Intravitreal Ranibizumab/ Lucentis (IVTL) injections in Glaucoma patients-Intraocular Pressure (IOP) elevation and the use of Anterior Chamber Paracentesis (ACP)

Abstract

Purpose

• To assess the short term effects of intravitreal Lucentis (IVTL) on intraocular pressure in patients with ocular hypertension and glaucoma

• To determine rate of anterior chamber paracentesis (ACP) required post-injection according to departmental protocol

Methods: This was a prospective, observational study carried out between August 2011 and February 2012 in the Department of Ophthalmology, Maidstone Hospital. 24 participants (13 female, 11 male) with established ocular hypertension (OHT) or glaucoma were chosen from a cohort of patients receiving intravitreal (IVTL) Ranibizumab (Lucentis) treatment for wet age related macular degeneration (wARMD). Apraclonidine 1% was given pre-injection, and baseline IOP was measured 30 min. after this, just before IVTL. IOP was measured at baseline, within 1 min of injection, 5 min, 15 min, 30 min up to 60min following a single IVTL treatment.

Anterior paracentesis was performed if:

• Immediate post injection IOP > 50mm Hg and OHT

• Immediate post injection IOP > 40 mm Hg and there was evidence of disc damage only

• Immediate post injection IOP > 30mm Hg with evidence of disc damage and visual field loss

Results: 79.2% had diagnosed disc damage and visual field loss (glaucoma); 12.5% had disc damage only (pre-perimetric glaucoma), whereas the remaining 8.3% had no evidence of disc damage or visual field loss i.e. ocular hypertension (OHT).

Administration of Apraclonidine 1% prior to IVTL did not cause a statistically significant IOP reduction in patients with OHT and glaucoma (paired Student’s t-test P = 0.368). Immediately post injection, mean IOP was 41.54mm Hg (SD 14.1, 95% CI 37.20 to 45.88; Paired T test results P <0.0001,) which confirmed a statistically significant difference between baseline and immediate post injection IOP.

13 out of 24 (58%) of the study patients required anterior chamber paracentesis (ACP) post IVTL according to our devised protocol. There was no statistically significant difference in baseline IOP between the paracentesis and non-paracentesis groups (p=0.4). The presence of a bleb post injection had no statistically significant bearing on immediate post intravitreal IOP (p=0.3).

ACP performed at 1min restored IOP to a safer level at 5min in all cases thus treated.

Conclusions: IVTL appears to cause a significant but transient rise in IOP which is reduced after a mean time of 5 minutes. Although the clinical significance of this IOP spike is still unknown, extreme care must be taken in patients with ocular hypertension and glaucoma particularly those with established disc damage and visual field loss. Apraclonidine 1% appears to have a limited role in the prophylactic lowering of IOP pre-injection. The authors propose the use of the formulated anterior chamber paracentesis protocol for IOP management in patients with OHT and glaucoma receiving intravitreal anti-VEGF treatment.