Prematurity and Vision

Friday 3 March 2006

Retinopathy of Prematurity

Brian Fleck
Elizabeth Wright

Quality of Life

• 244 infants who had severe retinopathy of prematurity as newborns
• Families interviewed at age 10 years
• Health Utility Index
• 0=dead
• 1=perfect health
• Sighted Median Score 0.87
• Blind/low vision Median score 0.27
• Blind/low vision 29% had a score < 0

History

• Uncontrolled oxygen in 1940s and 50s = epidemic of retrolental fibroplasia;
• Research in 1950s = low oxygen, low ROP, high mortality;
• Increased survival in 1980s = resurgence of ROP;
• Treatment ROP in 1990s

Current working understanding

• Early poor retinal blood vessel growth;
• Part of the retina ends up with no blood vessels;
• Increased demands of the growing retina;
• Abnormal blood vessel growth which leads to scar tissue;
• Scar tissue shrinks - Retinal detachment.

How are the infants examined?

How is treatment performed?

Looking to the future

• Can neonatologists prevent ROP?
• They think they can in Los Angeles!
• They have tried to in North East England
• Planned study of oxygen treatment

Causes of Visual Impairment in Children

• Cerebral Visual Impairment (CVI)
• Retinopathy of Prematurity
• Other diseases

Cerebral Visual Impairment - Context

• "Iatrogenic" – Often follows survival of infants who have received high quality neonatal care, who in other settings might have died.
• Hypoxic – Ischaemic Encephalopathy
• Prematurity (Incidence increasing)
• Brain Visual Impairment is associated with multiple handicap, unlike Eye Visual Impairment.
• Development and Education strategies DIFFERENT in BVI and EVI.
• Costs to society are x4 – x8 greater for BVI
• More likely to require long term financial and living support.

Cerebral Visual Impairment

• Hypoxic Ischaemic Encephalopathy (eg; "Birth Asphyxia")
• Cerebral Palsy of all 4 limbs
• Variable visual impairment
• Vision often improves during early years.

Cerebral Visual Impairment in Premature Infants

• Vision does NOT improve with time
• Crowding effects
• Difficulties with eye movements – nystagmus, strabismus
• MRI scan – Periventricular Leucomalacia (PVL)
• Pattern of injury DIFFERENT in premature than in full term infants.