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Editors Selection IGR 10-1
Clinical forms of glaucoma: Intravitreal triamcinolon and secondary glaucoma
Comment by Jost Jonas on:
20848 A Prospective Study of Early Intraocular Pressure Changes After a Single Intravitreal Triamcinolone Injection, Im L; Allingham RR; Singh I et al., Journal of Glaucoma, 2008; 17: 128-132
One of the two most common side-effects of intravitreal triamcinolone acetonide has been secondary ocular hypertension leading in relatively few patients to secondary steroid-induced open-angle glaucoma. In their study on early intraocular pressure changes after a single intravitreal triamcinolone injection, Im et al. (310) prospectively monitored intraocular pressure (IOP) within the first month after a single 4-mg intravitreal injection of triamcinolone given in 28 eyes with no history of glaucoma. Using the fellow eye as control eye, the authors observed an IOP rise to 24+ mm Hg in 43% of the eyes within the first four weeks after the injection. The most frequent time point that required IOP treatment was at two weeks after the injection. The authors concluded that early and frequent monitoring of IOP should be considered. Interestingly, two-thirds of the eyes that required medical control of IOP developed gonioscopic changes, characterized by a pigmented particulate matter in the inferior angle, not present at baseline. This relatively small clinical study agrees with previous investigations in which roughly 30% to 40% of eyes developed an IOP higher than 21 mmHg after a single intravitreal triamcinolone injection. Although the present study showed that the majority of the eyes included into the investigation developed the IOP rise at about two weeks after the injection, it may not lead to the conclusion that more than four weeks after the injection, an IOP elevation may become unlikely and that IOP controls may no longer be necessary. There have been reports about patients who developed IOPs higher than 40 mmHg more than six months after an intravitreal triamcinolone injection. This prolonged interval between the injection and the pressure rise may possibly depend on the dosage of triamcinolone applied. Due to the sometimes long interval between triamcinolone injection and IOP rise, and because the dosage given by a retina specialist may not exactly be known to the glaucoma specialist, one may ask the patients to return for regular IOP checks at intervals of about six weeks for at least six months after the triamcinolone injection, to avoid missing an undetected late IOP rise and the conversion of triamcinolone induced ocular hypertension into steroid induced open-angle glaucoma. The meaning of the new observation of anterior chamber angle changes observed by the authors in eyes who needed IOP lowering treatment remains unclear and may be subject of further research.
