Retinal endovascular surgery and intravitreal triamcinolone acetonide for central vein occlusion in young adults

The Effect of Intracameral Triamcinolone Acetonide on Controlling Common Complications following Phacoemulsification in Dogs

The intracameral injection of triamcinolone acetonide (TA) has achieved favorable clinical effects in controlling intraocular inflammatory reactions in humans after cataract surgery. However, the effect of this method remains unclear in veterinary practice. In this paper, 18 dogs with bilateral cataracts were randomly divided into three groups, with 6 dogs in each group. Phacoemulsification and intraocular lens implantation were performed on the 36 eyes of these dogs. A total of 0.1 mL of TA solution was injected into the oculus dexter (OD) anterior chambers. All oculus sinister (OS) anterior chambers of these dogs were used as controls. The results demonstrated that the corneal edema severity scores of the OD (1.5 mg TA) were lower than those of the OS from the 1st to 7th day after surgery, with a significant difference on the 3rd day after surgery (p = 0.033). The corneal edema severity scores in the OD (1.5 mg TA) were significantly lower than those in the OD (0.5 mg TA) on the 3rd day after surgery (p = 0.036). The aqueous humor protein concentration of the OD (1.5 mg TA) had a lower concentration than the OS on the 1st day after surgery (p = 0.004). Furthermore, on the 5th and 10th days, the aqueous humor protein concentration of the OD (1.5 mg TA) was lower than that of the OS (p = 0.038 and p = 0.044, respectively). The aqueous humor PGE2 concentration of the OD (1.5 mg TA) had a lower concentration than the OS on the 1st day after surgery (p = 0.026). The aqueous humor PGE2 concentrations in the OD (1.0 mg TA) and OD (1.5 mg TA) were lower compared to that in the OD (0.5 mg TA) on the 1st day after surgery (p = 0.041 and p = 0.037, respectively). It was demonstrated that TA-based treatment can be safely employed to effectively control common complications after phacoemulsification in dogs.

The Efficacy of Intravitreal Triamcinolone Acetonide on Macular Edema in Branch Retinal Vein Occlusion

PURPOSE

To evaluate the effectiveness of intravitreal triamcinolone acetonide as primary treatment of macular edema in branch retinal vein occlusion.

METHODS

Fifteen eyes of 15 patients with macular edema due to branch retinal vein occlusion (Group 1) who received 8 mg/0.2 ml of intravitreal triamcinolone injection as primary treatment were retrospectively evaluated. The control group (Group 2) consisted of 19 eyes of 19 patients who had received laser treatment for macular edema. The main outcome measures included best-corrected visual acuity, intraocular pressure, and macular edema map values of Heidelberg Retinal Tomograph II.

RESULTS

In Group 1, mean visual acuity improved significantly from a mean logMAR (logarithm of minimal angle of resolution) value of 0.98+/-0.19 at baseline to a maximum of 0.24+/-0.24 during a mean follow-up time of 6.3 months. In the control group, the mean baseline log-MAR visual acuity before laser treatment was 1.02+/-0.22, and it was 0.50+/-0.28 at 6-month examinations. Mean improvement in visual acuity at 1-, 3-, and 6-month examinations was significantly higher in Group 1 when compared with the control group (for each, p<0.001). The mean edema map value of Group 1 significantly decreased by 40% at 6-month examinations when compared with preinjection value (p<0.001). In Group 1, mean increase in intraocular pressure elevation was 19.8% at the 1-month, 26.9% at 3-month, and 5.7% at 6-month visits, but intraocular pressures were under control with topical antiglaucomatous medications.

CONCLUSIONS

Intravitreal triamcinolone acetonide injection may be a new and promising approach as initial therapy for macular edema due to branch retinal vein occlusion.

An Endovascular Cannulation Needle with an Internal Wire for the Fragmentation of Thrombi in Retinal Vein Occlusion

Purpose

We report a newly developed device to fragment thrombi in retinal vein occlusion.

Methods

The new instrument consists of a 23-gauge (G) pipe and a 37-G needle with an internal wire. A total of 40 porcine eyes were used; 20 eyes for experiments in the branch retinal vein (BRV group) and 20 eyes for experiments in the central retinal vein (CRV group). We placed 25-G 3-port trocars, and core vitrectomy was performed. Another 23-G scleral incision was performed for insertion of the needle. The needle pierced the retinal vein at a distance of three- to four- or one-disc diameters from the optic disc (BRV or CRV group, respectively), and the internal wire was advanced toward the disc. The success rates of needle piercing and cannulation of the internal wire were recorded in each group. In the CRV group, the cannulation was deemed successful when the tip reached inside the optic disc. Real-time optical coherence tomography imaging also was performed using the Zeiss Rescan 700 device in porcine eyes. Histologic examination of the retinal vessel inserted with the internal wire was performed.

