Subconjunctival Triamcinolone (TA)

Paganelli and Negi (slide 1 below) injected doses of 20-40 mg TA 40 mg/mL sub-Tenon with good results. We wanted to be able to visualize the resulting steroid depot and began injecting lower doses subconjunctivally. Subconjunctival TA has been described following cataract surgery as far back as 1966.

We prefer the subconjunctival location because the depot can be easily visualized under the conjunctiva, dissolution can be monitored (which is important), and it can be excised at the slit lamp if necessary. 

The optimal dose and depends on which triamcinolone product you use!

We have found that a subconjunctival dose of 4 mg Kenalog 10 mg/mL is optimal. Slide 3 shows results of our recent study: 4 mg Kenalog 10 has lower odds of IOP rise and macular edema than prednisolone + NSAID. Injecting the same dose of Kenalog 40 mg/mL has slightly lower odds of macular edema but 2x the odds of IOP rise. That's why we use 4 mg Kenalog 10. It spreads out more on the surface of the eye and dissolves a little faster than Kenalog 40. The depot optimally stays on the eye about 6 weeks. Kenalog 40 depots typically remained visible for 8-12 weeks which increases risk of IOP rise.

A study by Lindholm showed similar good results with 20 mg of Triesence. Triesence drug particles are smaller than Kenalog and dissolve faster, requiring a higher dose for effectiveness than Kenalog.

Injecting too close to the limbus increases the risk of IOP rise (slide 4 and 5). We have found that injecting at least 6 to 8 mm inferior to the inferior limbus is optimal. Tunneling the needle 1-2 mm under the conjunctiva also reduces reflux of drug when injecting. Injecting inferiorly, near the fornix also hides subconjunctival hemorrhages which occur from time to time (injecting with the needle bevel down reduces this).

Avoid injecting superiorly. We saw one patient that had a mild IOP spike 2 months after surgery. The steroid depot had migrated inferiorly closer to the limbus, likely due to the effects of gravity.

Avoid the inferotemporal and inferonasal forniceal quadrants as you may see more bleeding from larger vessels in these areas.

Recent evidence suggests that the brand of triamcinolone acetonide is very important. Our research is based on 15 years of injecting Kenalog (4 mg of Ken-10). Injecting the same 4 mg dose of Aurocort also appears to be safe and effective. 

Lindholm et al found that injecting 20 mg of Triesence was safe and effective. Other brands may have more or less potency depending on the average drug particle size. If you will be using another brand or generic drug that has not been studied, we recommend establishing the correct dose and concentration for optimal safety and effectiveness. The depot should be visible on the eye for about 6 weeks. A shorter duration may be less effective and a longer duration may risk an increase in IOP.

Intracameral antibiotic along with subconjunctival triamcinolone injection appears to be the lowest cost prophylaxis regimen. Published cost of Kenalog® 10 mg/mL vial (5 mL) is $22.23 (accessed 3/5/24). The multi-dose vial can be used for surgery in 12 eyes (0.4 mL/patient) with a cost of $1.85/eye.

• Ensure that the circulator shakes the drug vial thoroughly before the scrub draws up drug

• Inject with a small gauge needle that has a sufficient internal bore to allow the suspension to flow through freely

• Use a non-toothed forceps or cotton swab to stabilize the eye (or nothing at all). Instruct the patient to look to the top of their head to assist the inferiorly placed depot (at least 6 mm inferior to the inferior limbus)

• Avoid conjunctival blood vessels

• Insert the needle tip bevel down. This helps to avoid subconj hemorrhage.

• Avoid in younger patients with high myopia/longer axial lengths. Studies have shown they are at high risk of a steroid-related IOP rise.

• Eyes that are at high risk of damage from an IOP rise due to:

  • Glaucoma

  • Optic neuropathy

Monitor eyes for IOP until the depot is no longer substantially visible. We have found that once the depot is no longer substantially visible on external exam, the risk of IOP rise from the injection itself is no longer significant. 

Patients may be optimally followed postoperatively until the steroid depot is no longer substantially visible when first adopting this technique. Injecting 4 mg of Triamcinolone 10 mg/mL generally produces deposits that are no longer visible after 6-8 weeks, though there is some variability between patients.

Rarely, topical antihypertensive medications may be indicated to lower IOP until the depot is no longer visible. Excising the depot (at the slit lamp with topical anesthesia) normally results in IOP returning to baseline in 1 to 7 days.

4 mg of subconjunctival triamcinolone 10 mg/mL alone is associated with less risk of macular edema than a postop regimen of prednisolone + NSAID drops. Adding postop drops to the injection should not be necessary in routine cases. Additional research is needed to clarify the role of adding NSAID in eyes with diabetic retinopathy, previous macular edema, substantial epiretinal membrane, iritis and retinal vein occlusion.