Effect of Intravitreal Kenalog on Macular Function in Birdshot Chorioretinopathy

Abstract

 

Purpose

 

To assess macular function following intravitreal injection of Kenalog (Triamcinalone acetonide 40 mg/ ml) in Birdshot Chorioretinopathy (BCR).

 

Methods

 

Retrospective review of the charts, optical coherence tomography, fluorescein angiograms, ISCEV standard pattern and full field electroretinogram (PERG, ERG) and color contrast sensitivity (CCS, Chromatest system) of 7 HLA A29 positive patients with BCR who received 4 mg/ 0.1 ml Intravitreal kenalog. PERGs were recorded to standard (12x15°) and large (24x30°) checkerboard fields. All patients were consented for off label use of the drug prior to treatment. Fellow eyes provided control group data. Eight eyes of 7 patients received 11 treatments. One patient received intravitreal kenalog in the same eye on 3 occasions; pre and post treatment data were available only for the first and third injections. Another patient received 1 injection in 1 eye and 2 injections in the fellow eye; all with a gap of >/= 10 months. Six of the 10 treatments studied were for cystoid macular odema (CMO), the indication for the rest being delay in the photopic 30Hz flicker electroretinogram. All eyes were followed up for >/= 6 months after intravitreal injection, with 80% being followed up for >/= 18 months.

 

Results

 

The CMO had resolved completely at 6 weeks +/- 2 weeks after all 6 treatments for CMO, with no recurrences until last follow up. The visual acuity improved after 4 treatments, deteriorated after 1 and remained stable after 5. There was an increase from baseline, in the P50 amplitude of the PERG in the study group compared to controls, which was statistically significant for the large field PERG, both at 6 weeks +/- 2 weeks and 6 months +/- 2 months. The median % change from baseline for the standard and large field P50 amplitude for the study group and controls at both time points is shown in the table.There was improvement in the Protan axis threshold in 3 and in the tritan axis threshold in 2 of the 4 eyes tested. Two eyes developed raised intraocular pressure; one was managed successfully with timolol only. The other needed maximal medical therapy. Cataract surgery was required in 2 eyes. There were no instances of endophthalmitis or retinal detachment.

 

Conclusions

 

Intravitreal Kenalog is useful in treating macular odema in BCR. Long term resolution can be achieved with improvement in macular function in the absence of pre treatment structural retinal damage.

 

 

Keywords: 704 retinochoroiditis • 746 uveitis-clinical/animal model • 451 chorioretinitis