Retinal Sequelae in Adults Treated With Cryotherapy for Retinopathy of Prematurity

Cryotherapy, introduced in the mid-1980s, was the first treatment of severe retinopathy of prematurity (ROP) and resulted in ablation of larger retinal areas than did its later substitute, laser treatment. We defined the characteristics of the retinal structure and assessed visual function, in adult ex-preterms treated with cryotherapy.

A total of 28 ex-preterms, included in a prospective study of infants born in Stockholm between September 1988 and March 1993, were treated with cryotherapy because of severe ROP. Of these individuals, 14 took part in this follow-up study and underwent ophthalmologic assessment including visual acuity, fundus photography, perimetry, and retinal imaging using optical coherence tomography (OCT) in their third decade of life. Their gestational ages were 24 to 28 (median 25) weeks at birth.

The ex-preterms had reduced foveal depth (P < 0.0001) and increased thickness of the temporal retinal nerve fiber layer (RNFL; P > 0.001). A thicker temporal RNFL was not correlated with a thicker ganglion cell layer (P = 0.41, r = 0.29) as in controls (P = 0.0015, r = 0.78). Extreme thickening was seen in patients with pronounced retinal dragging.

In their third decade of life, ex-preterm adults treated with cryotherapy for ROP have major microstructural retinal abnormalities in terms of reduced foveal depth and an altered distribution of the peripapillary RNFL. The main contributors seem to be gestational age and ROP rather than the cryotherapy. The possibility to evaluate the retinal structure in these individuals, with today's conventional OCT, is limited by those anatomic deviations.