Search PubMed⌕ Search

Biomedical subjects

M J Cartwright

Publications and source records attributed to M J Cartwright.

At least 19 recordsLinked to original sources
PubMed1995

Evaluation and clinical significance of the mechanical properties of various palpebral springs.

Fourteen different wire materials were evaluated for use as palpebral springs. Three of these, stainless steel 0.010- and 0.012-in diameter, respectively, and Australian stainless steel 0.012-in diameter, fulfilled the designated criteria for suitability. The physiologic deflection range of palpebral springs was determined by examining 20 normal individuals. Angles that a spring would subtend were measured with eyes closed (42 +/- 3 degrees), in primary position (20 +/- 3 degrees), and in upgaze (6 +/- 3 degrees). The effects of spring design on load-deflection (the force required for angular deflection) were evaluated for 0.010- and 0.012-in stainless steel wire within the physiologic deflection range. Variations in spring design in addition to wire diameter (gauge) included alteration of external loop size, number of external loop coils, and resting spring angle. There was a direct linear relationship between force and angular deflection (load-deflection). Larger wire diameter increased the load-deflection. Australian stainless steel had a higher load deflection (stiffer) for a given gauge than regular stainless steel. Smaller diameter external loops and fewer external loop coils increased load-deflection. Although definite conclusions could not be drawn regarding the effect of resting angle on load-deflection, it appeared that no relationship (zero correlation) existed over the angles tested (55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees). These findings were consistent with predictions based on standard spring equations. The clinical significance of the findings is discussed with reference to surgical planning and evaluation of lid dynamics.

Adolescent↗
PubMed1995

Intraorbital wood foreign body.

It is frequently difficult to identify and localize organic intraorbital foreign bodies despite modern day high-resolution imaging studies. Although there can be grave complications associated with retention of organic intraorbital foreign bodies, many believe that removal of such bodies in most cases is unwarranted. A high clinical suspicion, proper choice of imaging studies, and removal by a skilled orbital surgeon probably make the risk of surgical exploration and foreign body removal less than the risk of foreign body retention. We present a case of an intraorbital wood foreign body that required two separate explorations for retrieval. An initial intraconal exploration failed to locate the foreign body. Although the clinical suspicion was high, the imaging studies were equivocal, complicating the management. A second exploration yielded a large intraorbital wooden foreign body in the inferior extraconal space. The patient fully recovered and regained visual acuity of 20/20. The evaluation of such patients and details of management strategy are discussed.

Child↗
PubMed1995

Microdeletion of chromosome 7P syndrome ocular manifestations.

Several syndromes have been associated with microdeletions of the autosomes. These syndromes are diverse in their morphology and frequently manifest abnormalities of the ocular adnexa. A child with an uncommon microdeletion of the short arm of chromosome 7P presented initially with congenital myogenic ptosis. After multiple systemic abnormalities were found during a routine examination, the child was referred for genetic evaluation where the defects were incidentally found. The child responded well with a fascia lata frontalis sling. The genetic disorder is discussed with an emphasis on the ophthalmologic findings.

Abnormalities, Multiple↗
PubMed1994

Measurements of upper eyelid and eyebrow dimensions in healthy white individuals.

Facial appearance is influenced by the anatomic relationship of the eyebrow and eyelid, and surgical procedures on these structures attempt to restore or preserve not only symmetry but also normal appearance. To provide useful benchmarks for such interventions, we measured the eyebrow height, upper eyelid crease height, and amount of visible pretarsal skin of 143 white subjects who had no facial abnormalities. An age effect was observed for all measures, indicating a direct relationship with age until the middle age range (41 to 60 years), when mean estimates leveled off or decreased somewhat relative to younger age groups. Within the 41- to 60-year age group, for example, the average (S.D.) values for pretarsal skin height, eyelid crease height, and eyebrow height were 1.4 mm (1.1 mm), 6.4 mm (1.2 mm), and 6.4 mm (1.8 mm), respectively. Eyebrow and pretarsal skin heights were greater in females than males, and eyelid crease height showed similar gender-related trends. With increasing age, variation around the mean estimates for eyelid and eyebrow measurement increased, which may be indicative of variability across individuals in the physiologic response to the aging process. As expected, a high degree of intereye correlation was observed (correlation coefficients of 0.87 to 0.96). These results emphasize the importance of providing a normal anatomic relationship that relates to the patient's age and gender, as well as an outcome that is symmetric, in corrective or cosmetic procedures on the eyelid and eyebrow.

Adolescent↗
PubMed1994

Drill guide for hydroxyapatite implants.

A drill guide to facilitate the second drilling of hydroxyapatite orbital implants is presented. The drill guide is adaptable to various drill types. It is nontraumatic and provides excellent, one-handed fixation, eliminating the need for an assistant. It allows for consistent, straight drilling to a predetermined depth and, because it is encased, it protects the patient from injury. The drill guide has been used on 30 patients and is without untoward effects.

Durapatite↗
PubMed1994

In vitro alteration of Schirmer's tear strip wetting by commonly instilled anesthetic agents.

The Schirmer's tear test is often performed with topical anesthesia to reduce reflex tearing. Fluress (Barnes-Hind, Sunnyvale, CA, U.S.A.) and Fluoracaine (Akorn, Abita Springs, LA, U.S.A.) are commonly used anesthetic-fluorescein preparations that contain viscous additives. Because the rate of Schirmer's strip wetting is dependent on capillary action, a property related to solution viscosity and surface tension, spurious results may be obtained if these agents are used for anesthesia. We report in vitro Schirmer's strip wetting rates for various concentrations of Fluress and Fluoracaine, as well as pure fluorescein solution using a tear substitute (Dacriose; IOLAB, Claremont, CA, U.S.A.) as a diluent. Results showed a direct concentration-dependent reduction of Schirmer's strip wetting with time for both Fluress and Fluoracaine dilutions compared with Dacriose alone (p < 0.001) or Dacriose-fluorescein solutions (p < 0.001). In addition, Schirmer's wetting with Dacriose-fluorescein solutions caused a separation of the Dacriose and fluorescein wetting fronts (p < 0.001) but did not affect the overall Dacriose wetting. These data have clinical implications concerning false-positive results when testing for dry eyes.

