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Biomedical subjects

J C Folk

Publications and source records attributed to J C Folk.

At least 37 records · Page 2Linked to original sources
PubMed1996

Epiretinal macular membranes in eyes with attached posterior cortical vitreous.

BACKGROUND: The authors define the clinical and anatomic characteristics of patients who had epiretinal membrane formation and traction over the macula in the absence of vitreous detachment from the retina. METHODS: Patients were treated and followed by one surgeon (JCF). All patients had epiretinal membrane formation over the macula without vitreous detachment. The clinical and surgical findings of these patients were compared along with histopathologic examination of the removed epiretinal membranes and posterior cortical vitreous. RESULTS: Fourteen patients were identified over a 9.75-year period. All patients had a thin and transparent-or at most minimally translucent-membrane overlying the posterior pole causing traction. The membrane appeared continuous with the posterior hyaloid face. At vitrectomy, no vitreous detachment was found in any eye. Transmission electron microscopy of all three specimens tested found collagen of less than 16 nanometers in diameter, consistent with native vitreous collagen. After surgery, visual acuity improved in 13 of 14 eyes, was 20/50 or better in 12 eyes, and was 20/25 or better in 7 eyes. CONCLUSION: Epiretinal membrane formation can occur in eyes without vitreous detachment probably because of cellular growth along the posterior hyaloid face. Such eyes respond particularly well to surgery.

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PubMed1996

The use of intravitreal tissue plasminogen activator in the treatment of experimental subretinal hemorrhage in the pig model.

PURPOSE: To clinically and surgically evaluate clot lysis in an animal model of subretinal hemorrhage after intravitreal injection of tissue plasminogen activator. METHODS: Autologous subretinal hemorrhages were created via a transvitreal approach in 18 pigs. The next day (day 1) animals were randomly selected to receive either an intravitreal injection of 0.1 mL balanced salt solution or 0.1 mL tissue plasminogen activator (25 micrograms) followed by observation or vitrectomy a day later. On day 2, six pigs (all treated with tissue plasminogen activator) underwent a vitrectomy in which aspiration of the subretinal hemorrhage was attempted. The other eyes were evaluated for clot lysis by ophthalmoscopy at days 3, 10, and 30. All eyes were examined histopathologically. RESULTS: The eyes that had been treated with tissue plasminogen activator demonstrated a color change at the peripheral margin, which suggested that clot lysis had occurred. At the time of the vitrectomy, the clots were liquefied partially; removal by aspiration alone, however, was not possible. Photoreceptor damage was moderate to severe by day 10 in all eyes, whether they were treated with tissue plasminogen activator or balanced salt solution. All eyes that underwent vitrectomy had moderate to severe photoreceptor damage. CONCLUSIONS: In this animal model, intravitreal tissue plasminogen activator was associated with features that suggested partial clot lysis; tissue plasminogen activator did not produce sufficient lysis to allow surgical removal by aspiration alone, however.

Animals↗
PubMed1995

Cotton-wool spots and the early diagnosis of giant cell arteritis.

BACKGROUND: Giant cell arteritis is a common cause of severe visual loss in older individuals. Patients often present to the ophthalmologist having already lost vision in one eye. Detection of early ophthalmoscopic signs that precede irreversible visual loss in giant cell arteritis would allow preventative treatment in an otherwise frequently blinding disease. METHODS: Case presentations. RESULTS: Seven patients with mild visual symptoms and results of an ophthalmologic examination significant for cotton-wool spots were found to have giant cell arteritis. On specific questioning, six of seven patients described constitutional symptoms consistent with giant cell arteritis. Six patients had an abnormally elevated Westergren erythrocyte sedimentation rate. Temporal artery biopsy confirmed giant cell arteritis in six patients. The seventh patient received a diagnosis of polymyalgia rheumatica. Prompt treatment with corticosteroids led to preservation of vision and uneventful resolution of the cotton-wool spots in all seven patients. CONCLUSION: Cotton-wool spots are an early ophthalmoscopic finding in giant cell arteritis and can precede severe visual loss. Recognition of the significance of cotton-wool spots, use of laboratory studies, and prompt treatment may preserve vision in an otherwise frequently blinding disease.

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PubMed1995

Subretinal fibrosis in central serous chorioretinopathy.

PURPOSE: To report unusual and heretofore unreported visually damaging manifestations of severe central serous chorioretinopathy. METHODS: Case studies. RESULTS: Each of six male patients (average age, 40 years) had a form of severe central serous chorioretinopathy with at least one eye containing fibrin in the subretinal space that then developed into a subretinal fibrotic scar. Scar formation was followed by a tenting up of the macula, vascularization of the fibrosis (subretinal neovascularization), or a retinal pigment epithelial rip. Four of the seven eyes with subretinal fibrosis had severe visual loss (20/400 or worse). CONCLUSION: Subretinal fibrin and other extracellular matrix molecules appear to stimulate the retinal pigment epithelium to undergo fibrous metaplasia, which results in subretinal fibrotic scar formation and other sequelae, all of which can lead to severe visual loss.

