Transient retinal artery occlusion during phacoemulsification cataract surgery

Purpose Transient retinal artery occlusion (TRAO) is a potentially underdiagnosed cause of immediate 'pad off' visual loss following phacoemulsification cataract surgery under sub-Tenon's anaesthesia. Methods We describe a series of three patients presenting with enigmatic 'pad off' visual loss following phacoemulsification surgery, each diagnosed with TRAO. We describe the variable clinical presentation, illustrate the value of optical coherence tomography (OCT) imaging in establishing the diagnosis, and present the final visual outcomes. Results Clinical findings alone may be subtle and inadequate in localising the pathology in patients with TRAO. Cross-comparison of superior and inferior macula OCT profiles in branch-pattern arterial occlusion-and between healthy and affected eyes in central-pattern arteriolar occlusion-is critical in clinching the diagnosis. The typical evolution of OCT appearance is acute-phase inner retinal thickening/oedema and hyperreflectivity followed by progressive, late-phase inner retinal atrophy. Visual acuity may recover but central scotomas, and defects in colour perception may persist. Conclusion The diagnosis of TRAO is challenging; delayed presentation may resolve fundal and retinal angiographic abnormalities. OCT may be the only imaging modality that can provide objective evidence of TRAO. Meticulous comparison/segmentation of OCT images is therefore mandatory in patients presenting with acute post-operative visual loss to exclude TRAO.