Biomedical subjects

David O Hodge

Publications and source records attributed to David O Hodge.

At least 73 records · Page 4Linked to original sources

PubMed2003

Long-term outcomes of out-of-hospital cardiac arrest after successful early defibrillation.

BACKGROUND: Mortality after out-of-hospital cardiac arrest from ventricular fibrillation is high. Programs focusing on early defibrillation have improved the rate of survival to hospital discharge. We conducted a population-based analysis of the long-term outcome and quality of life of survivors. METHODS: All patients who had an out-of-hospital cardiac arrest between November 1990 and January 2001 who received early defibrillation for ventricular fibrillation in Olmsted County, Minnesota, were included. The survival rate was compared with that of an age-, sex-, and disease-matched (2:1) control population of residents who had not had an out-of-hospital cardiac arrest and with that of age- and sex-matched controls from the general U.S. population. The quality of life was assessed with use of the Medical Outcomes Study 36-item Short-Form General Health Survey (SF-36) and compared with U.S. population norms. RESULTS: Of 200 patients who presented with an out-of-hospital cardiac arrest with ventricular fibrillation, 145 (72 percent) survived to hospital admission (7 died in the emergency department) and 79 (40 percent) were neurologically intact (good overall capability or moderate overall disability) at discharge. The mean (+/-SD) length of follow-up was 4.8+/-3.0 years. Nineteen patients died after discharge from the hospital. The expected five-year survival rate (79 percent) was identical to that among age-, sex-, and disease-matched controls (P=0.68) but lower than that among the age- and sex-matched U.S. population (86 percent, P=0.02). Fifty patients completed SF-36 surveys at the end of follow-up, and the majority had a nearly normal quality of life, with the exception of reduced vitality. CONCLUSIONS: Long-term survival among patients who have undergone rapid defibrillation after out-of-hospital cardiac arrest is similar to that among age-, sex-, and disease-matched patients who did not have out-of-hospital cardiac arrest. The quality of life among the majority of survivors is similar to that of the general population.

Aged↗

PubMed2003

Herpes zoster ophthalmicus in olmsted county, Minnesota: have systemic antivirals made a difference?

OBJECTIVE: To determine the frequency of complications and adverse outcomes due to herpes zoster ophthalmicus before and after the introduction of oral antiviral medications in a community-based setting. METHODS: We identified all Olmsted County, Minnesota, residents diagnosed with acute herpes zoster ophthalmicus from 1976 through 1998. The frequencies of complications within 6 months of disease onset were compared between untreated patients vs those treated with antivirals. MAIN OUTCOME MEASURES: Defined complications were ocular sequelae due to herpes zoster ophthalmicus. Adverse outcomes included visual acuity of 20/200 or worse, trichiasis, or eyelid malposition requiring surgical treatment. RESULTS: A total of 202 patients had been treated with antivirals, and 121 had not. Neurotrophic keratitis was the only complication that was less likely in the treated group (3.3% vs 0%; P =.02). The probability of an adverse outcome at 5 and 10 years was 8.9% among untreated patients and 2.1% among treated patients (P =.009). Among patients who had been treated, the mean time from symptom onset to initiation of therapy was 4.8 days in those who developed stromal keratitis, corneal edema, scleritis, uveitis, or glaucoma compared with 3.8 days in those who did not (P =.006). CONCLUSIONS: Neurotrophic keratitis was less frequent among patients who received antiviral therapy. However, among treated patients, development of a serious inflammatory complication was associated with a delay in therapy. Most important, adverse outcomes were less probable in the treated group. These data may support the early and routine use of systemic antiviral therapy for acute herpes zoster ophthalmicus.

Acute Disease↗

PubMed2003

Keratocyte density in the human cornea after photorefractive keratectomy.