Adult↗
PubMed1994

Non-caseating conjunctival granulomas in patients with multifocal choroiditis and panuveitis.

PURPOSE: This study describes a group of patients with clinical findings of peripheral punched-out lesions and panuveitis who had non-caseating granulomas found by non-directed conjunctival biopsy. METHODS: A series of 10 patients seen at The University of Iowa Hospitals and Clinics between August 1989 and August 1990 with ocular findings similar to those of multifocal choroiditis with panuveitis, including peripheral punched-out chorioretinal lesions, vitritis, and frequently, cystoid macular edema, was examined. All patients underwent ophthalmic examination, ancillary testing, and non-directed conjunctival biopsy. RESULTS: Of the ten patients, nine were women. Results of FTA-ABS were negative for all patients. A non-directed conjunctival biopsy disclosed non-caseating granulomata in seven of the patients. Acid-fast bacilli were not detected in any specimens. Four of the seven patients with positive biopsy results had either elevated serum angiotensin-converting enzyme levels or chest x-rays consistent with sarcoid. Six of these seven patients were 58 years of age or older. CONCLUSION: It is recommended that non-directed conjunctival biopsy specimens be examined to exclude the presence of non-caseating granulomata in uveitis patients with small, inferior, peripheral, punched-out chorioretinal scars, especially in women older than 55 years of age.

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PubMed1994

Retinal arteriolar macroaneurysms: long-term visual outcome.

Visual outcome was analysed in 16 consecutive eyes with symptomatic retinal arteriolar macroaneurysms treated by direct laser photocoagulation and 26 consecutive symptomatic eyes followed with no treatment. No difference existed between groups in presenting visual acuity, macular involvement, presence of macular subretinal fluid, or presence or location of associated haemorrhage. The mean follow up was 41 months. In the 26 untreated eyes, visual acuity was improved by 2 or more lines in 13 (50%), was unchanged in nine (35%), and decreased in four cases (15%). In the 16 treated cases, three improved (19%), seven were unchanged (43%), and six had decreased visual acuity (38%). The average minimum angle of resolution improved 0.53 log units in untreated cases and decreased 0.14 log units in treated cases (p = 0.02). Multivariable logistic regression modelling analysis revealed that laser treatment remained a significant risk factor for final visual acuity of less than 20/80 even when controlling for the effects of subretinal haemorrhage and foveal subretinal fluid (odds ratio 8.4, p = 0.01). Laser photocoagulation directly to the macroaneurysm did not improve the visual outcome in this series.

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PubMed1993

The association of HLA-B8, B51, DR2, and multiple sclerosis in pars planitis.

PURPOSE: To establish a human leukocyte antigen (HLA) association in a homogeneous population of patients with pars planitis. METHODS: A strict set of inclusion parameters was established for the diagnosis of pars planitis. Forty patients with pars planitis who met these criteria underwent HLA analysis of class I and II phenotypes. RESULTS: HLA-B8 was present in 15 (37.5%) of 40 patients versus 85 (19.7%) of 431 controls (relative risk, 2.44; P = 0.011). HLA-B51 was present in 9 (22.5%) of 40 patients versus 51 (11.8%) of 431 controls (relative risk, 2.16; P = 0.049). HLA-DR2 was present in 27 (67.5%) of 40 patients versus 121 (28.0%) of 431 controls (relative risk, 5.32; P < 0.0001). HLA-DR2 has been associated with multiple sclerosis (MS). Exclusion of five patients with pars planitis in whom MS subsequently developed did not change the significance of these findings. CONCLUSIONS: The strongest association of pars planitis with HLA-DR2 and the temporal development of MS in some patients with pars planitis further supports an association between pars planitis and MS.

Case-Control Studies↗
PubMed1993

Long-term visual outcome and complications associated with pars planitis.

PURPOSE: To identify the ocular complications and to statistically evaluate the possible association of pars planitis with multiple sclerosis (MS) in a homogeneous population of pars planitis patients. METHODS: The authors reexamined 36 patients and reviewed the records of an additional 18 patients (total: 54 patients, 108 eyes) with idiopathic pars planitis. RESULTS: The initial mean visual acuity of 20/46 (logMAR: 0.36 +/- 0.50) was not statistically different from the final mean visual acuity of 20/44 (logMAR: 0.34 +/- 0.45; P = 0.73), after a mean follow-up of 89.2 months. Complications included neovascularization with or without associated vitreous hemorrhage (7 eyes, 6.5%), moderate to severe cellophane retinopathy (7 eyes, 6.5%), chronic cystoid macular edema (CME) (9 eyes, 8.3%), visually significant cataracts (16 eyes, 14.8%), and retinal detachment (9 eyes, 8.3%). Significant lens opacification was associated with a greater risk of retinal detachment (P = 0.004). In four patients (7.4%), optic neuritis developed, and in an additional eight patients (14.8%) MS developed. Kaplan-Meier analysis of these data showed a 16.2% +/- 6.2% risk of MS solely developing in patients, and a 20.4% +/- 6.7% risk of either MS or optic neuritis developing, after 5 years of disease. The presence of periphlebitis at the time of pars planitis diagnosis increased the rate of development of these conditions (P = 0.002). Six patients (11.1%) had a family history positive for MS in a first-degree relative. CONCLUSIONS: This study demonstrates the overall favorable visual prognosis in patients with pars planitis. Patients with significant cataract formation appear to be at greater risk for retinal detachment. Periphlebitis at the time of diagnosis of pars planitis increases the risk of development of optic neuritis or MS. The strong association demonstrated between pars planitis and MS in this study further supports a link between the two disease states.

