OCULAR GENETICS IS CHANGING PAEDIATRIC OPHTHALMOLOGY

More support for ocular genetics training programmes, and more collaboration with ophthalmologists, are needed to realise the tremendous promise of genetic research to improve ophthalmic care, Alex V Levin MD, Chief of Paediatric Ophthalmology and Ocular Genetics at Wills Eye Hospital, Philadelphia, USA, told the 3rd World Congress of Paediatric Ophthalmology and Strabismus in Barcelona.

Dr Levin noted that the first examples of many categories of genetic disorders have ocular manifestations. These include piebaldism, the first autosomal dominant disorder described, and red-green colour blindness, the first X-linked recessive disorder other than haemophilia.

“Eye genetics rules. We are the first in so many areas. Why?” Dr Levin asked.

It may be that genetic variations are more easily observed in the transparent tissues of the eye than in other organs. For example, lyonization, in which heterozygous X-linked genes are randomly expressed in half the cells of females, can conceal a recessive X-linked disease such as ocular albinism in most body parts. But it appears as a mud-splattered pattern on the retina, where expression of the recessive gene is skewed, Dr Levin said.

Genetic research is leading to promising treatments for previously incurable disease, Dr Levin said. “When a 12-year-old comes in with retinitis pigmentosa we no longer have to say ‘sorry’, we can say it will be curable within your lifetime.”

But genetic diagnosis and counselling requires tremendous expertise and exhaustive effort tracing family histories and genetic tests – resources commonly available only in academic settings. More training programmes are needed to expand the supply of ocular geneticists, which currently stands at about 70 worldwide, Dr Levin said.