Biomedical subjects

R L Font

Publications and source records attributed to R L Font.

At least 37 records · Page 2Linked to original sources

PubMed1997

Detection of varicella-zoster virus DNA in keratectomy specimens by use of the polymerase chain reaction.

OBJECTIVE: To study the correlation of clinical findings, histopathologic features, and detection of varicella-zoster virus (VZV) DNA in keratectomy specimens. MATERIALS AND METHODS: Fourteen corneal buttons from patients with a confirmed history of herpes zoster ophthalmicus were examined by use of light microscopy and the polymerase chain reaction. The polymerase chain reaction techniques included gel electrophoresis and hybridization for the detection of VZV DNA. RESULTS: Seven (50%) of the 14 specimens were positive for VZV DNA. The positive findings in the specimens correlated with the clinical findings of uveitis (3/3) and the histopathologic features of chronic stromal keratitis (4/4). Patients with stromal scarring, granulomatous keratitis, and neurotrophic ulcers had negative findings. The largest interval between the initial appearance and detection of viral DNA was 51 years. CONCLUSIONS: The results suggest that VZV DNA is not detectable in the cornea in every patient and at every stage of zoster keratitis. This may be due to the low number of VZV particles present in the cornea or the lack of viral DNA in the keratocytes. It remains unclear whether the VZV-related keratopathy is caused by an immunologic response to a viral antigen, the viable virus itself, or both.

Adolescent↗

PubMed1997

Melanogenic neuroectodermal tumor of the retina (primary malignant melanoma of the retina).

A 35-month-old girl with leukocoria was clinically diagnosed with unilateral sporadic retinoblastoma. Macroscopic examination of her enucleated eye disclosed a white retinal tumor that appeared to be a retinoblastoma. Histopathologic examination, however, revealed that the tumor was composed of poorly differentiated neuroblastic cells, larger spindle-shaped cells, and anaplastic epithelioid cells, which is inconsistent with retinoblastoma. Immunohistochemical testing disclosed that the tumor cells were immunoreactive for melanoma-specific antigen HMB-45, while electron microscopy showed premelanosomes in the tumor cells, both of which are consistent with melanogenesis. To our knowledge, such an ocular tumor has not been reported previously.

Antigens, Neoplasm↗

PubMed1997

Pneumocystis carinii infection of the conjunctiva in a patient with acquired immune deficiency syndrome.

BACKGROUND: Ocular disease, especially the development of choroidal lesions, is a known extrapulmonary manifestation of Pneumocystis carinii infection in the acquired immune deficiency syndrome (AIDS). To our knowledge, conjunctival involvement due to P. carinii has not been described previously. METHODS: The authors describe a 33-year-old homosexual male with AIDS in whom a large placoid, white lesion developed involving the tarsal conjunctiva of the right upper lid. Conjunctival malignancy was suspected and biopsies and swabs were taken. At this time, the patient had been receiving monthly aerosolized pentamidine prophylaxis for 18 months, and there was neither a history of pneumonia nor any clinical signs of disseminated infection due to P. carinii. RESULTS: Histopathologic examination results of the conjunctival biopsy specimen showed a necrotic, frothy tissue surrounded by activated fibroblasts. Within this material, Gomori methenamine silver stains showed numerous round and cup-like cysts of P. carinii, confirming the diagnosis that had already been obtained by an indirect fluorescent-antibody stain of a conjunctival smear specimen. CONCLUSIONS: The presence of white placoid conjunctival lesions in a patient with AIDS may indicate an infection due to P. carinii. Conjunctival disease due to P. carinii widens the spectrum of AIDS-associated ophthalmic pneumocystosis.

AIDS-Related Opportunistic Infections↗

PubMed1997

Lensification of the posterior corneal surface. An unusual proliferation of lens epithelial cells.

BACKGROUND: Abnormal proliferation of lens epithelial cells occurs in a variety of situations, such as anterior and posterior subcapsular cataracts and secondary cataract formation. The purpose of this report is to document an unusual occurrence of diffuse proliferation of lens epithelium and capsule along the posterior corneal surface. METHODS: The authors performed penetrating keratoplasty to remove an edematous and scarred cornea is a 19-year-old Indian man. Three years previously, the patient had undergone penetrating keratoplasty and extracapsular cataract extraction to treat a nonhealing corneal ulcer. The keratectomy specimen was processed for conventional light microscopy. Five-micrometer sections were stained with hematoxylin-eosin and the periodic acid-Schiff methods. RESULTS: Intraoperatively, the eye was found to be aphakic with an intact posterior capsule. The iris tissue consisted of fibrotic, pigmented remnants adherent to the peripheral cornea for 360 degrees, closing the angle and capsular fornix. Histologically, cataractous lens material including proliferated lens epithelial cells and capsule diffusely lined the posterior corneal surface along a thick retrocorneal fibrous membrane. CONCLUSIONS: This case represents a new category of lens epithelial cell proliferation or migration or both that covers entirely the posterior corneal surface. The authors believe the term lensification is appropriate for the condition described herein.

