Medications
Antihistamines, antihypertensives, antideppresants, antiarrhythmics, diuretics, hormone replacement therapy and oral contraceptives are some of the medications that can become the bane of ocular comfort and clear vision.
Systemic disease
Along with systemic medication, systemic disease puts patients at risk for dry eye or more aptly, ocular surface disease (OSD). Autoimmune diseases, such as thyroid disease, rheumatoid arthritis, Sjogren's syndrome and systemic lupus erythematosus, place the ocular surface at risk for malfunction.
In the neurologic disease category, the ocular surface of Parkinson's disease patients is challenged by the triad of autonomic and motor dysfunction combined with the ill-effects of the anti-cholinergic medications prescribed to ameliorate the other symptoms of the disease. These patients suffer from reduced tear production and a reduced blink rate. The combined detrimental effects of reduced tear volume and reduced inter-blink interval are compounded by the drying effects of medication in these patients.
Diabetic patients are also at risk for dry eye as a concomitant pathology of the disease. The connection between the two ailments is confirmed in numerous studies: Corneal sensitivity, smoking and environmental factors
Reduced corneal sensitivity also becomes a significant source of OSD in patients other than diabetics. Contact lens wearers, post-surgical patients (particularly refractive surgery patients), pregnant patients, and patients who have been afflicted with herpetic corneal disease can also suffer a loss in corneal sensitivity.
Additionally, smokers have the dual risk of reduced corneal sensitivity and reduced quality and quantity of their tear films as demonstrated by a study of non, light and heavy smokers. An early study corroborates the harmful effects of cigarette smoking, revealing chronic irritative effects of cigarette smoking may lead to defects in ocular surface defense.
Certainly cigarette smoke can be bundled into the environmental conditions that can challenge the ocular surface. September 2010's issue of Toxicology Letters reviews the salient environmental, occupational and personal risk factors that alter the precorneal tear film. Irritants to the ocular surface/tear film included aggressive odors and aerosols, pollutants, combustion products, low humidity, high temperatures and drafts. Occupational environments/demands requiring visual tasking, such as computer work, can lead to computer vision syndrome (CVS). CVS, in part, is associated with ambient lighting, glare, screen display quality, increased ocular surface exposure and a decreased blink rate during long hours of focusing on computer screens.
The gender connection
Apart from the above-mentioned challenges in the work/world environment for dry eye, the complex goal of simply "looking good" in and of itself, can become an overlooked contributor to OSD. It has been established that the female gender, primarily due to declining hormonal support of the tear film with advancing age, is more at risk for the development of OSD signs and symptoms.
New finding on blepharitis
Blepharitis must also be considered as a contributing factor to dry eye. Generally, anterior and posterior blepharitis are comorbidities that interact to perpetuate the overall disease state of the eyelid. By causing inflammation, irritation, and/or hyperkeratinization of the lid margin, bacterial exotoxins and Demodex contribute to obstruction of the meibomian gland orifices which affects the oily layer of your tears being produced. This will hasten the evaporation of your tears and contribute to your dry eyes.
