Clinical signs and symptoms for dengue are not only high fever and platelet count but also cause congestion in the eyes and in rare cases, blindness.
It is important to diagnose infection in dengue patients early in order to control the damage say eye specialists. "Eye infections in dengue patients are a known complication and are sometimes an initial symptom. We recently had a patient who lost his vision due to the infection. His eyes were swollen and tests showed he was bleeding internally. We managed to save him but could not help him get his sight back," said Dr Bhavana Chawla, additional professor of ophthalmology at AIIMS.
Congestion in the eyes is seen in most dengue patients but rarely leads to blurry vision, said Dr Mukesh Mehra, senior consultant, internal medicine at Max hospital, Patparganj. "A 35-year-old man suffering from blurry vision due to dengue was discharged from our hospital this week," he said.
Data on the epidemiology of eye disease in dengue patients in India is limited. However it could range anywhere between 5% to 6%, experts say. It ranges between 16% and 40.3% in patients hospitalized with dengue.
According to a research published in a medical journal 'Survey of Ophthalmology'
, the time of onset of ocular symptoms can range between 2 days since the patient gets fever to even 5 months. In most cases, however, patients suffer from damage to the eyes when their platelet count drops severely.
"There is no known effective treatment for damaged retina. Active surveillance and steroid therapy are the main treatment modalities used. In some cases, the doctors have also experimented with immuno-suppressive therapy to hasten clinical recovery," the journal states.
Dengue is termed by many experts as the world's most rapidly spreading mosquito-borne viral disease. It follows a cyclical trend where there is an increase in the number of cases every 3-5 years. In the last decade, outbreaks have been reported in 2006 and 2010.
Dengue is caused by 4 serotypes. While type I and III are milder in nature causing classic fever and fever without shock, dengue type II and IV are considered deadly. These cause fever, bleeding and a drop in platelet count. The presence of all four serotypes could be behind increased frequency of the disease outbreak. Delhi has reported more than 280 dengue cases till date and two people have died due to the mosquito-borne disease this year.