OBJECTIVE: To perform a quantitative analysis of keratocyte density in human corneas after photorefractive keratectomy (PRK). METHODS: In a prospective comparative trial, 24 eyes of 14 patients received PRK to correct refractive errors of between -1.25 diopters (D) and -5.75 D. Corneas were examined by using confocal microscopy before and 1 day, 5 days, and 1, 3, 6, 12, 24, and 36 months after PRK. Keratocyte nuclei were counted in 5 stromal layers in 3 to 6 scans per eye per visit. Keratocyte density in each layer post-PRK was compared with the density in the corresponding layer of the pre-PRK full stroma (included stroma that would later be photoablated) and the pre-PRK future unablated stroma (thickness adjusted by omitting the future ablation depth) (Bonferroni-adjusted paired t test). RESULTS: Keratocyte density in the anterior 10% of the post-PRK stroma decreased by 25% (P =.002), 41% (P<.001), 40% (P<.001), 43% (P<.001), and 45% (P<.001) at 3, 6, 12, 24, and 36 months compared with the anterior 10% of the pre-PRK full stroma and was reduced by 15% at 36 months (P =.02) compared with the anterior 10% of the pre-PRK future unablated stroma. CONCLUSION: After PRK, keratocyte density in the anterior stroma is not restored to the high-density levels found in the preoperative stroma.

Adult↗

PubMed2003

What is the risk of developing pigmentary glaucoma from pigment dispersion syndrome?

PURPOSE: To determine the probability of converting from pigment dispersion syndrome to pigmentary glaucoma. DESIGN: Retrospective community-based study of all newly diagnosed cases of pigment dispersion syndrome or pigmentary glaucoma. METHOD: Subjects were patients newly diagnosed with pigment dispersion syndrome or pigmentary glaucoma from 1976 to 1999 in Olmsted County, Minnesota. Criteria for pigment dispersion syndrome were two of three signs: midperipheral, radial iris transillumination defects; Krukenberg spindle; heavy trabecular meshwork pigmentation. Criteria for pigmentary glaucoma were pigment dispersion syndrome and two of three findings: intraocular pressure (IOP) greater than 21 mm, optic nerve damage, or visual field loss. Kaplan-Meier survival curves were used to determine the probability of conversion to pigmentary glaucoma. RESULTS: A total of 113 patients were newly diagnosed with pigment dispersion syndrome over the 24-year period. Of these, 9 persons developed pigmentary glaucoma or elevated IOP requiring therapy. The probability of converting to pigmentary glaucoma was 10% at 5 years and 15% at 15 years. An additional 23 patients were found to have pigmentary glaucoma at their initial examination. The mean age at diagnosis of pigmentary glaucoma was 42 +/- 12 years; 78% of patients were male, whereas 58% of patients with pigmentary dispersion syndrome glaucoma were male. The most significant risk factor for conversion to pigmentary glaucoma was an IOP greater than 21 mm Hg at initial examination, whereas age, refractive error, and family history of glaucoma were not correlated with conversion. CONCLUSIONS: The risk of developing pigmentary glaucoma from pigment dispersion syndrome was 10% at 5 years and 15% at 15 years. Young, myopic men were most likely to have pigmentary glaucoma. An IOP greater than 21 mm Hg at initial examination was associated with an increased risk of conversion.

Adolescent↗

PubMed2003

Birth prevalence of visually significant infantile cataract in a defined U.S. population.

PURPOSE: To determine the birth prevalence of visually significant infantile cataract, using population-based comprehensive medical record retrieval, in a defined US population. DESIGN: Retrospective, population-based, medical record retrieval. METHODS: We reviewed records of all pediatric patients (0-17 years) coded as cataract during a 20-year period (1978 to 1997) using the resources of the Rochester Epidemiology Project. "Infantile cataract" was defined as a cataract diagnosed within the first year of life. "Possible infantile cataract" was defined as a cataract, diagnosed after the first year in a child born in Olmsted County, where there was no evidence of an acquired traumatic, acquired systemic, or acquired ocular etiology. Visually insignificant cataracts were excluded. RESULTS: Ten incident cases of visually significant infantile cataract were identified during the 20-year study period, yielding a birth prevalence of 3.0 per 10,000 live births (95% CI: 1.5-5.6 per 10,000). Five additional cases of visually significant "possible infantile cataract" were identified, diagnosed between the ages of 2 and 8 years. Inclusion of these "possible infantile cataracts" would result in an estimate of overall birth prevalence for visually significant infantile cataract of 4.5 per 10,000 live births (95% CI: 2.5-7.5 per 10,000). CONCLUSIONS: Using population-based medical record retrieval methods, we estimate the birth prevalence of visually significant infantile cataract to be 3.0 to 4.5 per 10,000. Infantile cataracts are an important cause of visual impairment in children and these data are useful in planning clinical trials and allocating health care resources.

Cataract↗

PubMed2003

Keratometric astigmatism after suture removal in penetrating keratoplasty: double running versus single running suture techniques.

