Alireza Ramezani, MD (Tehran, Iran), S. Morteza Entezari (Tehran, Iran), Siamak Moradian, MD (Tehran, Iran), Homa Tabatabaei, MD (Tehran, Iran), Shohreh Kadkhodaei, MD (Tehran, Iran)

PURPOSE:

Central retinal vein occlusion (CRVO) is the most common vascular event in the eye after diabetic retinopathy. This study was conducted to evaluate the therapeutic effect and safety of intravitreal triamcinolone acetonide (IVT) in acute CRVO.

METHODS:

In a prospective randomized sham-controlled clinical trial, patients with recent onset (less than 2 months) CRVO were enrolled. Previous ocular surgery or laser therapy, visual acuity (VA) = 20/40, ocular hypertension, and neovascularization were exclusion criteria. The eligible cases (27 eyes) were randomly assigned to two groups. The treatment group (13 eyes) received 4 mg IVT and the control group (14 eyes) received a sham subconjunctival injection. The outcomes were VA, occurrence of neovascularization of the iris (NVI), intraocular pressure, and central macular thickness (CMT) measured by optical coherence
tomography. Examination was repeated 1, 2, 3, and 4 months after intervention.

RESULTS:

Mean (standard error) of CMT before, 2 and 4 months after injection was 565(50), 259(15), and 290(53) microns in the treatment group and 629(43), 470(62) and 413(59) microns in the sham group respectively. The second month difference was significant (P=0.003). The comparison within each group also showed that the CMT reduction at 2 months was significantly greater in the cases compared to the controls, 332 vs. 153 microns respectively (P=0.039). The difference between VA changes (0.39 logMAR) was significant (P=0.013) only at 1 month. There was no meaningful difference in the occurrence of NVI between two groups. Statistical analysis demonstrated that the effect of IVT remained significant, regarding VA (P=0.019) and CMT (P=0.043) changes at 1 and 2 months respectively, even after adjustment for confounding factor of nonischemic vs. ischemic type. Intraocular pressurerise in the cases compared to the changes of the controls was significant at months
3 (P=0.003) and 4 (P=0.010).

CONCLUSION:

The therapeutic effect of IVT on acute CRVO is greatest at months 1 and 2 regarding to VA and macular thickness respectively that decreases up to the fourth month. This temporary beneficial effect would achieve in both nonischemic and ischemic types of the disease. Mean CMT in controls and eyes treated with 4 mg IVT at three time intervals. Mean logMAR corrected VA in controls and eyes treated with 4 mg IVT at five time intervals.