Fulminant toxoplasmic retino-choroiditis following intravitreal triamcinolone administration.

We report two cases of fulminant toxoplasmic retinochoroiditis following intravitreal triamcinolone acetonide (IVTA) administration. Case 1: A 42-year-old female received IVTA for presumed non-infectious panuveitis. Within 2 months, she developed diffuse macular retinochoroiditis with optic disc edema. Upon starting anti-toxoplasmic therapy (ATT), her intraocular inflammation resolved with catastrophic damage to the disc and macula. Case 2: A 30-year-old male received IVTA for presumed reactivation of previously scarred toxoplasmic retinochoroiditis. Despite simultaneous ATT, within 6 weeks, he developed extensive, multifocal macular retinochoroiditis. He continued to require ATT for 18 months and later underwent vitrectomy with silicone oil placement for severe epiretinal proliferation. Aqueous tap polymerase chain reactions were found positive for Toxoplasma gondii in both cases. In conclusion, IVTA administration can lead to fulminant toxoplasmic retinochoroiditis even when used with appropriate ATT. Extreme caution should be exercised while administering depot corticosteroids in eyes with panuveitis of unknown origin.

Experience with the Pascal® photocoagulator: An analysis of over 1200 laser procedures with regard to parameter refinement.

Aim: To systematically refine and recommend parameter settings of spot size, power, and treatment duration using the Pascal® photocoagulator, a multi-spot, semi-automated, short-duration laser system. Materials and Methods: A retrospective consecutive series with 752 Caucasian eyes and 1242 laser procedures over two years were grouped into, (1) 374 macular focal / grid photocoagulation (FP), (2), 666 panretinal photocoagulation (PRP), and (3) 202 barrage photocoagulation (BP). Parameters for power, duration, spot number, and spot size were recorded for every group. Results: Power parameters for all groups showed a non-gaussian distribution; FP group, median 190 mW, range 100 – 950 mW, and PRP group, median 800 mW, range 100 – 2000 mW. On subgroup comparison, for similar spot size, as treatment duration decreased, the power required increased, albeit in a much lesser proportion than that given by energy = power × time. Most frequently used patterns were single spot (89% of cases) in FP, 5 × 5 box (72%) in PRP, and 2 × 2 box (78%) in BP. Spot diameters as high as ≈ 700 μm on retina were given in the PRP group. Single session PRP was attempted in six eyes with a median spot count of 3500. Conclusion: Overall, due to the small duration of its pulse, the Pascal® photocoagulator tends to use higher powers, although much lower cumulative energies, than those used in a conventional laser. The consequent lesser heat dissipation, especially lateral, can allow one to use relatively larger spot sizes and give more closely spaced burns, without incurring significant side effects.