Biomedical subjects

R S Gonnering

Publications and source records attributed to R S Gonnering.

43 records · Page 3Linked to original sources

PubMed1986

Cystic lesions of the eyelid following ptosis repair.

The formation of epithelial cysts and pseudocysts of the eyelid is an uncommon complication of ptosis surgery. These lesions may originate at the time of surgery from the burying of conjunctival epithelium, from obstruction of the gland of Krause, or from injury to the main lacrimal gland or duct. Although surgical excision effectively cures lesions stemming from buried conjunctiva or obstruction of the gland of Krause, lacrimal gland pseudocysts must be drained into the conjunctival fornix. These complications are best avoided by a thorough understanding of eyelid anatomy and by meticulous surgical dissection.

Adult↗

PubMed1986

Treatment of hemifacial spasm with botulinum A toxin. Results and rationale.

Hemifacial spasm is characterized by unilateral, periodic, tonic contractions of facial muscles, thought to be caused by mechanical compression at the root-exit zone of the facial nerve. Electrophysiologic abnormalities such as ectopic excitation and synkinesis are typical. Although posterior fossa microsurgical nerve decompression is successful in bringing about relief of the spasm in most cases, it carries a risk to hearing. As an alternative treatment, 15 patients with hemifacial spasm were given a total of 41 sets of injections with botulinum A toxin, with a mean follow-up of 14.3 +/- 1.1 months. Relief of symptoms lasted a mean of 108.3 +/- 4.2 days. Mild transient lagophthalmos and ptosis were the only complications. Although the exact mechanism of its action and beneficial effect is speculative at this time, botulinum A toxin appears to offer an effective, safe alternative to more radical intracranial surgery for patients with hemifacial spasm.

Aged↗

PubMed1985

Gentle, technically simple repositioning of displaced lacrimal tubing.

Lateral displacement at the medial canthus is the most common complication following lacrimal intubation. Current procedures for dealing with this situation involve the removal of the tubing, and are either technically difficult or else involve retrograde passage of the knotted silicone through one of the canaliculi. By passing both probes of a second intubation set through the same punctum, the loop of the displaced tubing can be captured and gently repositioned without removal. This is particularly useful with early displacement of the tubing following microsurgical repair of a canalicular laceration.

Child, Preschool↗

PubMed1984

The cynomolgus monkey as a model for orbital research. I. Normal anatomy.

Significant differences in anatomy preclude the use of the more common small research animals in orbital studies. One must look to the anthropoid apes to find a species comparable to man in both bony skeleton and soft tissue contents. While the orbit of the cynomolgus monkey is remarkably similar to that of man, differences still do exist. In this monkey, the ethmoid, frontal and sphenoid sinuses are absent, and the os planum of the ethmoid is represented in only a minority of younger animals. A technique for microscopic examination of the soft tissue contents of the orbit has likewise shown a basic similarity to man, with minor, yet possibly significant, differences in extraocular muscles, connective tissue septae and the lacrimal gland. A recognition of these similarities and differences allows utilization of this animal as a useful model in orbital research.

Animals↗

PubMed1984

The cynomolgus monkey as a model for orbital research. II. Anatomic effects of lateral orbitotomy.

In order to assess the anatomic consequences of lateral orbitotomy in a disease-free muscle cone, a technique of microsurgical exposure of the ciliary ganglion in the cynomolgus monkey was formulated. Animals were sacrificed at 2 and 6 months following surgery, and microscopic sections of the whole orbit prepared and compared to sections taken from the non-operated contralateral orbits. Findings at two months were: periorbital thickening and hypercellularity along with osteoneogenesis at sites remote from the surgery, particularly the superior-lateral orbit, and lack of appreciable scar formation in the fat of the muscle cone itself. The thickened periorbita persisted at six months, although remodeling of the bone had largely restored the normal appearance of the orbital walls. These findings may possibly explain the restrictive myopathy sometimes seen following surgical and traumatic disruption of the bony orbit.

Animals↗

PubMed1984

The cynomolgus monkey as a model for orbital research. III. Effects on ocular physiology of lateral orbitotomy and isolation of the ciliary ganglion.

Five cynomolgus monkeys underwent unilateral lateral orbitotomy and isolation but not removal of the ciliary ganglion. Orbitotomized eyes were compared with untouched contralateral eyes with respect to intraocular pressure, aqueous humor formation rate, pupillary diameter and light reflex, corneal reflex, entry of intravenously administered fluorescein into the anterior chamber, anterior chamber volume, pharmacologically (pilocarpine, carbachol, echothiophate) induced accommodation, electroretinogram (ERG), visually evoked cortical response (VER), and clinical biomicroscopy, ophthalmoscopy, and fluorescein fundus angiography. Orbitotomized eyes accommodated significantly less than contralateral normal eyes in response to topical echothiophate one to two weeks after surgery. This difference was no longer present 15 to 20 weeks after orbitotomy. The implicit time on the light adapted ERG in the orbitotomized eyes was slightly but significantly shorter than in the normal eyes two to six weeks after orbitotomy; all the other ERG and VER parameters were the same in both eyes. Long-term ERG data were not obtained. There were no significant differences between normal and orbitotomized eyes with respect to any of the other parameters.

Accommodation, Ocular↗

PubMed1982

Silicone intubation for obstruction of the nasolacrimal duct in children.

We performed 63 intubations with silicone tubing for nasolacrimal duct obstruction in children in whom nasolacrimal duct probings had failed. Fifty-nine (93.7%) obstructions were congenital and four (6.3%) were acquired. The average length of intubation was 4.3 months. The final results for both congenital and acquired obstructions combined were good in 52 cases (82.5%), fair in three (4.8%), and poor in eight (12.7%). Complications, with the exception of some with infection, were easily treated or minimal and did not affect the outcome significantly. We recommend silicone intubation as the procedure of choice for congenital or acquired nasolacrimal duct obstructions in children after failure of medical therapy and nasolacrimal duct probings.

Child, Preschool↗