Results

The success rates of needle piercing into the BRV and CRV were 85% and 95%, respectively. The success rates of cannulation of the internal wire into the BRV and CRV were 85% and 0%, respectively. The process of cannulation was recorded successfully with the Rescan 700. Histologic examination showed no damages to the endothelial cell layer.

Conclusions

The needle and internal wire intended to be used for recanalization of BRV occlusion were successfully pierced and cannulated into the BRV.

Translational Relevance

This newly developed device could become a treatment modality for retinal vein occlusion to fragment thrombi that present treatment methods cannot reach and remove directly.

RETINAL VEIN OCCLUSIONS, FROM BASICS TO THE LATEST TREATMENT

PURPOSE

To review the pathophysiology, diagnosis, and updated treatments of retinal vein occlusions (RVOs).

METHODS

A review of the literature was performed, focusing on the epidemiology, pathophysiology, diagnosis, and treatments (including both medical and surgical treatments) of RVO. Based on this review, a comprehensive overview was provided regarding the topic of RVO and focused on recent treatment updates.

RESULTS

Retinal vein occlusions have an age- and sex-standardized prevalence of 5.20 per 1,000 for any RVO, 4.42 per 1,000 for branch RVO, 0.80 per 1,000 for central RVO. Worldwide, an estimated 16.4 million adults are affected by RVOs, with 2.5 million affected by central RVO and 13.9 million affected by branch RVO. Retinal vein occlusion is recognized as an important cause of blindness and the diagnostic approaches and treatment options for RVO are reviewed and reported. The current treatment options including medical treatments (bevacizumab, ranibizumab, aflibercept, triamcinolone, and dexamethasone implants) and surgical alternatives were reviewed and reported with summaries on the corresponding strength of evidence.

CONCLUSION

Despite the understanding of this disease entity, challenges persist in the long-term treatment of RVO-related complications and visual loss. This review provided a detailed summary on the rationality and efficacy of recently developed treatment regimes and evaluated the potential benefit of combination therapy.

Use of systemic steroid after successful macular surgery in eyes with epiretinal membrane: a randomized, controlled clinical study

PURPOSE

To evaluate the functional and morphological outcomes of postoperative systemic steroid therapy after successful macular surgery in eyes with macular edema due to idiopathic macular epiretinal membranes (ERMs).

DESIGN

Prospective, randomized, investigator-masked, controlled clinical study.

METHODS

Twenty-eight patients scheduled for 23-gauge vitrectomy combined with ERM and inner limiting membrane (ILM) peeling for macular edema due to ERM were included in this single center trial. Patients were randomized to receive oral steroid therapy (Prednisolone, 100 mg per day for 5 days) or no oral steroid (control group) after surgery. Main outcome measures included best corrected visual acuity (BCVA; Early Treatment Diabetic Retinopathy Study), central retinal thickness (CRT), retinal volume (RV), and macular morphology as determined by spectral domain optical coherence tomography (SD-OCT, Cirrus). Examinations were carried out preoperatively and at week 1, at months 1 and 3, postoperatively.

RESULTS

At month 3, mean BCVA improved to a eight-letter gain in each study group (P<0.01 compared with baseline for both groups), showing no statistically significant difference between both the groups (P=0.19). Morphologically, retinal surface folds resolved within 1 month after surgery in both treatment groups, followed by a progressive recovery of retinal layer integrity and a statistical significant (P<0.01) decrease in CRT and RV without significant differences between both groups (P=0.62, P=0.13, respectively, ANOVA between the groups).

CONCLUSION

The early postoperative use of systemic steroid treatment after successful vitrectomy combined with ERM and ILM peeling does not seem to improve significantly the anatomic and functional outcomes in eyes with ERM.

Enabling Technology for Microvascular Stenting in Ophthalmic Surgery

Microstenting is a potentially revolutionary approach to surgical treatment of microvascular retinal disorders that do not resolve using pharmaceutical treatment. This article presents a novel device called a stent deployment unit (SDU) that aims at enabling microstent placement in ophthalmic surgery. The clinical motivation for this work is highlighted in context of microvascular retinal surgery. The proposed SDU is designed for intraocular adjustment of the approach angle and the position of the stent with respect to the retina. The feasibility of this device is experimentally evaluated on chick chorioallantoic membranes and on agar vascular models. Experiments show dependency on the approach angle with respect to the vasculature and on the mobility of the vasculature. Successful placement of stents was achieved in both experimental media. To the best of our knowledge, this pioneering work is the first to demonstrate successful stent deployment in a scale suitable for retinal surgery. We believe that this technique has the promise of enabling effective vascular treatments for blinding conditions such as central and branch retinal vein occlusion.

