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A Randomized Trial of Peribulbar Triamcinolone Acetonide with and without Focal Photocoagulation for Mild Diabetic Macular Edema: A Pilot Study. Diabetic Macular Edema (DME). DME-most common cause of visual loss in patients with diabetes
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A Randomized Trial of PeribulbarTriamcinoloneAcetonide with and without Focal Photocoagulation for Mild Diabetic Macular Edema: A Pilot Study
Diabetic Macular Edema (DME) • DME-most common cause of visual loss in patients with diabetes • ETDRS- focal/grid laser reduced 3-year rate of moderate visual loss by 50% • Only 17% of patients with baseline acuity worse than 20/40 experienced moderate visual gain
Treatments for DME • Laser-Standard of care • Tight Glycemic Control • Corticosteroids-intravitreal, peribulbar • Anti-VEGF agents • Vitrectomy
Studies with Peribulbar Steroids DME • Bakri and Kaiser (2005)-63 eyes, 40 mg, VA improved from 20/80 to 20/63 at 12 months • Entezari et. al. (2005)-randomized trial, 64 eyes, 40 mg vs placebo injection, no benefit VA or OCT thick • Tunc et. al. (2005)-randomized trial, 60 pts, focal laser vs laser plus 20 mg, mild benefit in VA (2.5 lines in combined group vs 1.5 lines in laser group) • Cardillo et. al. (2005)-randomized trial, 24 eyes in 12 pts, 40 mg vs IVK (4 mg), short term impt greater in IVK grp (VA impt and decrease OCT thick • Bonini-Filho et. al. (2005)-randomized trial, 36 eyes, 40 mg vs IVK (4 mg), IVK has sign greater impt VA and decrease OCT thick • Ozdek et. al. (2006)-retrospective study, 126 eyes in 95 pts, 20 mg vs IVK (4 mg), both grps had sign impt in VA and decrease OCT thick with greater impt in IVK group Benefits of Peribulbar Steroids are Inconclusive
Potential Advantages of Peribulbar Steroids • Lower incidence of adverse effects compared with intravitreal steroids • Particular interest in eyes with good VA and mild DME • Combination with focal/grid laser may be beneficial
Study Design Phase 2 randomized, multi-center clinical trial • Major Eligibility Criteria Assessed: • >18 years old • Best corrected electronic-ETDRS letter score ≥ 69 (20/40 or better) • Retinal thickening due to DME on clinical exam • OCT CST≥ 250 microns • IOP < 24 mm Hg with no history of open-angle glaucoma Laser Anterior Peribulbar 20 mg Anterior Peribulbar 20mg+Laser Posterior Peribulbar 40 mg Posterior Peribulbar 40mg+Laser
Protocol Overview • Safety outcomes – elevated IOP, cataract, ptosis, other complications • IOP measured at each visit 4 Weeks 8 Weeks • Peribulbar injection repeated at if DME was still present 17 Weeks 34 Weeks • Primary Outcome: change in OCT- Measured central subfield thickening • After the primary outcome treatment was at the investigator’s discretion • Secondary outcome: frequency of retreatment and change in VA 1 Year 2 Year Safety Follow-up to two years
Treatment Protocol-Steroid Injection • Standard injection technique • Anesthesia at investigator’s discretion • 27-g 5/8 inch needle • Anterior (20 mg)-bulbar conj, lower lid • Posterior (40 mg)-subtenon’s space, ST quad, 10 mm post to limbus
Treatment Protocol-Focal Laser • Modified ETDRS • Laser burns-50 microns, gray intensity • Multiple settings (all completed in single setting)
Results No significant differences in primary outcome of central subfoveal thickness No differences in visual acuity outcomes at 34 weeks.
Subjects on IOP Lowering Medication or with IOP increase ≥ 10 mmHg
Intraocular Pressure Elevation *Subjects not on IOP lowering medication at the visit
Adverse Effects-Ptosis • Anterior – 4/48 (8%) • Posterior – 3/47 (7%) • focal/grid - none
Discussion • No significant effect on central retinal thickness or VA from peribulbar triamcinolone ± laser compared with laser alone • Anterior and posterior subtenon’s injections were similar • Need for retreatment reduced in peribulbar with focal/grid laser • Investigators not masked to treatment group
Discussion • Significant complication rate (elevated IOP, cataract, ptosis) in peribulbar steroid group • Worse for Anterior vs. Posterior • Important to follow-up patients for at least 2 years for adverse side effects
Conclusion • No benefit from peribulbar steroids as a therapy for mild DME • No justification to warrant phase 3 trial • Demonstrates the need for long term studies (2 years) to evaluate potential adverse effects