Adult↗

PubMed1997

Unilateral retinoblastoma in an adult: report of a case and review of the literature.

PURPOSE: The authors report the clinical, cytologic, and histopathologic findings of a unilateral retinoblastoma occurring in a 26-year-old woman. This tumor usually affects young children; the mean age at the time of diagnosis usually ranges from 10 to 25 months. METHODS: Histopathologic examination of the enucleated right eye included using standard techniques, as well as immunohistochemical stains of formalin-fixed, paraffin-embedded tissues. RESULTS: Histologic examination of sections of the eye showed a retinal tumor that was centered in the equatorial region and had the typical features of a poorly differentiated retinoblastoma. Focal choroidal invasion and seeding of the anterior and posterior chambers were observed. Immunoreactivity of the tumor cells for neuron-specific enolase confirmed that the tumor is a neuronal neoplasm consistent with retinoblastoma. CONCLUSION: Retinoblastoma occurring in adults is a rare finding. In most large series of retinoblastomas, no adults are included. Only eight patients 20 years of age or older with retinoblastomas have been documented previously. In the current case, the patient had no evidence of orbital recurrence or metastasis 6 years after enucleation of the eye. It may be important for clinicians to consider this diagnosis when confronted with a retinal mass of unknown etiology in adults.

Adult↗

PubMed1997

Congenital malignant teratoid neoplasm of the eye and orbit: a case report and review of the literature.

BACKGROUND: Medulloepithelioma is a tumor of the primitive medullary epithelium overlying the ciliary body. Most become evident early in life, and they may be malignant, although distant metastases are rare. The purpose of this report is to describe a unique case of congenital malignant teratoid neoplasm of the eye and orbit. METHOD: A patient with a congenital malignant teratoid tumor of the eye and orbit is described, and a detailed histopathologic study of the ocular findings with a review of the literature is presented. RESULTS: Histopathologic study showed that the lesion was a malignant teratoid neoplasm with a large orbital extension. Several intracranial structural abnormalities were identified. CONCLUSION: The tumor described herein must be added to the differential diagnosis of congenital orbital masses. The clinician should be alert to the association of this lesion with complex intracranial abnormalities.

Diagnosis, Differential↗

PubMed1997

Orbital granulocytic sarcoma.

AIM: Orbital granulocytic sarcoma is a localised tumour composed of cells of myeloid origin. Histological diagnosis can be difficult in patients with poorly differentiated orbital tumours and no evidence of systemic leukaemia. The naphthol AS-D chloracetate esterase (Leder stain) and immunohistochemical stains for lysozyme and MAC387 were used to determine the staining characteristics of these tumours. A case series of seven patients with orbital granulocytic sarcoma is presented. METHODS: Seven patients with orbital granulocytic sarcoma were studied. Haematoxylin and eosin, Leder, and lysozyme stained sections were available in seven cases. Unstained formalin fixed paraffin embedded sections of seven cases were available for immunohistochemical evaluation using the avidin-biotin-complex technique for MAC387. RESULTS: The mean age of presentation of the orbital tumour was 8.8 years. Four patients presented with an orbital tumour before any systemic manifestations of leukaemia. In two cases the diagnosis of the orbital tumour and systemic leukaemia was made simultaneously. There was one case of established systemic myeloid leukaemia in remission with the subsequent development of orbital granulocytic sarcoma. Six of seven cases (86%) were positive for the Leder stain. Five of seven cases (71%) showed positive immunoreactivity with lysozyme. The immunohistochemical stain for MAC387 was positive in all seven cases (100%) including one case that was negative for both lysozyme and Leder stains. CONCLUSIONS: Orbital granulocytic sarcoma is a tumour that affects children and can present with rapidly progressive proptosis. This tumour may develop before, during, or after the occurrence of systemic leukaemia. The combination of Leder and lysozyme stains is useful in the diagnosis of orbital granulocytic sarcoma. MAC387 may be a more reliable marker for orbital granulocytic sarcoma.

