title: Laser damage to retinal ganglion cells: the effect on circadian rhythms.
abstract: Laser therapy (LRx) may affect the retinal ganglion cells (RGC), which play a role in circadian rhythms. This study assesses the effect of LRx on the circadian variation of cortisol (F), measured in 20 Type 2 diabetic patients (DM), 10 following LRx for diabetic proliferative retinopathy (DPR), and 10 control (CTR) without laser Rx or retinopathy. The diurnal F variation in the CTR followed a normal pattern. Compared with CTR, the F levels of the DPR group were significantly higher at 1600 and 2400 h (10.2+/-2.5 vs. 6.9+/-4.0 microg/dl, P<.05, and 6.4+/-2.5 vs. 2.6+/-1.7 microg/dl, P<.001, respectively). These results provide evidence that DM patients, following bilateral LRx for proliferative diabetic retinopathy, experienced nocturnal hypercortisolemia and loss of normal circadian cortisol variation, probably secondary to LRx damage to the RGC.
authors.affiliation: Department of Medicine, Rancho Los Amigos National Rehabilitation Center, Downey, CA, and Division of Endocrinology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA. bughi@usc.edu
authors.forename: Stefan
authors.initials: S
authors.lastname: Bughi
authors.forename: Sylvia
authors.initials: S
authors.lastname: Shaw
authors.forename: Alice
authors.initials: A
authors.lastname: Bessman
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D002940:Circadian Rhythm / Q000502:physiology*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications / Q000601:surgery; D003930:Diabetic Retinopathy / Q000097:blood / Q000601:surgery; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D053685:Laser Therapy / Q000009:adverse effects*; D008875:Middle Aged; D008954:Models, Biological; D012160:Retina / Q000293:injuries* / Q000601:surgery*; D012165:Retinal Ganglion Cells
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D006854:Hydrocortisone