Comparison of 99mTc complexes for renal imaging.

The distribution of 17 different agents for renal imaging was compared in the rabbit by organ radioassay at 1 hr. Similarly, 99mTc complexes of iron-ascorbate, glucoheptonate (GHA) and 2,3-dimercaptosuccinic acid (DMS), and 203Hg-chlormerodrin were compared in the dog. The distribution of 99mTc-GHA and DMS was assessed in the human by blood and urinary clearance, external renal measurements, and scintillation camera imaging, and compared with older renal radiopharmaceuticals. Radiation dose estimates, based chiefly on human data, were calculated. Technetium-99m-DMS reaches a high concentration in the renal cortex and its urinary excretion rate and blood clearance are slow. It is excellent for imaging the renal parenchyma without activity in pelvocalyceal collecting system. However, it readily oxidizes and must be used within 30 min of preparation. The biologic distribution of 99mTc-GHA is similar to gluconate and iron-ascorbate complex. Its renal concentration is not as great as that of DMS but its blood and urinary clearances are much faster, resulting in lower radiation doses to most organs. Early camera images with this agent usually demonstrate both the renal parenchyma and collecting system. In later images, ther is excellent demonstration of the parenchyma alone, superior to that obtained with 99mTc-Sn-DTPA. It is a very stable complex and may be used for at least 5 hr after preparation. All radioactive renal agents examined to date have a significant concentration in the liver, making an accurate quantitative comparison between the two kidneys difficult.

Sensitivity to vasovagal maneuvers in normal children and adults.

In 15 male and 15 female healthy subjects who were 10 to 48 years of age, we studied alterations in heart rate and finger blood flow in response to the cold pressor test and four strong vasovagal maneuvers: diving response (apneic facial exposure to an ice water bag), Valsalva maneuver (forced expiration against a column of mercury to 40 to 50 mm Hg), unilateral carotid sinus massage, and oculocardiac reflex (inflation of a Honan balloon against one eye). Peripheral vasoconstriction as a consequence of the diving response paralleled the vasoconstriction from the cold pressor test, but it preceded the bradycardia that resulted from the diving response maneuver. In contrast, the rate of finger blood flow was high during the bradycardia that followed stage 4 of the Valsalva maneuver. Changes in heart rate correlated with age for the diving response, the Valsalva maneuver, and the oculocardiac reflex. Changes in heart rate and finger blood flow were not dependent on sex. The change in heart rate noted with the diving response was significantly correlated with that noted with the Valsalva maneuver and the oculocardiac reflex. Changes in finger blood flow did not correlate with changes in heart rate for any maneuver. This study provides a response profile of relative sensitivities to strong vasovagal maneuvers in normal children and adults.

Hypobaric ocular trauma from a Popper.

We have observed 3 cases of ocular trauma in children that were caused by an atypical, hypobaric mechanism induced by a toy called a Popper. When we initially notified the United States Consumer Product Safety Commission in 1990, Poppers disappeared from store shelves. We are concerned that this potentially harmful toy is making a comeback in 1998 (Smilemakers Inc, Spartanburg, SC; June-July 1998 catalog, p. 57). In 1990, packaged poppers cautioned against applying to face or skin; we are not sure that such warnings accompany current Poppers.

Bilateral monocanalicular silicone loop: predictable home removal of nasolacrimal stents.

Premature dislocation, a potential disadvantage of conventional, unilateral silicone intubation for lacrimal disease, can be alleviated with a firmly-tied, bilateral, superior canaliculus intubation. Since the looped silicone stent can be removed easily at home by parents, this technique is particularly beneficial for remote patients for whom postoperative, clinic removal is a financial burden.

Susceptibility to retinopathy of prematurity in Alaskan Natives.

Threshold retinopathy of prematurity occurred in 11 of 34 Alaskan natives compared with 10 of 93 non-natives. Natives constitute 16% of the state population. This significant Alaskan native preponderance was not explained by differences in prenatal or intensive care unit morbidity except that the intervals from birth to extubation and birth to cryotherapy were shorter for natives.

Corneal crystals, myopathy and nephropathy: a new syndrome?

A case with ocular (corneal crystals and retinal pigment epithelial mottling), muscle (oropharyngeal and hand weakness and atrophy), and renal (proteinuria and hypertension) abnormalities is described. We believe that this represents a previously unrecognized syndrome.

Acquired divergent strabismus: presumed metastatic gastric carcinoma to the medial rectus muscle.

A patient with rapidly progressive metastatic gastric carcinoma developed diplopia and diminished adduction of the right eye. The right medial rectus muscle belly was enlarged, as shown by computed tomography. This case is unusual, because gastric carcinoma comprises only 1% of orbital metastases and less than 5% of all orbital metastases localize to extraocular muscle.

Iris color alone does not predict susceptibility to the oculocardiac reflex in strabismus surgery.

PURPOSE: To test prior published observations that patients with brown irides were more susceptible to the oculocardiac reflex. SUBJECTS AND METHODS: 466 adults and children underwent surgery on an extraocular muscle under general anesthesia without anticholinergic blockade. The first rectus muscle isolated was given a predetermined specific force pull during electrocardiograph monitoring. Iris color was retrieved from the deliberate clinical charting. RESULTS: The occurrence of the oculocardiac reflex did not correlate with age, but did profoundly for the inferior rectus and least for the lateral rectus. Iris color did not influence the incidence of occurrence of moderate or severe oculocardiac reflex. CONCLUSION: The prediction of oculocardiac reflex propensity remains elusive.

Vision loss associated with a stiff neck complicating strabismus surgery.

