Second-eye non-arteritic anterior ischaemic optic neuropathy following cataract surgery: Diagnostic uncertainty in patients with polymyalgia rheumatica

Purpose: To report a case of second-eye Non-Arteritic Anterior Ischaemic Optic Neuropathy (NAION) occurring shortly after uncomplicated cataract surgery, and to highlight the diagnostic and management uncertainty in di^erentiating arteritic from non-arteritic optic neuropathy in patients with polymyalgia rheumatica.

Setting: Ophthalmology department, James Paget University Hospital NHS Foundation Trust, United Kingdom.

Report of Case: A 73-year-old male with a background of hypertension and polymyalgia rheumatica on low-dose prednisolone (5 mg once daily) presented with sudden painless visual loss in the right eye. Visual acuity 6/60 (pinhole), with blurred optic disc margins. Optical coherence tomography demonstrated findings consistent with optic disc oedema. Confrontation visual field testing revealed an inferior visual field defect.

Inflammatory markers, including CRP, ESR and platelet count were within normal limits. Given the patient’s age and underlying polymyalgia rheumatica, arteritic anterior ischaemic optic neuropathy was initially suspected and treated with high-dose steroids (60mg). However, the absence of systemic symptoms, normal inflammatory markers, and a negative temporal artery biopsy made giant cell arteritis unlikely, supporting a diagnosis of non-arteritic anterior ischaemic optic neuropathy. Steroids were subsequently tapered and discontinued.

Two weeks later the patient underwent uncomplicated cataract surgery in the left eye for visually significant cataract (pre-operative visual acuity 6/18). In early post-operative period, visual acuity deteriorated to 6/45 with new optic disc swelling, consistent with second-eye NAION. Oral prednisolone was restarted (40mg once daily) and a diagnosis of second - eye non arteritic anterior ischaemic optic neuropathy was made.

Conclusions: Second-eye non-arteritic anterior ischaemic optic neuropathy may occur following cataract surgery in patients with vascular risk factors and prior NAION, although causal relationship remains uncertain. This case highlights the diagnostics and management uncertainty in distinguishing arteritic from non-arteritic optic neuropathy in patients with polymyalgia rheumatica, where failure to recognise arteritic disease may result in irreversible bilateral vision loss.

Careful pre-operative counselling is essential in patients with prior NAION, as second- eye involvement can lead to substantial visual impairment. In addition, perioperative steroid management requires careful consideration, as reduction or cessation may complicate the interpretation of post-operative visual loss and introduce diagnostic ambiguity. Close clinical monitoring is important to enable timely diagnosis and appropriate management in this high-risk group.