Chirurgische Therapie retinaler Venenverschlüsse

The range of therapeutic options for the treatment of retinal vein occlusions has been decisively extended by three new surgical methods: radial optic neurotomy (RON) and retinal endovascular lysis (REVL) for central retinal vein occlusion, and arteriovenous dissection (AVD/sheathotomy) for branch retinal vein occlusion. None of those methods has been tested in randomised studies meeting the requirements of evidence-based medicine. It is therefore difficult to assess the relative values of the individual procedures and determine in what precise circumstances each is indicated. The difficulties are compounded further by the use of these techniques in association with new and promising intravitreally injected drugs (e.g. steroids and angioinhibitors), which makes it even more difficult to assess the real efficacy of the surgical methods. In this paper we discuss the three different surgical methods and try to evaluate their clinical benefit.

Interventions for Central Retinal Vein Occlusion

TOPIC

To assess the evidence for the effectiveness of interventions to improve visual acuity (VA) and prevent or treat neovascularization secondary to central retinal vein occlusion (CRVO).

CLINICAL RELEVANCE

Central retinal vein occlusion is a common cause of visual morbidity and blindness. Many different interventions have been advocated, but the evidence justifying their use remains unclear.

METHODS/LITERATURE REVIEWED

English and non-English language articles were retrieved using a keyword search of Medline (1966 onwards), Embase, the Cochrane Collaboration, the National Institutes of Health Clinical Trials database, and the Association for Research in Vision and Ophthalmology (2003-2005). This was supplemented by manually searching references of review articles. Two investigators independently identified all randomized clinical trials (RCTs) on interventions in CRVO with more than 3 months' follow-up.

RESULTS

Of 4133 citations retrieved, 17 RCTs comparing intervention with a control group were identified. There were 4 RCTs on laser photocoagulation. Grid macular laser photocoagulation did not improve VA in CRVO with macular edema. Prophylactic panretinal photocoagulation did not prevent angle and iris neovascularization in ischemic CRVO, but resulted in regression of angle and iris neovascularization and reduced progression to neovascular glaucoma. There were 4 RCTs that reported improvement in VA with inpatient hemodilution, 2 RCTs with no significant improvement, and 1 RCT showing deterioration in VA after outpatient hemodilution. Randomized clinical trials evaluating ticlodipine, troxerutin, and streptokinase showed a limited or no benefit.

CONCLUSIONS

This review found limited level I evidence for any intervention to improve VA in patients with CRVO. Panretinal photocoagulation resulted in regression of neovascularization. Hemodilution may improve vision in some patients, but the data conflict. More robust randomized controlled trials evaluating current treatments for CRVO are needed. The results of ongoing RCTs on intravitreal triamcinolone, anti-vascular endothelial growth factor agents, and chorioretinal anastomosis are awaited with interest.

Retinal endovascular lysis in ischemic central retinal vein occlusion: one-year results of a pilot study

PURPOSE

Retinal endovascular lysis is a new therapeutic option for patients with central retinal vein occlusion (CRVO). In this procedure, a fibrinolytic agent is injected directly into a cannulated retinal vein after pars plana vitrectomy.

DESIGN

Prospective interventional case series.

PARTICIPANTS

Thirteen strictly defined patients with ischemic CRVO.

METHODS

Patients with a decimal visual acuity (VA) of 0.2 or worse were scheduled for surgery within the first 5 months after onset of CRVO. A full ocular examination, determination of VA (Early Treatment Diabetic Retinopathy Study charts), and fluorescein angiography were done preoperatively and 6, 12, 26, and 52 weeks postoperatively.

MAIN OUTCOME MEASURE

Visual acuity 1 year after retinal endovascular lysis. Secondary study end points were (1) correlation of VA and successful recombinant tissue plasminogen activator injection into a retinal vein, (2) complication rate, and (3) number of additional surgical procedures within the first year after retinal endovascular lysis.

