A 23-year-old female was accidentally exposed to a Q-switched Nd:YAG laser operating at 1064 nm in October 2002. The laser fired inadvertently while the patient was adjusting target without the use of her protective goggles. Immediately after the exposure, she experienced a bright flash of light followed by a sudden loss of vision in her right eye. Pulse duration and energy density were not assessed. Her best-corrected visual acuity was 20/100 OD and 20/20 OS. The Amsler grid revealed metamorphopsia and central scotoma. Intraocular pressure and anterior segment biomicroscopy were unremarkable bilaterally. Fundoscopic examination of the right eye revealed a macular laser burn and vitreous hemorrhage (Fig. 1). Corticosteroids, in the form of 60 mg prednisolone, were administered orally with a 10 mg per week taper. The following day, her visual acuity remained 20/100 OD, and fluorescein angiography revealed a round area of hypofluorescence with early and late macular hyperfluorescence (Fig. 2a). Two days later, there was no hyperfluorescence on indocyanine green angiography (Fig. 2b).

Nineteen days following the exposure, visual acuity remained at 20/100 OD and fundoscopic examination revealed a small amount of vitreous hemorrhage and a distinct epiretinal membrane (Fig. 3). Seven weeks later, the epiretinal membrane had extended and the retinal folds became more prominent, though there was no change in visual acuity. Six months later, the patient continued to have a visual acuity of 20/100 OD and fundoscopic examination at that time revealed spontaneous regression of the epiretinal membrane and a prominent chorioretinal scar with central pigmentation at the site of injury (Fig. 4). Visual acuity assessment and fundoscipic photography were performed at three month intervals, but did not reveal significant changes. Six years later, the patient's visual acuity remained at 20/100 OD and fundoscopic examination demonstrated the continued presence of a chorioretinal scar with more prominent central pigmentation compared to previous visits (Fig. 5). At six years follow-up, there was neither choroidal neovascularization nor macular hole formation.

Q-switched Nd:YAG laser injuries result in disruption of the choriocapillaris, Bruch's membrane, and the retinal pigment epithelium. The presence of subretinal and vitreous blood suggests that the major site of injury is the choriocapillaris. Previous cases of accidental Nd: YAG laser injuries include several common features such as retinal and vitreous hemorrhage.4,5

Here, we describe a case of Nd: YAG laser injury with six year follow-up. The exposure resulted in the presence of vitreous hemorrhage, which likely acts as a stimulant for fibroglial proliferation, resulting in an epiretinal membrane. The ensuing retinopathy is based on the development of a contractile membrane on either the internal or external surface of the retina. In the present case, the membrane formed externally. A previous report described the presence of striae resulting from contraction of the laser scar in lieu of a membrane.3 At 20 months follow-up, our patient demonstrated spontaneous regression of the epiretinal membrane by slit lamp ophthalmoscopy using a 78D lens rather than by optical coherence tomography. In contrast to previously reported cases,4-7 the best corrected visual acuity failed to recover, even after spontaneous resolution of the epiretinal membrane. In addition, the patient did not experience macular hole or cyst formation, though they are common findings in Nd: YAG laser injuries.4-7 Furthermore, we were unable to identify any choroidal neovascularization within the 6 year follow-up period, which is known to occur by intense laser photocoagulation breaking the retinal pigment epithelium-Bruch's membrane-choroid complex.8

A systemic corticosteroid was administered orally in an attempt to decrease the extent of injury by reducing the cellular response. Corticosteroids remain the most widely employed treatment for laser injuries.9

Laser devices are playing an increasingly large role in modern industry, research and medicine. This has led to a concomitant increase in laser-induced injuries, particularly ocular injuries as energy focuses on the retina. Gabel et al.10 have reported cases of unnoticed laser burns on routine eye examination in workers using laser devices. Further research is required to better define the mechanisms of tissue damage and improve existing therapy and protection to meet the demands of the increasing threat due to expanding laser application.