Radiation retinopathy is a potentially severe complication of radiation therapy for orbital disease. Findings range from intraretinal hemorrhages, cotton-wool spots, and macular edema (nonproliferative radiation retinopathy) to extensive retinal capillary ischemia leading to neovascularization and vitreous hemorrhage (proliferative radiation retinopathy). Kinyoun et al1 reported that eyes with proliferative radiation retinopathy had poor visual prognosis despite treatment with panretinal photocoagulation. We report a case of a man with proliferative radiation retinopathy treated with laser therapy who retained excellent vision for 5 years.
A 39-year-old man with a history of pineoblastoma had decreased vision in his left eye. The patient received 45 Gy of external beam irradiation in November 1992 (dose fraction, 1.8 Gy; 25 treatments in 36 days). Seventeen months later an examination revealed visual acuities of 20/25 OD and 20/40 OS, nonproliferative radiation retinopathy in the right eye, and neovascularization with vitreous hemorrhage and clinically significant macular edema confirmed by contact lens examination in the left eye. Fluorescein angiogram of the left eye demonstrated severe capillary nonperfusion and diffuse cystoid macular edema (Figure 1, A and B). The patient received grid laser treatment and panretinal photocoagulation in the left eye (Figure 1, C). He required a pars plana vitrectomy for nonclearing vitreous hemorrhage. Visual acuity improved to 20/25 OU with resolution of the macular edema and vitreous hemorrhage. The patient has had no recurrence of proliferative radiation retinopathy or macular edema in the left eye (Figure 2), and his visual acuity after cataract extraction 1 year later has remained stable at 20/20 OU for 3 years. A fluorescein angiogram performed 47 months after development of proliferative radiation retinopathy demonstrated intact foveal capillaries and no retinovascular leakage in the left eye. Early proliferative radiation retinopathy was present in the right eye.
A, Venous phase fluorescein angiogram of the left eye demonstrating extensive capillary nonperfusion. B, Late-phase angiogram of same eye shows diffuse macular edema. C, Color fundus photograph of the same eye after grid and panretinal photocoagulation laser treatment showing vitreous hemorrhage.
A, Venous phase fluorescein angiogram of the left eye 5 years after first visit with proliferative radiation retinopathy. B, Perifoveal capillaries are patent and macular edema is not evident in the late phase of the angiogram. C, Color fundus photograph of the left eye at 5-year follow-up showing grid and panretinal photocoagulation laser and without evidence of active proliferative radiation retinopathy or macular edema.
Head and neck irradiation can cause ophthalmic complications including cataracts, optic neuropathy, and radiation retinopathy.1 Radiation retinopathy has been reported in radiation doses as low as 11 Gy, but is infrequent below the dose of 45 Gy.2,3 Our patient received 45 Gy of irradiation. While visual prognosis in patients receiving laser therapy for radiation-induced macular edema is favorable, poor visual outcome is reported for patients treated for proliferative radiation retinopathy, presumably due to severe capillary nonperfusion and ischemia of the macula.4
Kinyoun et al1 documented that panretinal photocoagulation halted new vessel formation in eyes with proliferative radiation retinopathy; however, 86% of patients developed visual acuities less than 20/200 OU and no eyes had visual acuity better than 20/50 OU after a mean follow-up time of 75 months. Ninety-three percent of their patients with proliferative radiation retinopathy also had optic neuropathy, 86% had macular edema, and 100% had macular ischemia.1 Our patient, who had no signs of optic neuropathy, had regression of neovascularization, resolution of macular edema and capillary nonperfusion, and restoration of a visual acuity of 20/20 OU after laser therapy.
We agree that patients receiving head and neck irradiation need to be screened for radiation retinopathy. However, it is possible that proliferative radiation retinopathy itself does not confer a poor visual prognosis if other irreversible forms of vision loss such as optic neuropathy and macular ischemia are not present. Indeed, early detection of proliferative radiation retinopathy and treatment with laser may improve visual acuity.
Corresponding author: Albert M. Maguire, MD, Scheie Eye Institute, 51 N 39th St, Philadelphia, PA 19104.
Thorne JE, Maguire AM. Good Visual Outcome Following Laser Therapy for Proliferative Radiation Retinopathy. Arch Ophthalmol. 1999;117(1):123-124. doi: