A new study in Cornea examined the incidence of recurrent corneal erosions (RCEs) using standard diagnostic methods and a new technique called the corneal sweep test (CST).
What is the corneal sweep test?
It might be easier to show you than to explain in writing. Here is a great video demonstrating the technique.
Why do we need a new way to diagnose RCEs?
Because, according to the authors, there is a subset of erosions, called occult corneal erosions, that do not have physical findings (ie, no evidence of nonuniform or negative staining of the corneal epithelium with NaFl).
The symptoms of occult corneal erosions can vary widely, potentially misleading the clinician into making a wrong diagnosis, such as dry eye syndrome.
Because no definitive diagnostic tool exists, much of the onus falls on the clinician to maintain RCEs high on the differential diagnosis when treating a patient with an ocular pain syndrome.
The study details.
A retrospective chart review was conducted on 58 eyes of 51 patients with a diagnosis of RCE from July 2018 to June 2020. All patients underwent a thorough history and physical examination.
The CST was performed as a confirmatory test on any eye that lacked visible corneal pathology.
What did they find?
The CST was necessary on 49 of the 58 eyes to help confirm the diagnosis of a corneal erosion. Among them, 34 had an occult corneal erosion, which is defined as having a normal-appearing cornea on slit-lamp examination, but a loose corneal epithelium with the CST.
Clear corneal cataract surgery was the most common presumed mechanism of injury (48.2%), with 20 (71.4%) eyes developing symptoms only after cataract surgery. All 20 eyes had an erosion located directly over a clear corneal cataract incision.
The take home.
The CST is a new and effective technique to help diagnose corneal erosions in the absence of visible corneal findings. Clear corneal cataract surgery is an under-recognized but important risk factor to consider because the incision can be the source for an erosion.
Using the CST could lead to a paradigm shift in the way clinicians approach treating RCEs and patients with a persistent ocular pain syndrome.