Congenital CMV on newborn screening: eye findings only in symptomatic infants

Design

Population-based retrospective review of a screening programme

Population

394 infants screen-positive for congenital CMV in Ontario, 347 examined

Primary outcome

CMV-related ophthalmic findings

Effect

2/347 (0.58%), both symptomatic; 0 in asymptomatic infants

Ontario screens newborn dried blood spots for congenital CMV. This Pediatrics study reviewed eye examinations for the 394 infants who screened positive between July 2019 and January 2022; 347 (88%) were examined, of whom 51 had symptomatic infection.

Only two infants had CMV-related eye findings — unilateral chorioretinal scars — both with symptomatic infection and both already referred to ophthalmology because of obvious systemic disease before screening results were known. That is 0.58% of all screen-positive infants and 3.9% of symptomatic ones. No asymptomatic infant had a CMV-related eye finding.

Consensus guidelines recommend an eye examination for every infant with congenital CMV, and that guidance has not changed. As screening expands, however, these data support a conversation about whether examinations can be prioritised for symptomatic infants. Hearing follow-up, which matters most in asymptomatic infection, is a separate question this study does not address.

• Refer every infant with symptomatic congenital CMV for prompt ophthalmology review.
• Continue to follow current guidance on eye examination for asymptomatic infants pending any revision.
• Do not let eye-examination workload displace audiology follow-up, which matters for all CMV-positive infants.
• Units planning CMV screening programmes can use these data to plan ophthalmology capacity.

Why it matters

Universal CMV screening multiplies referrals, and this shows where the eye findings actually are.

Don't overread it

Guidelines still recommend eye examination for all infants with congenital CMV; one population cohort is not a reason to stop.

The statistics, in plain English

Zero findings in about 296 asymptomatic infants examined suggests the true rate is low — roughly below 1% by the usual rule of three — but not that it is zero.

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