Glaucoma is a disease that is uncommon in people under the age of 50. It damages the optic nerve and gradually narrows the visual field. It is the most common cause of blindness among the elderly. Between one and two per cent of all 50-year-old persons and five and seven per cent of all 75-year-old persons suffer from glaucoma. Of these, almost 40 per cent are blind in at least one eye.
In cases of chronic glaucoma, early symptoms are barely noticeable, and approximately 50 per cent of patients are therefore undiagnosed. In Sweden, there are approximately 100,000 patients and a similar number who are as yet undiagnosed.
"The problem with glaucoma is that the disease creeps up on you. Patients themselves can’t tell that their visual field, because the healthier eye compensates for the diseased one," says Enping Chen.
That is why it is important to make as early and as precise a diagnosis as possible. With the right treatment, disease progression can, in most cases, be halted.
"It is not possible to recover the vision you have already lost, but it is often possible to prevent further deterioration," explains Enping Chen.
Successful care requires cooperation
It is not yet known exactly what causes glaucoma, but it is clear that there is a link between intraocular pressure and the disease. Age, blood circulation and hereditary can also play a part.
"Pressure-lowering drops have long been used to treat this condition, and its clinical benefit has been confired by many studies," says Enping Chen.
Eye drops are the most common treatment for glaucoma and are administered by the patient. This is a lifelong treatment because the disease is chronic and cannot be cured. Despite correct and regular medication being crucial in helping patients retain their vision missing the eye drops is a common problem.
"Successful glaucoma care is the result of lifelong cooperation between doctor and patient. It is hugely important to arrange follow-ups at regular intervals," says Enping Chen.
Refining diagnostic tests and measurement methods
The earlier a diagnosis can be made, the better the prognosis for the patient. There are a variety of diagnostic methods. Enping Chen has chosen to investigate different advanced methods to examine the optic nerve, for example to map the optic nerve and its nerve fiber with a laser.
"By working with instruments, we can make diagnostic tests more reliable. These methods can also be used to follow up on disease progression in our glaucoma patients."
Enping Chen is also trying to determine the true intraocular pressure to be able to tailor treatments to his patients. In short, there are a number of factors that affect the measured value. Corneal thickness and resistance are examples of such factors. A hard cornea produces a higher measured value and a soft one a lower value.
"However, corneal thickness has no bearing on development of glaucoma; it is only the pressure inside the eye that is significant. For that reason, we want to identify ways to eliminate the influence of the cornea from measurements," says Enping Chen.
Another concern with measuring intraocular pressure is that results are obtained in such a short space of time, just a few seconds.
"Our research shows that intraocular pressure changes markedly throughout the day and at night and also between the eyes. A single pressure measurement on one occasion therefore tells us very little. We are currently conducting a trial in which we offer a certain patient category pressure measurement at home. This could help significantly improve individual adaptation of treatment."
Enping thinks that the most exciting aspect of his research is identifying patient benefits – establishing findings that can actually be used to treat patients.
"Glaucoma is a common disease that affects a lot of people. There is so much more we need to know, and I am curious!."
Text: Lisa Thorsén