RESULTS

All patients had an ischemic CRVO and completed the 1-year follow-up visit. Preoperative decimal VA was 0.063 +0.025/-0.018 (VA range, light perception [LP]-0.2); 6-week postoperative VA, 0.049 +0.024/-0.016 (LP-0.4); 3-month postoperative VA, 0.043 +0.019/-0.014 (LP-0.3); 6-month postoperative VA, 0.035 +0.022/-0.013 (blindness-0.4); and 12-month postoperative VA, 0.04 +0.026/-0.016 (blindness-0.4). Visual acuity changed 1 year after retinal endovascular lysis by -1.923+/-1.619 lines (+6 to -16 lines; P = 0.258). We considered the retinal endovascular lysis procedure to have been technically successful in 10 eyes. Visual changes did not depend on successful lysis. Six eyes developed neovascular glaucoma, of which 2 globes ended up with painful phthisis and had to be removed. Retinal detachment was found in 3 eyes and cataract in 4. Together, the 13 eyes needed 22 additional surgical procedures. Preoperative and postoperative angiographic examinations showed no significant changes.

CONCLUSION

Ischemic CRVO patients did not profit from retinal endovascular lysis in this pilot study. Visual results and the risk of developing iris neovascularization and neovascular glaucoma took the natural course. Although these results may be due to the overall bad prognosis of these particular ischemic eyes, the number of postoperative complications is unacceptably high.

Effects of intravitreal triamcinolone injection on macular edema and visual prognosis in central retinal vein occlusion

AIM

To determine the effect of intravitreal triamcinolone injection on macular edema and the visual prognosis in cases with CRVO.

METHODS

Eyes with CRVO were classified as ischemic or nonischemic according to extend of retinal capillary nonperfusion. The patients received intravitreal triamcinolone acetonide injection (4 mg/0.1 ml). A complete ophthalmologic evaluation together with flourescein angiography (FA) and optical coherence tomography (OCT) were performed for each patient at presentation and at follow-up visits. The functional and anatomical results of both groups were assessed separately.

RESULTS

A total of 22 eyes (11 ischemic, 11 nonischemic) were included in the study. Mean duration of symptoms before steroid injection was 4.9+/-5.5 months. Mean follow-up time was 11.5+/-2.4. All the eyes completed at least 9 months of examination. At least 3 lines of visual acuity increase using snellen visual acuity chart was observed in 81.8% of the eyes in nonischemic group, while only in 18.2% of the eyes in the ischemic group. In ischemic group, the mean foveal thickness was 766+/-320.7 microm at presentation, which significantly decreased to 441.7+/-166.9 microm at 9th month. In nonischemic group, the mean foveal thickness was 667+/-223 microm at presentation, which significantly decreased to 320+/-175.5 at 9th month. Significant IOP elevation was observed in 8 (36.4%) of the eyes, 75% of which could be controlled with medical treatment.

CONCLUSION

Intravitreal triamcinolone injection may be a promising and effective method for the treatment of macular edema associated with CRVO. Although anatomical results are similar in both groups, functional results are better in non-ischemic CRVO cases.

Intravitreal triamcinolone acetonide: a change in a paradigm

BACKGROUND

Based on experimental studies and clinical observations by Robert Machemer, Gholam Peyman and others, the vitreous cavity has increasingly been used as a reservoir of drugs for the direct treatment of intraocular diseases.

METHODS AND RESULTS

The most widely injected drug so far has been triamcinolone acetonide for various intraocular neovascular and edematous diseases. Comparing the various diseases with respect to effect and side effects of the treatment, the best response in terms of gain in visual acuity has been achieved for intraretinal edematous diseases such as diffuse diabetic macular edema, branch retinal vein occlusion, central retinal vein occlusion, and pseudophakic cystoid macular edema. In eyes with various types of noninfectious uveitis including acute or chronic sympathetic ophthalmia and Adamantiadis-Behçet's disease, visual acuity increased and the degree of intraocular inflammation decreased. Some studies have suggested that intra- vitreal triamcinolone may be useful as an angiostatic agent in eyes with iris neovascularization and proliferative ischemic retinopathies. Intravitreal triamcinolone may possibly be helpful as adjunct therapy for exudative age-related macular degeneration, particularly in combination with photodynamic therapy. In eyes with chronic, therapy-resistant ocular hypotony, intravitreal triamcinolone can induce an increase in intraocular pressure and may stabilize the eye. The complications of intravitreal triamcinolone therapy include secondary ocular hypertension in about 40% of the eyes injected; medically uncontrollable high intraocular pressure leading to antiglaucomatous surgery in about 1-2% of the eyes; posterior subcapsular cataract and nuclear cataract leading to cataract surgery in about 15-20% in elderly patients within 1 year after injection; postoperative infectious endophthalmitis with a rate of about 1:1,000; noninfectious endophthalmitis, perhaps due to a reaction to the solvent agent, and pseudoendophthalmitis with triamcinolone acetonide crystals appearing in the anterior chamber. Intravitreal triamcinolone injection can be combined with other types of intraocular surgery including cataract surgery, particularly in eyes with iris neovascularization. Cataract surgery performed some months after the injection does not show a markedly elevated complication rate. The injection may be repeated, if vision redecreases. In nonvitrectomized eyes, the duration of the effect and side effects of a single intravitreal injection of triamcinolone is about 6-9 months for a dosage of about 20 mg, and about 2-4 months for a dosage of 4 mg. It has remained unclear so far, whether and how to remove the solvent agent. In the future, intravitreal triamcinolone may be combined with other antiangiogenic drugs for the treatment of exudative age-related macular degeneration or with neuroprotective drugs for treatment of diabetic retinopathy.

