Reducing glaucoma burden hinges on many factors, including standardized definitions

Early diagnosis, long-term treatment and community outreach are needed to address glaucoma, especially in Asia, an expert said.

The ophthalmic community must unite in a concerted effort to improve clinical research, training and public awareness of glaucoma in order to reduce blindness from the disease, a clinician said.

“We need to improve the training as well as the human resources that are available to us,” Ramanjit Sihota, MD, FRCS, said at the 25th APAO Congress. “We need to standardize and simplify early diagnosis of primary glaucomas. We need to have cheap and safe means to manage common glaucomas. We also need to increase our outreach.”

Dr. Sihota focused on the current global short-term and long-term clinical priorities in glaucoma research, emphasizing the need to look for epidemiological data in different regions of the world to determine local priorities. Glaucomatous optic neuropathy attributed to primary open-angle glaucoma and primary angle-closure glaucoma may be slowed, or even halted, she said. In addition, loss of vision and many secondary types of glaucoma may be prevented with timely diagnosis and intervention.

“We have a better understanding of pathogenesis in some areas. Concerted programs are now possible. Global monitoring and evaluation is feasible,” she said. “But I think we do need to see where we go with clinical research today.”

Standardizing definitions

Standardizing definitions of glaucoma is at the top of clinical research priorities, Dr. Sihota said.

“We need to know a little more about pathogenesis and natural history, especially in terms of angle closure,” she said. “But in the long term, we need to be able to say that this definition is easily applicable around the world for a particular type of glaucoma we are seeing.”

Current priorities in clinical diagnosis should include screening modalities, such as anterior segment optical coherence tomography and electrophysiologic perimetry. Short-term research should focus on early diagnosis by objective measurement techniques for optic nerve head, retinal nerve fiber layer and ganglion cell abnormalities and genetic screening.

Long-term strategies should emphasize teleophthalmology and efficient population screening, she said.

“We should move away from subjective measurements to something that is objective,” Dr. Sihota said. “We also need to have one machine that will provide a consolidated report on the probability of a patient having a glaucomatous optic neuropathy or the presence of any retinal nerve fiber defects.”

Research should also concentrate on identifying definitive biomarkers, molecular pathways and mRNA or protein expression levels associated with glaucoma, Dr. Sihota said.

Public awareness

Currently, community services should conduct longitudinal studies using available diagnostics to target eyes that are at risk of progressing to glaucoma, an increasing burden in Asia.

“What we in Asia all need is the community’s involvement,” Dr. Sihota said.

Short-term goals should involve increasing community awareness and organizing eye care infrastructure comprising tertiary centers, satellite clinics and village outposts. Later, the focus should be target population screening and monitoring, she said.

“We need to actually increase awareness and to organize the care appropriate to our countries,” she said. “And we need to increase the chances of developing these diagnostic tests locally, so that we can afford to screen the population, advise standardized therapy and monitor them in the long run.”

Teleophthalmology would enhance outreach and optimize public awareness of glaucoma at all levels of society, from local communities to the entire population of India, Dr. Sihota said.

“It needs to be introduced and introduced as quickly as possible into many rural areas and finally developed into a countrywide network that can be used,” she said.

Long-term treatment

In disease management, current research should address patient adherence to medication, a major issue for glaucoma patients around the world. Short-term strategies should involve development of long-lasting glaucoma medications. Long-term efforts need to focus on the possible development of an annual glaucoma injection, she said.

Currently, clinicians need to identify patients who respond to a given medication. In the long term, they should be devising ways to enhance trabecular meshwork function and develop vaccines, biologic shunts and a titratable stent pump.

A better understanding of glaucoma pathogenesis would enhance diagnosis and disease management, Dr. Sihota said.

“This is still very important because we don’t actually know very much about why the IOP rises, why the eye progresses to open-angle glaucoma, why one eye out of many anatomically predisposed progresses to angle-closure glaucoma. I think it is very important to predict the onset of angle closure, which would make it possible to prevent half of the blindness currently attributed to glaucoma worldwide,” she said.

Short-term efforts should center on improving the prediction of angle closure onset, while longer-term strategies should focus on preventing angle closure in susceptible eyes early, perhaps by the age of 20 years.

“We urgently need to understand the normal and abnormal functions of the optic nerve head ganglion cells, and probably give early therapy with something as simple as an antioxidant,” Dr. Sihota said. – by Matt Hasson

• Ramanjit Sihota, MD, FRCS, can be reached at Dr. RP Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India; +91- 011-65-61-123; fax: +91-011-68-52-919; e-mail: rjsihota@hotmail.com.