Glaucoma leading cause of low vision, blindness in Taipei City

Statistics should be used to develop better public assistance programs for preventable diseases and increase patient education, clinician says.

ByJessica Loughery

Glaucoma appears to be the leading cause of low vision and blindness in Taipei City, according to a new analysis of patients registered with the Department of Social Welfare.

“We all know that glaucoma is a silent killer, and early diagnosis is an important issue,” I-Lun Tsai, MD, told Ocular Surgery News in an e-mail interview.

I-Lun Tsai

Dr. Tsai said the incidences of angle-closure glaucoma and myopia were shown to be higher in Taipei City residents than in patients in other places.

“The most important thing is that glaucoma is a disease that can be controlled with modern medicines,” she said.

However, “glaucoma awareness is always a problem in public health,” Dr. Tsai said.

She recommended that the public be educated on the benefits of early intervention in glaucoma.

“We must provide this information to the social welfare agents to let them know what kind of help they can provide for these patients,” she said.

The study

“It is very difficult to estimate the real incidence and actual causes of low vision and blindness in Taipei City,” Dr. Tsai said.

To help provide statistical insight, the study authors analyzed the registry of patients identified by the Department of Social Welfare as having low vision or blindness. They published their results in the European Journal of Ophthalmology.

All cases were registered between January 1995 and December 2004. Information was obtained from Disability Identification Registration forms, which registrants voluntarily filled out, according to the study.

The investigators used the World Health Organization’s criteria for low vision and blindness. Specifically, patients with a visual acuity between 20/60 and 20/400, or visual field loss to worse than 20° in the better eye with correction, were identified as having low vision. Those with a visual acuity worse than 20/400, or visual field loss to worse than 10º in the better eye with correction, were identified as being blind.

Of the 2,912 registered cases that fit the inclusion criteria, 1,625 (55.8%) had low vision and 1,287 (44.2%) were blind, the authors found.

Aside from glaucoma, optic neuropathy, diabetic retinopathy, retinitis pigmentosa, age-related macular degeneration and myopic macular degeneration were found to be leading causes of low vision and blindness.

In addition, low vision and blindness were low until registrants reached the age of 50 years, the authors noted. Among those between 50 and 64 years of age, diabetic retinopathy was the most common cause of blindness, whereas glaucoma and AMD were the most common causes of low vision and blindness among those older than 65 years.

Notable changes

The investigators found that the incidence of diabetic retinopathy, optic neuropathy and AMD reported as causes of blindness increased after 2002. The incidence of glaucoma, diabetic retinopathy and AMD reported as causes of low vision also increased after 2002.

Dr. Tsai identified the increase in cases of diabetic retinopathy as the most significant change in the causes of blindness in the Taipei City population.

“Diabetic retinopathy is a big problem in middle-aged and older people in many countries, especially in civilized cities, although it is preventable and treatable,” she said. Based on the study results, the authors recommended that public health officials increase efforts to educate people with diabetes about the risk of retinopathy.

Dr. Tsai also identified a need for increased AMD awareness. Previously, the population of Taipei City had a lower incidence of AMD when compared with Caucasian patients, she said. The incidence has increased in recent years.

“We think the major reason is the prolongation of life expectancy in our population,” Dr. Tsai said.

As with glaucoma and diabetic retinopathy, the authors said they hope that these new numbers will increase education efforts and awareness.

Low vision, blindness registration

Since 1995, the Department of Social Welfare has seen an increase in the number of people registering with low vision, although the number of blind registrants has stayed the same. The increase may be because of the efforts of various groups advocating for the visually impaired, the study authors said.

People who register with the Department of Social Welfare may be eligible for financial assistance depending on the degree of visual impairment, as well as social support. Dr. Tsai said by providing more statistical information on the causes of blindness and low vision, the authors hoped to help improve the services available for these patients, as well as emphasize the call for increased education.

“We ophthalmologists should strongly encourage people with low vision and blindness to register,” Dr. Tsai said. “Many people do not know the benefits of registration.

“We must also help our government and our ophthalmological society to know the true causes and incidences of low vision and blindness,” she said.

For more information:

I-Lun Tsai, MD, can be reached at Taipei City Hospital, 145 Zheng Zhou Road, Taipei City, Taiwan, R.O.C.; +02-2552-3234; e-mail: ilunt@ms49.hinet.net.

Reference:

Tsai IL, Woung LC, et al. Trends in blind and low vision registrations in Taipei City. Eur J Ophthalmol. 2008;18:118-124.

Jessica Loughery is an OSN Staff Writer who covers all aspects of ophthalmology.