1. Why don’t we achieve expected outcome in vitreoretinal surgery

2. 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

3. 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

4. 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

5. 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