The problem of pressure elevation associated with intravitreal triamcinolone

IS A DECREASED NITRIC OXIDE CONCENTRATION AFTER TRIAMCINOLONE ACETONIDE INTRAVITREAL INJECTION ONE OF THE REASONS FOR INTRAOCULAR PRESSURE RISE?

Diabetic macular edema is the most common cause of vision loss in patients affected by diabetes mellitus. For eyes with persistent retinal thickening despite anti-VEGF therapy, treatment with intravitreal triamcinolone may be considered, especially in pseudophakic eyes. The aim of this study was to examine aqueous humor nitric oxide concentration changes in pseudophakic eyes with persistent diffuse diabetic macular edema after intravitreal injection of triamcinolone acetonide, as well as the potential impact of these changes on the intraocular pressure values. In 10 pseudophakic eyes with persistent diffuse diabetic macular edema, paracentesis of anterior chamber with aspiration of aqueous humor and nitric oxide concentration measurements were done on the day of the intravitreal application of 20 mg triamcinolone acetonide, and after 1, 3, 6 and 9 months. Also, we were recording intraocular pressure values before the intravitreal triamcinolone acetonide injection and during the next 9 months. One month after the intravitreal triamcinolone acetonide injection, we noticed a decrease of nitric oxide concentration (45.37±5.55 µmol/L) by 31.79% compared to the initial values (66.52±7.66 µmol/L). After that, nitric oxide concentrations began to rise slightly, and at the end of the ninth month the mean nitric oxide concentration was similar to that recorded at the beginning of the study. Intraocular pressure values had increasing trend one month after the intravitreal triamcinolone acetonide injection (23.70±4.08 mm Hg) compared to the initial values (16.21±1.55 mm Hg), but after nine months these values returned to normal levels. Decreased concentration of nitric oxide could be one of the reasons for increased intraocular pressure after intravitreal application of triamcinolone acetonide in the treatment of diffuse diabetic macular edema.

UK national survey of current practice and experience of intravitreal triamcinolone acetonide

AIMS

In recent years, intravitreal triamcinolone acetonide (IVTA) injections have become widely used in the treatment of macular oedema. IVTA can cause elevation of intraocular pressure (IOP), which can be sight threatening. We carried out a nationwide study, which aimed to (i) assess the current usage of IVTA, (ii) estimate the incidence of 'severe' IOP rise following IVTA, in routine practice.

METHODS

A postal survey was carried out in January 2007. A questionnaire was mailed to senior ophthalmologists (all consultants and associate specialists) in the United Kingdom. We asked about the use of IVTA over the past year and whether there had been any cases of severe IOP rise (defined as elevation in IOP, commencing after IVTA therapy, requiring laser or surgery to treat the raised pressure).

RESULTS

Response rate was 56% (611/1089). Among respondents, 33% (206) had used IVTA during the 12 months of 2006 giving a total of 3899 IVTA injections. There were 45 reported cases of severe IOP rise, following IVTA injections, which were given under their care of the respondent. A further 28 cases were reported to have been referred from colleagues; it is unclear whether any or all of these cases were included in the initial 45. The reported rate of severe IOP rise following IVTA was therefore at least 45/3899 or at least 1.1%.

CONCLUSIONS

Usage of IVTA in the United Kingdom is widespread. Severe IOP rise, requiring laser or surgery to control IOP, was reported in at least 1.1% of cases.

Indocyanine-green-mediated photothrombosis (IMP) with intravitreal triamcinolone acetonide for macular edema secondary to group 2A idiopathic parafoveal telangiectasis without choroidal neovascularization: a pilot study

BACKGROUND

The purpose of this study was to determine the feasibility, safety and clinical effect of indocyanine green (ICG)-mediated photothrombosis (IMP) combined with intravitreal triamcinolone acetonide (IVTA) in patients with macular edema secondary to idiopathic parafoveal telangiectasis (IPFT) group 2A without choroidal neovascularization (CNV).

METHODS

Nine eyes of six patients that were treated with IMP immediately followed by IVTA at a dose of 4 mg participated in the study. Patients had a mean follow-up of 23.3 months (range 12-36 months). Patients underwent one or two sessions of IMP combined with IVTA ("study group"). An IVTA-only group of 19 eyes from 14 patients with macular edema secondary to IPFT group 2A that underwent an IVTA 4 mg without IMP ("IVTA-only group") was included for comparison. In addition, a matched control group of 40 eyes from 20 patients selected retrospectively from our medical records with macular edema secondary to IPFT group 2A without any therapy was included ("observation group").

RESULTS

The best-corrected visual acuity (BCVA) remained stable in five eyes (55.5%). Four eyes (44.4%) demonstrated improvement of BCVA (> or = two ETDRS lines), and no eyes experienced worsening of visual acuity (> or = two ETDRS lines). A significant decrease in hyperfluorescence was not seen with fluorescein angiography (FA), however optical coherence tomography (OCT) showed a decrease in the size of inner intraretinal hyporeflective spaces or cystic edema. Two (22.2%) eyes developed an increase in intraocular pressure. However, it was medically controlled with topical anti-glaucoma medications. Cataract developed in five eyes (55.5%). Six of nine eyes (66.6%) required one retreatment during the study period. At the last follow-up (mean 21.1 months, range 12-30 months) in the IVTA-only group, 5 (25.3%) eyes improved BCVA, 11 (57.9%) eyes remained within two lines of baseline BCVA and 3 (15.8%) eyes lost BCVA. In the observation group, with similar follow-up, 87.5% of eyes showed either stabilization or deterioration of BCVA over time.

CONCLUSIONS

Combined IMP and IVTA may provide stability or improvement in BCVA and fundus findings in eyes with macular edema secondary to IPFT group 2A without CNV at a minimum follow-up of 12 months.