Ophthalmologists administering intravitreal injections for age-related macular degeneration need to be aware of the increased risk of elevated IOP elevation and angle closure says Sydney glaucoma specialist, Dr. Ivan Goldberg.
Dr. Goldberg’s comments were in response to a poster presented at the American Glaucoma Society meeting by Dr. Joanne C. Wen Assistant Professor of Ophthalmology at University of Washington. Dr. Wen and colleagues studied 21 eyes of 21 patients who received intravitreal anti-VEGF injections for the treatment of neovascular age-related macular degeneration.
They found that IOP elevation may be associated with increased narrowing of nasal angle measurements after intravitreal anti-VEGF injections.
The researchers measured mean pre- and immediate post-injection IOP, and took measurements of the anterior segment including angle opening distance, trabecular-iris space area and scleral spur angle.
They noted that the mean increase in IOP after anti-VEGF injection was 23.4 ± 11.4 mm Hg. Additionally, they reported that all eyes had significant narrowing of the temporal angle opening distance and angle measurements. There was significantly more narrowing of the nasal angle in phakic eyes compared with pseudophakic eyes.
“Physicians performing intravitreal injections should be aware of these dynamic anterior segment changes following intravitreal injections and the possibility that there may be increased risk of angle closure with prolonged elevation of IOP in predisposed eyes,” the authors said.
Dr. Gold described the finding as “interesting and reasonably intuitive: after all, anything that abruptly increases the volume of the vitreous body could be anticipated both to cause an IOP spike and to shift forwards the lens-iris diaphragm. It is this latter phenomenon that precipitates the anterior segment changes reported”.
“The observed IOP spike has been reported to be worse in patients with all types of glaucoma than it is in people without glaucoma. Frank acute angle closure crisis, induced in this way, fortunately is much rarer than the IOP spike.
“It behoves ophthalmologists administering intra-vitreal injections to be cognisant of these observations and to have systems in place that identify and protect patients as necessary,” said Dr. Goldberg.