Intravitreal triamcinolone acetonide for treatment of intraocular oedematous and neovascular diseases

Tumor volume reduction using combined phacoemulsification and intravitreal triamcinolone injection for the management of cataract with treated uveal melanoma and atypical nevi

PURPOSE

To study the reduction in tumor size and the safety and efficacy of combined phacoemulsification and intravitreal triamcinolone acetonide injection (phaco-IVTA) in patients with treated melanoma and atypical nevi.

SETTING

Bascom Palmer Eye Institute, Miami, Florida, USA.

METHODS

The medical records of 49 consecutive patients (51 eyes) with treated melanoma or atypical nevi treated with phaco-IVTA were evaluated retrospectively for changes in Snellen visual acuity, tumor volume, and frequency of complications. Main outcome measures included a postsurgical change in tumor size greater than or equal to 0.5 mm of height or 1.0 mm of basal diameter by echographic analysis, improvement in visual acuity at 6 months and final follow-up, and complications including endophthalmitis, cystoid macular edema, epiretinal membrane, increased intraocular pressure, and persistent corneal edema.

RESULTS

The median baseline visual acuity was 20/80 in the affected eye. At the 6-month follow-up examination, 13 (68%) of 19 eyes had achieved better than 20/40 visual acuity. Treated uveal melanomas (n=30) and atypical choroidal nevi (n=21) were stable with combined therapy, and echographic measurements improved in 12 eyes. Intraocular pressure increased from baseline to 25 mm Hg or more postoperatively in 4 of 51 eyes (8%). No other significant complications occurred.

CONCLUSIONS

Combined phacoemulsification and IVTA was reasonably safe in patients with treated melanoma and atypical nevi. Tumors remained stable or decreased slightly in size. Intravitreal triamcinolone acetonide injection at the time of cataract surgery in patients with treated melanoma or nevus may reduce rates of tumor progression in these patients.

Exacerbation of central serous chorioretinopathy following intravitreal triamcinolone injection

BACKGROUND

This report describes a case of central serous chorioretinopathy following intravitreal triamcinolone acetonide injection.

METHODS

A 42-year-old man presented with a 4-month history of decreased visual acuity (0.4) in his left eye. The left eye demonstrated macular edema due to branch retinal vein occlusion. Triamcinolone acetonide 4 mg/ 0.1 mL was injected intravitreally to treat the macular edema.

RESULTS

Pigmentary retinal discoloration, retinal pigment epithelium leakage and a slight neurosensorial detachment with cystoid macular edema at the temporal macula were present prior to intravitreal triamcinolone injection. Three weeks after injection, visual acuity had decreased to 0.2 and metamorphopsies appeared in the left eye. A sharply demarcated serous macular elevation and a progressively increasing hyperfluorescence of the pre-existing leakage point led to the diagnosis of "exacerbation of the pre-existing asymptomatic central serous chorioretinopathy" following intravitreal triamcinolone injection. Macular elevation spontaneously resolved by the 4th month post-injection. At the 6th month, the patient experienced recurrence of a small serous detachment at the temporal macula.

CONCLUSION

Central serous chorioretinopathy exacerbation may arise as a complication of intravitreal triamcinolone acetonide injection.

Fluocinolone acetonide sustained drug delivery device for chronic central retinal vein occlusion: 12-month results

PURPOSE

To determine treatment outcomes of a long-acting intravitreal fluocinolone acetonide sustained drug delivery implant in eyes with central retinal vein occlusion (CRVO) and chronic refractory macular edema.

DESIGN

Prospective, noncomparative, interventional case series.

METHODS

Fourteen eyes of 14 patients with chronically persistent macular edema associated with CRVO underwent intraocular implantation of a three-year fluocinolone acetonide sustained drug delivery system. Best-corrected Early Treatment of Diabetic Retinopathy visual acuity (VA), central foveal thickness determined by optical coherence tomography, and intraocular pressure (IOP) were recorded after the first 12 months after implant insertion.

RESULTS

The median (range) vein occlusion and macular edema duration were 12.5 months (range, seven to 49). No eye experienced intraoperative complications. At baseline, median VA was 20/126, improved to 20/60 by two months, and was 20/80 by 12 months. A significant proportion of eyes had gained lines of VA at 12 months compared with baseline (P = .002). At 12 months, the mean and median central retinal thickness decreased from 622 and 600 microm before surgery, respectively, to 307 and 199 microm after surgery, respectively (P = .008). By month 12, cataract had developed in all five phakic patients, and 13 of 14 eyes required medical or surgical IOP-lowering interventions.