Acute Disease↗

PubMed1997

Effect of mitomycin C on the optic nerve in rabbits.

AIM: To prevent scarring after surgical optic nerve sheath decompression, it has been suggested that treating the area of fenestration with mitomycin C (MMC) might be effective. An animal model was used to test whether this toxic substance may cause optic neuropathy. METHODS: The optic nerves of 15 rabbits were exposed to balanced salt solution (BSS) or mitomycin C (MMC) in a concentration of 0.2 or 0.5 mg/ml. The unoperated fellow eyes and the eyes that received BSS served as controls. Steady state visual evoked potentials (VEPs) at 40, 50, and 60 Hz were recorded before and 4 weeks after surgery. The nerves were examined by light and electron microscopy after 5 weeks. RESULTS: VEPs in all non-operated eyes and eyes treated with BSS before and 4 weeks after surgery demonstrated responses at all three stimulus frequencies tested. Eyes operated with MMC had extinguished responses for one, two, or all the different temporal frequencies after 4 weeks with marked reduction in VEP amplitude. Eyes operated with MMC at a concentration of 0.5 mg/ml had significantly more reduced VEP responses than those where MMC 0.2 mg/ml was used. On histopathological examination, special stains for myelin and axons showed normal axons and myelin. On electron microscopy, no distinct abnormalities were seen among nerves operated with MMC and controls. CONCLUSION: The data from this study suggest that in rabbits, the application of MMC to the optic nerve has a dose dependent toxic effect in the short term postsurgical follow up period. While a functional alteration could be demonstrated reproducibly by steady state VEPs, the extent was not obvious on histopathological examination of the nerves.

Animals↗

PubMed1997

Combined subretinal and sub-retinal pigment epithelium neovascular membranes in age-related macular degeneration: a clinicopathologic study of six cases.

BACKGROUND AND OBJECTIVE: Subfoveal neovascular membranes are usually located either in the subsensory retinal space or below the retinal pigment epithelium (RPE). This article describes the clinical and histopathologic features of subfoveal membranes with both subretinal and sub-RPE components (combined membranes). PATIENTS AND METHODS: Six surgically excised subfoveal neovascular membranes from six patients were examined histopathologically. Preoperative and postoperative clinical information was obtained from each patient. RESULTS: Clinically, the combined membranes had no special characteristic features. The most common fluorescein angiographic finding postoperatively was a window defect of the RPE. Visual acuity improved in three patients and became worse in the other three patients. CONCLUSIONS: All patients with combined subfoveal neovascular membranes had age-related macular degeneration. In this disease, a single subfoveal membrane may extend into both the subretinal and the sub-RPE spaces. Patients may benefit from surgical removal of the membrane.

Aged↗

PubMed1997

Conjunctival cilia entrapment: an unrecognized cause of ocular irritation.

Conjunctival entrapment of cilia is form of ocular irritation that to our knowledge has not yet been described. Scarring predisposes the conjunctiva to this phenomenon by creating blind recesses in which loose cilia can become entrapped. Once caught, the rigid cilia can act as a mechanical irritant or act as a nidus for microbial growth. We present herein three patients with entrapped cilia and discuss their pathophysiology and management. The symptoms in all three patients resolved with conjunctivoplasty and removal of the cilia.

Adult↗

PubMed1996

Cytomegalovirus keratitis in acquired immunodeficiency syndrome.

A man with acquired immunodeficiency syndrome developed a generalized rash and bilateral dendritic epithelial keratitis without retinitis. Cytologic examination of superficial corneal scrapings showed many megalosyncytial giant cells that were highly characteristic of cytomegalovirus (CMV) infection. Viral cultures yielded CMV from 2 separate specimens obtained by corneal epithelial debridement from both eyes. The slightly elevated, opaque, branching, nonulcerative epitheliopathy recurred after corneal scrapings and persisted despite oral and topical antiviral therapy. Stromal keratouveitis subsequently developed. This case report confirms that CMV can produce corneal involvement and suggests that CMV keratitis may be an emergent complication of acquired immunodeficiency syndrome.

Acquired Immunodeficiency Syndrome↗

PubMed1996

Botryomycosis of limbal conjunctiva with Splendore-Hoeppli phenomenon.