BACKGROUND AND OBJECTIVE: To compare astigmatism after suture removal in a retrospective sequential series of patients who had penetrating keratoplasty with either a double running suture technique or an adjustable single running suture technique. During the first year postkeratoplasty, when sutures were in place, the latter technique had produced less astigmatism. MATERIALS AND METHODS: Keratometry and keratometric astigmatism were measured before and after suture removal. We compared these variables in 30 grafts with the double running suture technique to the same variables in 24 grafts with the single running suture technique. RESULTS: The final portion of the double running suture was removed 408 +/- 177 (mean +/- SD) days after keratoplasty, whereas the single running suture was removed 611 +/- 224 days after keratoplasty (P<0.001). After suture removal, there was no difference between the double running and single running groups in either mean keratometry [46.5 +/- 1.8 diopters (D) versus 45.6 +/- 2.0 D, P=0.09, minimum detectable difference (MDD)=1.5D] or mean astigmatism (4.6 +/- 2.7 D versus 5.2 +/- 3.2D, P=0.72, MDD=2.3). CONCLUSION: In this consecutive series of corneal transplants performed by one surgeon, the results suggest no difference in astigmatism between the two suturing techniques after all sutures have been removed.

Astigmatism↗

PubMed2003

Estimated incidence of pseudoexfoliation syndrome and pseudoexfoliation glaucoma in Olmsted County, Minnesota.

PURPOSE: To determine the incidence of newly diagnosed pseudoexfoliation syndrome and pseudoexfoliation glaucoma in residents of Olmsted County, Minnesota from 1976 to 1991. MATERIALS AND METHODS: The database of the Rochester Epidemiology Project was used to identify all patients residing in Olmsted County who were newly diagnosed with pseudoexfoliation syndrome from 1976 to 1991. The criterion used to diagnose pseudoexfoliation syndrome was the presence of pseudoexfoliation material on 1 or more anterior segment structures. Criteria used to diagnose pseudoexfoliation glaucoma were diagnosis of pseudoexfoliation syndrome with evidence of glaucomatous changes or ocular hypertension receiving therapy. The overall age and sex-adjusted annual incidences of pseudoexfoliation syndrome and pseudoexfoliation glaucoma, adjusted to the 1990 US white population, were determined with differences across age and sex using Poisson regression. RESULTS: Pseudoexfoliation syndrome was diagnosed in 290 patients (mean age, 73 +/- 10 years). Two hundred twenty-one (76%) were female. The overall age and sex-adjusted annual incidence of pseudoexfoliation syndrome was 25.9 per 100,000. The age-adjusted incidence was higher in females than in males (32.7 vs 16.9 per 100,000; P<0.001). Pseudoexfoliation syndrome diagnoses increased with age, from 2.8 per 100,000 in persons 40 to 49 years to 205.7 per 100,000 in persons > or =80 years (P<0.001). Thirty-five patients were excluded from pseudoexfoliation glaucoma diagnosis. Of the remaining 255 patients, 113 (44%) were diagnosed with pseudoexfoliation glaucoma during the study period (mean age, 76 +/- 10 years), 84 (74%) of whom were female. The overall age- and sex-adjusted annual incidence of pseudoexfoliation glaucoma was 9.9 per 100,000. The age-adjusted incidence was higher in females than in males (11.7 vs 7.2 per 100,000; P < 0.001). Pseudoexfoliation glaucoma was increasingly diagnosed with age, rising from 0.6 per 100,000 in persons 40 to 49 years to 114.3 per 100,000 in persons > or =80 years, (P<0.001). CONCLUSIONS: In a defined population, the estimated overall age- and sex-adjusted annual incidence of pseudoexfoliation syndrome was 25.9 per 100,000 population, while the estimated overall age- and sex-adjusted annual incidence of pseudoexfoliation glaucoma was 9.9 per 100,000 population. The incidence of both diseases was higher in females and increased with advancing age.

Adult↗

PubMed2003

Benign essential blepharospasm among residents of Olmsted County, Minnesota, 1976 to 1995: an epidemiologic study.