CONCLUSIONS

VA improved and macular edema decreased in a significant proportion of implanted eyes with chronic, CRVO-associated macular edema. Cataract formation and elevated IOP, the main side effects, were managed, respectively, with cataract extraction and medical or surgical IOP control, or both. This system is a promising novel alternative to currently available treatments for this challenging patient population.

Intravitreal micronized triamcinolone versus triamcinolone acetonide: a clinical and morphological comparative study

Nowadays many authors suggest the use of intravitreal triamcinolone acetonide (TA) for the treatment of vitreoretinal diseases, although it can be associated with a high risk of local toxicity. In order to develop a safer injection for clinical use, the purpose of our study is to evaluate the in situ safety of two different triamcinolone preparations, a commercially available TA and a micronized triamcinolone. The experiments were performed on 18 adult male age-matched New Zealand rabbits. The clinical examination included funduscopy with an indirect ophthalmoscope and intraocular pressure (IOP) measurement. At the end of the clinical observations, the animals were sacrificed and the eyes enucleated and processed for the morphological evaluation. In our study the main side effect observed was the IOP elevation in the group injected with triamcinolone acetonide. In addition, in the TA-injected group, one eye was enucleated following an endophthalmitis. Our study highlights that doses as low as 4 mg of triamcinolone acetonide injected into the rabbit vitreous may have a local toxic effect in terms of IOP elevation, endophthalmitis occurrence and changes in the retinal morphology. In contrast, the micronized triamcinolone injection shows a less toxic effect in situ, thus suggesting the alternative use of this more reliable preparation which seems to be safer for a clinical use.

Combined intravitreal bevacizumab and photodynamic therapy for neovascular age-related macular degeneration

BACKGROUND

Our aim was to evaluate the short-term safety and efficacy of combined photodynamic therapy (PDT) with verteporfin and intravitreal bevacizumab in neovascular age-related macular degeneration (AMD).

METHODS

A prospective non-randomized interventional case series of 30 eyes of 30 patients with choroidal neovascularization (CNV) caused by AMD was studied. All patients were treated with PDT followed by an intravitreal injection of bevacizumab (1.5 mg) on the same day. Ophthalmic evaluations included determination of best-corrected visual acuity by using ETDRS charts. CNV lesion characteristics were determined by fluorescein angiography, and retinal morphology by optical coherence tomography. Review examinations were performed 1, 4, and 12 weeks following treatment.

RESULTS

The median ETDRS letter scores increased by 3 letters after 4 weeks and 4.3 letters after 12 weeks. Median central retinal thickness decreased from the baseline by 145 microm (week 1), 205 microm (week 4), and 171 microm (week 12), respectively (P < 0.0001, for all comparisons). One patient experienced a transient moderate vision loss after 4 weeks post treatment. Leakage on fluorescein angiography was resolved in all patients at week 12. No significant ocular or systemic side-effects were observed.

CONCLUSIONS

Short-term results suggest that a single PDT in combination with intravitreal bevacizumab is safe and associated with stabilization of visual acuity and decrease of intraretinal and subretinal fluid accumulation in the macula. Further evaluation of this treatment strategy for neovascular AMD appears warranted.

Cyclodextrin microparticles for drug delivery to the posterior segment of the eye: aqueous dexamethasone eye drops

Delivery of steroids to the retina is currently undertaken with invasive injections into the vitreous cavity. This paper describes a non-invasive method to deliver steroids in therapeutic levels to the retina in rabbits. Dexamethasone was formulated as somewhat water-soluble dexamethasone/gamma-cyclodextrin (gammaCD) microparticles in a low-viscosity aqueous eye drop suspension. The mean (+/-standard deviation) diameter of the particles was 20.4+/-10.3 microm, with no particles larger than 60 microm. The aqueous suspension formulation was tested in rabbits and compared with an aqueous dexamethasone eye drop solution containing randomly methylated beta-cyclodextrin (RMbetaCD). The dexamethasone concentration was identical in both formulations (15 mg mL(-1)). The drug was administered to the left eye but determined in both eyes. The amount reaching different eye tissues via the topical route was determined by subtracting the amount found in the right eye from the amount found in the left eye. Two hours after single application of the dexamethasone/gammaCD eye drops to rabbits the mean (+/-s.d.) concentration in vitreous was 29+/-16 ng g(-1), 86% of which reached vitreous via the topical route and in retina the concentration was 57+/-22 ng g(-1) (49% via topical route). For the RMbetaCD the values were 22.6+/-9 and 66+/-49 ng g(-1) (73 and 14% via topical route), respectively. These steroid levels are comparable with the dexamethasone concentration achieved 1 month after intravitreal injection. The aqueous dexamethasone/gammaCD eye drop formulation was chemically stable during 7 months storage and well tolerated with no visible short-term side effects.