An 84-year-old man complained of irritation of the left eye of several months' duration. He had had several previous surgical procedures including removal of bilateral pterygia and bilateral cataract extraction. Examination of the bulbar conjunctiva on the left eye disclosed a collection of cilia (eyelashes) located adjacent to the limbus at the 11:30-o'clock position. This aggregate of cilia was associated with irregular yellowish deposits 1.5 mm in diameter. The cilia and redundant conjunctival tissues were surgically excised. Histopathologic examination showed a botryomycotic granule surrounded by a prominent acidophilic ring (Splendore-Hoeppli phenomenon). Gram stains demonstrated the presence of microcolonies of gram-positive cocci and gram-negative rods within the granule. We postulate that the entrapment of displaced cilia provided a nidus for the bacterial colonization forming the botryomycotic granule. To our knowledge, botryomycosis of the conjunctiva has not been reported previously.

Aged↗

PubMed1996

Cytologic evaluation of lymphoproliferative lesions of the orbit/ocular adnexa: an analysis of 46 cases.

The cytologic features of 46 lymphoproliferative ophthalmic lesions were evaluated using the "squash" technique and/or touch imprints at the time of frozen section. Of the 46 lesions, 33 were located in the orbit, 12 in the conjunctiva, and one in the eyelid. Fifteen cases were benign (reactive) hyperplasias, and 31 were diagnosed as malignant lymphoproliferative tumors. The cytologic features of the reactive group included a polymorphic lymphoid population intermixed with scattered tingible body macrophages. Within the malignant category, there were 28 malignant lymphomas. All 28 cases were diagnosed as non-Hodgkin's lymphomas. Cytologically, the malignant group consisted of a monomorphic population of atypical lymphoid cells. Of the 31 malignant lymphoid lesions, 58% (18 tumors) were small lymphocytic proliferations. The remaining 13 tumors were classified as follows: mixes small/large cell or pure large cell lymphomas (nine), plasmacytoma (three), and Burkitt's lymphoma (one). Final classification using the Working Formulation was made after evaluating the cytologic preparations and surgical material. In selected cases, the monoclonal nature of the malignant lymphoproliferative lesions was confirmed by flow cytometry and/or immunocytochemistry. Cytologic preparations of the fresh specimens preserve the morphologic details of the tumor cells, which is especially important when evaluating lymphoid lesions. Additionally, multiple smears can be prepared simultaneously for ancillary studies such as immunocytochemistry. Of our 46 lymphoproliferative lesions, two-thirds were diagnosed as malignant lymphomas. Based on the morphologic and immunophenotypic findings, all the malignant lymphomas were B-cell tumors, 50% of which were low grade using the Working Formulation.

Conjunctival Diseases↗

PubMed1996

Invasive keratoacanthoma of the eyelid and ocular adnexa.

PURPOSE: To report three patients with superficially invasive crateriform squamous proliferations of periocular tissue. METHODS: The authors identified three patients with superficially invasive periocular tumors that had clinical features of keratoacanthoma. Clinical histories, radiographs, and surgical pathologic specimens were reviewed. RESULTS: All three tumors arose over several weeks, had a crateriform configuration, and exhibited superficial invasion of underlying tissues, including perineural invasion and infiltration into skeletal muscle. All three tumors were classified as invasive keratoacanthoma. One tumor exhibited late perineural extension into the cavernous sinus and convincing histologic features consistent with squamous cell carcinoma. CONCLUSION: The clinical importance of recognizing invasive keratoacanthoma is that although the tumor has the potential for spontaneous involution, locally aggressive behavior with deep perineural invasion is possible. This tumor is considered to represent a variant of squamous cell carcinoma. The authors recommend complete surgical excision of crateriform squamous proliferations with frozen section control of margins of resection.

Adult↗

PubMed1996

Ultrastructural features and prevalence of tubuloreticular structures in the ocular vasculature of patients with AIDS: a study of 23 cases.

BACKGROUND: Tubuloreticular structures (TRS) are subcellular inclusions that are most commonly found in endothelial cells and lymphocytes of patients with autoimmune or collagen vascular disorders. In AIDS, TRS have been described in various tissues throughout the body including the lung, kidney, liver, muscle, and skin. METHODS: Ocular tissues from 23 patients with AIDS were examined by electron microscopy. These included 17 postmortem eyes in addition to three chorioretinal and three conjunctival biopsy specimens. RESULTS: The overall prevalence of TRS in the ocular and conjunctival endothelial cells was found to be 83% (19/23). CONCLUSIONS: This is the first documented study of the prevalence of these structures in the ocular structures of patients with AIDS. Given the high frequency of their occurrence in AIDS, it is recommended that the presence of TRS in ocular or conjunctival tissues be an indication for obtaining an HIV antibody titre. Additionally, a rheumatological examination for HIV seronegative patients is suggested.

