Japanese researchers claim to have successfully identified factors that increase the risk of severe myopia and related vision loss.

Myopia or nearsightedness affects a large number of people across the world, with many cases of vision loss being reported in the developing countries.

To pinpoint the causes leading to myopia, the Japanese researchers followed 429 patients with a severe form of the disease for an average of 12 years. Their study found that that a condition called myopic maculopathy became significantly worse in 40 percent of the participants.

Macula is the part of the eye that provides clear, detailed vision. The types and patterns of abnormalities that developed in the macula influenced the extent to which vision was affected among these patients, the study authors explained in a news release from the American Academy of Ophthalmology.

"Our findings suggest that a patient's age, degree of nearsightedness, eye (axial) length and a specific abnormal bulging of the back surface of the eye (a posterior staphyloma) may be important factors that affect the severity of myopic maculopathy," says Dr. Kyoko Ohno-Matsui of the Tokyo Medical and Dental University, who lead the research group.

"Also, our results show that in eyes that are likely to progress to serious disease, the first observable sign may be a tessellated fundus (a specific abnormality in the macula)," he says. Dr. Kyoko's is the first study to specifically describe the association between disease pattern and vision loss.

The new findings can help eye specialists identify the patients who require the closest monitoring, and help offer them the most appropriate treatments besides leading to improved screening and treatment of people with the eye disorder, the researchers say.