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.

Cytomegalovirus retinitis following intravitreal injection of triamcinolone: report of two cases

CONTEXT

Cytomegalovirus (CMV) retinitis usually affects severely immunosuppressed individuals. However, some exceptional and isolated cases of CMV retinitis have been described in immunocompetent patients.

METHODS

We report two cases of non-immunodeficient patients seen in our institution over a period of 6 months, who presented with CMV retinitis a few weeks after an intravitreal injection of triamcinolone acetonide.

RESULTS

Although the cellular and molecular mechanisms underlying the development of CMV in an immunocompetent patient's eye have not yet been precisely established, the well known immunosuppressive properties of corticosteroids suggest that triamcinolone probably plays a role in the endogenous reactivation of latent CMV.

CONCLUSIONS

Our two patients received high doses of triamcinolone. Both had also pseudophakia, vitrectomy and a past medical history of type 2 diabetes mellitus. Such features, individually or combined, may be risk factors for local reactivation of CMV and should be considered prior to the administration of triamcinolone acetonide in ophthalmology.

A case of mycotic endophthalmitis after triamcinolone acetonide-assisted pars plana vitrectomy

Only two cases of bacterial endophthalmitis after triamcinolone acetonide (TA)-assisted pars plana vitrectomy (PPV) have been reported. As far as we are aware there has been no report of fungal endophthalmitis occurring after TA-assisted PPV. We report a case of endophthalmitis due to Fusarium after TA-assisted PPV. An otherwise healthy 61-year-old woman suffered from branch retinal vein occlusion with macular edema, which led to reduced visual acuity and metamorphopsia. Because she complained of severe discomfort, TA-assisted PPV was performed to reduce the macular edema. At the end of the surgery 4 mg TA was injected into the vitreous cavity. Two weeks after the surgery her visual acuity had improved to 20/20. Six weeks after the surgery her visual acuity decreased to 20/200 but without pain. Slit lamp examination showed no conjunctival hyperemia and no inflammatory cell infiltration in the anterior chamber. Fundus examination showed several small, creamy-white, circumscribed retinal lesions, epiretinal membranes, vitreoretinal traction, and rhegmatogenous retinal detachment. PPV was performed again. Intra-operative light microscopy revealed filamentous fungi in the epiretinal membrane, which was removed during the second PPV. Five days after the second surgery, retinal detachment recurred. A third PPV with encircling procedures and silicone oil tamponade was performed. Fungal cultures from the epiretinal membrane were identified as Fusarium sp. Seven months after the third surgery the silicone oil was removed. The retina remained attached and visual acuity was 20/200. Any patient who has undergone TA-assisted PPV should be carefully followed up for possible post-operative endophthalmitis, even if the anterior segment abnormality is minor.

Measuring triamcinolone acetonide in aqueous humor by gas chromatography-electron-capture negative-ion mass spectrometry

Intravitreal triamcinolone acetonide (IVTA) injection has been used in the treatment of various posterior segment diseases. One of the side effects of IVTA is raised intraocular pressure, which may be secondary to triamcinolone acetonide (TAA)'s effects on the trabecular meshwork that affects aqueous outflow. In order to study the biological effects of TAA on the trabecular meshwork, we firstly need to reliably and accurately detect the concentration of TAA in tissue cells or fluids. In this study we have described a technique of using gas chromatography-electron-capture-negative-ion mass spectrometry (GC-NCI-MS) to develop a simple, sensitive, selective and validated method to detect TAA in aqueous humor (AH) of rabbits following IVTA and subconjunctival TAA injections. We derivatized TAA from extracted aqueous sample by acetic anhydride and BSTFA, respectively, and analyzed by GC-NCI-MS. The detection limit was 0.3ng/ml, linearity over 0.995 from 0 to 300ng/ml. The reproducibility ranged from 10.4 to 3.9 for concentrations from 3 to 300ng/ml, and recovery was over 95% for the concentrations 10, 60, and 200ng/ml. No interference was found from 159 aqueous samples. There was no TAA residue carried to the next injection from previously high concentration injection, 10,000ng/ml. We have provided an alternative, rapid, and robust method other than LC-MS-MS for TAA detection in AH.

