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James C Folk

Publications and source records attributed to James C Folk.

9 recordsLinked to original sources
PubMed2007

Complement factor H polymorphism p.Tyr402His and cuticular Drusen.

OBJECTIVE: To determine the histidine frequency in patients with the cuticular drusen phenotype of age-related macular degeneration (AMD). METHODS: Fifty individuals were identified who met the criteria for the cuticular drusen phenotype using a standard threshold photograph. We genotyped DNA samples using a polymerase chain reaction-based restriction digest assay. Seven hundred individuals with typical AMD and 252 controls were also genotyped. Fisher exact test was used to analyze the significance of allele frequency differences. RESULTS: The histidine variant was present in 70% (frequency +/- SE, 0.70 +/- 0.05) of the cuticular cohort, 55% (frequency +/- SE, 0.55 +/- 0.01) of the more typical AMD cases, and 34% (frequency +/- SE, 0.34 +/- 0.02) of controls. The association between the cuticular drusen phenotype and the histidine allele was highly significant (P = .003; odds ratio, 2.0; 95% confidence interval, 1.21-3.07; vs AMD cases P<.001; odds ratio 4.54; 95% confidence interval, 2.79-7.50; vs controls). Genotype distribution between the 3 groups was similarly significant (P<.001). CONCLUSION: The cuticular drusen phenotype is highly associated with the Tyr402His variant of the complement factor H (CFH) gene. The significantly higher histidine allele frequency in this group compared with the typical AMD cohort suggests that the complement cascade may play a greater role in the pathogenesis of the cuticular drusen subtype than in AMD as a whole. CLINICAL RELEVANCE: The c.1204T>C, p.Tyr402His allelic variant in the CFH gene is associated with a 3-fold increased risk for AMD. A high frequency of the histidine allele has also been noted in patients with membranoproliferative glomerulonephritis type II.

Adult↗
PubMed2005

Long-term juxtafoveal retinal telangiectasia.

PURPOSE: To determine the long-term natural history of idiopathic juxtafoveal telangiectasia (IJRT). METHODS: Record review in 2 university-based and 2 private vitreoretinal practices sought patients with IJRT documented by color photographs and fluorescein angiograms (FAs) during the period January 1, 1980, to December 31, 1993. Patients then had repeated examinations and FAs. RESULTS: Twenty patients with IJRT in 32 eyes had follow-up examinations. Fifteen patients had color photographs and FAs, and one had color photographs alone. Follow-up varied from 10 years to 21 years (average, 15 years). Six eyes were treated by laser photocoagulation at onset. Twenty-four of the 26 untreated eyes lost vision as measured by Snellen testing. Visual loss and morphologic progression depended on IJRT type. Six of 8 untreated eyes with type IA IJRT lost vision by >/ or = 3 lines (Snellen), 4 to 20/70 or worse. Vision loss was caused by progressive telangiectatic changes and intraretinal edema. Fifteen of 20 initially untreated eyes with type IIA IJRT developed either central retinal pigment epithelium membranes or subretinal neovascularization with loss of vision to 20/80 or less. CONCLUSION: IJRT prognosis depends on type and clinical features. Long-term prognosis for central vision is poor.

Adult↗
PubMed2004

Comparison of color to fluorescein angiographic images from patients with early-adult onset grouped drusen suggests drusen substructure.

PURPOSE: Recent structural and histochemical data from our laboratory indicate that human drusen often possess distinct, structural core domains. A similar, corelike structure is frequently noted clinically in some drusen-related conditions. To assess the nature of the corelike structures observed clinically, we evaluated color photographs and fluorescein angiograms from patients with early-adult onset grouped drusen (EAOGD). DESIGN: Retrospective case series. METHODS: The areas of the six largest drusen and hyperfluorescent lesions for eight patients confirmed to have EAOGD were estimated by two masked examiners (RRG, JCF). Data were normalized using a logarithmic transformation and evaluated using a mixed model analysis to account for intragrader, interobserver and intrasubject effects. RESULTS: The average color to hyperfluorescence drusen area ratio was 2.29 (SE, 0.06). The area of drusen viewed in color photographs significantly exceeds that of the corresponding area of hyperfluorescence (P <.0001). The average drusen area (geometric mean) was 0.014 mm(2) (SE, 0.001 mm(2)) and the average hyperfluorescent lesion area was 0.006 mm(2) (SE, 0.0005 mm(2)). The areas of the hyperfluorescent lesions do not vary among the capillary, venous, and washout angiographic phases. The lesions exceed choroidal intensity and demonstrate prominent, uniformly hyperintense fluorescence throughout all but the choroidal phases of the angiogram. CONCLUSIONS: These data show that large visible drusen in EAOGD are concentric to regions of hyperfluorescence, suggesting that drusen may possess clinically detectable, substructural domains. Ongoing studies seek to determine whether clinical evidence of drusen substructure may exist in other drusen-associated disorders, such as in age-related macular degeneration.

