Decreased corneal sensitivity and tear production in fibromyalgia.
http://www.ncbi.nlm.nih.gov/pubmed/19324850
Instituto de Neurociencias, Universidad Miguel Hernandez-CSIC, San Juan de Alicante, Spain.
Purpose: To investigate corneal sensitivity to selective mechanical, chemical, heat and cold stimulation in fibromyalgia (FM) patients. Methods: Twenty FM patients (18 female, 2 male; 51,9+/-2,3 years old) and 18 control subjects (16 female, 2 male; 51,7+/-2,4 years) participated voluntarily in the study. Subjective symptoms of ocular dryness were explored and Schirmer's 1 test was performed. The response to selective stimulation of the central cornea with the Belmonte gas esthesiometer was measured. Results: The majority (18 out of 20) of FM patients reported dry eye symptoms, being the ocular dryness score significantly higher than in healthy subjects (2,3+/-0,1 vs. 0,05+/-0,02; p<0,001). Schirmer's test values were significantly reduced in FM patients compared to those of the control group (10,5+/-,2 mm and 30,6+/-1,6 mm, respectively; p<0,001). Mean corneal threshold sensitivity to chemical stimulation (31,16+/-2,04 %CO2 FM; 15,72+/-0,67 %CO2 control) to heating (1,87+/-0,11 degrees C FM; 0,99+/-0,05 degrees C control) and to cooling (-2,53+/-0,11 degrees C FM; -0,76+/-0,05 degrees C control) were increased in FM patients while threshold to mechanical stimulation did not vary significantly (123,0+/-8,0 ml/min FM; 107,8+/-4,4 ml/min control). Conclusions: The reduced corneal sensitivity of patients with fibromyalgia is attributable to a moderate decrease of corneal polymodal and cold nociceptor sensitivity, that may be the consequence or the cause of the chronic reduction in tear secretion also observed in these patients.
PMID: 19324850 [PubMed - as supplied by publisher]
