Why don’t we achieve expected outcome in vitreoretinal surgery

Retinal toxicity - phototoxicity - chemical toxicity Inadvertent retinal trauma ; dehydration injury Retinal ischemia Optic neuropathy - NAION - Traumatic optic neuropathy Intraocular gas expansion Anesthesia-related Vision Loss

Longer operative times Phototoxicity Longer operative times Endoilluminators Photochemical injury prolonged cumulative exposure to light (absorption of light energy -> formation of reactive oxygen species) Augmentation spectral irradiance duration of light exposure Thermal damage higher-intensity light absorption, primarily at the level of the RPE Mechanical injury plasma transients and resultant shock waves formed by tissue absorption of short, ultrahigh energy laser pulses

Chemical toxicity (Silicone Oil) Central vision loss macula-sparing retinal detachment undergoing silicone oil tamponade developed deep central scotomata, often around the time of oil removal multifocal ERG : decreased central visual response pattern ERG indicated pathology within the macula Electrolyte shifts within the vitreous cavity at the time of oil removal leading to excitotoxicity within the retina Intraoperative phototoxicity, especially in cases of combined cataract extraction and oil removal Environmental light phototoxicity during silicone oil tamponade as the result of poor short wavelength filtering by silicone oil - Direct retinal toxicity

To avoid Silicone oil-related toxicity must be monitored regularly must rule out more common causes of vision loss ; corneal toxicity (band or bullous keratopathy), cataract, refractive error, retinal detachment, ERM, cystoid macular edema, and secondary glaucoma in patients experiencing vision loss while having long-term silicone oil tamponade