Bernardete Pessoa, Pedro Baptista, Joao Coelho, Joao Melo Beirao, Angelina Meireles, Portugal

Introduction:
A vitrectomized eye shows a distinct pharmacokinetic profile from a non vitrectomized eye. Based on this fact, it is possible that vitrectomized and nonvitrectomized eyes have a different pattern of intraocular pressure (IOP) variation. The purpose of this study is to compare long-term IOP response after a single implant of Fluocinolone acetonide (FAc, 0.2μg/day) in vitrectomized and nonvitrectomized eyes with diabetic macular edema.

Methods:
Eyes that had been treated with a single FAc implant for DME were included in this retrospective study. All eyes had a minimum of 24 months of follow up. Patients were divided in two groups: vitrectomized and non-vitrectomized eyes The main outcome measured was IOP and its evaluation was made at baseline, 6, 12 and 24 months and compared between groups. Glaucoma surgery (pre and post Fac) were registered.

Results:
Twenty-eight eyes were included in the study. Nineteen eyes (68%) were vitrectomized at baseline. Pre-Fac implant IOP was 15.04 ± 2.66 mmHg (mean±standard deviation) in total population. Post-Fac implant, IOP increased to a mean maximum of 16.96 ± 4.62 mmHg at month 6 (Δ +1.92 mmHg, p=0.280), showing a non-statistically significant variation during whole follow up period. Secondary ocular hypertension (defined as IOP ≥ 25 mmHg) was found in five eyes (18%). Two eyes (7%) had an IOP rise of ≥ 10 mmHg over baseline at any time after post-implant day. Three of twenty-eight patients (11%) were submitted to IOP lowering surgery at a medium time of 17.7 ± 2.7 months after Fac implant. 100% of these were already under at least 2 IOP drug medication due to previous short-term intravitreal corticotherapy. The IOP profile was the same in both nonvitrectomized and vitrectomized eyes. Both groups present a non-statistically significant IOP variation during follow up when compared to baseline values and between groups; in vitrectomized eyes, IOP at baseline was 14.94 ± 2.39 mmHg reaching maximal IOP at month 24 (17.00 ± 4.00 mmHg; p=0.244). IOP in non-vitrectomized eyes changed from 15.25 ± 3.37 mmHg at baseline to a maximum of 19.00 ± 5.95 mmHg at month 6 (p=0.404). Seven of nineteen eyes (37%) in vitrectomized and three of nine eyes (33%) in non-vitrectomized group had an elevation of IOP exceeding 21mm Hg.

Conclusions:
This retrospective study shows that a 3 months interval seems to be a safe approach to manage IOP. It is crucial to continue monitoring IOP even after 12 months follow up, particularly in patients pre-FAc needing IOP lowering medication due to short term corticosteroids. This study also shows similar non-statistically significant trends in IOP variation with FAc implant treatment for DME in vitrectomized and non-vitrectomized eyes. These current findings suggest that vitrectomy does not seem to influence the safety profile of FAc intravitreal implant for DME. Further data is required to support these findings with larger population and longer follow-up.

Contact Details:

Bernardete Pessoa
Centro Hospitalar e Universitário do Porto
Porto
Portugal
Cell Phone : 00351938469884
Work Phone : 00351938469884
Email : bbtpessoa@gmail.com