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Biomedical subjects

C C Collins

Publications and source records attributed to C C Collins.

48 records · Page 3Linked to original sources
PubMed1967

Evoked pressure responses in the rabbit eye.

In the rabbit, a sensory stimulus of low intensity evokes a characteristic transient intraocular rise in pressure with an amplitude as great as 10 millimeters of mercury. This alpha- adrenergically mediated phenomenon occurs concomitantly with a general arousal response and appears to be caused by contraction of the orbital smooth muscle of Müller.

Animals↗
PubMedDate not supplied

Effect of varying drug loading on particle size distribution and drug release kinetics of verapamil hydrochloride microspheres prepared with cellulose esters.

Microspheres containing two different drug loadings of a calcium channel blocker, verapamil hydrochloride, were prepared with three different cellulose esters namely cellulose acetate (CA), cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB) of approximately similar molecular weights using the emulsion-solvent evaporation method. Increasing the drug loading from 33.3 to 50% w/w increased the geometric mean diameter of the microspheres as well as the T50% values, i.e. time required to release 50% of the drug from microspheres prepared with all the three cellulose esters. Drug release from the microspheres was affected by the nature of polymer. Mathematical modelling of drug release data by fitting the data to various equations revealed that the data did not fit the conventional Higuchi's and Baker-Lonsdale's models for drug release from spherical matrices. Instead, the data fitted the log-probability and the Weibull models quite well.

Capsules↗
PubMedDate not supplied

Combined cataract extraction and epikeratophakia in children.

Nineteen children between the ages of 2 1/2 and 6 1/2 years who had cataracts not associated with trauma and who were judged to be poor candidates for contact lens wear underwent combined cataract extraction and epikeratophakia, followed by intensive amblyopia therapy. Follow-up ranged from 6 months to 7 years. In these monocularly aphakic children, three (16%) of the original 19 procedures failed and the tissue lenses were removed; two of these were repeated successfully. The success rate for the surgery was 86% (18/21) and 95% (18/19) for the patients. Postoperative visual acuity of 20/50 or better was achieved in six (33%) of the 18 patients with successful surgery. Another 11 (61%) achieved between 20/60 and 20/200. Postoperative astigmatism ranged between 0 and 4 diopters, with an average of 1.7 diopters. The results demonstrate that epikeratophakia can be successfully combined with cataract extraction in children with visually significant non-traumatic cataracts and that the majority of such children demonstrate an improvement in visual acuity.

Cataract Extraction↗
PubMedDate not supplied

Eye muscle prosthesis.

We inserted a silicone rubber elastic band along the course of a paralyzed lateral rectus and of a paralyzed superior oblique to restore alignment and to provide a spring against which the antagonist could pull. The lateral rectus band has been in place for 7 years. It provides alignment and a field of single binocular vision of 20 degrees. The superior oblique band has been in place for 17 months. It provides alignment and single vision over 30 degrees from the primary position except for a restriction in upgaze-adduction to 25 degrees (Brown syndrome) and in downgaze-adduction to 20 degrees. Such engineered elastic bands are a useful addition to current surgical techniques for management of cases of paralysis and restriction.

Adult↗