Adult↗
PubMed1992

North Carolina macular dystrophy and central areolar pigment epithelial dystrophy. One family, one disease.

The autosomal-dominant macular dystrophies known as North Carolina macular dystrophy and central areolar pigment epithelial dystrophy were originally described as distinct disease entities in three separate families. However, these disorders have several phenotypic features in common. The single large family with North Carolina macular dystrophy, which descended from three Irish brothers in 1790, has undergone extensive genealogic studies expanding the kindred to more than 2000 family members. As a result, two previously described families with central areolar pigment epithelial dystrophy have been found to descend from these same three Irish brothers with North Carolina macular dystrophy and, therefore, also have North Carolina macular dystrophy. This helps simplify the nosology of the disease and expands the phenotype of North Carolina macular dystrophy to include choroidal neovascular membranes.

Child↗
PubMed1992

Retained nuclei after cataract surgery.

The authors reviewed the medical records of 36 patients in whom the nucleus or nuclear fragments were retained in the eye after cataract surgery. In 4 patients, there was no further surgery, and visual acuity deteriorated to counting fingers or worse (mean follow-up time, 14 months). Thirty-two patients underwent vitrectomy to remove the retained, unencapsulated nuclear material. Sixty percent (6 of 10) of patients in whom vitrectomy was performed after 3 weeks had chronic glaucoma on long-term follow-up, whereas this complication developed in only 18% (4 of 22) of patients in whom vitrectomy was performed in less than 3 weeks. Sixty-three percent (21 of 32) of vitrectomy patients had final visual acuity of 20/200 or better after removal of the retained nuclear fragments. The causes of the poorest visual outcome (less than 20/200) included 1 or more of the following: corneal decompensation, chronic inflammation, chronic glaucoma with optic atrophy, and retinal detachment.

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PubMed1992

Genetic linkage of autosomal dominant neovascular inflammatory vitreoretinopathy to chromosome 11q13.

Autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV) is an inherited eye disease characterized by retinal and iris neovascularization, abnormal retinal pigmentation, anterior chamber and vitreous inflammation, cystoid macular edema, vitreous hemorrhage, and traction retinal detachment. Some of these clinical features are shared by more common, potentially blinding, conditions including diabetic retinopathy, uveitis, and retinitis pigmentosa. Elucidation of the molecular pathogenesis of ADNIV has the potential to provide insight into the mechanisms of these common disorders. One hundred and sixteen members of an eight generation family affected with ADNIV were examined. A combination of slit lamp biomicroscopy, ophthalmoscopy, and electroretinography was used to establish the diagnosis and 34 family members were found to be affected. Blood samples were obtained from thirty-three of these individuals and nine spouses and used for chromosome linkage analysis with denaturing gradient gel and short tandem repeat polymorphisms. Two markers that map to chromosome 11q13 were found to be significantly linked to the ADNIV phenotype. There were no recombinants between the disease phenotype and marker D11S527 and multipoint analysis yielded a maximum LOD score of 11.9 centered on this marker.

Adult↗
PubMed1992

Ill-defined choroidal neovascularization within ocular histoplasmosis scars.

Seven patients with scars typical of ocular histoplasmosis syndrome presented with new symptoms of decreased vision or metamorphopsia. In each patient the symptoms corresponded to an atrophic or "punched-out" histoplasmosis scar in the macula. Clinically, a small amount of subretinal fluid overlying the scars and slight hyperfluorescence were seen on fluorescein angiography. These findings were due to a choroidal neovascular membrane growing within the margins of the atrophic scar. The membranes were difficult to diagnose because of the absence of hemorrhage, pigmentation, or growth of vessels beyond the margins of the scar. Clinicians should be aware that these patients may have early and growing choroidal neovascularization and may need to undergo photocoagulation or to be followed closely.

Adult↗
PubMed1992

Effects of collaborative education on patient satisfaction and knowledge.

This study details an experimental study that utilized a collaborative educational approach for teaching 50% of a group of patients diagnosed with Diabetic Macular Edema and who underwent Focal Argon Laser treatment. The control group received teaching only by their physician. The registered nurses cared for the control patients, providing comfort interventions and maintaining a safe environment, but did not participate directly in the teaching program.

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