PURPOSE: To describe the incidence, patient demographics, and response to treatment of benign essential blepharospasm (BEB) in a population-based cohort. METHODS: In this epidemiologic study, we searched the Rochester Epidemiology Project database for patients diagnosed with blepharospasm or related disorders between 1976 and 1995. The incident rate denominator was based on a linear interpolation of decennial census data from Olmsted County. The 95% confidence interval for the incidence rate was based on the Poisson distribution. RESULTS: Olmsted County residents (n = 295) were diagnosed with blepharospasm or related disorders between 1976 and 1995. Of these, 8 patients met the criteria for BEB. The calculated incidence rate of BEB is 1.2 persons per 100,000 population per year (95% CI, 0.37 to 2.02). At the time of BEB diagnosis, the median patient age was 61.5 years, and symptoms had been present for a median of 24 months. Four patients were men and 4 were women. Four of the 8 patients had Meige syndrome. Three of 4 patients treated with oral medications reported symptomatic improvement. Botulinum toxin injection was offered to all patients, but only 4 elected treatment. All who were treated with botulinum toxin had temporary symptomatic improvement. No patient underwent surgical treatment for BEB. Two patients had resolution of symptoms within the follow-up period. CONCLUSIONS: BEB is a rare disorder. In this small, population-based sample, women and men were affected with equal frequency, and half of patients had lower facial dystonia (Meige syndrome). Only half of patients with BEB elected botulinum toxin injections, and none required surgery. Disease remission occurred in 2 of 8 patients.

Adult↗

PubMed2003

Prevalence and clinical outcomes of patients with multiple potential causes of syncope.

OBJECTIVE: To determine the prevalence, predictors, and prognosis of patients with multiple potential causes of syncope. PATIENTS AND METHODS: This is a retrospective cohort study with prospective follow-up of consecutive patients with syncope of uncertain cause who were referred to the electrophysiology service for syncope evaluation from January 1, 1996, through December 31, 1998. The main outcome measures were prevalence of multiple potential causes of syncope, survival of patients with multiple potential causes of syncope compared with survival of patients with a single cause, and clinical predictors of multiple potential causes of syncope. RESULTS: A total of 987 patients were studied (mean +/- SD age, 58.0 +/- 21.4 years; male, 550 [55.7%]). Multiple potential causes were present in 182 patients (18.4%). Patients with multiple potential causes of syncope had a lower survival rate at 4 years, 73.1% (95% confidence interval, 64.6%-82.8%), vs those with a single cause, 89.3% (95% confidence interval, 86.4%-92.2%) (P < .001). Multivariate predictors of multiple potential causes were older age, atrial fibrillation, use of cardiac medications, and New York Heart Association classification II, III, and IV. CONCLUSION: Of the patients evaluated for syncope, 18.4% had multiple potential causes. The presence of multiple potential causes was an independent predictor of increased mortality among patients with syncope.

Age Factors↗

PubMed2002

Sudden death after radiofrequency ablation of the atrioventricular node in patients with atrial fibrillation.

OBJECTIVES: We evaluated the incidence and predictors of sudden death after atrioventricular (AV) node ablation and pacemaker implantation. BACKGROUND: Sudden death may occur after radiofrequency catheter ablation of the AV node and pacemaker implantation in patients with atrial fibrillation (AF). Whether it is related to the procedure or to pre-existing heart disease remains unclear. METHODS: All patients who had radiofrequency catheter ablation of the AV node and pacemaker implantation for rate control of medically refractory AF were identified retrospectively and observed prospectively. All patients with sudden death after ablation were identified. The relationship between the procedure and sudden death was defined on the basis of the time between the two as "likely," "possibly" or "unlikely." RESULTS: Of 334 consecutive patients with AF who underwent AV node ablation, nine had sudden death after the ablation. Four patients (1.2%) had sudden death likely related to the procedure: in 3 patients, arrest occurred within 48 h after the procedure; in one patient, arrest occurred four days after the procedure. In three other patients (0.9%), sudden death was possibly related to the procedure because the event occurred within three months afterward. The remaining two deaths were unrelated to the procedure. Diabetes, New York Heart Association functional class (>or=II), preprocedure ventricular arrhythmia, mitral or aortic stenosis, aortic regurgitation and chronic obstructive pulmonary disease were independent predictors for sudden death. CONCLUSIONS: Sudden death likely or possibly related to catheter ablation occurred in 7 of 334 patients (2.1%). Risk of sudden death is highest within two days after the procedure.

Aged↗

PubMed2002

Prognostic value of the Duke treadmill score in the elderly.

