One of the most important risk factors for glaucoma is high intraocular pressure (IOP). If the pressure inside the eye is high, it damages the optic nerve. Since this process in insidious, visual field of the affected eye is gradually lost. In the late stages of glaucoma, only central vision is present. This can be compared to your field of vision if you look through a tube. You will be able to see only a small field (at the end of the tube). This small field of vision is called as Tunnel Vision.
When all nerve fibers of the optic nerve are damaged, complete loss of vision is the final outcome. Blindness caused by glaucoma is irreversible and the normal vision cannot be restored by any mode of treatment.
Apart from many known and unknown factors causing high IOP, one interesting factor was investigated by a study in 2003 – effect of a tight necktie on intraocular pressure. The investigators hypothesized that the tight necktie would obstruct the flow of blood from the head to the heart which could result into back-pressure and ultimately higher IOP in the eyes.
They studied 40 eyes of 20 normal subjects and 20 patients of open angle glaucoma. IOP was measured in three situations:
1. Without the necktie, when the shirt collar was open.
2. Three minutes after placing and tightening the necktie ‘to the point of slight discomfort’.
3. Three minutes after loosening the necktie.
The results showed that 70% of normal subjects and 60% of glaucoma patients experienced significant rise in the eye pressures when their necktie was tight around their neck. No difference was found between IOP elevation in normal subjects and glaucoma patients.
There were two main conclusions of the study:
1. That a tight necktie is a risk factor for high intraocular pressure.
2. The IOP may be falsely high in the patients who wear a tight necktie at the time of IOP measurement during routine follow-up examinations of glaucoma patients. This could lead to error in judgment about the status of glaucoma and consequent treatment of the patients.
Another study however concluded that if the necktie is used for extended period of time, the IOP initially increases but eventually comes down even if the necktie is not loosened. This effect was mainly applicable to glaucoma patients. According to this study therefore, in patients of glaucoma, avoiding extended wear of tight neckties is not necessary.
It is important to note that any fluctuation in IOP in glaucoma patients is harmful and is not desired in any manner. Completely avoiding neckties may not be necessary if the collar of the shirt has more circumference than the neck and the necktie is not tight. Additionally, patients with advanced glaucoma should be more careful than the patients with early glaucoma, since frequent fluctuations in IOP, howsoever small they may be, can cause more appreciable visual loss in advanced cases of glaucoma.