ROP surgery and ocular circulation

Visual results following vitreoretinal surgery for stages 4 and 5 retinopathy of prematurity are often disappointing, even when anatomic results are good. This poses the question whether the surgery or the post-operative care causes the optic atrophy. A hypothesis is proposed that ocular perfusion pressure (mean blood pressure minus intraocular pressure) during or after surgery may be too low to provide adequate ocular blood flow.

This report analyses the published results of retinopathy of prematurity surgery, the techniques used, as well as data about blood pressure and intraocular pressure in premature infants.

Mean blood pressure in conscious premature infants is low and labile; it falls further under anaesthesia. Pre-operative intraocular pressure in retinopathy of prematurity patients is unknown, but intraocular pressure during vitrectomy is elevated, and likely elevated postoperatively.

Conditions during and after vitreoretinal surgery for retinopathy of prematurity are conducive to low ocular perfusion pressure and consequent ischaemia of the retina and optic nerve, which can contribute to poor visual results. Improved monitoring and control of ocular perfusion pressure is warranted.