MyVisionTest News Archive
Nov 25, 2009
Intravitreal steroid for refractory diabetic macular edema
The majority of eyes with diabetic macular edema (DME) and impaired vision despite previous laser treatment that initially experienced improvement in visual acuity following intravitreal triamcinolone acetonide (IVTA) maintained their gain after 5 years of follow-up, according to a new study.
Macular edema is the most common cause of reduced visual acuity in diabetic retinopathy, which in turn is the leading cause of blindness in North America. The treatment of macular edema, standardized by the Early Treatment Diabetic Retinopathy Study (ETDRS), demonstrated that focal laser treatment reduces the risk of moderate visual loss (3 or more lines of visual acuity) from 24% to 12%. Unfortunately, not all patients respond to focal laser treatment, stimulating the investigation of other treatments such as grid laser photocoagulation, pars plana vitrectomy, antivascular endothelial growth factor therapy, and intravitreal triamcinolone.
Although important issues such as the optimal dose and retreatment regimens still need to be addressed, it does seem that intravitreal triamcinolone acetonide (IVTA) can be efficacious for advanced diabetic macular edema (DME), at least in the short-term. An important question that remains unanswered, however, is whether treatment with IVTA is safe and efficacious for more extended periods. Another unanswered question is whether the duration of macular edema at the time of treatment affects the anatomic and functional response.
Methods and Results
This study was a prospective, double-masked, randomized clinical trial. After completing the 2-year visit, all eyes, including those initially randomized to receive placebo, received IVTA.
A total of 69 eyes (41 patients) were entered into the study, with 34 eyes initially receiving active treatment (which consisted of intravitreal injection of 0.1 ml of 40 mg/ml triamcinolone acetonide with adjunctive laser therapy where appropriate) and 35 eyes receiving placebo. Five-year data were available for 44 of 67 eyes (66%). For the 23 eyes with missing 5-year data, of which 13 received placebo and 10 received IVTA, the last observation was carried forward.
Improvement of best-corrected logarithm of the minimum angle of resolution visual acuity by ≥5 letters after 5 years compared with baseline and 2 years, and incidence of adverse events. Secondary outcome was the change in central macular thickness.
Improvement of ≥5 letters after 5 years was found in 14 of 33 eyes (42%) initially treated with IVTA compared with 11 of 34 eyes (32%) initially treated with placebo. Foveal thickness decreased by 30 µm less in the initial-IVTA group than in the initial-placebo group at 5 years; 5 of 11 eyes (45%) from the initial-IVTA group that were phakic at commencement of the third year required cataract surgery. A similar number of eyes from each group required ongoing treatment from the third year onward with both laser and IVTA, indicating that IVTA treatment for 2 years does not lead to reduction in the risk of recurrent edema.
Discussion and Conclusions
In this report presents the longest term data available concerning the safety and efficacy of intravitreal injections of IVTA for DME. We found that the initial beneficial effect of treatment continued to hold up in most eyes with respect to the primary outcome, with 42% of eyes in the initial-IVTA group gaining 5 or more letters since baseline after 5 years compared with 56% after 2 years.
The safety profile of IVTA was acceptable in the third to fifth years of the study. Surgery had been performed in 55% of initially treated eyes in the first 2 years of the study, mainly in the second year. Thereafter, another 4 cataracts were removed from the 11 eyes in the initial-IVTA group that were still phakic at the beginning of the third year of the study. Glaucoma medication continued to be required at a similar rate in those receiving IVTA treatment. Glaucoma surgery was required by 9% of eyes in the initial-IVTA group over the 5 years of the study.
Cataract surgery was associated with poor outcomes in some eyes in this study. Three of 4 eyes that became unresponsive to treatment with IVTA did so after cataract surgery. These 3 eyes each lost more than 10 letters and developed marked macular edema, thereby affecting the mean values for the entire group. Although it was standard practice to inject IVTA at the time of surgery in this study, we have since formed the impression that injection of IVTA approximately 4 weeks before surgery may result in better outcomes. The management of steroid-induced cataract in eyes with advanced DME has been poorly studied and warrants further research.
In conclusion, this study suggests that the beneficial effect of IVTA in eyes with DME persists for up to 5 years in most eyes without a large increase in steroid-related adverse events. A 2-year delay in instituting treatment did not seem to affect outcomes adversely. Removal of steroid-induced cataract in eyes with advanced DME may be associated with poor outcomes in a minority and warrants further research. The researchers state that treatment with IVTA may still be considered in carefully selected cases of impaired vision caused by advanced DME that is not responding to other interventions.
