Evaluation of cochlear implant electrode scalar position by 3 Tesla magnet resonance imaging.

The estimation of scalar electrode position is a central point of quality control during the cochlear implant procedure. Ionic radiation is a disadvantage of commonly used radiologic estimation of electrode position. Recent developments in the field of cochlear implant magnets, implant receiver magnet position, and MRI sequence usage allow the postoperative evaluation of inner ear changes after cochlear implantation. The aim of the present study was to evaluate the position of lateral wall and modiolar cochlear implant electrodes using 3 T MRI scanning. In a prospective study, we evaluated 20 patients (10× Med-El Flex 28; 5× HFMS AB and 5× SlimJ AB) with a 3 T MRI and a T2 2D Drive MS sequence (voxel size: 0.3 × 0.3 × 0.9 mm) for the estimation of the intracochlear position of the cochlear implant electrode. In all cases, MRI allowed a determination of the electrode position in relation to the basilar membrane. This observation made the estimation of 19 scala tympani electrode positions and a single case of electrode translocation possible. 3 T MRI scanning allows the estimation of lateral wall and modiolar electrode intracochlear scalar positions.

Electrode Afterload: A Valuable Technique in a Case of Short Electrode Insertion.

Introduction. The location of the electrode inside the cochlea is important for speech performance. However, many variables, including array length, insertion depth, and individual anatomy, may affect the intracochlear position of the electrode. Insertion deeper than 20 mm and revision surgery are critical situations in which residual hearing and electrode integrity may be at risk. This case report challenges this hypothesis and raises the following question: is it possible to achieve a better speech understanding with an electrode afterload without compromising residual hearing? Case Report. A 73-year-old female patient showed up for evaluation of hearing loss. The patient was operated four times in an external hospital due to cholesteatoma formation in the right ear. Related to a poor aided speech understanding, a CI-surgery was performed. 5 months after the surgery, the subject returned with poor speech understanding. A revision surgery was performed, where the first white marker of the electrode was seen in the round window (20 mm). The electrode was inserted 4 mm deeper into the cochlea. After six and twelve months, the results of the Freiburger monosyllabic speech test improved till 25% and 45%, respectively. Discussion. Hearing preservation is possible with a revisional deeper insertion from 20 mm to 24 mm. In this case, a partial obliteration of an open cavity made the electrode surgically easily accessible. This allowed the deeper insertion during the revision surgery. In a regular surgical field with a posterior tympanotomy, the revision surgery is more challenging and brings the electrode into the risk of an iatrogenic destruction. Conclusion. This case of an electrode afterload after having inserted the electrode initially to mm, demonstrates that hearing can be preserved and speech perception can improve after performing this maneuver.

Dynamic intracochlear pressure measurement during cochlear implant electrode insertion.

Background: Electrode insertion into the cochlea can cause significant pressure changes inside the cochlea with assumed effects on the cochlea's functionality regarding residual hearing. Model-based intracochlear pressure (ICP) changes were performed statically at the cochlear helix. Aims/objectives: The aim of this study was to observe dynamic pressure measurements during electrode insertion directly at the cochlear implant electrode. Material and methods: The experiments were performed in an uncurled cochlear model that contained a volume value equivalent to a full cochlea. A microfibre pressure sensor was attached at one of two positions on a cochlear implant electrode and inserted under different insertional conditions. Results: We observed the ICP increase depending on the insertional depth. A sensor-position-specific pressure change is insertional-depth dependent. Interval insertion did not lead to a lower peak insertional ICP. Conclusions and significance: In contrast to the static pressure-sensor measurement in the artificial model's helix, a dynamic measurement directly at the electrode shows the pressure profile to increase based on the insertional depth. A mechanical traumatic relevance of the observed pressure values cannot be fully excluded.

The Pull-Back Technique for the 532 Slim Modiolar Electrode.