CONCLUSIONS

Despite an exponentially increasing number of mostly case-series studies, the intravitreal injection of triamcinolone may still be considered an experimental procedure until randomized studies have been presented.

Carboxymethylcellulose as a new carrier substance for intravitreal injection of reproducible amounts of triamcinolone

BACKGROUND

Intravitreal application of triamcinolone acetonide has become increasingly popular for the treatment of various retinal disorders. However, dosage, mode of preparation and application differ worldwide. The aim of this study was to find a safe vehicle that would allow intravitreal injection of an exact amount of triamcinolone acetonide without potentially retinotoxic preservatives.

METHODS

Solutions of triamcinolone acetonide with a theoretical concentration of 4 mg/0.2 ml were prepared following one sedimentation (A) and two filtration (B, C) methods. In addition, a filtration method using carboxymethylcellulose 2% as a carrier (D) was established. During processing and after injection into an eye model, the crystals were quantified by weight and high-performance liquid chromatography (HPLC), and, hence, the rate of crystal loss during this process was determined.

RESULTS

The initial preparation contained 93-106% of the calculated quantity. Method A, containing the entire vehicle, delivered 45%+/-7.3% of the target quantity to the eye model, whereas the vehicle-free methods B and C delivered 15%+/-6.9% and 11%+/-3.2%, respectively. Using carboxymethylcellulose 2% as a preservative-free vehicle, we found 93%+/-3.7% of the calculated amount in the eye model. The missing crystals were mainly sticking to the walls of the syringes and needles used for transfer.

CONCLUSION

Common methods for preparing triamcinolone acetonide vary in the amount of drug actually injected intravitreally. Carboxymethylcellulose is an ideal carrier substance for intravitreal application of an exact dose of triamcinolone acetonide without preservatives.

Photographic estimation of the duration of high dose intravitreal triamcinolone in the vitrectomised eye

AIM

To determine the duration of residence of triamcinolone in the vitrectomised eye.

METHODS

23 eyes of 23 patients underwent intravitreal injection of high dose (20 mg) decanted triamcinolone acetonide (Kenalog) at the conclusion of vitrectomy surgery or in previously vitrectomised eyes with macular oedema from diabetes, uveitis, cataract surgery, or other surgery.

RESULTS

The median time to disappearance of triamcinolone in the vitrectomised eye was 113 days (95% confidence interval (CI) 85 to 191). In the phakic eyes the median time to disappearance was 191 days (95% CI 148 to 191). In the pseudophakic eyes the median time to disappearance was 102 days (95% CI 85 to 113). This difference was not significant (p = 0.12). There were no cases of endophthalmitis or severe inflammatory reaction. Five eyes (22%) experienced intraocular pressure rise >/=10 mm Hg.

CONCLUSIONS

High dose decanted intravitreal triamcinolone has a median residence time of 113 days in the vitrectomised eye. Although this appears to be shorter than in the non-vitrectomised eye, this study suggests that a sufficient duration of action will be present to be clinically useful.

Intravitreal triamcinolone acetonide for treatment of intraocular oedematous and neovascular diseases