Anesthetics, Local↗
PubMed1993

A modification of the transcoronal flap that enhances orbital exposure and cosmesis.

The transcoronal surgical approach for the treatment of orbital disease has become increasingly popular since it affords excellent surgical exposure through a cosmetically acceptable incision. Exposure of the inferior orbit, however, can be difficult due to limited flap mobility in the frontal plane. Increased inferior exposure may be obtained by extending the incision inferiorly in preauricular skin. In children and young adults without excess preauricular skin folds or wrinkling, however, the wound may be quite apparent, compromising cosmesis. To overcome this drawback, we demonstrate a modified transcoronal incision that redirects the inferior limbs into the postauricular sulcus. This incision not only results in superior cosmesis, but avoids important preauricular neurovascular structures and enhances orbital exposure.

Humans↗
PubMed1993

Ophthalmic contact lens with internal fixation light for examination of the optic nerve head.

Stereoscopic slitlamp examination of the optic nerve head in one-eyed patients is difficult because there is currently no way to provide the patient with a fixation target. This situation is often aggravated in glaucoma patients by a miotic and fixed pupil. We have developed a funduscopic contact lens which incorporates a fixation target, allowing the patient to view the target with the eye being examined. The device has been successfully tested on normal volunteers.

Contact Lenses↗
PubMed1993

Sporothrix schenckii endophthalmitis presenting as granulomatous uveitis.

Sporothrix schenckii occurs worldwide as a chronic subcutaneous mycotic infection, but can result in intraocular infection of cryptogenic origin without evident systemic infection. A case of S schenckii endophthalmitis is presented without a history of trauma or systemic infection originally diagnosed as granulomatous uveitis that resulted in scleral perforation.

Adult↗
PubMed1993

Sulfated glucuronyl glycolipids and gangliosides in the optic nerve of humans.

Pathologically delayed visual evoked potentials may be present in patients with neuropathy associated with IgM M-proteinemia, which is directed against myelin-associated glycoprotein and sulfated glucuronyl glycolipids (SGGLs), but there are no reports of these antigens in the optic nerve. We recently examined human optic nerve and occipital lobe tissues for the occurrence of SGGLs using the technique of immunostaining on thin-layer chromatographic plates and found them in the optic nerve, but not the occipital lobe. SGGLs in the optic nerve may represent target antigens for CNS involvement by the M-protein in patients with neuropathy. We also studied the ganglioside composition of the optic nerve and found it different from that of the brain. Human optic nerve is characterized by an abundance of the b-series gangliosides, including GD1b, GT1b, and GQ1b. GD1a, which is usually a major component of brain gangliosides, is only a minor species of the optic nerve ganglioside fraction.

Chromatography, Thin Layer↗
PubMed1992

Immune-related disease and normal-tension glaucoma. A case-control study.

We reviewed the charts of 67 patients with the diagnosis of normal-tension glaucoma listed in the Bascom Palmer Eye Institute computer database. These patients were matched with respect to age, race, and sex with an equal number of patients having ocular hypertension. All medical diagnoses in the charts for both groups were tabulated and classified as either immune-related or non-immune-related. Twenty (30%) patients with normal-tension glaucoma had one or more immune-related disease(s) compared with five (8%) patients in the comparison group (P = .00134, McNemar statistic with continuity correction).

Aged↗
PubMed1992

Acute dacryoadenitis and Crohn's disease: findings and management.

Concurrent orbital pseudotumor and Crohn's disease, although rare, have been described. To the best of our knowledge, pseudotumor isolated to the lacrimal gland (dacryoadenitis) with concurrent Crohn's disease has never been reported. We present the clinical course and ultrasonographic and radiologic findings of an acute case of isolated bilateral lacrimal gland pseudotumor in a patient with Crohn's disease. The treatment and review of the literature are discussed.

Acute Disease↗
PubMed1992

Tension pneumoorbitus.

Posttraumatic tension orbitus developed in a young man causing subconjunctival emphysema and proptosis. Intraocular pressures were monitored as a means of indirectly measuring intraorbital pressure. The patient was serially examined for evidence of compressive optic neuropathy. Because of the possibility of orbital pressure increasing several hours from the time of injury, we recommend monitoring of these patients through intraocular pressure measurement and evaluation of the optic nerve for evidence of compression. Our findings, however, do support previous documentation that the intraocular pressure rise following orbital trauma with orbital emphysema is usually not of sufficient severity or duration to result in visual compromise.

Adult↗
PubMed1992

Tension pneumocephalus associated with rupture of a middle fossa encephalocele. Case report.

Acquired nontraumatic (spontaneous) encephaloceles of the middle fossa are not common. Rupture of an encephalocele frequently leads to a cerebrospinal fluid fistula. Tension pneumocephalus consequent to rupture of an encephalocele has not been previously reported, but conceivably occurs by means of a ball-valve mechanism in the ensuing fistulous tract. An unusual case is presented of an elderly man who suffered acute life-threatening neurological symptoms from a tension pneumocephalus that likely developed from rupture of an acquired nontraumatic encephalocele of the left middle fossa. The symptoms correlated with the location of the intracranial abnormalities. The literature is reviewed and the pathophysiology of the lesion is discussed.

Aged↗