Diode laser photocoagulation for retinopathy of prematurity: a histopathologic study

Laser photocoagulation has largely supplanted cryotherapy as an effective treatment for retinopathy of prematurity. This case describes the ocular histopathologic findings of a pair of eyes in a severely premature male infant treated with diode laser photocoagulation for bilateral stage 3 retinopathy of prematurity (ROP) for 360 degrees in zone 1 with severe plus disease. The right eye responded to treatment; the left eye developed persistent vitreous hemorrhage and total retinal detachment. The histopathologic examination of laser burns in the right eye disclosed segmental areas of chorioretinal scarring with retinal atrophy and gliosis, loss of RPE and extensive atrophy of the choroid and its vasculature, which involved both the choriocapillaris and larger vessels. The left eye had iris neovascularization, a chronic organized vitreous hemorrhage and a totally detached retina. The histopathologic findings in an eye of a premature infant with threshold ROP treated with diode laser photocoagulation resembled those reported after transsceral cryotherapy. Diode laser photocoagulation may produce less severe chorioretinal damage.