Evaluation of clinical outcomes of raised intraocular pressure following intravitreal triamcinolone acetonide injection.

Aim: To assess the incidence, risk factors, and treatment outcomes in intravitreal triamcinolone acetonide injection (IVTA) induced intraocular pressure rise and to compare IOP rise in 1-mg and 2-mg IVTA. Materials and methods: Prospective observational study conducted in all eyes receiving IVTA. Any pre-existing glaucoma and patients who received IVTA or dexamethasone implant in the last 6 months were excluded. Results: 9 between 61-70 years of age developed an IOP spike. The mean and standard deviation of age in years was 61.95 ± 8.70. Maximum eyes had ME due to Diabetic Retinopathy (53.3%). All cases of uveitic ME were reported to have an IOP spike. 2 out of 3 high myopic eyes and 1 eye with thyroid abnormality had an IOP spike. High IOP was found in 13 eyes, with more than 25 mm Hg rise in 4 eyes and more than 5 mm Hg rise from baseline IOP in 9 eyes. The mean and standard deviation of time taken for IOP raise (in days) was 46.39 ± 37.68. A total of 38 eyes received 1 mg of IVTA and the rest 22 received 2 mg of IVTA. 23.7% of 1 mg eyes experienced an IOP rise while it was 18.2% in eyes with 2 mg IVTA. The injection was repeated in 12 eyes and 41.7% developed an IOP spike among them. The independent "t" test results showed that there was a significant difference in the mean of IOP (Pre-injection) concerning the IOP rise (P=0.007*). 1 eye had IVTA crystals in the anterior chamber with raised IOP of 30 mm Hg. 1 out of 13 eyes with raised IOP needed 2 AGMs, the other 12 eyes responded well to 1 AGM. Discussion: IVTA is widely used in refractory cases of ME and steroid-induced glaucoma is the most common side effect of IVTA. To the best of our knowledge, there is a lack of literature on prospective studies on IVTA-associated risk factors, patterns of IOP elevation, and treatment outcomes. The pre-injection mean ± SD baseline IOP for uneventful eyes was 12.87±2.65 and the pre-injection mean IOP for eyes with IOP event was 15.23±2.89 (P=0.007*). Conclusion: We proposed that TA is an independent risk factor for post-intravitreal injection IOP spike. IVTA causes a maximum IOP spike at 1 to 2 months and has a protracted course that responds to anti-glaucoma medications. High baseline IOP, a repeated dose of IVTA, the presence of TA crystals in the anterior chamber, and high myopia were associated with significant IOP elevation. Abbreviations: ACD = Anterior chamber depth, AS = Anterior segment, AGM = Anti-glaucoma medications, ARMD = Age-related macular degeneration, BCVA = Best-corrected visual acuity, BRVO = Branch retinal vein occlusion, CCT = Central corneal thickness, CRVO = Central retinal vein occlusion, CME = Cystoid macular edema, CNVM = Choroidal neovascularization membrane, CSME = Clinically significant macular edema, DR = Diabetic retinopathy, ERM = Epiretinal membrane, IOP = Intraocular pressure, IGS = Irvine-Grass syndrome, GAGs = Glycosaminoglycans, IVTA = Intravitreal triamcinolone acetonide injection, ME = Macular edema, NVG = Neovascular glaucoma, OHT = Ocular hypertension, PDS = Pigment dispersion syndrome, PACG = Primary closed angle glaucoma, POAG = Primary open-angle glaucoma, PXF = Pseudoexfoliation, VA = Visual acuity, VEGF = Vascular endothelial growth factors, VH = Vonherick's grading, SD = Standard deviation, TA = Triamcinolone acetonide, TIGR = Trabecular meshwork inducible glucocorticoid response.