OBJECTIVES: The purpose of this study was to test the hypothesis that the Duke treadmill score works less well for risk stratification in patients age 75 years or above. BACKGROUND: Although the Duke treadmill score is generally effective for risk stratification, its prognostic value in the elderly may be limited because they have a higher prevalence of coronary artery disease (CAD), more severe CAD and a lower exercise tolerance. METHODS: The study population consisted of 247 patients age 75 years or above, and the control population consisted of 2,304 patients below 75 years of age. All patients were symptomatic, had undergone exercise thallium testing between 1989 and 1991 and were followed for a median of >6.5 years. The Cox regression model was used to test the association of the Duke score (utilized both as a continuous variable and using previously published risk group cutoffs) with outcomes (cardiac death, nonfatal myocardial infarction [MI], late revascularization). RESULTS: Using the Duke score to risk-stratify the elderly, 26% were in the low risk group, 68% were in the intermediate risk group and 6% were in the high risk groups; seven-year cardiac survival was 86%, 85% and 69%, respectively (p = 0.45). There was also no significant association between these Duke score risk groups and all other outcome end points in the elderly. The Duke score as a continuous variable did not predict cardiac death (p = 0.43) or cardiac death or MI (p = 0.42), but did predict total cardiac events (which included late revascularization) (p = 0.0027). For the control population, more patients (55%) were in the low risk group, and the Duke score (as a continuous variable or in risk groups) was highly predictive of all end points (p = 0.0001). CONCLUSIONS: The Duke score predicted cardiac survival in younger patients but not in patients age 75 years or above. The majority of the elderly were classified as intermediate risk by the Duke score. Only a minority of the elderly were classified as low risk, but this group still had an annual cardiac mortality of 2%/year.

Age Factors↗

PubMed2002

Effects of adjustment for referral bias on the sensitivity and specificity of single photon emission computed tomography for the diagnosis of coronary artery disease.

PURPOSE: Referral bias, in which the result of a diagnostic test affects the subsequent referral for a more definitive test, influences the accuracy of noninvasive tests for coronary artery disease. This study evaluates the effect of referral bias on the apparent accuracy of single photon emission computed tomography (SPECT). METHODS: Over a 10-year period, 14,273 patients without known coronary artery disease underwent stress SPECT. Coronary angiography was performed within 3 months after the stress test in 1853 patients (13%). The apparent sensitivity, specificity, and likelihood ratios of SPECT were determined in these patients, and then adjusted for referral bias using two different formulas. RESULTS: The overwhelming majority (95%) of patients who underwent angiography had abnormal SPECT images. Apparent values for test indices were a sensitivity of 98%, a specificity of 13%, a likelihood ratio for a positive test of 1.1, and a likelihood ratio for a negative test of 0.15. Test indices adjusted for referral bias (using the two methods) were a sensitivity of 65% or 67%, a specificity of 67% or 75%, a likelihood ratio for a positive test of 2.0 or 2.7, and a likelihood ratio for a negative test of 0.44 or 0.52. CONCLUSION: Referral bias has a marked effect on the apparent accuracy of stress SPECT for the diagnosis of coronary disease. Adjustment for referral bias yields estimates for sensitivity and specificity and likelihood ratios that better reflect the accuracy of the technique.

Adenosine↗

PubMed2002

Pupillary response to four concentrations of pilocarpine in normal subjects: application to testing for Adie tonic pupil.

PURPOSE: To determine the amount of pupillary constriction to four different concentrations of pilocarpine in normal human subjects and to determine if pupillary constriction correlates with bioavailability of the instilled concentrations. The amount of pupillary constriction to dilute pilocarpine is utilized as a diagnostic test for Adie tonic pupil as distinguished from a normal pupil response. DESIGN: Twenty healthy volunteers had automated binocular infrared pupillography in the dark after instillation of four different concentrations of dilute pilocarpine. Ocular penetration of eye drops was also assessed using 2% fluorescein sodium as a tracer. METHODS: Prospective institutional double-masked study of both eyes of twenty healthy volunteers, ten with brown irides, ten with blue irides, between the ages of 20-40 years. RESULTS: A pilocarpine dose-dependent curve showed decreased pupil size within 15 minutes, peaking at 30-60 minutes. No difference was noted between right and left eyes, iris color, or corneal permeability. CONCLUSIONS: Normal pupils constrict to dilute concentrations of pilocarpine (0.25% or 0.125%), but constrict insignificantly to concentrations of 0.0313% or 0.0625%. Pupil constriction with 0.0625% pilocarpine should distinguish an Adie pupil from normal. This confirms the utility of this simple office diagnostic procedure.

