Cataract Surgery and Dry Eye: Protecting the Ocular Surface

Cataract surgery is the most frequently performed operation in medicine and one of the most successful — but its outcome depends on more than the implanted lens. The ocular surface determines the quality of the measurements taken before surgery and the quality of vision afterwards: a dry, irregular surface makes biometry less accurate and leaves patients with fluctuating, uncomfortable vision despite a technically perfect result. The 2021 Chinese expert consensus on prevention and treatment of dry eye in the cataract perioperative period sets out a structured approach.

Before surgery: screen and treat first

Patients should be assessed for dry eye before the operation, using a symptom questionnaire — the consensus recommends the Chinese Dry Eye Questionnaire, with the Ocular Surface Disease Index, the Dry Eye Questionnaire-5, the McMonnies questionnaire and the SPEED questionnaire as alternatives — together with tear film break-up time, preferably measured by a non-contact method such as an ocular surface analyser or corneal topographer when available, surface staining, tear secretion testing and assessment of the meibomian glands. Where dry eye is found, it should be treated before surgery: lubricants, lid hygiene and, in more significant cases, anti-inflammatory drops, because operating on an inflamed surface worsens it and distorts the measurements used to choose the lens.

During surgery

Intraoperative protection is specific: minimising the time the surface is exposed, using balanced rather than toxic solutions, keeping the corneal epithelium intact, protecting the surface with viscoelastic or intermittent irrigation, avoiding excessive light and instrument contact, and preferring smaller, well-sealed incisions. Choice and duration of topical anaesthesia and the use of povidone-iodine at appropriate concentration also affect the surface.

After surgery

Postoperative care should anticipate dry eye rather than react to it. The consensus recommends preservative-free lubricants during the intensive-drop period, minimising the duration of preserved steroid and antibiotic drops, using non-steroidal drops cautiously because they can affect the surface, and reviewing the ocular surface at each postoperative visit. Lid hygiene and warm compresses continue for patients with gland dysfunction. Symptoms typically peak in the first week and settle over one to three months, though they can persist longer, particularly in patients with pre-existing disease.

Measuring the outcome

Success is not just visual acuity. Ask for the result in terms of both: how many lines you gained, and how stable and comfortable vision is through the day. Fluctuating vision that clears on blinking is the classic signature of tear film instability, and it responds to surface treatment. In patients with significant astigmatism or premium lens implants, an unstable surface undermines the precision of the whole procedure.

Practical guidance

Before surgery tell your surgeon about dryness, grittiness, contact lens intolerance, lid inflammation, diabetes or autoimmune disease, and any drops you use regularly. Bring the drops you use — including over-the-counter ones — because preserved formulations are a common hidden cause. After surgery, use lubricants as prescribed even if the eye feels fine, keep follow-up appointments, and report persistent grittiness or fluctuation rather than assuming it is normal healing.