INTRODUCTION: The distance between the modiolus and the electrode array is one factor that has become the focus of many discussions and studies. Positioning the electrode array closer to the spiral ganglion with the goal of reducing the current spread has been shown to improve hearing outcomes. The perimodiolar electrode arrays can be complemented with a surgical manoeuvre called the pull-back technique. This study focuses its attention on the recently developed 532 slim modiolar electrode. OBJECTIVE: To investigate the intracochlear movements and pull-back technique for the 532 slim modiolar electrode. MATERIAL AND METHODS: A decapping procedure of the cochlea was performed on 5 temporal bones. The electrode array was inserted, and the intracochlear movements were microscopically examined and digitally captured. Three situations were analysed: the initial insertion, the overinsertion, and the pull-back position. The position of the three white markers of the electrode array in relation to the round window (RW) was evaluated while performing these three actions. RESULTS: The initial insertion achieved an acceptable perimodiolar position of the electrode array, but a gap was still observed between the mid-portion of the array and the modiolus (the first white marker was seen in the RW). When we inserted the electrode more deeply, the mid-portion of the array was pushed away from the modiolus (the second and third white markers were seen in the RW). After applying the pull-back technique, the gap observed during the initial insertion disappeared, resulting in an optimal perimodiolar position (the first white marker was once again visible in the RW). CONCLUSION: This temporal bone study demonstrated that when applying the pull-back technique for the 532 slim modiolar electrode, a closer proximity to the modiolus was achieved when the first white marker of the electrode array was visible in the round window.

Intraoperative optical coherence tomography in macula involving rhegmatogenous retinal detachment repair with pars plana vitrectomy and perfluoron.

PurposeTo investigate microanatomical relationships during surgical repair of macula involving retinal detachment with pars plana vitrectomy (PPV) and perfluoron (PFO) with a microscope-integrated intraoperative optical coherence tomography (iOCT) device.Patients and methodsThis consecutive case series included nine eyes of nine patients with macula involving retinal detachment operated by a single surgeon at the Cincinnati Eye Institute. All patients underwent PPV, PFO injection, endolaser, and air-fluid exchange. The macula was imaged with iOCT before PFO injection, after PFO injection, and after air-fluid exchange in all eyes.ResultsiOCT imaging was ergonomically easy to obtain in all eyes. iOCT clearly demonstrated submacular fluid (SMF) at the beginning of the surgery, macular flattening under PFO in all eyes, small residual SMF under PFO in six of nine eyes, and increased occult SMF following air-fluid exchange in all eyes.ConclusionMicroscope-integrated iOCT is a versatile and powerful imaging modality that holds a great deal of promise in the future. Its confirmation of persistent occult SMF in this small series of macular involving retinal detachment repair with PFO, may inform surgical decision making, and demonstrates a pathophysiological rationale for initial face-down positioning after retinal detachment repair.

Analysis of long-term outcomes for combined pars plana vitrectomy (PPV) and glaucoma tube shunt surgery in eyes with advanced glaucoma.

PURPOSE: To analyze 12- and 24-month visual acuity, intraocular pressure, and complications associated with combined pars plana vitrectomy (PPV) and glaucoma tube shunt placement in eyes with glaucoma. PATIENTS AND METHODS: A retrospective chart review was performed of patients with advanced glaucoma who underwent combined PPV and tube shunt surgery from 2006 to 2010. A minimum of 12 months of follow-up was required for their inclusion in the study. Visual acuity, intraocular pressure, complications, and number of glaucoma medications at 1 and 2 years postoperatively were analyzed. RESULTS: Twenty-eight eyes met the inclusion and exclusion criteria. Baseline visual acuity was 20/200 or worse in 14/28 eyes (50.0%) and 20/40 or better in 2/28 eyes (7.1%). Visual acuity remained 20/200 or worse in 50.0% (P=0.921) and 44.4% (P=0.973) of eyes after 1 and 2 years postoperatively, respectively. At baseline, the mean intraocular pressure was 30.4 mm Hg. There was significant improvement in mean IOP at 1 year (14.7 mm Hg, P=0.001) and at 2 years (15.2 mm Hg, P=0.001) postoperatively. Baseline number of glaucoma medications averaged 3.0±1.09 (SD), and improved to 1.8±1.28 (SD) at 1 year (P=0.0002) and to 1.4±1.33 at 2 years (P<0.0001) postoperatively. CONCLUSION: In this retrospective interventional case series, surgical management of advanced glaucoma with a combination of PPV and glaucoma tube shunt resulted in significantly reduced IOP and glaucoma medications at 1 and 2 years postoperatively.

Retinal tears after posterior vitreous detachment and vitreous hemorrhage in patients on systemic anticoagulants.

UNLABELLED: AIMS OR PURPOSE: To determine the rate of retinal tears (RTs) after posterior vitreous detachment (PVD) and vitreous hemorrhage (VH) in patients on systemic anticoagulants. METHODS: In all, 260 eyes of 260 patients with an acute PVD and VH were followed for evidence of an RT or detachment. Patients were divided into those taking systemic anticoagulants and those not taking anticoagulants. RESULTS: A total of 137 patients (53%) were taking anticoagulants, 123 (47%) were not. Overall, 72% of patients not taking any anticoagulant had evidence of an RT, whereas 46% of patients taking an anticoagulant had an RT (P-value 0.0002). Also, 37% of patients not taking an anticoagulant had a retinal detachment (RD), whereas 23% of patients taking any anticoagulant had an RD (P-value 0.01). CONCLUSIONS: In patients with an acute PVD and VH using anticoagulants, RTs and RDs were common. Anticoagulation status may be an important contributing factor in predicting the incidence of an RT or detachment.

Indocyanine green-assisted peeling of the retinal internal limiting membrane during vitrectomy surgery for macular hole repair.

OBJECTIVE: To determine the efficacy and safety of indocyanine green (ICG)-assisted retinal internal limiting membrane (ILM) peeling during macular hole repair. DESIGN: Interventional, noncomparative, prospective case series. PARTICIPANTS: Twenty-four consecutive patients (24 eyes) with stage 3 or 4 macular holes. INTERVENTION: All eyes underwent a pars plana vitrectomy, including peeling of the posterior cortical hyaloid when necessary. Indocyanine green dye (0.5%) was instilled into the posterior vitreous cavity over the macula and left in place for 3 to 5 minutes. After removal of the ICG, the retinal ILM was peeled. Medium- to long-acting gas tamponade was used in all cases, and all patients were asked to position face down for 1 to 2 weeks. MAIN OUTCOME MEASURES: Intraoperative staining properties of ICG, technical ease of peeling of the retinal ILM, postoperative anatomic results, visual acuity, and complications were recorded. RESULTS: Indocyanine green stained the retinal ILM, but did not stain the underlying retina. Indocyanine green staining greatly facilitated the surgeons' ability to visualize and peel the ILM in each case. Peeled tissue was sent for both light and electron microscopic studies, which confirmed that the ICG-stained tissue was truly retinal ILM. Patients were observed after surgery for an average of 123 days (range, 23-195 days). Anatomic closure of the macular hole was achieved in 21 eyes (88%) with a single surgery. Visual acuity improved in 23 of 24 patients (96%) after surgery. There were no intra- or postoperative complications related to ICG use, and there was no clinical or fluorescein angiographic evidence of ICG toxicity. CONCLUSIONS: Indocyanine green stains the retinal ILM. This property facilitates ILM peeling by providing a stark contrast between the stained ILM and the unstained retina. Indocyanine green staining of the ILM appears to be a safe and useful adjunct in vitreous surgery for macular hole repair.

Anterior transposition of the inferior oblique muscle as the initial treatment of a snapped inferior rectus muscle.

Snapping or tearing of an extraocular muscle refers to its rupture across its width, usually at the junction between muscle and tendon several millimeters behind the insertion. Tearing occurs during strabismus or retinal reattachment surgery, or after trauma. If the proximal end of the muscle cannot be located, transposition procedures are necessary to achieve ocular realignment. These surgical procedures carry the risk of anterior segment ischemia, especially in the elderly. Anterior transposition of the inferior oblique muscle has been used for the treatment of inferior oblique overaction, especially in the presence of a dissociated vertical deviation, and in patients with fourth nerve palsy. We transposed the inferior oblique muscle insertion in a 73-year-old woman with a snapped inferior rectus muscle.

Macular traction detachment and diabetic macular edema associated with posterior hyaloidal traction.

PURPOSE: To review the clinical, photographic, fluorescein angiographic, and optical coherence tomographic findings in patients with the diabetic macular traction and edema (DMTE) associated with posterior hyaloidal traction (PHT). METHODS: We performed a prospective review of nine eyes of nine patients with diabetic macular edema (DME) and PHT on clinical examination. The patients had a comprehensive ophthalmic history and examination, color photographs, fluorescein angiography, and optical coherence tomography (OCT). RESULTS: All patients had diabetic retinopathy and DME. Of the nine eyes, eight patients had previous focal or grid photocoagulation. All nine eyes had a thickened, taut, glistening posterior hyaloid on clinical biomicroscopic examination with no posterior vitreous separation. Fluorescein angiography was performed on seven eyes, and all had early hyperfluorescence with deep, diffuse, late leakage in the macular area consistent with DMTE associated with PHT. Optical coherence tomography scans of the macular region revealed retinal thickening in all eyes with a mean retinal thickness of 556.9 +/- 114.7 microns. In addition, eight of the nine eyes had a shallow macular traction detachment associated with PHT. CONCLUSION: Eyes with DME associated with PHT may have a shallow, subclinical, macular detachment. Optical coherence tomography may be useful in evaluating patients with DME to see if a macular detachment is present.

Ocular fixation to nasal periosteum with a superior oblique tendon in patients with third nerve palsy.

PURPOSE: To report a new surgical approach that uses ocular fixation to the nasal periosteum with superior oblique tendon for patients with complete third nerve palsy. METHODS: Prospective study of 15 patients with complete third nerve palsy who underwent surgery using a superior oblique tenectomy and ocular fixation to the nasal periosteum with the superior oblique tendon fragment. RESULTS: Eleven (73%) patients achieved good ocular alignment, 1 (7%) patient had a cosmetically acceptable result, and 3 (20%) patients had a cosmetically unacceptable result. Five (30%) patients had preoperative diplopia; all achieved resolution of their double vision in the primary position of gaze after surgery. Two patients without preoperative diplopia did not achieve good alignment and had diplopia postoperatively. Follow-up ranged from 8-41 months (mean: 19 months). No operative complications occurred. CONCLUSION: Ocular fixation to the nasal periosteum with superior oblique tendon is a safe, effective, and technically undemanding option for the surgical management of patients with complete third nerve palsy.

A comparison of manual kinetic and automated static perimetry in obtaining ptosis fields.

OBJECTIVE: To compare examination time and visual field loss for ptosis fields obtained with manual kinetic (Goldmann) perimetry and automated static (Humphrey) perimetry. METHODS: Both eyes of 12 patients with bilateral aponeurogenic ptosis were prospectively examined using Goldmann and Humphrey (ptosis protocol) perimetry with the eyelids ptotic and taped into a normal position. RESULTS: Bilateral examination time for Goldmann fields was 10 +/- 2 minutes and for Humphrey fields was 50 +/- 10 minutes (P<.001, n = 12). Superior fields at the 12:00 meridian were 46 degrees +/- 6 degrees taped, and 28 degrees +/- 12 degrees untaped for Goldmann perimetry (P<.001), and 38 degrees +/- 8 degrees taped, and 24 degrees +/- 12 degrees untaped for Humphrey perimetry P<.001). Goldmann field loss was 18 degrees +/- 9 degrees (taped minus untaped). Humphrey field loss was 14 degrees +/- 13 degrees (P<.04, n = 24). Mean Goldmann radial fields were 56 degrees +/- 6 degrees taped and 39 degrees +/- 13 degrees untaped (P<.001). Goldmann superior hemifield areas were 5,167 +/- 964 degrees2 taped and 2,830 +/- 1,466 degrees2 untaped (P<.001). Humphrey mean vertical superior hemifield was 37 degrees +/- 9 degrees taped and 21 degrees +/- 11 degrees untaped (P<.001). Mean sensitivity of Humphrey fields was 15 +/- 3 dB taped and 9 +/- 5 dB untaped (P<.001). Mean vertical center of gravity was 23 degrees +/- 3 degrees taped and 16 degrees +/- 5 degrees untaped (P <.001). CONCLUSION: Goldmann manual kinetic and Humphrey automated static visual field testing are both effective in documenting ptosis associated visual field loss. Humphrey automated ptosis fields, as performed in this study, require longer examination times than Goldmann manual fields and may be a less sensitive indicator of field loss.

Vertical fusional amplitudes in patients wearing vertical anisometropic correction.

OBJECTIVE: To examine the relationship between vertical anisometropic spectacle correction and vertical fusional amplitudes in patients. DESIGN: Comparative observational case series. PARTICIPANTS: Twenty-one patients exposed to greater than 0.5 diopters of vertical anisometropic spectacle correction were compared with 46 patients not exposed to anisometropic correction. METHODS: Vertical fusional amplitudes were recorded in all patients using a prism bar. MAIN OUTCOME MEASURES: Vertical fusional amplitudes and vertical anisometropia. RESULTS: In patients exposed to greater than 0.5 diopters of vertical anisometropic spectacle correction, vertical fusional amplitudes measured 5.2+/-1.4 prism diopters. Patients not exposed to anisometropic correction had vertical fusional amplitudes of 2.7+/-1.2 prism diopters (P < 0.0001). CONCLUSION: Patients with vertical anisometropic correction have increased vertical fusional amplitudes. This finding is relevant when evaluating patients with ocular motility disorders, especially with regard to distinguishing acquired versus longstanding deviations.