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.

Visual acuity change after intravitreal bevacizumab for exudative age-related macular degeneration in relation to subfoveal membrane type

PURPOSE

To examine an association between the subfoveal neovascular membrane type and visual acuity change after intravitreal bevacizumab injection for exudative age-related macular degeneration (AMD).

METHODS

We carried out a clinical, retrospective, interventional case-series study including 66 consecutive patients (67 eyes) with exudative AMD who received an intravitreal injection of 1.5 mg bevacizumab. Study subgroups included the occult type without or with minimally classic subfoveal neovascularization (n = 28 eyes, 42%), predominantly or purely classic subfoveal neovascularization (n = 22 eyes, 33%), and eyes with retinal pigment epithelium detachment (n = 17 eyes, 25%). Follow-up was >or= 2 months.

RESULTS

The maximal visual acuity (VA) gain (mean +/- standard deviation - 0.07 +/- 0.30 logMAR, 0.5 +/- 2.9 Snellen lines; p = 0.87), and VA gain at 1 month (p = 0.10), 2 months (p = 0.77) and 3 months (p = 0.35) after the injection did not vary significantly between the three study subgroups. Correspondingly, a multivariate analysis did not reveal a statistically significant (p = 0.57) influence of subfoveal lesion type on gain in VA.

CONCLUSIONS

Visual improvement after intravitreal bevacizumab does not differ markedly between various types of subfoveal neovascularization in AMD.

Preclinical investigation of fluorometholone acetate as a potential new adjuvant during vitreous surgery

OBJECTIVE

To examine the effects of intravitreal fluorometholone acetate (FMT) on the morphology and function of the retina and to investigate its possible use for vitreous surgery.

METHODS

Brown Norway rat eyes (n = 6, 12 groups) were injected with 0.05 ml of SF6 gas for vitrectomization. Four weeks later, FMT solution was injected into the vitreous cavity/subretinal space of the vitrectomized eyes at doses of 10, 20, and 40 mg/ml (0.05 ml/eye, n = 12 for each group). The retinal function was evaluated by electroretinography (ERG) at 4 and 8 weeks after FMT injection. Retinal toxicity was also assessed histologically by a light microscopy. Sham-operated eyes (0.05 ml of irrigating solution, n = 12) were used as control animals. FMT-assisted pars plana vitrectomy with internal limiting membrane (ILM) peeling was performed in primate eyes (n = 2). Retinal toxicity was assessed by ophthalmoscope, fluorescein angiography and electron microscopy three months after the vitreous surgery.

RESULTS

There was no remarkable reduction in any ERG waves at either time interval at 4 and 8 weeks after the intravitreal/subretinal injection of FMT. No obvious histological change was observed in any of the rat eyes either. Using ophthalmoscope, fluorescein angiography and electron microscopy, the appearance of the primate retinas remained to be in a non-pathological condition.

CONCLUSION

FMT appears to be a potentially useful tool in assisting vitreous surgery including safe ILM peeling.

A review of drug options in age-related macular degeneration therapy and potential new agents

Age-related macular degeneration (AMD) is the leading cause of legal blindness in people > 50 years of age in the developed world. AMD is both a debilitating and costly disease for the individual and the community. Greater understanding of the mechanisms and pathways involved in causing the visual loss in AMD has resulted in the advent of several newer and more effective treatment options, making it an exciting time in the management of AMD. This paper will examine the principles behind the existing drug therapies available, as well as those being developed in the management or prophylaxis of AMD and its vision-threatening complications.

Visual Acuity Change After Intravitreal Triamcinolone in Various Types of Exudative Age-Related Macular Degeneration

OBJECTIVE

The aim of this study was to compare the visual acuity change after an intravitreal high-dose injection of triamcinolone acetonide (TA) in various types of exudative age-related macular degeneration (AMD).

