Case Series: Sustained elevation of intraocular pressure in patients treated with intra-vitreal anti-Vascular Endothelial Growth Factor agents.

1. Simon E Skalicky^1,2
2. I-van Ho^1,2,3,4
3. Ashish Agar^5,6
4. Ee-mun Chia³
5. Ridia Lim^1,2
6. Allan Bank^5,6

¹Sydney Eye Hospital, Sydney, Australia
²Faculty of Medicine, University of Sydney, Sydney, Australia
³Retina Associates, Sydney, Australia
⁴Australian School of Advanced Medicine, Macquarie University, Sydney, Australia
⁵Prince of Wales Hospital, Sydney, Australia
⁶Faculty of Medicine, University of New South Wales, Sydney Australia

Purpose
To document cases of unilateral sustained elevation of intraocular pressure (IOP) while receiving courses of intravitreal anti-vascular endothelial growth factor (VEGF) agents.

Methods
A retrospective analysis of all cases managed by the authors and colleagues was performed.

Results
Seven patients developed sustained IOP rises while receiving intraocular anti-VEGF injections, four of whom required glaucoma filtering surgery.

Ranibizumab was used in six cases while one received bevacizumab. Four patients received unilateral and three bilateral anti-VEGF agents. Two had a past history of primary open angle glaucoma and one of pseudoexfoliative glaucoma, all of whom had stable IOP on topical pharmacotherapy prior to anti-VEGF treatment. Angles were open with one exception of narrow angles but no pre-existing glaucoma or elevated IOP. Peak IOPs averaged 43 mmHg, ranging from 27 – 60 mmHg. Four patients required trabeculectomy, two SLT and the remainder multiple topical medication to control the IOP elevation.

Conclusions
A sustained rise in IOP requiring multiple glaucoma medications and/or glaucoma filtering surgery is a rare but potentially important treatment complication for patients receiving intravitreal anti-VEGF therapy, especially those with pre-existing glaucoma or glaucoma risk factors. Proposed mechanisms include direct toxicity to trabecular meshwork (TM) cells, TM obstruction by aggregates of anti-VEGF antibody or antibody fragments, and TM obstruction by silicone contaminants from the syringe or rubber stopper.