Haemophilus influenzae associated scleritis.

AIMS: To describe the clinical course and treatment of Haemophilus influenzae associated scleritis. METHODS: Retrospective case series. RESULTS: Three patients developed scleritis associated with ocular H influenzae infection. Past medical history, review of systems, and laboratory testing for underlying collagen vascular disorders were negative in two patients. One patient had arthritis associated with an antinuclear antibody titre of 1:160 and a Westergren erythrocyte sedimentation rate of 83 mm in the first hour. Each patient had ocular surgery more than 6 months before developing scleritis. Two had cataract extraction and one had strabismus surgery. Nodular abscesses associated with areas of scleral necrosis were present in each case. Culture of these abscesses revealed H influenzae in all patients. Treatments included topical, subconjunctival, and systemic antibiotics. Scleral inflammation resolved and visual acuity improved in each case. CONCLUSION: H influenzae infection may be associated with scleritis. Accurate diagnosis and treatment may preserve ocular integrity and good visual acuity.

Direct orbital manometry in patients with thyroid-associated orbitopathy.

PURPOSE: To determine orbital tissue tension and orbital compartment compliance in patients with and without thyroid-associated orbitopathy (TAO). DESIGN: Prospective case series. PARTICIPANTS: Orbits of patients with TAO (18 orbits) and control patients without TAO (35 orbits) were studied. METHODS: An orbital manometer was designed to directly measure orbital tissue tension in patients undergoing ocular or orbital surgery. MAIN OUTCOME MEASURES: Tissue tension was recorded before, during, and for 5 minutes after a 5-ml retrobulbar injection of anesthetic. Orbital compliance was calculated as change in volume divided by change in tissue tension. RESULTS: Resting orbital tissue tension was 4.4 +/- 2.2 mmHg (mean +/- SD) in normal orbits and 9.7 +/- 4.8 mmHg in orbits of TAO patients (P = 0.0005) Following retrobulbar injection, orbital tissue tension rose to 12.0 +/- 3.6 mmHg (P = 0.0000000000000006 compared with baseline) in the control group and to 36.3 +/- 15.2 mmHg in the TAO group (P = 0.0000007 compared with baseline, and P = 0.000008 TAO group versus control group). Orbital compartment compliance was 0.80 +/- 0.50 ml/mmHg in the control group and 0.27 +/- 0.21 ml/mmHg in the TAO group (P = 0.00001). Resting orbital tissue tension in 8 TAO orbits with compressive optic neuropathy was 12.4 +/- 4.9 mmHg, and was 7.8 +/- 3.5 mmHg in 10 orbits of TAO patients without compressive optic neuropathy (P < 0.05). No adverse events occurred. CONCLUSIONS: Retrobulbar injection causes consistent measurable changes in orbital tissue tension. Orbital manometry safely demonstrated higher orbital tissue tension and lower orbital compartment compliance in the orbits of TAO patients versus those of normal subjects. Resting orbital tissue tension was higher in the orbits of TAO patients with compressive optic neuropathy than in those orbits without. Compressive optic neuropathy may partially result from an orbital compartment syndrome in some patients with TAO. Directly assessing orbital dynamics in vivo may prove useful as an adjunct in the clinical evaluation of patients with TAO and other orbital disorders.

Direct orbital manometry in healthy patients.

PURPOSE: To determine orbital tissue tension and orbital compartment compliance in normal patients. METHODS: An orbital manometer was designed to directly measure orbital tissue tension before, during, and after a 5-ml retrobulbar injection of anesthetic in patients undergoing ocular surgery. Tissue tension was recorded for 5 minutes after the injection. Orbital compliance was calculated as change in volume divided by change in pressure. Data were collected from 18 normal orbits. RESULTS: Resting orbital tissue tension was 4.0 +/- 1.5 mmHg (mean +/- standard deviation). After retrobulbar injection, orbital tissue tension rose to 11.6 +/- 2.6 mmHg (p = 0.00000000009 compared with baseline). After 5 minutes, tissue tension declined to 6.6 +/- 1.9 mmHg (p = 0.00000001 compared with preinjection and p = 0.00002 compared with postinjection). Orbital compartment compliance was 0.74 +/- 0.31 ml/mmHg. No adverse events occurred. CONCLUSIONS: The authors' orbital manometer safely determined orbital tissue tension and orbital compartment compliance in normal orbits. Retrobulbar injection causes consistent measurable changes in orbital tissue tension. Directly assessing orbital dynamics in vivo may prove useful both as an adjunct in the clinical evaluation of patients with disorders resulting in an orbital compartment syndrome as well as in assessing the risk of retrobulbar injection in orbits at greater risk for complications from this procedure.