Read more...
Ophthalmology. 2009 Nov;116(11):2182-7
The majority of eyes with diabetic macular edema (DME) and impaired vision despite previous laser treatment that initially experienced improvement in visual acuity following intravitreal triamcinolone acetonide (IVTA) maintained their gain after 5 years of follow-up, according to a new study.Macular edema is the most common cause of reduced visual acuity in diabetic retinopathy, which in turn is the leading cause of blindness in North America. The treatment of macular edema, standardized by the Early Treatment Diabetic Retinopathy Study (ETDRS), demonstrated that focal laser treatment reduces the risk of moderate visual loss (3 or more lines of visual acuity) from 24% to 12%. Unfortunately, not all patients respond to focal laser treatment, stimulating the investigation of other treatments such as grid laser photocoagulation, pars plana vitrectomy, antivascular endothelial growth factor therapy, and intravitreal triamcinolone.
Methods and Results
This study was a prospective, double-masked, randomized clinical trial. After completing the 2-year visit, all eyes, including those initially randomized to receive placebo, received IVTA.
A total of 69 eyes (41 patients) were entered into the study, with 34 eyes initially receiving active treatment (which consisted of intravitreal injection of 0.1 ml of 40 mg/ml triamcinolone acetonide with adjunctive laser therapy where appropriate) and 35 eyes receiving placebo. Five-year data were available for 44 of 67 eyes (66%). For the 23 eyes with missing 5-year data, of which 13 received placebo and 10 received IVTA, the last observation was carried forward.
Improvement of best-corrected logarithm of the minimum angle of resolution visual acuity by ≥5 letters after 5 years compared with baseline and 2 years, and incidence of adverse events. Secondary outcome was the change in central macular thickness.
Improvement of ≥5 letters after 5 years was found in 14 of 33 eyes (42%) initially treated with IVTA compared with 11 of 34 eyes (32%) initially treated with placebo. Foveal thickness decreased by 30 µm less in the initial-IVTA group than in the initial-placebo group at 5 years; 5 of 11 eyes (45%) from the initial-IVTA group that were phakic at commencement of the third year required cataract surgery. A similar number of eyes from each group required ongoing treatment from the third year onward with both laser and IVTA, indicating that IVTA treatment for 2 years does not lead to reduction in the risk of recurrent edema.
Discussion and Conclusions
In this report presents the longest term data available concerning the safety and efficacy of intravitreal injections of IVTA for DME. We found that the initial beneficial effect of treatment continued to hold up in most eyes with respect to the primary outcome, with 42% of eyes in the initial-IVTA group gaining 5 or more letters since baseline after 5 years compared with 56% after 2 years.
The safety profile of IVTA was acceptable in the third to fifth years of the study. Surgery had been performed in 55% of initially treated eyes in the first 2 years of the study, mainly in the second year. Thereafter, another 4 cataracts were removed from the 11 eyes in the initial-IVTA group that were still phakic at the beginning of the third year of the study. Glaucoma medication continued to be required at a similar rate in those receiving IVTA treatment. Glaucoma surgery was required by 9% of eyes in the initial-IVTA group over the 5 years of the study.
Cataract surgery was associated with poor outcomes in some eyes in this study. Three of 4 eyes that became unresponsive to treatment with IVTA did so after cataract surgery. These 3 eyes each lost more than 10 letters and developed marked macular edema, thereby affecting the mean values for the entire group. Although it was standard practice to inject IVTA at the time of surgery in this study, we have since formed the impression that injection of IVTA approximately 4 weeks before surgery may result in better outcomes. The management of steroid-induced cataract in eyes with advanced DME has been poorly studied and warrants further research.
In conclusion, this study suggests that the beneficial effect of IVTA in eyes with DME persists for up to 5 years in most eyes without a large increase in steroid-related adverse events. A 2-year delay in instituting treatment did not seem to affect outcomes adversely. Removal of steroid-induced cataract in eyes with advanced DME may be associated with poor outcomes in a minority and warrants further research. The researchers state that treatment with IVTA may still be considered in carefully selected cases of impaired vision caused by advanced DME that is not responding to other interventions.
Read more...
Ophthalmology. 2009 Nov;116(11):2182-7
