A 39-year-old otherwise healthy man presented to the New England Eye Center for evaluation of dry eye disease (DED). He had undergone LASIK in both eyes (OU) 5 years earlier, followed by refloating of the flap and scraping of epithelial downgrowth in the right eye (OD) 2 weeks later, and LASIK enhancement in OD 3 years later.
Symptoms of foreign body sensation started shortly after LASIK, being more intense in OD. The Ocular Surface Disease Index (OSDI)1 was 65 measured on a scale from 0 to 100. The Ocular Pain Assessment Survey (OPAS)2 measured 2.7 in a scale from 1 to 10 for both 24 hour- and 2 week-pain intensity, 2/10 for impact in quality of life (QoL), and 90% worsening in windy/dry conditions. He had been using different artificial tears (most recently TheraÂTears, Akorn) 12 times daily, without relief. Although dissolvable punctal plugs temporarily improved dryness in OD, symptoms persisted.
His uncorrected visual acuity (UCVA) was 20/25 in OD and 20/20 in the left eye (OS). Pupils, motility, and IOPs were unremarkable. He was noted to have bilateral low tear films and mild superficial punctate keratopathy (SPK) inferiorly. Schirmer’s I test measured 1 mm in OU. Tear break-up time was 7 seconds in OU. LASIK flaps were intact, except for inferotemporal subepithelial haze in OD. The remainder of the ophthalmic examination was unremarkable.
While the patient had minimal response to Schirmer’s I test, blood markers for Sjögren’s syndrome were negative. Corneal in vivo confocal microscopy (IVCM) provides noninvasive high-resolution images of the corneal nerve plexus at the cellular level (Heidelberg Retina Tomograph 3/Rostock Cornea Module, Heidelberg Engineering). This “optical corneal biopsy” revealed severely decreased nerve density and abnormal morphology of the central subbasal nerve plexus in OD, while OS appeared intact (Figure 1A/B, Page 30).