Purpose
Steroids are known to cause increase in intraocular pressure (IOP); clinical experience suggests that intravitreal dexamethasone implant (Ozurdex) leads to a less pronounced IOP rise than intravitreal triamcinolone (Kenalog) injection (IVK). We analyzed the rate and extent of IOP rise, need for IOP lowering medications or procedures, and interval time to IOP rise after administration and compared the results to a prior data set from the same institution using intravitreal triamcinolone.
Methods
This retrospective cohort study looked Ozurdex injections from 6/1/2009 to 4/1/2014 at UTSW and analyzed 13 patients with 41 injections. Patient age, history of glaucoma, previous intraocular surgery, prior steroid exposure, type of retinal pathology treated, pre- and post-injection IOP, and pre- and post-injection glaucoma medications and procedures were tabulated. Post-injection IOP was recorded for the first follow up visit as well as the maximum IOP recorded. Those without at least 6 weeks of follow-up were excluded. A one-tailed student's paired t-test was used for statistical analysis.
Results
The average baseline IOP was 17.02 (standard deviation 5.43). The IOP at the first follow up visit was not statistically significantly higher at 17.75 (standard deviation 4.69, p=0.21). The max IOP was 20.03 (standard deviation 4.87), which was significant compared to baseline (p<0.001). At baseline the mean number of IOP drops was 1.32 (standard deviation 1.15), which rose to 1.56 (standard deviation of 1.07) after Ozurdex (p=0.015). 12 injections led to an IOP rise of between 5-9 mmHg; in 1 case this rise exceeded 9 mmHg. 24.4% of injections led to a >30% rise in IOP, with mean IOP increase of 22.1%. The IOP was >21 after 9 injections and >30 twice. The average time to the maximum IOP was 62.5 days. 29.3% of Ozurdex treatments had an increase in IOP of 5-9 mmHg compared to 62% in our IVK series (p<0.001). 2.4% of the Ozurdex cohort had an IOP rise >9 compared to 30% of IVK patients. 12.1% of Ozurdex injections resulted in additional IOP drops versus 32.5% with IVK. Mean time to peak IOP was 48.3 days with IVK vs 62.5 days with Ozurdex.
Conclusions
Ozurdex is associated with increased IOP in about 24% of patients. IOP rise was easily managed with observation or glaucoma drops in this series. The time course for this elevation was 7 weeks. Ozurdex may have a more favorable effect on IOP than IVK.