Adult↗
PubMed2004

Photodynamic therapy of subfoveal and juxtafoveal choroidal neovascularization in ocular histoplasmosis syndrome: a retrospective case series.

PURPOSE: To evaluate the safety and effect on visual acuity of photodynamic therapy (PDT) with verteporfin in patients with subfoveal and juxtafoveal choroidal neovascular membranes from ocular histoplasmosis syndrome (OHS). METHODS: Retrospective case series. The visual outcome of 11 patients with subfoveal (n = 6) and juxtafoveal (n = 5) choroidal neovascularization treated with PDT was reviewed. At 1 to 3 months of follow-up, retreatment with PDT was performed if angiography showed leakage. RESULTS: Within the subfoveal group, 3 patients (50%) had improved vision (two or more lines better than initial vision), 2 patients (33.3%) had no change in vision (within 1 line), and 1 (16.7%) lost four lines of vision. At last follow-up, 3 patients (50%) had vision between 20/20 and 20/40 compared with only 1 patient (16.6%) at the initial visit. Mean follow-up was 13.7 months. Within the juxtafoveal group, 3 patients (60%) had improved vision, 1 patient (20%) had no change in vision, and 1 patient (20%) lost nine lines of vision. At last follow-up, 3 of 5 patients (60%) had vision between 20/20 and 20/40 compared with 2 patients (40%) at the initial visit. Mean follow-up was 10.2 months. No significant adverse effects were reported. CONCLUSION: PDT is a safe and promising option for patients with OHS with choroidal neovascularization that is subfoveal or juxtafoveal.

Adolescent↗
PubMed2003

Vitreous amino acid concentrations in patients with glaucoma undergoing vitrectomy.

OBJECTIVE: To measure vitreous concentrations of glutamate and other amino acids in patients with glaucoma undergoing vitrectomy. METHODS: Undiluted vitreous samples were collected from patients undergoing vitrectomy at the University of Iowa (Iowa City) between 1997 and 1998 (n = 69). Vitreous concentrations of 16 amino acids, including glutamate, were determined using high-pressure liquid chromatography. Patients with a history of diabetes mellitus were excluded from the analysis. The study group consisted of those with a history of glaucoma (n = 8), and the control group included those with an epiretinal membrane and/or macular hole with no history of glaucoma (n = 17). Comparison of amino acid concentrations between the 2 groups was performed using a multifactor main effects model that adjusted for the effect of 10 selected covariates. Power analysis was done to determine the level of significant difference in amino acid concentrations. RESULTS: The glaucoma group comprised vitreal specimens from patients with primary open-angle (n = 3) and angle-closure glaucomas that included aqueous misdirection (n = 2), uveitis with secondary angle-closure (n = 2), and Axenfeld Rieger syndrome (n = 1). Indications for vitrectomy in this group included epiretinal membrane, retinal detachment, aqueous misdirection, and uveitis. The control group included specimens from patients with a macular hole (n = 11) and epiretinal membrane (n = 7), with 1 eye having both. Surgical indications in controls were macular hole, retinal detachment, and epiretinal membrane. The mean +/- SD levels of vitreous glutamate, glycine, gamma-aminobutyric acid, and alanine were 6.1 +/- 2.4, 16.3 +/- 7.5, 0.8 +/- 0.3, and 260.5 +/- 101.9 microM, respectively, in glaucoma and 5.2 +/- 2.3, 8.5 +/- 2.5, 0.6 +/- 0.2, and 159.5 +/- 54.9 microM in controls (P >.05 for all). None of the 16 amino acid concentrations measured showed a statistically significant difference between glaucoma and controls (P values between.06 and >.99). A power analysis indicated that a 1.8-fold elevation in the glutamate level was needed to reach significance. MAIN OUTCOME MEASURES: Vitreous amino acid concentrations. CONCLUSIONS: None of the 16 amino acids measured, including glutamate, were significantly elevated in the vitreous of glaucomatous eyes compared with controls. Our results are not consistent with the simple hypothesis of glutamate excitotoxicity in glaucoma. Instead, our findings indicate the dynamic nature of extracellular glutamate, whose concentration is dependent on complex mechanisms not yet fully understood. Further studies are needed to fully elucidate the role of glutamate in the pathogenesis of glaucoma.

