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Snow Blindness

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Snow Blindness Photokeratitis- `welder's flash' or `snow blindness'. The greatest retinal exposure to blue light UV occurs outside standing/walking in a field of snow without eye protection= exposure to levels exceeding occupational exposure limits. Failure to wear ski goggles can result in several effects upon the eye, sometimes loosely referred to as `snow-blindness'. Unusually intense reflection of light and UVR from the snow. * Fresh snow reflects 85% of the UVR compared to only * 1 or 2% from grass. * Goggles with side-shields, or a closely fitting wrap-around design, the specification of 99% or 100% UV blocking. * UV light can enter the eye from the sides and also by reflecting off the edges of the sunglasses. Therefore, side shields and overhead protection are critical and can be provided with wrap-around sunglasses or goggles. * Polarising sunglasses protect against excessive glare. Prevention of UV exposure Protection: * broad-brimmed hat or visor can help shield the eyes from both visible and invisible light * The eyelids, the same as the skin elsewhere on the body, should be protected by use of a sunscreen. * UV-absorbing spectacles. Large frames and wraparound designs offer the greatest protection to both the eyes and the eyelids. UV-absorbing contact lenses are available from a number of lens manufacturers and are preferred to non-UVabsorbing materials in individuals who spend a lot of time outdoors. ...read more.


Ophthalmic oncologists use high frequency ultrasound to diagnose and follow iris tumors for evidence of growth. Characteristics which suggest that an iris tumor is cancerous include seeing blood vessels within the tumor, evidence that the pupil is deformed, and the development of a cataract beneath the tumor. Tapioca-colored iris tumor has pulled the iris pigment epithelium out onto the surface of the iris stroma. The most important finding is documented growth. Since iris melanomas are commonly small, and rarely (1-5%) spread to other parts of the body, these tumors are usually watched for evidence of growth before treatment is considered. Treatment: Most pigmented iris tumors do not grow. They are photographed and monitored with periodic observation. When an iris melanoma is documented to grow, we know that it can damage the eye (usually cause glaucoma). Then, treatment (despite its risks) becomes more reasonable. Small melanomas: Most small iris melanomas can be surgically removed. Medium-sized melanomas: Large iris resections are possible, but plaque radiotherapy may be considered for these tumors. A cataract is likely to develop, but since the radiation plaque is far from the central retina, vision limiting radiation retinopathy is unlikely. Large-sized melanomas: These cases can be difficult to treat with eye-sparing therapies. Many of these tumors cause untreatable glaucoma and may require removal of the eye. Squamous cell carcinoma A cancer that develops from squamous cells found in the skin that covers the outside and lines the inside of the body * Second most common malignant eyelid neoplasm in the United States, after basal cell carcinoma. ...read more.


along the surface and an atrophied inner portion, creating a "pearly," indurated outer margin with an excavated center; and 3. Less frequently, the sclerosing or morpheaform basal cell carcinoma form, which has a firm, pale, waxy yellow plaque with indistinct borders. There is no single known cause for all forms. There is a distinct association with increasing age and exposure to UV radiation. Caucasians have a much greater chance of developing basal cell carcinoma than other races. Progression of this tumor is, in most cases, exceedingly slow. Left untreated the lesion may in time invade deeper structures. Fortunately, metastasis is rare, and complete recovery is possible with proper therapy. Basal cell carcinoma can be treated with * surgical excision, * radiation therapy or * chemotherapy. The preferred course for most cases is surgery, with broad margins to ensure complete removal. Local radiation therapy and/or systemic chemotherapy can manage basal cell carcinoma when surgery is intolerable or refused by the patient. Both of these modalities carry significant side effects, however, and neither is as effective as surgical intervention. * Basal cell carcinoma is rarely life-threatening because of its non-metastatic, slow-growing nature. However, this tumor does possess the capacity, over time, to cause significant local destruction, and must always be treated appropriately. * Early biopsy is often the key to diagnosis. Biopsy all suspicious lid lesions which demonstrate irregular growth, changes in color or appearance, or purulent or bloody discharge to rule out cancer. You should refer confirmed malignancies promptly to an oculoplastics specialist or, if possible, an ocular oncologist. ...read more.

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