PARTICIPANTS

The interventional comparative case series study included 142 patients (146 eyes) with progressive exudative AMD differentiated into the occult type (n = 78; 53.4%), minimal classic type (n = 45; 30.8%), predominantly classic type (n = 17; 11.6%), and the purely classic type (n = 6; 4.1%). Mean follow-up was 9.7 +/- 7.0 months (3-35.7 months).

METHODS

Single intravitreal injection of approximately 20 mg of TA.

OUTCOME MEASURES

Visual acuity, intraocular pressure (IOP).

RESULTS

Gain in visual acuity measured at 1 month (P = 0.20), 2 months (P = 0.43), and at 3 months (P = 0.38) after the intravitreal injection of triamcinolone and maximal gain in visual acuity during the whole follow-up (P = 0.81) did not vary significantly between the 4 study groups. Correspondingly, the size of a retinal pigment epithelium detachment was not significantly associated with the change in visual acuity at 1 month (P = 0.62), 2 months (P = 0.24), 3 months (P = 0.96), or the maximal gain in visual acuity during follow-up (P = 0.93). The amount of rise in IOP, compared with the baseline value (6.5 +/- 7.4 mmHg), was statistically not associated with the type of subfoveal membrane (P = 0.20; 95% confidence interval: -0.52, 2.45).

CONCLUSIONS

The change in visual acuity and the rise in IOP in patients with exudative AMD receiving an intravitreal triamcinolone monotherapy is statistically independent of the type of subfoveal membrane, including the size of a retinal epithelium detachment.

Ocular oxygenation and the treatment of diabetic retinopathy

Retinal photocoagulation and vitrectomy both reduce diabetic macular edema and neovascularization in diabetic retinopathy. We suggest that this clinical effect is based on the effect these treatment modalities have on retinal oxygenation, and we present a theory to explain why retinal photocoagulation and vitrectomy influence edema and neovascularization in diabetic and other ischemic retinopathies.

Bevacizumab zur Therapie des sekundären Makulaödems nach venösen Gefäßverschlüssen

Application of VEGF inhibitors represents a treatment option for macular edema secondary to retinal vein occlusion that targets the disease at the causal molecular level. First reports on intravitreal injections of bevacizumab show promising morphological and functional effects and demonstrate that bevacizumab is a potent antiedematous agent in this context. A significant reduction of the central retinal thickness followed by a rapid improvement of visual acuity may be achieved within days. In a pilot study with a review period of 3 months, we found a significant improvement of one or more lines in 93% and four or more lines in 27% of eyes. This was associated with a concomitant significant reduction in central retinal thickness, which, however, was not sustained by a single injection (64% reduction after 1 month and 28% after 3 months). No relevant adverse events were noted. The duration of action after intravitreal bevacizumab administration is currently unknown. Reinjections will be necessary to maintain a lasting beneficial effect. Prospective, controlled long-term studies are mandatory to develop standardized treatment protocols that allow a safe and effective application of this off-label therapy.

Decreasing efficacy of repeated intravitreal triamcinolone injections in diabetic macular oedema

BACKGROUND/AIM

Intravitreal triamcinolone (IVTA) results in transient improvements in diabetic macular oedema (DMO), necessitating repeated injections. The authors report a case series of 10 eyes of 10 patients with DMO, who received a repeat injection of 4 mg IVTA, at least 26 weeks after the first injection of the same dose.

METHOD

Pre-injection and at 2, 4, 9, and 17 weeks post-injection, best corrected visual acuity (BCVA) and central foveal thickness (CFT) on optical coherence tomography, after the first and repeat injections, were compared using paired t test. Side effects were monitored.

RESULTS

BCVA, CFT, intraocular pressure (IOP), and cataract scores were not significantly different before initial and repeat injections (given at 32.5 (SD 3.5) weeks after the first injection). Transient improvements of BCVA and CFT were achieved after both injections. However, after the repeat injection, the BCVA was significantly worse at all time points (p<0.05) and so were the best achieved CFT and the CFT at 4 weeks post-injection (p = 0.034 and 0.011 respectively), compared with the initial injection. Post-injection maximum IOPs and increase in cataract scores were not significantly different between the two injections.

CONCLUSION

A repeat injection of 4 mg of IVTA may not be as effective as an initial injection for the treatment of DMO.