A 55-year-old man experienced permanent vision loss in his right eye following uncomplicated cataract surgery, highlighting the diagnostic challenges of post-cataract surgery nonarteritic anterior ischemic optic neuropathy (NAION).
While the condition is a known, albeit uncommon, complication of phacoemulsification, the patient’s eight-month delay in seeking care prevented clinicians from documenting the acute optic disc edema required for a definitive diagnosis, Cureus reported.
The patient underwent routine phacoemulsification with intraocular lens implantation, initially improving his best-corrected visual acuity from 20/80 to 20/30. Approximately one month after the procedure, he reported intermittent blurring that progressed to complete, painless vision loss in the operated eye. By the time he sought an ophthalmic evaluation eight months later, he had no light perception and a dense relative afferent pupillary defect.
Clinical examination revealed diffuse optic disc pallor and attenuated retinal arterioles, but the lack of optic disc edema made identifying the cause difficult. Optical coherence tomography (OCT) showed thinning of the peripapillary retinal nerve fiber layer and the macular ganglion cell-inner plexiform layer.
Because the patient presented long after the acute event, doctors had to rule out other causes of vision loss, including arteritic anterior ischemic optic neuropathy and chronic central retinal artery occlusion.
Fluorescein angiography confirmed the absence of choroidal filling delays, which typically signal arteritic processes. A temporal artery biopsy was considered but ultimately deferred due to the low clinical suspicion and the patient’s normal inflammatory profile.
Management of the patient’s remaining vision focuses on protecting the unoperated left eye, which still contains a dense congenital cataract. Research indicates that patients with a history of NAION face a higher risk of sequential optic neuropathy in the fellow eye following cataract surgery. Consequently, the patient and his medical team opted to leave the left cataract in place to avoid the potential risks associated with further ocular intervention.
Why is early evaluation critical after cataract surgery?
The diagnostic window to document acute optic disc edema—a hallmark of NAION—is typically four to eight weeks. After this period, the edema resolves into optic disc pallor, which is a nonspecific sign of optic atrophy that can be caused by various conditions.
What are the primary risk factors for NAION?
Standard systemic risk factors include hypertension, diabetes mellitus, and dyslipidemia. Obstructive sleep apnea is also recognized as a strong independent risk factor for the condition.
Does surgery directly cause NAION?
Causation is difficult to establish because many patients possess systemic risk factors independent of the surgery. While cohort studies indicate a modestly increased risk of NAION following cataract extraction, the absolute risk remains low.