Vision Vitreous

An unusual condition that has been tentatively ascribed to clomiphene is persistence of the hyperplastic primary vitreous, that is fetal ophthalmic tissue that normally resolves before birth. If more than a trace of the material persists, ocular complications, including cataract and retinal detachment, can result. In a case reported from Canada, there had been an estimated 3 weeks of exposure to high doses of clomiphene (100 mg/day) after gestation, and the child s vision was severely impaired (20). This is probably not a mere chance association, since several cases of visual defects of various types after exposure to clomiphene have been described before, and in some animal studies the drug does adversely affect ocular development. 

The drug is slowly cleared from vitreous with a half-life of approximately 55 hours in humans and is subsequently cleared from the retina. Measurable concentrations of drug are not detected in the systemic circulation following intravitreal administration. Immediate therapy of CMV retinitis with fomivirsen was more effective in delaying progression than deferred treatment in a recent clinical trial. Concurrent systemic anti-CMV therapy is recommended to protect against extraocular and contralateral retinal CMV disease. Potential side effects include iritis and vitreitis as well as increased intraocular pressure and changes in vision. An interval of at least 2-4 weeks is recommended between cidofovir administration and use of fomivirsen because of the risk of ocular inflammation. 

When cataracts necessitate lens removal to restore vision, the kinetics between aqueous and vitreous humor change. A major barrier to molecular transport is removed, and more rapid exchange can occur between aqueous and vitreous contents and various ocular components. In one experimental study the concentration of a topically applied anti-inflammatory agent, flurbiprofen, was increased in retinal tissues, vitreous humor, and choroid after lens removal. 

The Vitrasert has proved to be safe and effective for treatment of CMV retinitis as an adjimct to continued systemic therapy. Although use of the Vitrasert is relatively safe, it is not free of complications. Adverse events can occur in 10% to 20% of patients and can result in significant loss of vision. Acute and long-term complications associated with the Vitrasert or its surgical procedure include retinal detachment, vitreous hemorrhage, and endophthalmitis. 

Intermediate uveitis tends to affect younger patients, ranging from their teens to early forties. The most common presentation involves vague complaints of blurry vision and persistent floaters, with a slow insidious onset. Pain and photophobia are imcommon symptoms. Whereas the signs of anterior uveitis are primarily seen in the aqueous and iris, the diagnosis of intermediate uveitis typically involves evaluation of the vitreous and peripheral retina. Bilateral involvement at initial presentation is near 80%, and approximately one-third of unilateral cases ultimately become bilateral. Intermediate uveitis has been reported... 

Clinical features of ARN must include (1) focal well-demarcated areas of retinal necrosis located in the retinal periphery, (2) rapid circumferential progression of necrosis, (3) evidence of occlusive vasculitis, and (4) moderate to severe anterior chamber and vitreal inflammation. Mild presentations may manifest low-grade anterior chamber inflammation with or without blurred vision, whereas severe cases may include episcleritis, scleritis, and pain on eye movement. Early clinical findings include anterior and posterior uveitis, keratic precipitates, and presence of vitreous cells. Within several days to weeks, the patient develops dramatic progressive retinal whitening in multifocal and confluent patches, vasculitis of both retinal arteries and veins, and possible optic nerve head... 

Factors that mimic glaucomatous visual field loss include branch retinal artery occlusion chorioretinal scars retinal areas treated by photocoagulafion or cryotherapy demyelin-afing disorders cerebrovascular accidents, tumors, or other lesions affecting the optic nerve, chiasm, optic tract, optic radiation, ancPor the remaining course of nerve fibers to the occipital cortex. Other abnormalities that could account for pseudo-glaucomatous visual field defects or vision loss include vitreous hemorrhage, proliferative retinopathy or other retinal disorders. 

A 39-year-old woman complained of increasing pain and complete loss of vision in the left eye 1 month after insertion of a ganciclovir implant. The eye was enucleated and pathological examination showed a vitreous abscess the implant suture tab was intrascleraUy located. 

Severe retinal hemorrhage with a slowly reversible loss of visual acuity, and massive vitreous hemorrhage recurring after further G-CSF treatment and resulting in irreversible loss of vision in the affected eye have each been reported in single patients (SEDA-21, 378) (SEDA-22, 408). Concomitant hyperleukocytosis was suggested as a possible cause in the first patient, whereas G-CSF-induced reactivation of primary ocular inflammation (probably infectious in origin) was advanced as an explanation in the second case. 

Vision has been called the vital sign of the eye. Normal visual acuity implies intact light transmission through the optic system (cornea, lens, and vitreous humor) to the retina (the light sensing organ). The retina converts the light into nerve impulses which are sent to the occipital cortex via the optic tracts. Abnormalities in any of these components may diminish visual acuity or produce blindness. 

HeierJS +, Ophthalmology I 13(4), 642 (2006) Rosenfeld PJ +, Ophthalmology I 13(4), 632 Maculopathy Ocular pain Ocular pruritus Ocular xerosis Retinal vein occlusion (2006) HeierJS +, Ophthalmology I 13(4), 642 Subretinal fibrosis Vision blurred Visual disturbances Vitreous floaters... 

In another trial, triamcinolone acetonide was injected into the vitreous cavity of 14 eyes within six weeks of PDT (53). Eleven received one initial combined treatment and three received an additional combined treatment after six months. Median follow-up was 18 months (range 12-25 months). Overall, 7% gained 30 or more letters, 50% maintained stable vision, 14% lost 15-29 letters, and 29% lost 30 or more letters. The mean number of PDT treatments during the first year was 2.57. Side effects were mild and included IOP elevation in 28.5% and cataract progression in 50% of phakic eyes. 

Some other uncommon complications include macular edema, vitreous hemorrhage, hypotony, cataract (Fig. 6), temporary reduced vision secondary to astigmatism, implant malposition, and retinal detachment, which is more likely if the CMV infection involves over 25% of the retina (100). Lim and colleagues evaluated a series of 110 ganciclovir implant procedures and noted posterior segment complications in 12% (111). Some of these eyes had undergone multiple prior implant procedures and... 

The typical presenting complaints of endophthalmitis are pain, decreased vision, and conjunctival hyperemia (1). The earliest findings are periphlebitis accompanied by anterior chamber reaction and vitreous cellular debris (2). In the typical case, the vitreous is too opaque to view retinal detail. Hypopyon is considered the hallmark of an infection although severe sterile inflammation may cause hypopyon in some instances. Wound abnormalities are commonly noted in endophthalmitis cases. Lid edema is a frequent finding. 

Severe visual impairment. Large dark spot at or near center of vision. Large floating objects in eye. May see blood. External exam normal. Internal exam foveal retinal lesion(s) that may be obscured by vitreous hemorrhage. Foveal retinal burn, with vitreous or subretinal hemorrhage (Visible or near-infrared laser, high dose). Evacuate. Needs physician/PA evaluation. ... 

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