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Biomedical subjects

L Apt

Publications and source records attributed to L Apt.

At least 55 records · Page 3Linked to original sources
PubMed1980

Pupillary dilatation with single eyedrop mydriatic combinations.

We studied the mydiatic effect of three solutions containing a combination of two mydriatic drugs in 80 adult patients. The solutions tested were cyclopentolate HCl 0.5% with phenylephrine 2.5%, tropicamide 0.5% with phenylephrine 2.5%, and tropicamide 1.0% with phenylephrine 2.5%. We evaluated the effect of prior instillation of proparacaine 0.5% eyedrops. All three mydriatic combination solutions evaluated produced pupillary dilatation of about 7 mm within 60 minutes. Additional pupillary dilatation of 1 mm occurred when proparacaine was instilled before the mydriatic combination eyedrop. Mydriasis was resistant to bright light during indirect ophthalmoscopy in all patients. Pupils of younger patients dilated better than those of older patients, but sex and iris color were factors in the amount of pupillary dilatation obtained. Wide and sustained pupillary dilatation can be obtained for satisfactory indirect ophthalmoscopy by the instillation of one drop of proparacaine solution followed by a single drop of any of the three mydriatic combination solutions evaluated. By eliminating the need for multiple instillations of drugs, the use of a single eyedrop mydriatic combination is convenient in terms of time saved and also lessens the change of systemic drug toxicity.

Adolescent↗
PubMed1980

An improved scleral spatula needle.

I devised a new spatula needle (DO-5) that improves the performance of the established DO-1 needle of the Davis and Geck Co. The diamond-shaped tip of the needle was lengthened to improve its penetration force through the sclera and the widened shoulder of the point was narrowed to enable the needle to pass through the sclera more easily and to provide closer contact between suture and scleral tissue.

Humans↗
PubMed1980

The oculocardiac reflex as a surgical aid in identifying a slipped or 'lost' extraocular muscle.

The oculocardiac reflex during strabismus surgery has generally been regarded as a hazard capable of causing death. Six cases are presented which show a beneficial use of the oculocardiac reflex. Isolation of a previously slipped or 'lost' extraocular muscle can be difficult. In this series identification of the tissue as muscle was substantiated by observing a positive oculocardiac reflex when traction was placed on the suspected tissue. Each of the 6 dislodged extraocular muscles was the medial rectus muscle. Three of the muscles had been resected and 3 either recessed or tenotomised. In one patient, despite 6 previous strabismus operations, including 2 strabotomies on a muscle that slipped, and in another patient, who had a lapse of 6 years since the last strabotomy, when the slipped muscle was isolated, the oculocardiac reflex could still be elicited. To avoid abolishing the oculocardiac reflex during surgery the anaesthetist should be instructed to avoid the use of an intravenous parasympatholytic agent, such as atropine, at the time of induction and during the operation.

Adult↗
PubMed1980

An anatomical reevaluation of rectus muscle insertions.

Certain strabismus operations require a thorough knowledge of the anatomy of rectus muscle insertions. Earlier anatomical studies were based on a small sample size and did not use precise microscopic techniques for measurements. To obtain accurate measurements of rectus muscle insertion relationships, 100 consecutive normal adult autopsy eyes were examined with a Vernier caliper and a dissecting microscope for high magnification. Statistical analysis of these data provided a set of normal values for (1) distances from anterior and posterior limbus to rectus muscle insertions, (2) distances between anterior and posterior limbus, (3) length of line ("width") of rectus muscle insertions, and (4) distances between rectus muscle insertions. Although most of the determinations were somewhat similar to previous studies, statistically they were significantly different. The ophthalmologist can make use of the revised set of figures for rectus muscle insertion relationships in operations such as transposition procedures for A-V patterns and cranial nerve palsies, large recessions, and advancements in reoperations after recessions.

Adult↗
PubMed1979

Mydriatic effect of anticholinergic drugs used during reversal of nondepolarizing muscle relaxants.