An exotropic 60 year old suffered a scleral-choroidal penetration and vitreous hemorrhage during and after strabismus surgery on a highly myopic eye when her anesthetic airway management was complicated by her previously asymptomatic and unrecognized rigid cervical spine which placed both the surgeon and the anesthetist in disadvantaged positions both physically and medically. Restoration of vision and binocularity ultimately required vitrectomy and intraocular lens implantation.

The attenuating effect of heat and hypovolemia on the human diving response.

Seven healthy adult volunteers underwent 30-second facial immersions in ice water before and during 36 minutes exposure to intense ambient heat (68 degrees C) on separate, non-consecutive days: one normovolemic and the second with thiazide-induced, 10% hypovolemia. The normovolemic, preheat immersion induced a heart rate (H.R.) decrease from 74 +/- 6 to 48 +/- 5 bpm (-35%) and a forearm blood flow (F.B.F.) decrease from 3.5 +/- 1.6 to 0.8 +/- 0.3 ml/(100 ml min) (-77%). Pre-heat changes were similar for hypovolemic subjects. After 36 minutes of heat exposure there was a 07 degrees C increase in esophageal temperature and a four-fold increase in F.B.F. for normovolemic and a two-fold increase in F.B.F. for hypovolemic subjects. Heating reduced diving bradycardia more than did superimposed hypovolemia. Four subjects had diving tachycardia after hypovolemic heating. We concluded that the bradycardia response to facial immersion can be overridden by reducing the central circulating blood volume by heat and that this effect is enhanced by hypovolemia.

The effect of peripheral vasodilators on the human diving response.

Five healthy subjects performed seated, 30-second mid-inspiratory breath hold, facial immersions in water at 1 degree C, 10 degrees C and 25 degrees C under control conditions and under the influence of three separate vasodilators. A temperature dependent bradycardia and decrease in forearm blood flow were observed during control dives. Nitropaste produced little change in diving bradycardia. Hydralazine reduced diving bradycardia only in 1 degrees C immersion. Prazosin produced consistent reductions in temperature dependent bradycardia. There was a temperature dependent change in dive forearm blood flow which was not affected by vasodilators. This data suggest the importance of acute peripheral vasoconstriction to the bradycardia of the human diving response.

The detection of congenital glaucoma by photoscreen interpretation.

Photoscreening is designed to detect abnormalities in children's eye, particularly abnormal refractive errors, which can lead to amblyopia. An Alaska Bind Child Discovery MTI Polaroid photoscreen in one girl resulted in diagnosis and treatment of congenital glaucoma. Patients with known pediatric eye disease underwent photoscreening. Subtle non-refractive changes in photoscreen images may reveal eye disease even more serious than amblyopia. We suggest that human or computer interpretation of photoscreening images, particularly when retained, be done conscientiously with respect to the refractive state and alignment of the eyes, but also regarding other potentially serious ocular pathology.

An emergency corneal ulcer kit.

Bacterial corneal ulcer is a potentially blinding emergency which should ideally be treated by an ophthalmologist aided by slit lamp biomicroscopy, microbial stain and cultures, and then selected fortified topical antibiotics. We suggest an emergency corneal ulcer kit for the initial treatment of patients with suspected corneal ulcers who are unable to readily travel to an ophthalmologist.

Palinopsia with bacterial brain abscess and Noonan syndrome.

Though positive visual symptoms can be psychological in nature, or can result from a perceptive or anxious patients recognizing optical principals in the eye itself, this case illustrates how a thorough history is required to delineate those rarer signs which accompany serious macular or neuro-ophthalmic pathology.

Stevens-Johnson syndrome secondary to ingestion of salmon berries.

Stevens-Johnson syndrome is an immune mucocutaneous disorder which can follow viral infections, mycoplasma infections and the ingestion of some drugs. There is also evidence supporting this disease as a hypersensitivity disorder. We observed a four-year-old girl with Stevens-Johnson syndrome attributed to ingestion of salmon berries (Rubus spectabilis).

Neonatal respiratory distress caused by cryptic dacryoceles.

Two cases of neonatal respiratory distress responded with treatment of bilateral dacryocele. In one case, no visible or palpable external evidence of dacryocele was present until mucopurulent discharge commenced more than a week after birth. While the incidence of typical congenital nasolacrimal duct obstruction is about 6%, dacryocele is 200 times less common.

The Alaska Blind Child Discovery project: rationale, methods and results of 4000 screenings.

BACKGROUND: Photoscreening allows lay persons to adapt the Enhanced Brückner Test to preschoolers in an attempt to identify refractive amblyopia. The Alaska Blind Child Discovery (ABCD) project is charitably funded and administered. METHODS: MTI photoscreening was offered to children in rural and urban communities in southern Alaska from 1996 through June 1999. Parents answered questions concerning the child's health, family ocular history and whether the child had any eye "Warning Signs." The MTI images were interpreted by two eye doctors using a modification in MTI published guidelines. RESULTS: Out of 4000 screenings performed on 3930 children, there was an overall "not normal" interpretation of 9% and an inconclusive rate of 1%. The mean S.D. age was 3.9 2 years. Only 6% had had a prior eye exam. The average number of Polaroid pictures per screening was 1.16. Follow-up data on "not normal" results was obtained on just over 50%. The positive predictive value during the first two years was 77% but improved to 92% from 1998-1999. Affirmative answers to the questions concerning previous eye exam, child's health, siblings eye health and positive "Warning Signs" were significantly associated with "not normal" interpretations but affirmative answers about eye health of mother, father and relatives were not. Community penetrance of photoscreening to the target age-group ranged from only 5% for Anchorage to almost 100% for the Bristol Bay public health nurses. Five percent of parents of "positive" results surveyed would not have recommended screening for their friends. Equipment functioned dependably even in remote Alaska. CONCLUSION: Charitable volunteer Polaroid photoscreening detected amblyopia and significant pediatric eye disease in over 300 children during the first 3.5 years of ABCD.