A vision exam focused on premies

Many babies born prematurely grow up to be healthy, happy kids. But those who weigh below 2 ¾ pounds at birth could have problems seeing well. This is something Michelle T. Cabrera, an associate professor of ophthalmology at the University of Washington School of Medicine and a pediatric ophthalmologist at Seattle Childrens, wants to help fix.

She is using handheld, swept source optical coherence tomography in a study of 50 premature infants.  The device obtains high-resolution, cross-sectional images of the vitreous in the babies’ eyes.  The vitreous is the eye’s gel-like filling.  The pictures Cabrera is taking can show fine details, including abnormalities such as floating spots and bands.   

This work may help doctors better understand and predict visual impairment in premature infants.

About 90 percent of premature infants will be diagnosed with retinopathy of prematurity, but they will outgrow it.  Another 10 percent, however, will require medical attention or need surgery.

During the last 12 weeks of pregnancy, a baby’s eyes develop rapidly. In a full-term infant, the retinal blood vessel growth is mostly complete. If a baby is born prematurely, this aspect of eye development is interrupted and the edges of the retina may not get enough oxygen and nutrients.

Scientists believe that the periphery of the premature infant’s retina then sends out signals to other areas of the retina for nourishment. As a result, new, abnormal vessels begin to grow. These fragile, weak vessels can bleed, which could lead to retinal scarring. When these scars shrink, they pull on the retina and cause it to detach from the back of the eye.  Retinal detachment is the main cause of visual impairment and blindness in these infants.

Cabrera’s study is made possible by a $65,000 research grant from the Knights Templar Eye Foundation.

-- Bobbi Nodell, UW Medicine, 206.543.7129

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