If a patient complains of nagging dry eye symptoms months after cataract surgery, their real diagnosis could be persistent postsurgical pain (PPP), a new study suggests.

A group of Miami researchers found PPP in the form of persistent dry eye–like symptoms was present in approximately 34% of individuals six months after cataract surgery. Additionally, the study found the frequency of PPP after cataract surgery mirrored other post-procedure periods, including laser refractive surgery, dental implants and genitourinary procedures, which suggests cataract surgery could be classified as a medium-risk procedure.

Since the cornea is among the most densely innervated tissues in the body, investigators sought to find out whether PPP occurred after ocular procedures. Researchers conducted phone interviews with 119 individuals who had cataract surgery performed by a single surgeon at the Bascom Palmer Eye Institute. Investigators did the interviews six months following the surgery and placed the participants in two groups: patients with PPP who had a Dry Eye Questionnaire Five (DEQ-5) score greater than six and those without PPP with a DEQ-5 score of less than six, half a year following the procedure. The average age of the participants was 73.

Based on the results of the DEQ-5, 41 individuals reported having PPP (34%) and 78 individuals reported having no symptoms. Researchers noted the frequency of severe PPP was 18% (22 people).

Investigators found most medical comorbidities and medications were not associated with an increased risk of PPP. However, they found individuals with an autoimmune disease such as rheumatoid arthritis, systemic lupus, Sjögren’s, polymyalgia rheumatica or multiple sclerosis had an increased risk of PPP. Patients who had pain disorders—headache, migraine, lower back pain or fibromyalgia—were also more prone to PPP. And for those patients who had dry eye issues before cataract surgery, their risk also increased. 

Patients at a greater risk of PPP were female, had an autoimmune or non-ocular chronic pain disorder or used antihistamines, anti-reflux medication, antidepressants or anti-insomnia medications. PPP patients also reported more frequent use of artificial tears, higher ocular pain levels and greater neuropathic ocular pain symptoms, specifically burning, wind sensitivity and light sensitivity.

 “Dry eye symptoms are classically believed to arise because of a disturbance in either the tear film or the orbital structures that give rise to or interact with the tear film, but recent consensus has highlighted a concomitant role of neurogenic stress and ocular surface inflammation,” the researchers wrote in their paper. “Dense innervation of the cornea and the known corneal nerve injury that occurs at a surgical incision likely form the backdrop for the development of PPP after cataract surgery.”

Symptom management after cataract surgery may focus on minimizing ocular surface nerve damage by careful surgical dissection, pre-surgical treatment of modifiable comorbid risk factors like anxiety, and perioperative pain control, the study noted.

Sajnani R, Raia S, Gibbons A, et al. Epidemiology of persistent postsurgical pain manifesting as dry eye-like symptoms after cataract surgery. Cornea. 2018 Dec;37(12):1535-41.