Ionic contrast agent-mediated endothelial injury causes increased platelet deposition to vascular surfaces.

Contrast agent-mediated endothelial injury may be clinically relevant to the development of acute thrombosis after coronary interventions. We sought to investigate the extent to which contrast agents increase platelet deposition by measuring deposition of indium-111 radiolabeled platelets in an isolated perfused rabbit carotid artery model. Carotid artery segments were perfused at physiologic temperature, pressure, and shear. Vessels were subjected to angioplasty or no angioplasty before exposure to either buffer, diatrizoate (high osmolal/ionic), ioxaglate (low osmolal/ionic), or ioversol (low osmolal/nonionic). Subsequent deposition of indium-111 radiolabeled platelets was quantified. In vessels without balloon angioplasty, platelet deposition (platelets/cm2) was 110,000 +/- 95,000 for buffer perfused vessels, 280,000 +/- 210,000 for vessels perfused with diatrizoate, 290,000 +/- 160,000 for vessels perfused with ioxaglate, and 130,000 +/- 98,000 for vessels perfused with ioversol. After balloon angioplasty, platelet deposition was 1,300,000 +/- 590,000 for buffer controls, 1,800,000 +/- 320,000 for diatrizoate-perfused vessels, 1,500,000 +/- 450,000 for ioxaglate-perfused vessels, and 1,000,000 +/- 180,000 for ioversol-perfused vessels. In vessels without balloon angioplasty, diatrizoate and ioxaglate increased platelet deposition 2.5-fold and 2.6-fold, respectively, relative to buffer-perfused vessels (p < 0.05 and p < 0.01), whereas no increase was seen with ioversol. After balloon angioplasty, diatrizoate increased platelet deposition 1.4-fold over control (p < 0.05), whereas ioxaglate and ioversol showed no statistically significant increase. We conclude that ionic contrast media may cause more endothelial injury and associated localized platelet deposition than nonionic contrast media. These findings may be relevant to coronary interventions, specifically with regard to acute closure and chronic restenosis.

Spontaneous and glucocorticoid-inhibited adrenocorticotropic hormone and cortisol secretion are similar in healthy young and old men.

We investigated the effects of age on pituitary-adrenocortical function in healthy young (21-38 yr, n = 11) vs. old (66-78 yr, n = 11) men by drawing frequent serial basal blood samples from 2000-0800 h for measurement of ACTH and cortisol, followed by an iv ovine CRH (oCRH) stimulation test. Subjects were readmitted at intervals and given increasing doses of oral dexamethasone (0.15, 0.3, 0.6, 1 mg) at midnight, followed by repeat blood sampling from 0400-0800 h and oCRH testing. We compared mean hormone levels for the entire 12-h and three component 4-h periods of the basal visit, and for each 4-h dexamethasone visit using the Mann-Whitney U test and repeated measures analysis of variance. Pulsatile secretion was characterized using the Pulsar computer program. Basal mean 12-h and 4-h ACTH and cortisol values did not differ with age (P greater than 0.1). Pulse analysis revealed no age change in the corresponding values for peak frequency, amplitude, or duration for either hormone examined. Increasing doses of dexamethasone produced progressive inhibition of mean ACTH and cortisol levels (P less than 0.001) as well as decreased (P less than 0.01) pulse frequency, amplitude, and duration with no age differences (P greater than 0.1). ACTH and cortisol responses to oCRH were progressively suppressed by increasing doses of dexamethasone (P less than 0.02) and did not differ between age groups (P greater than 0.3) except for a slightly higher peak cortisol response (P = 0.05) in the older men at the 0.3 mg dexamethasone dose. We conclude that basal and oCRH-stimulated ACTH and cortisol secretion, as well as sensitivity of the ACTH-cortisol axis to glucocorticoid feedback suppression, are essentially unaltered with age in healthy men.