Studying the biomechanical properties of biological tissue is crucial to improve our understanding of disease pathogenesis. The biomechanical characteristics of the cornea, sclera and the optic nerve head have been well addressed with an extensive literature and an in-depth understanding of their significance whilst, in comparison, knowledge of the retina and choroid is relatively limited. Knowledge of these tissues is important not only to clarify the underlying pathogenesis of a wide variety of retinal and vitreoretinal diseases, including age-related macular degeneration, hereditary retinal dystrophies and vitreoretinal interface diseases but also to optimise the surgical handling of retinal tissues and, potentially, the design and properties of implantable retinal prostheses and subretinal therapies. Our aim with this article is to comprehensively review existing knowledge of the biomechanical properties of retina, internal limiting membrane (ILM) and the Bruch’s membrane–choroidal complex (BMCC), highlighting the potential implications for clinical and surgical practice. Prior to this we review the testing methodologies that have been used both in vitro, and those starting to be used in vivo to aid understanding of their results and significance.

Complications associated with intravitreal anti-vascular endothelial growth factor (VEGF) therapies are inconsistently reported in the literature, thus limiting an accurate evaluation and comparison of safety between studies. This study aimed to develop a standardized classification system for anti-VEGF ocular complications using the Delphi consensus process. Systematic review and Delphi consensus process. 25 international retinal specialists participated in the Delphi consensus survey. A systematic literature search was conducted to identify complications of intravitreal anti-VEGF agent administration based on randomized controlled trials (RCTs) of anti-VEGF therapy. A comprehensive list of complications was derived from these studies, and this list was subjected to iterative Delphi consensus surveys involving international retinal specialists that voted on inclusion, exclusion, rephrasing, and addition of complications. As well, surveys determined specifiers for the selected complications. This iterative process helped refine the final classification system. The proportion of retinal specialists who choose to include or exclude complications associated with anti-VEGF administration. After screening 18,229 articles, 130 complications were initially categorized from 145 included RCTs. Participant consensus via the Delphi method resulted in the inclusion of 91 (70%) complications after three rounds. After incorporating further modifications made based on participant suggestions, such as rewording certain phrases and combining similar terms, 24 redundant complications were removed, leaving a total of 67 (52%) complications in the final list. A total of 14 (11%) complications met exclusion thresholds and were eliminated by participants across both rounds. All other remaining complications not meeting inclusion or exclusion thresholds were also excluded from the final classification system after the Delphi process terminated. In addition, 47 out of 75 (63%) proposed complication specifiers were included based on participant agreement. Using the Delphi consensus process, a comprehensive, standardized classification system consisting of 67 ocular complications and 47 unique specifiers was established for intravitreal anti-VEGF agents in clinical trials. The adoption of this system in future trials could improve consistency and quality of adverse event reporting, potentially facilitating more accurate risk-benefit analyses.

Background. This case highlights the importance of recognising multiple pathologies within the eye which may not necessarily be linked. Both birdshot retinochoroiditis and astrocytoma are rare conditions. The case underlines the need for early identification and treatment of birdshot retinochoroiditis with steroids and disease modifying drugs. Astrocytoma in the absence of tuberous sclerosis is also uncommon. Case Presentation. A 36-year-old male presented with 3-month history of bilateral progressive flashing lights and floaters. He was systemically well with no significant past medical history. Fundal examination revealed retinal vasculitis and active creamy lesions in the choroid radiating from the optic nerve. In the supranasal periphery of the right eye there was a raised white, jagged lesion protruding into the vitreous. Fluorescein angiogram and indocyanine green showed marked venous vasculitis, hypofluorescence, and disc leakage in keeping with birdshot retinochoroiditis. The supranasal lesion features were in keeping with astrocytoma and this was thought to be a coincidental finding. Conclusions. Retinal astrocytoma may be present as an isolated ocular finding; however, patients must still be investigated for tuberous sclerosis which is the most common association. Birdshot retinochoroiditis typically responds well to steroid therapy, and disease modifying drugs should be considered as soon as possible.