Intravitreal triamcinolone acetonide (IVTA) has increasingly been applied as treatment for various intraocular neovascular and oedematous diseases. Comparing the various diseases with respect to effect and side-effects of the treatment, the best response in terms of gain in visual acuity (VA) has been achieved for intraretinal oedematous diseases such as diffuse diabetic macular oedema, branch retinal vein occlusion, central retinal vein occlusion and pseudophakic cystoid macular oedema. In eyes with various types of non-infectious uveitis, including acute or chronic sympathetic ophthalmia and Adamantiadis-Behcet's disease, VA increased and the degree of intraocular inflammation decreased. Some studies have suggested that intravitreal triamcinolone may be useful as angiostatic therapy in eyes with iris neovascularization and proliferative ischaemic retinopathies. Intravitreal triamcinolone may possibly be helpful as adjunct therapy for exudative age-related macular degeneration (AMD), particularly in combination with photodynamic therapy. In eyes with chronic, therapy-resistant ocular hypotony, intravitreal triamcinolone can induce an increase in intraocular pressure (IOP) and may stabilize the eye. The complications of intravitreal triamcinolone therapy include: secondary ocular hypertension in about 40% of the eyes injected; medically uncontrollable high IOP leading to antiglaucomatous surgery in about 1-2% of the eyes; posterior subcapsular cataract and nuclear cataract leading to cataract surgery in about 15-20% of elderly patients within 1 year of injection; postoperative infectious endophthalmitis occurring at a rate of about one per 1000; non-infectious endophthalmitis, perhaps due to a reaction to the solvent agent, and pseudo-endophthalmitis with triamcinolone acetonide crystals appearing in the anterior chamber. Intravitreal triamcinolone injection can be combined with other intraocular surgeries, including cataract surgery, particularly in eyes with iris neovascularization. Cataract surgery performed some months after the injection does not show a markedly elevated complication rate. The injection may be repeated if the resultant benefits decrease after the initial IVTA injection. In non-vitrectomized eyes, the duration of the effect and side-effects of a single intravitreal injection of triamcinolone is about 6-9 months for a dosage of about 20 mg, and about 2-4 months for a dosage of 4 mg. So far, it has remained unclear whether the solvent agent should be removed, and if so, how.

Vehicle of triamcinolone acetonide is associated with retinal toxicity and transient increase of lens density

BACKGROUND

Intravitreal triamcinolone acetonide (TA) has been widely used as a therapeutic method for many ocular diseases, but a consensus on an appropriate safe therapeutic window of dosage for intravitreal injection, and whether vehicle of TA should be reduced or eliminated, has not yet been reached. The aim of this article is to investigate these issues.

METHODS

Forty New Zealand white rabbits were divided into four experimental groups and one control group. Four or 25 mg TA, with vehicle either reduced or not, was injected into the vitreous cavity of rabbits in experimental groups. Rabbits in the control group received 0.2 ml intravitreal sterile saline solution. Intraocular pressures (IOP) were measured by a Tonopen tonometer. Values of lens density were measured by a Pentacam system. Soluble protein, total antioxidation capacity, reduced glutathione (GSH), glutathion peroxidase (GSH-px), and superoxide dismutase (SOD) in lens were measured by specific kits. ERG and pathological examinations, including light and electron microscopy of the retina, were also performed.

RESULTS

Elevation of IOP was noted in all experimental groups after intravitreal TA (P<0.01, paired t-test). Significant increase of lens density was noticed at 1 week after intravitreal TA in the 25 mg vehicle-containing group (P<0.0001, paired t-test). Significant loss of GSH-px activity was noticed at the end of the study (P<0.05, paired t-test), while SOD activity increased (P<0.05, paired t-test). Amplitudes of ERG waves declined significantly in vehicle-containing groups (P<0.01, paired t-test) at the end of the study. Pathological examination showed obvious retinal toxicity in vehicle-containing groups.

CONCLUSIONS

Vehicle of TA should be eliminated or reduced before intravitreal injection to avoid potential retinal toxicity and transient increase in lens density.

Intravitreal triamcinolone acetonide for treatment of intraocular proliferative, exudative, and neovascular diseases

Within the last three years, triamcinolone acetonide has increasingly been applied intravitreally as treatment option for various intraocular neovascular edematous and proliferative disorders. The best response in terms of gain in visual acuity after the intravitreal injection of triamcinolone acetonide was found in eyes with intraretinal edematous diseases such as diffuse diabetic macular edema, branch retinal vein occlusion, central retinal vein occlusion, and pseudophakic cystoid macular edema. Visual acuity increased and degree of intraocular inflammation decreased in eyes with various types of non-infectious uveitis including acute or chronic sympathetic ophthalmia and Adamantiadis-Behcet's disease. Intravitreal triamcinolone may be useful as angiostatic therapy in eyes with iris neovascularization and proliferative ischemic retinopathies. Possibly, intravitreal triamcinolone may be helpful as adjunct therapy for exudative age-related macular degeneration, possibly in combination with photodynamic therapy. In eyes with chronic, therapy resistant, ocular hypotony, intravitreal triamcinolone can induce an increase in intraocular pressure and may stabilize the eye. The complications of intravitreal triamcinolone therapy include secondary ocular hypertension in about 40% of the eyes injected, cataractogenesis, postoperative infectious and non-infectious endophthalmitis, and pseudo-endophthalmitis. Intravitreal triamcinolone injection can be combined with other intraocular surgeries including cataract surgery. Cataract surgery performed some months after the injection does not show a markedly elevated rate of complications. If vision increases and eventually decreases again after an intravitreal triamcinolone acetonide injection, the injection can be repeated. The duration of the effect of a single intravitreal injection of triamcinolone depended on the dosage given. Given in a dosage of about 20mg to non-vitrectomized eyes, the duration of the effect and of the side-effects was 6-9 months. Intravitreal triamcinolone acetonide may offer a possibility for adjunctive treatment of intraocular edematous and neovascular disorders. One has to take into account the side-effects and the lack of long-term follow-up observations.

