Several sutures have been developed for use in ophthalmic surgery. Many have unique features particularly suited to a specific surgical intervention, while others are essentially interchangeable. Properties such as absorbability, tensile strength, elasticity, handling and tying characteristics, and propensity to incite an inflammatory tissue reaction are all features that determine the surgeon’s selection of suture material. Moreover, several surgical needle designs are available, varying in both tip shape and shaft configuration.

This chapter will review the characteristics of the most common types of sutures and needles available to the ophthalmic surgeon.

Suture Material

Note: The tensile strength and duration of a suture depend on the suture material as well as the diameter of the suture and the tissue environment into which it is placed. The absorption characteristics discussed here are approximate and reflect the duration of effective tensile strength, not the length of time residual suture material remains in the tissue.

Nonabsorbable Sutures

1. Nylon (polyamide)

a. Duration: Losses 10–15% of tensile strength per year.

b. Tissue reactivity: Minimal

c. Other characteristics:

  i. Monofilament material.

 ii. High tensile strength.

iii. Relatively elastic.

iv. Stiff suture ends.

2. Silk

a. Materials

  i. Virgin silk: Natural silk filaments (fibrin coated by sericin), twisted together to form a fine diameter suture.

 ii. Braided silk: Degummed silk (sericin removed), braided to form a multifilament suture.

b. Duration: 3–6 months.

c. Tissue reactivity: Moderate.

d. Other characteristics

  i. Easy tying and handling characteristics

 ii. Soft suture ends are well tolerated by patients.

iii. Inelastic.

iv. Braided sutures have a tendency to fray when handled.

 v. Braided sutures produce more tissue drag than monofilament materials.

vi. Multifilament structure may act as a nidus of infection.

3. Polypropylene (e.g., Prolene, Ethicon, Inc.)

a. Duration: Essentially permanent, retaining tensile strength for over 2 years.

b. Tissue reactivity: Minimal.

c. Other characteristics

  i. Monofilament material.

 ii. High tensile strength.

iii. Most elastic suture.

iv. Very stiff suture ends.