Acquired Immunodeficiency Syndrome↗

PubMed1996

Trilateral tumors in four different lines of transgenic mice expressing SV40 T-antigen.

PURPOSE: A line of transgenic mice containing the simian virus (SV) 40 T-antigen (T-ag) gene driven by the beta-luteinizing hormone (BLH) promoter developed bilateral retinoblastoma and primitive neuroectodermal tumors (PNET) of the midbrain. Midbrain tumors arose from the subependymal layer of the cerebral aqueduct. Bilateral ocular and brain tumors ("trilateral") were found in three other SV40 T-ag transgenic murine lines containing different promoters (murine interphotoreceptor retinoid-binding protein (IRBP), human IRBP, and alpha A-crystallin). To gain insight into the regulatory mechanisms involved in central nervous system tumorigenesis, the authors examined brain tumors from four lines of SV40 T-ag mice with different promoters. METHODS: Formalin-fixed brain tumors were examined from four lines of transgenic mice containing different promoters linked to the protein coding region of the enhancerless SV40 T-ag oncogene. Transgenes contained the following promoters: BLH, mouse 1.8-kb IRBP, human 1.3-kb IRBP, and alpha A-crystallin. RESULTS: Mice with a 1.8-kb IRBP promoter develop retinal photoreceptor and pineal tumors. Intracranial tumors arising from the subependymal layer of the third ventricle also were observed. Mice with a 1.3-kb IRBP promoter exhibit bilateral retinal PNET and PNET originating from the subependymal layer of the third ventricle. Mice with the alpha A-crystallin promoter exhibit bilateral lens tumors and PNET of the midbrain. CONCLUSIONS: Ocular tumors in these mice may be ascribed to the promoter-driven, tissue-specific expression of SV40 T-ag. The common finding of PNET arising from the subependymal layer of the diencephalon is unlikely to be promoter related. These findings indicate that a regulatory region specific to the subependymal layer of the cerebral aqueduct and third ventricle resides in the structural region of the SV40 T-ag gene.

Animals↗

PubMed1996

Infectious crystalline keratopathy caused by Candida parapsilosis.

Infectious crystalline keratopathy is a chronic infection of the cornea, characterized by branching intrastromal opacities without inflammation. These changes are usually due to accumulations of bacterial colonies, most commonly viridans streptococci, but this entity has previously been reported in association with Candida albicans and Candida tropicalis. We present the case of a 66-year-old man who had previously undergone penetrating keratoplasty and developed infectious crystalline keratopathy due to Candida parapsilosis. Histopathology showed interlamellar accumulations of viable yeasts with no inflammation. Chronic topical corticosteroid use in this patient produced relative immunosuppression, allowing for the infection by Candida parapsilosis and the lack of inflammation in the cornea. The spectrum of causative organisms in infectious crystalline keratopathy continues to grow, emphasizing the need for laboratory evaluation in the management of this disorder.

Aged↗

PubMed1995

Corneal lipidosis in patients with the acquired immunodeficiency syndrome.

PURPOSE: Certain drugs bind to anionic phospholipids of lysosomal membranes and produce progressive intracellular accumulation of lamellar inclusions. We studied two patients treated for opportunistic infections associated with the acquired immunodeficiency syndrome (AIDS), who developed bilateral ocular surface changes suggestive of drug-induced corneal lipidosis. METHODS: Two patients with AIDS had translucent vacuoles within the corneal epithelium and mild conjunctival hyperemia. Because the differential diagnosis included microsporidial keratoconjunctivitis, biopsies of the ocular surface were performed for histopathologic analysis. RESULTS: Transmission electron microscopy of corneal epithelial debridement and conjunctival biopsy specimens showed intracellular, electron-dense lipoidal bodies and multilaminated lysosomal inclusions suggestive of a drug-induced lipidosis. Both patients also had tubuloreticular inclusions in conjunctival capillary endothelial cells. The ocular surface changes resolved within one to three months after dosage reduction or discontinuation of systemic ganciclovir and acyclovir. CONCLUSIONS: Drug-induced phospholipidosis is a cause of punctate corneal epitheliopathy during AIDS, but the responsible agent remains to be identified.

AIDS-Related Opportunistic Infections↗