Large doses of anticholinergic drugs (atropine, glycopyrrolate) produced mydriasis in a group of adults with no eye abnormalities except strabismus, though the usual intramuscular and intravenous doses of these drugs do not have this tendency. Such large doses are often given intravenously during general anesthesia to prevent the side effects of neostigmine methylsulfate, which is used to reverse the effect of nondepolarizing muscle relaxants. Neostigmine methylsulfate (Prostigmin) reduced the mydriatic effect when given intravenously in conjunction with atropine or glycopyrrolate. Mydriasis was more likely to occur in lightly pigmented eyes than in eyes with dark irides. Pilocarpine eyedrops instilled at the beginning of anesthesia caused miosis that persisted after the large intravenous doses of atropine or glycopyrrolate were given. To prevent an attack of acute angle-closure glaucoma in any patient who is to receive large doses of anticholinergic drugs during general anesthesia, miotic drug therapy should be continued before, during, and after anesthesia at the same frequency as when awake.

Adolescent↗
PubMed1978

Inferior oblique muscle recession.

Surgical recession of the inferior oblique muscle is simpler to perform if the inferior rectus muscle, rather than either the lateral rectus muscle or the inferior oblique muscle insertion, is used as a landmark. We measured 200 consecutive autopsy eyes to determine the distance from the commonly used 8-mm recession site determined by the Fink technique to the lateral border of the inferior rectus muscle insertion. It was easier to reach this point by measuring 4.0 mm posterior and 4.4 mm superior to the lateral insertion of the inferior rectus muscle, or 2.9 mm superior (on a line parallel to the corneoscleral limbus) and 5.1 mm posterior (on the line perpendicular to the corneoscleral limbus) to the lateral insertion of the inferior rectus muscle. We made anatomical studies to grade the amount of inferior oblique muscle recession and to evaluate the proper placement of the posterior border of the recessed inferior oblique muscle.

Humans↗
PubMed1978

Generalized fibrosis of the extraocular muscles.

We studied four patients with the general fibrosis syndrome. One patient had bilateral inguinal hernias and unilateral cryptorchism; the other patients had no other congenital abnormalities. The patients developed normally both neurologically and metally. We successfully treated amblyopia and achieved good functional and cosmetic results with strabismus and blepharoptosis surgery. Histopathologic study revealed fibrous infiltration of extrinsic eye muscle and Tenon's capsule without inflammatory changes.

Amblyopia↗
PubMed1977

Eye position of strabismus patients under general anesthesia.

We studied the change in eye position under general anesthesia in 317 patients undergoing strabismus surgery. We used the prism cover test to measure preoperative eye position, and the prism reflex test (Krimsky's method) to measure the eye position under general anesthesia. Almost all patients had divergence under anesthesia. We calculated a linear equation and curve to relate the eye position under anesthesia to the preoperative eye position. Patients with a normal amount of divergence (within one standard deviation of the mean) had a higher rate of successful surgical results than those with an abnormal amount of divergence under anesthesia (greater than one standard deviation from the mean).

Adolescent↗
PubMed1976

Experimental suture studies in strabismus surgery. I. Reattachment rate of extraocular muscles after recession and resection operations.

We described a method for measuring the in vivo tensile strength of the muscle-scleral junction in rabbits. Data obtained on the reattachment time of extraocular muscles after recession and resection operations indicate the rate of healing is similar for both operations. Adequate wound healing is present by the 5th day after surgery, and sutures are probably unnecessary after 8 to 9 days. An ideal suture for strabismus surgery would be one that retains its strength during the first 8 to 9 days following surgery, then undergoes rapid absorption.

Animals↗
PubMed1976

Experimental suture studies in strabismus surgery. II. Comparison of tensile strength of plain catgut with polyglycolic acid (Dexon) sutures after extraocular muscle surgery.

From our experimental studies it appears Dexon satisfies more of the criteria for an ideal suture for strabismus surgery than plain catgut for the following reasons. Its handling, tying, and knot-holding (if tighthened firmly) qualities are excellent. Tissue reaction is minimal. It seems to be non-antigenic. Of paramount importance. Dexon's tensile strength is high initially and it retains its strength through the critical period of muscle-scleral wound healing, then dissolves in a rapid uniform manner.

Animals↗