RETINAL ENDOVASCULAR SURGERY FOR CENTRAL RETINAL VEIN OCCLUSION

PURPOSE

The rate and magnitude of spontaneous visual recovery are very poor in central retinal vein occlusion (CRVO). In the first follow-up year, the Central Vein Occlusion Study Group reported that only 6% of eyes recovered > or = 3 lines of vision and none recovered > or = 8 lines of vision. Retinal endovascular surgery (REVS) is vitrectomy followed by cannulation of retinal vessels with injection of tissue plasminogen activator. After reports of one surgeon's experience suggested that the procedure promotes recovery of vision, other surgeons began to offer REVS to their patients. This report discusses the initial experience of four surgeons using REVS to treat CRVO.

METHODS

In this prospective, consecutive case series, patients with CRVO for > 1 week and visual acuity of < 20/50 were offered REVS and were followed by the authors. The main outcome measure was recovery of visual acuity.

RESULTS

This series represents the initial 25 consecutive REVS cases of the 4 authors (5-7 cases per author). The median CRVO duration was 2 months (mean 2.9, months), and the average preoperative visual acuity was 20/400 (< or = 20/200 in 80% of cases). Intravitreal triamcinolone acetonide (IVTA) was administered intraoperatively in three cases and at some time postoperatively in six cases. Overall, 18 eyes (72%) recovered > or = 3 lines of visual acuity, and 9 (36%) recovered > or = 8 lines of vision. Among the surgeons, the rates of > or = 3-line visual recovery ranged from 57% to 100%, and the rates of > or = 8-line visual recovery ranged from 14% to 71%. Of the 22 eyes that initially underwent REVS without intraoperative IVTA injection, 13 (59%) recovered > or = 3 lines of vision and 5 (23%) recovered > or = 8 lines of vision. Complications included macular edema (28%), anterior segment or retinal neovascularization (24%), and subsequent cataract surgery (5 [23%] of the 22 preoperatively phakic eyes). One eye had an intraoperative retinal detachment that was treated but recurred 4 months after REVS, and two of the eyes with anterior segment neovascularization developed late-onset traction retinal detachments (at 8 and 13 months after REVS).

CONCLUSION

Although the authors were on the "learning curve" of experience during this series, REVS appears to promote visual recovery far in excess of what would be expected to occur spontaneously, and IVTA injection greatly improved outcomes. We believe that mastery of REVS techniques and the inclusion of IVTA injection may lead to better visual results and lower complication rates.

Intravitreal triamcinolone acetonide for cystoid macular edema in nonischemic central retinal vein occlusion

PURPOSE

The effectiveness of intravitreal triamcinolone acetonide in the treatment of cystoid macular edema from central retinal vein occlusion (CRVO) was investigated.

DESIGN

A noncomparative, prospective, interventional case series.

METHODS

In a clinical practice, 18 patients were enrolled with nonischemic CRVO and cystoid macular edema. Two milligrams of triamcinolone acetonide were injected into the vitreous of only one eye from each patient. The outcome measures were 1-mm mean central retinal thickness on optical coherence tomography and visual acuity.

RESULTS

Mean duration of symptoms before surgery was 2 months (SD, 1.3 months). Ten patients required repeated injections for recurrent cystoid macular edema (mean, 1.8 injections). Mean visual acuity significantly improved from 20/300 to 20/166 (P = .007) at 1 month, 20/100 (P = .0005) at 2 months, 20/130 (P = .007) at 3 months, and 20/150 (P = .02) at 6 months but deteriorated again to 20/270 (not significant) at 12 months. There was a significant improvement in retinal thickness from presentation 518 microm, to 363 microm (P = .03) at 1 month, 304 microm (P = .04) at 2 months, and 353 microm (P = .01) at 3 months but not from presentation at 6 months (mean, 383 microm) and 12 months (mean, 406 microm). Eleven patients suffered intraocular pressure rises requiring intervention. Intravitreal triamcinolone acetonide did not prevent collateral circulation formation, which was seen in 10 patients.