Adult↗

PubMed2002

Keratocyte density of central human cornea after laser in situ keratomileusis.

PURPOSE: To determine changes in keratocyte density in the first year after laser in situ keratomileusis (LASIK). DESIGN: Prospective interventional cohort study. METHODS: Seventeen eyes of 11 patients received LASIK with a planned 180-microm flap to correct refractive errors between -2.0 diopters and -11.0 diopters. Images of the full-thickness cornea were obtained by using confocal microscopy in vivo before LASIK and at 1 week, 1, 3, 6, and 12 months after LASIK. Bright objects (that resembled keratocytes) in images without motion blur were manually counted by one observer. Cell densities were determined in anterior and posterior halves of the stromal flap, anterior and posterior halves of the layer 100 microm-thick immediately deep to the ablation (retroablation layer), and in the posterior third of the stroma. The region of stroma that was ablated (as measured 1 month after LASIK) was omitted from the preoperative analysis. RESULTS: Keratocyte density in the anterior flap was 28,978 +/- 5849 cells/mm(3) (mean +/- SD) pre-LASIK, and was decreased at all postoperative examinations, but the difference was not significant until 12 months after LASIK (22% decrease). Keratocyte densities in the posterior flap were 20,397 +/- 4215 cells/mm(3) pre-LASIK and were decreased by 20%-40% at all postoperative examinations 1 week to 1 year after LASIK. Keratocyte densities in the anterior half of the retroablation layer were 16,605 +/- 3595 cells/mm(3) pre-LASIK and decreased by 16%-30% between 3 and 12 months after LASIK. Keratocyte densities in the posterior half of the retroablation layer and posterior stroma did not change. CONCLUSIONS: Keratocyte densities in the posterior flap and anterior retroablation layer (regions adjacent to the lamellar cut) decrease at 1 week and 3 months, respectively, after LASIK and remain decreased in these regions at 12 months after LASIK. In the anterior flap, keratocyte density decreases 1 year after LASIK. The long-term effects of these cellular deficits, if any, require further study.

Adult↗

PubMed2002

Blindness and glaucoma: a comparison of patients progressing to blindness from glaucoma with patients maintaining vision.

PURPOSE: To compare patients becoming legally blind from glaucoma with those who did not go blind. DESIGN: Retrospective, cohort, and case-control study. METHODS: A retrospective community-based longitudinal study of residents of Olmsted County, Minnesota, who were newly diagnosed with open-angle glaucoma between 1965 and 1980 and followed through 1998. A case-control study was performed comparing patients progressing to legal blindness from glaucoma with aged-matched and visual field-matched patients not progressing to blindness. RESULTS: Fifty-six of 290 patients progressed to legal blindness in at least one eye over the 34-year period of the study. Most who progressed to blindness had moderate to advanced visual field loss at the time of diagnosis of glaucoma. Those becoming legally blind had mean intraocular pressures (IOP) on therapy lower than or similar to patients who did not go blind, although the variability of IOP was higher in the blind group. Different susceptibilities to IOP were apparent, as some eyes with initially normal disks and visual fields became blind at an IOP of 20 mm, while others did not worsen. Changes in medical therapy after progression of visual field damage were less effective in lowering IOP in the group becoming blind than in the nonblind group. CONCLUSIONS: Patients at greatest risk of blindness had visual field loss at the time of diagnosis of glaucoma. Different susceptibilities to IOP were apparent, with some patients becoming blind at pressures that others tolerated without significant progression. This suggests that continued monitoring of visual fields and reassessment of target IOP levels when field damage occurs are fundamental in the management of glaucoma.

Aged↗

PubMed2002

Keratocyte density in keratoconus. A confocal microscopy study(a).

