Current Challenges in the Management of Vitreoretinal Conditions

In the dynamic realm of ophthalmology, the management of vitreoretinal conditions stands as a testament to both significant progress and ongoing challenges [...].

Scientific and Regulatory Policy Committee Points to Consider: Fixation, Trimming, and Sectioning of Nonrodent Eyes and Ocular Tissues for Examination in Ocular and General Toxicity Studies

A Working Group of the Society of Toxicologic Pathology's Scientific and Regulatory Policy Committee conducted a technical and scientific review of current practices relating to the fixation, trimming, and sectioning of the nonrodent eye to identify key points and species-specific anatomical landmarks to consider when preparing and evaluating eyes of rabbits, dogs, minipigs, and nonhuman primates from ocular and general toxicity studies. The topics addressed in this Points to Consider article include determination of situations when more comprehensive evaluation of the globe and/or associated extraocular tissues should be implemented (expanded ocular sampling), and what constitutes expanded ocular sampling. In addition, this manuscript highlights the practical aspects of fixing, trimming, and sectioning the eye to ensure adequate histopathological evaluation of all major ocular structures, including the cone-dense areas (visual streak/macula/fovea) of the retina for rabbits, dogs, minipigs, and nonhuman primates, which is a current regulatory expectation for ocular toxicity studies.[Box: see text].

Selected Aspects of Ocular Toxicity Studies With a Focus on High-Quality Pathology Reports: A Pathology/Toxicology Consultant's Perspective

Ocular toxicity studies are the bedrock of nonclinical ocular drug and drug-device development, and there has been an evolution in experience, technologies, and challenges to address that ensures safe clinical trials and marketing authorization. The expectations of a well-designed ocular toxicity study and the generation of a coherent, integrative ocular toxicology report and subreports are high, and this article provides a pathology/toxicology consultant's perspective on achieving that goal. The first objective is to cover selected aspects of study designs for ocular toxicity studies including considerations for contract research organization selection, minipig species selection, unilateral versus bilateral dosing, and in-life parameters based on fit-for-purpose study objectives. The main objective is a focus on a high-quality ocular pathology report that includes ocular histology procedures to meet regulatory expectations and a report narrative and tables that correlate microscopic findings with key ophthalmic findings and presents a clear interpretation of test article-, vehicle-, and procedure-related ocular and extraocular findings with identification of adversity and a pathology peer review. The last objective covers considerations for a high-quality ophthalmology report, which in concert with a high-quality pathology report, will pave the way for a best quality toxicology report for an ocular toxicity study.

Treatment of radiation-induced maculopathy with fluocinolone acetonide

PURPOSE

Chronic macular oedema is a well-known presentation of radiation-induced maculopathy (RM) following external beam photon therapy, plaque radiotherapy and proton beam radiotherapy for choroidal tumours. Current therapies vary in respect of efficacy and clinical benefit. The potential of fluocinolone acetonide (FAc) slow-release implants is unknown. We hypothesised that local continuous delivery of low-dose corticosteroids might improve symptoms of RM.

METHODS

Five-two male and three female-patients from 37 to 68 years presented with RM following ¹⁰⁶Ru-plaque brachytherapy or stereotactic radiation therapy (STx) with photons using a hypofractionated schedule of 5 × 10 Gy. All were treated with triamcinolone injections in first line and proofed to be refractory to steroids. In addition, two patients had received Ozurdex® implants as a second-line treatment, though without any clinical benefit. FAc slow-release implants were injected, and patients were followed up to monitor clinical improvement.

RESULTS

All patients responded to therapy by means of a decrease in macular oedema. In four of five (80%) patients, visual acuity improved, and one patient showed stable visual acuity. No toxic effects or complications were observed.

CONCLUSION

Slow-release implants of FAc are a promising therapeutic potent steroid treatment option to benefit anatomical structures of the fovea and visual function. Slow-release implants with FAc reduce the frequency of intravitreal injections and the therapeutic burden.