Swelling of collagen intracanalicular implants.
BACKGROUND
Absorbable intracanalicular collagen implants are used to attempt to determine if permanent closure of the tear drainage system will diminish or alleviate the signs and symptoms of dryness. The rate of swelling of the collagen implants was measured in vitro in this study.


METHODS
Collagen implants were submersed in saline, Refresh Plus artificial tears or Tobrex antibiotic solution on a hanging drop microscope slide. The diameter of the collagen rod was measured over time using videotaping and image processing.


RESULTS
The 0.3- and 0.4-mm diameter collagen implants swelled approximately 55% to 65% in Unisol 4 Preservative Free saline and Refresh Plus artificial tear solution, with the majority of the swelling occurring over the first 30 minutes. The 0.4-mm diameter implants took slightly longer to reach the fully swollen state than did the 0.3-mm implants. They swelled somewhat less in Tobrex Ophthalmic Solution.


CONCLUSIONS
Collagen implants swell approximately 60%, with the majority of the swelling occurring in the first 30 minutes. Thus, it will take approximately 30 minutes after insertion of the implants for the full occlusive effect to occur.
Lowther
G E
GE
Borish Center for Ophthalmic Research, School of Optometry Indiana University, Bloomington, IN 47405, USA.
Collins
J O
JO
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003094:Collagen / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D018715:Microscopy, Video; D009883:Ophthalmic Solutions / Q000494:pharmacology*; D019736:Prostheses and Implants; D012965:Sodium Chloride / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D009883:Ophthalmic Solutions; D012965:Sodium Chloride; D003094:Collagen