Depression and dry eye
This study really packs a punch: It says that dry eye was the ONLY ocular disease that is specifically associated with depression.
It is specifically compared with:
age-related macular degeneration
any type of glaucoma
lower visual acuity
Not all that surprising to me, but nonetheless impressive to see this documented.
So what's unique about dry eye? The top things that come to mind for me are pain (including all of the sensations it can cause that reduce quality of life and impair daily functions) and trivialization by the medical community and the public.
2018 Aug 10;13(8):e0202132. doi: 10.1371/journal.pone.0202132. eCollection 2018.
Jonas JB1,2, Wei WB3, Xu L1, Rietschel M4, Streit F4, Wang YX1.
To assess the prevalence of depression in the general population of Beijing and its association with ocular diseases.
The population-based Beijing Eye Study was conducted in a rural and an urban region of Greater Beijing. The study participants underwent a detailed ophthalmological examination and an interview including questions on the socioeconomic background. Depressive symptoms were evaluated using a Chinese depression scale adapted from Zung´s self-rated depression scale. The total score of depression symptoms was 80. Depression was defined as having a depression score >44.
Out of 3468 study participants, 3267 (94.2%) individuals (1419 men) with an age of 64.5±9.7 years (range: 50-93 years) participated in the interview and answered all questions on depression. The mean depression score was 25.0±5.9 (median: 23.3; range:20-64). Depression (depression score >44) was present in 66 individuals (2.0%; 95% confidence interval (CI): 1.5, 2.5), and 5 individuals (0.2%; 95%CI: 0.02,0.3) had a depression score ≥59. In multivariate regression, analysis, a higher depression score was associated (regression coefficient r2: 0.22) with a higher number of days with dry eye feeling (P<0.001; standardized regression coefficient beta: 0.09; non-standardized regression coefficient B: 0.20; 95%CI: 0.12,0.29) and shorter corneal curvature radius (P = 0.03;beta:-0.04; B:1.01; 95%CI: -1.90,-0.12), after adjusting for age, gender, region of habitation, body mass index, cognitive function score, life quality score and blood concentration of triglycerides. Adding age-related macular degeneration (P = 0.10), glaucoma (P = 0.77), diabetic retinopathy (P = 0.77), nuclear cataract (P = 0.35), cortical cataract (P = 0.58) or posterior subcapsular cataract (P = 0.28) as single parameters to the model revealed no significant correlation with the depression score. Lower best corrected visual acuity showed a marginal significant association (P = 0.05; beta: 0.04; B: 1.56; 95%CI: -0.01, 3.13).
Dry eye feeling was the only common ocular disorder associated with an increased depression score, while the occurrence of age-related macular degeneration, any type of glaucoma, diabetic retinopathy, any type of cataract and keratoconus were not significantly associated with an increased depression score. Lower visual acuity was marginally associated. The prevalence of depression in the population aged 50+ years in Greater Beijing was 2.0% (96%CI: 1.5, 2.5).