Sulfur mustard exposure and non-ischemic central retinal vein occlusion

A 41-year-old man was referred with a complaint of visual loss in his left eye and his best corrected visual acuity was 20/80. Slit lamp examination showed arborizing conjunctival vessels and dry eye. Fundus examination and fluorescein angiography revealed a non-ischemic central retinal vein occlusion. Cardiovascular, rheumatologic, and hematologic work up showed no abnormal findings. An ascertained history of exposure to sulfur mustard during the Iran-Iraq war was documented in his medical history. Four sessions of intravitreal bevacizumab injections were done as needed. After two-year follow-up, visual acuity in his left eye improved to 20/25 and macular edema was resolved without any need for further interventions. We conclude that sulfur mustard gas exposure may be considered as a predisposing factor for central retinal vein occlusion, as was found in our patient [an Iranian war veteran] by excluding all yet known etiologies and predisposing factors

Bilateral Macular Hole Following Myopic Photorefractive Keratectomy

A 42-year-old man was admitted to our clinic complaining of visual distortion in his left eye two months after bilateral myopic photorefractive keratectomy (PRK). Macular optical coherence tomography (OCT) showed a stage II macular hole in the left eye. Simultaneous OCT in the right eye showed vitreous traction and distortion of the outer retina. One month later, the patient underwent vitrectomy for the left eye, and the macular hole was closed. Two months after that, the patient complained of visual distortion in the right eye, and OCT revealed increased traction and accentuated outer retinal distortion indicating a stage IB macular hole. Traction attenuated later without any intervention. The short interval between PRK and hole formation, bilateral involvement, and the moderate refractive error in this case highlight the possible role of PRK in aggravating vitreoretinal interface abnormalities. We recommend the addition of PRK to the list of procedures that may be associated with the formation of a macular hole.

Pattern visual evoked potentials in patients with type II diabetes mellitus

To evaluate cortical and retinal activity by pattern visual evoked potentials [PVEP] in patients with type II diabetes mellitus. PVEP was recorded in 40 diabetic patients including 20 subjects with nonproliferative diabetic retinopathy [NPDR] and 20 others without any retinopathy on fundus photography, and compared to 40 age- and sex-matched normal non-diabetic controls. P100 wave latency was significantly longer in diabetic patients as compared to normal controls [P<0.001]; both diabetic subjects without retinopathy and those with NPDR had significantly longer P100 latency than controls [P<0.001 for both comparisons]. There was significant reduction in N75 [P=0.037] and P100 [P=0.001] amplitudes in diabetic subjects. No correlation was observed between VEP amplitude or wave latency, and the level of glycemia or duration of diabetes mellitus. Increased PVEP latency may be a sign of retinal ganglion cell damage which takes place before the appearance of the first ophthalmoscopically detectable signs of diabetic retinopathy. PVEP may be considered as a method for detecting prediabetic retinopathy and has the potential to reduce diabetic complications.