Canon CR-1  The State of the Art in Non Mydriatic Retinal Imaging using the Canon CR-1

One in four patients with severe diabetic-related retina damage end up blind because they come in too late.  The National Diabetic Eye Registry showed that out of  36952 diabetic patients who were screened from 2007-2009,   13,973 patients (38%) had diabetic retinopathy,  3,311 (9%) suf­fered severe retinal damage and of them, 774 (2%) could no longer get their blindness reversed.  This condition was often missed because it was asymptomatic, with some seeing floaters or having blurred vision. For this reason,  all diabetic patients must get their eyes examined at least once a year.   

Retinal damage occurs when the thin layer of the retina is detached from the eye-wall and patients could suffer bleeding in the eye-ball as well. Blockage  in  the eyes'  blood vessels results in new blood vessels growing into the eye cavity to compensate for the blockage and this process pulls  the retina away from the back wall of the eye. It also occurs when protein leaks from the vessel into the surrounding retina and causes swelling.   High-risk groups included those with long standing and poorly controlled diabetes,  high blood pressure,  high blood cholesterol, smoking habit, anaemia and diabetes in pregnancy.  

Reichert 7 - Auto Tonometer

Glaucoma is a disease in which the optic nerve is damaged by high intraocular eye pressure, leading to progressive vision loss.  Untreated glaucoma leads to permanent damage of the optic nerve, resulting in visual field loss, which can lead to blindness.  Normal eye pressure ranges from 10 to 21 mm Hg. Ocular hypertension is an eye pressure that is high­er than normal, that is, more than 21 mmHg.  

A person with a healthy optic nerve can potentially have higher eye pressure without damage to this nerve,  even though the eye pressure is above 21 mmHg. However, in an elderly person with poor general health and a weak optic nerve, an eye pressure of 15min Hg or 16mm Hg could be considered damaging enough. Hence, if eye pressure is deemed to be inappropriately high (even if it's below 21 mmHg), it has to be brought down so that the optic nerve does not get damaged. 

A person after 40 should go for regular eye checks every one  to two years.

The commonest types of glaucoma are open-angle glaucoma and angle-closure glaucoma. The less common type is congenital glaucoma, which occurs at birth or at the age of four or five. There is also the "miscellaneous" group or secondary glaucoma, caused by injury or eye diseases such as inflammation or uveitis.