Purchase this article with an account.
H. Nomoto, Y. M. Paulus, R. Dalal, R. F. Gariano, D. Palanker, M. S. Blumenkranz; The Effect of Triamcinolone Acetonide on the Healing of Retinal Photocoagulation Lesions. Invest. Ophthalmol. Vis. Sci. 2009;50(13):215.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Intravitreal triamcinolone acetonide (TA) is commonly used in patients undergoing retinal photocoagulation to treat retinal vascular disorders. However, the effect of triamcinolone on the healing of retinal laser burns has not been studied. We evaluate the effect of intravitreal TA on healing of the retinal photocoagulation lesions using drug and laser dosing regimens typically employed in clinical practice.
A 532nm Nd:YAG laser (PASCALTM) with a retinal beam diameter of 267 µm was applied to 40 eyes of 20 Dutch-Belted rabbits in vivo. Lesions of varying clinical intensities were produced in each eye with pulses from 5 to 100 ms at a constant power of 175 mW. Each eye received either 2mg TA/50uL, or the same volume of balanced salt solution (BSS). An intravitreal injection was administered either one week prior to or immediately following laser treatment. Lesions were assessed acutely ophthalmoscopically and then histologically at 1 day, 3 days, 1 week, 1 month, and 2 months after laser application.
Immediately after photocoagulation followed by the intravitreal injection, intense lesions in the TA and BSS groups were ophthalmoscopically indistinguishable. However, histological analysis revealed that the lesions in the TA injected eyes were wider and exhibited slightly more coagulative necrosis at 1 day. In intense lesions the diameter of RPE-photoreceptor defect at 1 day was 23% larger with TA (336 ± 6.8 µm) than with BSS (272 ± 13 µm). At 3 days, lesions were 133% larger (436 ± 63 µm) with TA than with BSS (197 ± 7.0 µm), and at 1 week the TA lesions were 80% larger (310 ± 14 µm vs. 172 ± 17 µm). At 1 month the TA lesions were still larger by 57%, and at 2 months the difference decreased to 41% (172 ± 35 µm vs. 122 ± 6.8 µm). Similarly, the diameter of histologically evident damage in the outer nuclear layer was 60% larger in TA-injected eyes at 7 days and 43% larger at 2 months.
Intravitreal TA injection immediately following intense laser photocoagulation significantly alters healing of the laser lesions; in particular, lesion size is significantly enlarged. This effect is most pronounced within the first week, but persists to a lesser degree for up to 2 months. The impact of intravitreal triamcinolone on the retinal wound healing when administered one week prior to treatment or following mild to moderate burns is currently under investigation and will also be presented.
This PDF is available to Subscribers Only