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The following is a summary of “Corneal Sensory Changes and Nerve Plexus Abnormalities in Chronic Neuropathic Ocular Pain and Dry Eye Post-Refractive Surgery,” published in the April 2025 issue of American Journal of Ophthalmology by Vázquez et al. 

Chronic neuropathic ocular pain (NOP) often developed alongside chronic dry eye (DE) following laser-assisted in-situ keratomileusis (LASIK), but its specific characteristics were poorly understood.   

Researchers conducted a retrospective study to compare the clinical characteristics of patients with both DE and NOP after LASIK to those with only DE and asymptomatic patients of LASIK, aiming to facilitate the diagnosis of NOP.   

They included 89 post-LASIK subjects, divided into 3 groups: 34 in the NOP-DE group (both NOP and DE), 25 in the DE group (only DE), and 30 asymptomatic controls. Clinical assessments included questionnaires (Ocular Surface Disease Index (OSDI), Modified Single Item Dry Eye Questionnaire (mSIDEQ), Numerical Rating Scale (NRS), Wong-Baker Faces Pain Rating Scale (WFPRS)), anxiety and depression evaluation (HADS (Hospital Anxiety and Depression Scale)), and tests for tear film stability (osmolarity, Tear Break-up Time (TBUT)), tear production (Schirmer), and ocular surface integrity. Corneal mechanical and thermal sensitivity were measured using Belmonte’s non-contact esthesiometer, while tactile sensitivity was assessed before and after topical anesthesia using the Cochet-Bonnet esthesiometer (CB). Sub-basal nerve plexus and dendritic cell (DC) density in the central cornea were examined using in vivo confocal microscopy (IVCM). Group comparisons and correlations were performed.   

The results showed that patients in the NOP-DE group exhibited significantly more DE symptoms (mSIDEQ, P =0.019) and higher pain levels (NRS, WFPRS) compared to the DE group. The NOP-DE group also used more ocular lubrication (P =0.003) and had a higher frequency of pathological results on anxiety and depression questionnaires (P <0.001). Additionally, a greater prevalence of central sensitization syndromes was observed (P <0.001). The patients with NOP-DE showed higher tactile corneal sensitivity post-anesthesia (P =0.002) and IVCM analysis revealed lower nerve density (P =0.049) and higher microneuroma density (P =0.008) in the sub-basal nerve plexus of the NOP-DE group. Most nerve metrics correlated with clinical parameters.   

Investigators concluded that persistent high corneal tactile sensitivity post-anesthesia, reduced nerve density, and increased microneuroma density in the central cornea and were the diagnostic indicators for confirming NOP in patients with chronic DE post-LASIK.   

Source: ajo.com/article/S0002-9394(25)00172-2/abstract