CONCLUSION

Intravitreal corticosteroid injection is very effective in reversing cystoid macular edema and improving visual acuity in recent-onset nonischemic CRVO in the first 6 months, but this is unfortunately not sustained at 1 year.

Intravitreal triamcinolone acetonide for treatment of persistent macular oedema in branch retinal vein occlusion

BACKGROUND

To evaluate the efficacy of intravitreal triamcinolone acetonide injection on persistent macular oedema in branch retinal vein occlusion that fails to respond to previous laser photocoagulation.

MATERIAL AND METHODS

A total of 19 eyes of 19 patients with persistent macular oedema due to branch retinal vein occlusion were treated with 8 mg/0.2 ml of intravitreal triamcinolone acetonide injection. The main outcome measures included best-corrected visual acuity, intraocular pressure, and macular oedema map values of Heidelberg Retinal Tomograph II (HRT II) before and after intravitreal triamcinolone injection.

RESULTS

The mean follow-up time was 6.2+/-1.0 months. The mean baseline best-corrected logarithm of minimal angle of resolution (LogMAR) value for visual acuities of the patients before intravitreal triamcinolone injection was 1.01+/-0.16. After treatment, it was 0.55+/-0.22 at the 1-month, 0.56+/-0.22 at 3-month, and 0.62+/-0.22 at the last visits and the differences were statistically significant when compared with baseline values (for each, P<0.001). The mean oedema map values on HRT II significantly decreased by 28.5% at 1-month, 23.8% at 3-month, and 23.8% at the last visit when compared with preinjection values (for each, P<0.001). Intraocular pressure elevation exceeding 21 mmHg was observed in 26.3% of eyes at 1-month, 15.7% at 3-month, and 5.2% at the last visit, but was controlled with topical anti-glaucomatous medications in all eyes.

CONCLUSION

Intravitreal triamcinolone acetonide application is a promising approach in the treatment of persistent macular oedema due to branch retinal vein occlusion non-respondent to laser photocoagulation.

Surgical treatments of central retinal vein occlusion

Central retinal vein occlusion is a common retinal disease with usually severe complications. At present no safe treatment exists promoting the recovery of lost vision. Several surgical approaches to modify the natural course of the disease have been proposed in recent years. These options include laser-induced chorioretinal venous anastomosis, the injection of tissue plasminogen activator into a retinal vein, optic nerve decompression, and vitrectomy for macular edema. Even though all the proposed treatments have not yet been supported by randomized clinical trials, these techniques can be considered as innovative in an area where no effective treatment is available. Larger clinical trials are required to assess both the effectiveness and complication rate of surgical treatments designed to reverse the natural evolution of central retinal vein occlusion.

[Intravitreal triamcinolone acetonide for the treatment of intraocular edematous and neovascular diseases]

BACKGROUND

Within the last 2 years, intravitreal application of triamcinolone acetonide has exponentially increased as a treatment option for various intraocular neovascular and edematous proliferative disorders.

METHODS AND RESULTS

The best response to intravitreal triamcinolone acetonide injection in terms of gain in visual acuity was obtained for eyes with intraretinal edematous diseases such as diffuse diabetic macular edema, branch retinal vein occlusion, central retinal vein occlusion, and pseudophakic cystoid macular edema. Visual acuity increased and degree of intraocular inflammation decreased in eyes with various types of noninfectious uveitis including sympathetic ophthalmia. Intravitreal triamcinolone may be useful as angiostatic therapy in eyes with iris neovascularization and proliferative ischemic retinopathies. Possibly, intravitreal triamcinolone may be helpful for exudative age-related macular degeneration, alone or in combination with photodynamic therapy. In eyes with chronic, therapy-resistant, ocular hypotony, intravitreal triamcinolone can induce an increase in intraocular pressure and may stabilize the eye. The complications of intravitreal triamcinolone therapy, such as secondary ocular hypertension in about 40% of the eyes injected, cataractogenesis, postoperative infectious and noninfectious endophthalmitis, and pseudo-endophthalmitis will be covered in another article. Intravitreal triamcinolone injection can be combined with other intraocular surgeries including cataract surgery. Cataract surgery performed some months after the injection did not show a markedly elevated rate of complications. If vision increases after the intravitreal triamcinolone injection, the injection can be repeated. The duration of the effect of a single intravitreal injection of triamcinolone ranges between 2 and 9 months, probably depending on the dosage used.

CONCLUSIONS

Intravitreal triamcinolone acetonide may offer a possibility for adjunctive treatment of intraocular oedematous and neovascular disorders. One has to take into account the side effects and the lack of long-term follow-up observations.