning, stinging and blurred vision.

RESULTS

Both treatments were equally effective in controlling postoperative inflammation following phacoemulsification. No statistically significant differences between groups were observed for the efficacy, safety and tolerance variables, and no serious adverse events were observed.

CONCLUSIONS

Intracameral TA of 1 mg can effectively be used to control postoperative inflammation after uncomplicated cataract surgery with phacoemulsification. This makes it possible to decrease the dosage and duration of topical prednisolone acetate.

Intravitreal and posterior subtenon triamcinolone acetonide in idiopathic bilateral uveitic macular oedema

PURPOSE

To study the efficacy of intravitreal triamcinolone acetonide (IVTA) versus posterior subtenon triamcinolone acetonide (PSTA) in bilateral macular oedema secondary to idiopathic intermediate uveitis.

METHODS

In a prospective, interventional case series, 10 patients (20 eyes) with bilateral uveitic macular oedema were included. Patients underwent fundus fluorescein angiography, record of visual acuity and intraocular pressure (IOP). Patients received IVTA 4 mg/0.1 mL in one eye and PSTA 20 mg/0.5 mL in the fellow eye at an interval of > or =4 weeks. The outcome measures were record of IOP, best corrected visual acuity and angiographic resolution of cystoid macular oedema at 3 and 6 months.

RESULTS

The mean pre-intervention IOP at baseline between the IVTA and the PSTA group was comparable. At 1 week, the mean IOP recorded was greater in the eyes that received IVTA than those that received PSTA (P < 0.001). However, at 1- and 3-month follow up, the mean IOP between the two groups was similar. Best corrected visual acuity of > or =6/12 achieved at 3 and 6 months in the IVTA and PSTA group was comparable (77.8% vs. 44.4% [P = 0.14] and 88.9% vs. 77.8% [P = 0.53]). There was also no significant difference in angiographic resolution of cystoid macular oedema at 3 (P = 0.32) and 6 months (P = 0.53) between the two groups. Recurrence of macular oedema was seen in one and two eyes that received IVTA and PSTA, respectively, at 6 months.

CONCLUSION

Triamcinolone acetonide injection, whether administered intravitreally or via posterior subtenon route, is an effective treatment option in achieving complete anatomic and functional improvement in cases treated for macular oedema secondary to idiopathic intermediate uveitis.

Effect of intravitreal injections and volume changes on intraocular pressure: clinical results and biomechanical model

PURPOSE

Intravitreal injections are used extensively to treat retinal diseases. Performing an intravitreal injection increases intraocular volume by the amount of fluid brought into the eye. Whether this influences intraocular pressure (IOP) was investigated here.

METHODS

A biomechanical model relying on 3-dimensional elasticity theory was developed to determine the short-term effect of volume changes on IOP. We calculated the effect for intravitreal injections of 0.1 ml in myopic, emmetropic and hyperopic eyes. Our calculations were compared with IOP measurements obtained immediately after intravitreal injection of 4 mg triamcinolone in 0.1 ml solution (IVTA) in 22 patients. Shortly after the measurement had been taken, IOP was reduced by paracentesis.

RESULTS

Immediately after IVTA, measured IOP was elevated by a mean of 40.6 +/- 12.1 mmHg compared with initial pressure (p < 0.001). Measured and calculated IOP were comparable. Eyes with shorter axial length had higher IOP immediately after the injection (p < 0.05).

CONCLUSIONS

The effect of injected volumes on IOP can be calculated with a biomechanical model. Our results show that paracentesis might be recommended when injecting 0.1 ml of a substance to avoid a short-term increase in IOP. As intravitreal injections are mostly applied in diseases that are due to vascular compromise, it might be prudent not to impair perfusion in those eyes, even for short periods of time.

Impact of triamcinolone acetonide on retinal endothelial cells in a retinopathy of prematurity mouse model

PURPOSE

To evaluate the efficacy of different concentrations of triamcinolone acetonide (TA) on retinal endothelial cell proliferation in a retinopathy of prematurity (ROP) mouse model.

METHODS

A total of 24 C57BL/J6 mice were exposed to 75% oxygen from postnatal day 7 to day 12. On day 12, 10 mice (group B) were injected with 20 microg intravitreal TA (IVTA) and 14 mice (group C) were injected with 40 microg IVTA in one eye. The contralateral eyes were injected with isotonic saline (control group = group A). Four non-exposed mice served as negative controls (group D). The mice were killed on day 17 and the eyes removed for quantitative analysis of preretinal neovascularization. Neovascularization was quantified by counting the endothelial cell nuclei on the vitreal side of the inner limiting membrane of the retina.

RESULTS

The endothelial cell count per histological section was lower in groups B (1.4 +/- 1.7 cells; p < 0.00001) and C (0.9 +/- 1.4 cells; p < 0.000001) compared with the control group (group A, 17.0 +/- 4.8 cells). However, there was no significant difference in cell count between groups B and C (p = 0.430).

CONCLUSIONS

Triamcinolone acetonide suppresses endothelial cell proliferation in an ROP mouse model in vivo. There is no difference between dosages of 20 microg and 40 microg IVTA in experimental use in the suppression rates of endothelial cell proliferation.

Full-thickness macular hole in a patient with diabetic cystoid macular oedema treated by intravitreal triamcinolone injections

PURPOSE

Full-thickness macular hole associated with diabetic macular oedema is a rare feature and its pathogenesis remains incompletely elucidated. We report the occurrence of a full-thickness macular hole, documented with optical coherence tomography (OCT), in a patient with diabetic cystoid macular oedema treated by intravitreal triamcinolone injections.

CASE REPORT

A 48-year-old woman with refractory diabetic cystoid macular oedema underwent successive intravitreal triamcinolone injections, which were followed by a progressive thinning of the neurosensory retina at the fovea, and then by a full-thickness macular hole, associated with a perifoveal posterior hyaloid detachment, visible on OCT. During pars plana vitrectomy, a thin epiretinal macular membrane was diagnosed and removed.

DISCUSSION

Pathogenesis of the present full-thickness macular hole associated with diabetic macular oedema is different from that of idiopathic macular holes because anteroposterior vitreous tractions were not involved in its formation. Recurrent intravitreal triamcinolone injections may have had an indirect role in the development of the macular hole, by favouring the rupture of distended Muller cells and intraretinal pseudocysts.