PURPOSE: To estimate keratocyte density in human corneas with keratoconus by confocal microscopy. DESIGN: Prospective, observational cohort study. METHODS: Twenty-nine unscarred corneas of 19 patients with keratoconus and 29 corneas of 19 controls matched for age (+/-3 years) and contact lens wear were examined by using confocal microscopy. Images were recorded from the full-thickness central cornea. A masked observer manually counted bright objects (keratocyte nuclei) in images without motion blur. Cell densities in anteroposterior stromal layers of keratoconus corneas were compared with densities in corresponding layers of control corneas. RESULTS: In keratoconus patients, age 40 +/- 15 years (mean +/- standard deviation), keratocyte density was 19% lower in those who wore contact lenses (16,894 +/- 4032 cell/mm(3), n = 12) than in those who did not wear contact lenses (20,827 +/- 4934 cell/mm(3), n = 17, P =.03). In control patients, age 39 +/- 16 years, there was no difference in keratocyte density between those who wore contact lenses (n = 12) and those who did not wear contact lenses (n = 17, P =.80). Among contact lens wearers, keratocyte density was 25% lower in keratoconus corneas (16,894 +/- 4, 032 cell/mm(3), n = 12 [9 = rigid gas-permeable lenses, 3 = soft lenses]) than in control corneas (22,579 +/- 2, 387 cell/mm(3), n = 12 [3 = rigid gas-permeable lenses, 9 = soft lenses], P =.002), the result of cell density being lower in the most anterior keratocyte layer (P =.001) and the layers between 0% to 10% (P <.001), 67% to 90% (P <.001), and 91% to 100% (P <.001) of stromal thickness. Among noncontact lens wearers, there was no difference in cell density between keratoconus and controls (P =.41). CONCLUSION: Keratocyte density is decreased in the anterior and posterior stroma of keratoconus patients who wear contact lenses.

Adult↗

PubMed2002

Effect of myopic laser in situ keratomileusis on epithelial and stromal thickness: a confocal microscopy study.

PURPOSE: To determine changes in central epithelial and stromal thickness in human corneas in vivo after laser in situ keratomileusis (LASIK). DESIGN: Prospective, nonrandomized, comparative trial. PARTICIPANTS: Eighteen eyes of 12 patients received LASIK (performed using the VISX Star laser [VISX, Santa Ana, CA]) with a planned 180- micro m flap (created using an automated Hansatome microkeratome [Bausch & Lomb, Irvine, CA]) to correct refractive errors between -2.0 diopters (D) and -11.0 D. METHODS: Corneas were examined by using confocal microscopy in vivo before LASIK and at 1 week and 1, 3, 6, and 12 months after LASIK. Epithelial thickness was the distance between images of the surface epithelium and subbasal nerve plexus or, when nerves were not visible, the subbasal peak (if present in the light intensity profile). Total flap thickness was the distance between images of the surface epithelium and interface debris (or peak), and total stromal thickness was the distance between images of the most anterior keratocytes and endothelium. MAIN OUTCOME MEASURES: Corneal epithelial and stromal thickness. RESULTS: Epithelial thickness before LASIK was 46 +/- 5 micro m (mean +/- standard deviation) and increased 22% by 1 month after LASIK (56 +/- 5 micro m; P = 0.01). Thereafter, epithelial thickness did not change, but remained thicker at 12 months after LASIK (54 +/- 8 micro m) than before LASIK (P = 0.02). Total flap thickness at 1 month after LASIK was 160 +/-28 micro m and did not change thereafter. Changes in total stromal thickness between 1 and 12 months after LASIK were not significant. CONCLUSIONS: The central corneal epithelium was thicker in the first year after LASIK than before LASIK. There was no change in central stromal thickness between 1 month and 12 months after LASIK.

Adult↗

PubMed2002

Long-term outcome and the use of revascularization in patients with heart failure, suspected ischemic heart disease, and large reversible myocardial perfusion defects.

BACKGROUND: The potential role of coronary revascularization in the management of patients with congestive heart failure and suspected ischemic heart disease remains to be defined. Myocardial perfusion imaging can identify patients with ischemic heart disease as the etiology for left ventricular dysfunction who might benefit from revascularization. METHODS: We retrospectively identified heart failure patients with suspected ischemic heart disease who had large reversible perfusion defects to determine their long-term outcome and rate of revascularization. The study group consisted of 77 patients with congestive heart failure, left ventricular ejection fraction <45%, and suspected ischemic heart disease who underwent myocardial perfusion imaging during the period of January 1, 1991, to December 31, 1997, and had large reversible perfusion defects. RESULTS: The 5-year mortality rate was 57.6%. The revascularization rate was only 13% for 5 years of follow-up. The number of patients undergoing revascularization was too small to assess its impact on outcome. CONCLUSION: These results indicate a high 5-year mortality rate and a low utilization of coronary revascularization in patients with heart failure and large reversible perfusion defects. The low rate of revascularization reflects at least in part the absence of the generalizability of the existing literature to the optimal means of treating patients with heart failure and myocardial ischemia and points to the need for a randomized clinical trial.

Aged↗