Supplemental oxygen therapy in infants with prethreshold ROP was studied to determine the safety and efficacy of this intervention. The use of supplemental oxygen to maintain pulse oximetry saturations between 96% and 99% did not cause additional progression of prethreshold ROP. It also did not significantly reduce the number of infants requiring peripheral ablative surgery. A subgroup analysis suggested supplemental oxygen was beneficial to infants who had prethreshold ROP without plus disease; however, this finding was not statistically significant.
The AAP recommends surgical intervention when ROP reaches prethreshold. Cryotherapy and laser photocoagulation are two surgical interventions used to treat severe ROP. The goal of surgical intervention is to prevent progression of the disease, retinal detachment, and minimize vision loss. Both methods work on the principle of ablating areas of avascularized retina, thereby decreasing the production of angiogenic factors.
Cryotherapy was developed in the 1960s and 1970s and became widely used in the 1980s after the Cryotherapy for Retinopathy of Prematurity Study. This cryotherapy study was terminated early because of a significant benefit in the treated eyes. Cryotherapy uses a probe cooled with liquid nitrogen. The probe is inserted on the medial aspect of the eye through the dilated pupil. Sequential portions of the avascularized retina are frozen, arresting further proliferation. Infants treated with cryotherapy run the risk of retinal detachments from the scars created by the treatment, as well as macular coloboma-like lesions.[22,23] Long-term studies, 10 years after treatment, showed that eyes treated with cryotherapy had a decreased chance of blindness compared with untreated eyes.[24,25]
Laser photocoagulation uses an argon or diode laser to ablate areas of avascularized retina. With the development of the indirect laser ophthalmoscope, laser photocoagulation is replacing cryotherapy. The argon and diode lasers produce partial thickness chorioretinal scars without damage to the sclera and conjunctiva. Infants treated with lasers have a small risk of developing cataracts in treated eyes.
The risks/benefits of cryotherapy and laser photocoagulation have been studied. Both methods of treatment carry an increased incidence of myopia and decreased peripheral vision. This is thought to be related to preservation of the eye's structure, which would lead to retinal detachment without treatment. A 10-year follow-up of cryotherapy versus laser treatment found laser-treated eyes were less myopic and had better functional and structural outcomes.[27,28,29] Laser photocoagulation appears to be less stressful to the infant than cryotherapy. Although laser treatment was initially found to be at least as effective as cryotherapy in the treatment of ROP, it has proved to be more cost effective. Currently, laser photocoagulation is the surgical intervention of choice because of cost-effectiveness, ease of therapy, and improved visual outcomes compared with cryotherapy.[27,28,31,32,33]
NAINR. 2003;3(3) © 2003 W.B. Saunders
Cite this: Does My Child Really Need to Wear These Glasses? A Review of Retinopathy of Prematurity and Long-Term Outcomes - Medscape - Sep 01, 2003.