Biomedical subjects
Publications and source records attributed to J Chess.
Ocular melanosis is usually diffuse but may be sectoral. An unusual case of isolated unilateral hemispheric choroidal melanosis is presented in a patient with uveitis. Details of the embryologic basis for this condition remain speculative.
Proposed mechanisms for rhegmatogenous retinal detachment after branch retinal vein occlusion (BRVO) include hole development from preexisting retinal cysts and vitreoretinal traction secondary to retinal neovascularization. Damage caused by choriocapillary obstruction may also occur in some of the retinal breaks. Vitreoretinal traction without associated retinal neovascularization has not been previously emphasized as a pathogenetic mechanism. We document both iatrogenic and idiopathic vitreoretinal traction as causes of rhegmatogenous retinal detachment in ischemic retina after BRVO. A literature review of the role of retinal traction with and without associated neovascularization in the development of retinal tears after BRVO is included.
The acute retinal necrosis (ARN) syndrome has recently been associated with intraocular infections with one or more members of the herpesvirus family. There have been 14 cases in the literature linking ARN with a preceding or subsequent herpetic dermatitis. We report the development of bilateral ARN (BARN) after unilateral Herpes zoster ophthalmicus as the presenting sign of acquired immunodeficiency syndrome (AIDS) in a previously healthy man. The development of BARN after diffuse Herpes simplex dermatitis in AIDS patients is also discussed. These cases further illustrate the central role of the herpes-virus family in the etiology of ARN and alert the clinician to a new presenting sign for AIDS.
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Fibrinogen was injected in the vitreous cavity of 29 rabbits with follow-up for 75 days. Vitreous membrane formation was detected by indirect ophthalmoscopy and confirmed by histopathological study. Membrane formation was significantly more common in the fibrinogen group than in the control group. Fifteen days after injection, the membranes decreased in size and gave place to vitreous liquefaction in the majority of eyes in the fibrinogen group. Histochemical stains for fibrinogen were positive in half of the vitreous membranes. Fibrinogen is thought to be transformed into a long fibrin polymer forming a matrix for surrounding cells to proliferate in the vitreous. An effective fibrinolytic system in the vitreous explains the ultimate resolution of most of the fibrinogen-induced membranes. Simple fibrinogen injections do not provide a good model for long-term vitreous band formation, yet they add more evidence to the role of fibrin in the pathogenesis of vitreoproliferative diseases. The spontaneous resolution of some proliferative vitreoretinopathies parallels the reversibility of most of the fibrinogen-induced vitreous membranes.
Bare lymphocyte syndrome (BLS) is a rare, severe combined immunodeficiency characterized by lack of expression of HLA A, B and C antigens and the absence of B2 microglobulins. Patients with BLS exhibit functional deficiency of both T and B cells resulting in bacterial as well as viral and fungal infection. Ophthalmic findings in this group of disorders have not been reported. We present a case of candida retinitis in a terminally ill 5-year-old girl with BLS.
Ghost cell glaucoma (GCG) has recently been described following vitrectomy, cataract extraction, and penetrating or blunt trauma. We describe the occurrence of GCG in a phakic eye with no prior ocular trauma or surgery following vitreous hemorrhage from diabetic retinopathy. We postulate the occurrence of a spontaneous rupture of the anterior hyaloid face which allowed passage of ghost cells into the anterior chamber. A therapeutic vitrectomy was complicated by intraoperative vitreous hemorrhage. Two weeks postvitrectomy, GCG recurred and was successfully controlled by irrigation through an anterior chamber approach. This is the procedure of choice in GCG following vitrectomy and may eliminate the need for a second vitrectomy.
Four patients underwent cataract extraction with implantation of intraocular lenses. Preoperative ultrasonography did not include a comprehensive diagnostic B-scan analysis. Postoperative examination revealed uveal melanomas. The clinical presentations as well as the histopathologic findings of the two enucleated eyes are discussed. These cases emphasize the necessity for B-scan ultrasonography prior to cataract surgery when media opacity prevents adequate visualization of the fundus.
The clinicopathologic findings in 17 eyes which were surgically enucleated or removed at autopsy as well as the histopathology of 72 corneal buttons removed from eyes with intraocular lenses are described. In four of five autopsy eyes the intraocular lens was well tolerated; however, in all cases, changes related to the pseudophakos were found. In seven of 12 surgically enucleated eyes, postsurgical bacterial or fungal endophthalmitis had developed. On histopathological examination, one eye revealed clinically unsuspected endophthalmitis phacoanaphylactica after extracapsular cataract extraction and intraocular lens implantation. In two cases, choroidal melanoma became evident after cataract extraction and insertion of a pseudophakos. In both cases preoperative ultrasonography was limited to A-scan axial measurements. The 72 corneal buttons were removed from patients with pseudophakic bullous keratopathy; histologically the most striking findings were guttata-like changes in 50% of the specimens and retrocorneal membranes in 13.9% of the specimens.