Aged↗
PubMed2002

Birdshot retinochoroiditis: long term follow-up of a chronically progressive disease.

PURPOSE: To determine the long-term course of birdshot retinochoroiditis by reviewing patient records from The University of Iowa Hospitals and Clinics. DESIGN: A descriptive case series. METHODS: We conducted a retrospective review of 19 patients seen at The University of Iowa for birdshot retinochoroiditis. Inclusion criteria were set before review. Goldmann perimetry isopters were converted to an area measurement in steradians and the I2e and I4e isopters were evaluated at each time point. The visual acuity, electroretinography (ERG), and visual field findings were compared to the clinical appearance of the fundus. RESULTS: Follow-up ranged from one visit to 220 months. Of the 14 patients who were tested, all were HLA-A29-positive. Seven patients were followed for >or=60 months. Eleven patients were followed for >or=30 months. The initial visual acuity was 20/50 or better in 36 of 38 eyes and 20/60 and 20/80 in the remaining two. Visual acuity was worse than 20/50 in three of 22 eyes followed for more than 30 months. Visual field data demonstrated progressive loss of area for either the I4e or I2e isopters in six of seven patients who were followed for >or=60 months. Multiple ERGs were performed over time on eight of 19 patients; seven of eight patients demonstrated progressive loss of electrophysiologic indices. CONCLUSION: Retinal function in birdshot retinochoroiditis deteriorated progressively over a period of years despite stable visual acuity. Late in the course of disease, visual acuity may be lost due to chorioretinal atrophy in the posterior pole. Visual acuity alone is not an adequate parameter with which to monitor disease activity and may falsely suggest that a patient is stable or doing well. Intermittent treatment of the inflammatory exacerbations did not prevent progressive visual loss. Other treatment strategies such as prolonged corticosteroid or immunosuppressive treatment should be investigated for patients with birdshot retinochoroiditis.

Adult↗
PubMed2002

Long-term follow-up of patients with serpinginous choroiditis.

PURPOSE: To evaluate the long-term clinical course of serpiginous choroiditis-a recurrent inflammatory disease that causes progressive visual loss-and to determine the efficacy of immunosuppressive therapy. METHODS: A retrospective study of patients who met inclusion criteria for serpiginous choroiditis at The University of Iowa Hospitals and Clinics was performed. Information collected included duration of follow-up, number of recurrences of inflammation, visual acuities, and development of choroidal neovascularization. The number of recurrences of inflammation in patients treated with immunosuppressive agents was compared with that in patients treated only with corticosteroids or observation. RESULTS: Seventeen patients were identified who had a mean age at presentation of 39.6 years. The mean duration of follow-up was 149.2 months, with 13 patients who were followed up for >60 months. Twelve eyes either presented with or developed macular choroidal neovascularization during follow-up. Thirteen of the patients were followed up for >12 months. Of these 13 patients, 6 received treatment with immunosuppressive agents along with corticosteroids. Four of the six patients developed no further inflammatory recurrence. Seven of the 13 patients were treated with corticosteroids or observation. All of these patients developed recurrences (P = 0.021, Fisher exact test). CONCLUSIONS: Immunosuppressive agents appear to reduce the rate of recurrent disease in serpiginous choroiditis compared with corticosteroids.

Adolescent↗