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.

Because the depot can be easily visualized under the conjunctiva, dissolution can be monitored, and it can be excised at the slit lamp if necessary. 

Injecting 12 mg or more subconjunctivally is associated with a significant increased risk of IOP rise (slide 2 below). This is also the case when injecting the 40 mg/mL strength drug.  These doses and concentration are probably too high for routine cases.

We have found that a subconjunctival dose of 4 mg triamcinolone acetonide 10 mg/mL (TA 10 mg/mL) is optimal. Slide 3 shows results of our recent study. 4 mg TA 10 mg/mL is associated with lower odds of macular edema than topical prednisolone alone or in combination with NSAID and slightly lower odds of a glaucoma-related event (e.g., IOP rise). A randomized control trial also found less inflammation in the 4 mg TA 10 group compared to topical steroid.

Injecting the more dilute solution of 10 mg/mL is associated with less odds of a postop IOP rise than injecting the same dose of the more concentrated strength of TA 40 mg/mL.

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,

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.

Intracameral antibiotic along with subconjunctival triamcinolone injection appears to be the lowest cost prophylaxis regimen. 

Postoperative subconjunctival injections of Kenalog®, Triessence®, and Aurocort® have been studied (slide 6) with good results. While Kenalog® has been labeled as "not for intraocular use," (e.g. into the vitreous), subconjunctival (and SubTenon) injections are periocular, not intraocular.

 Care should be exercised in injecting generic or brand products that have not been studied. The pharmacokinetics of products may differ which may affect the propensity for IOP rise. When adopting this technique with a non-studied product, it is advisable to follow IOP postop in patients until the depot is no longer visible on external exam until familiarity with the product is obtained.

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 0.1 mL syringe with a 29-gauge needle with a large internal bore (slide 7)

• Use a non-toothed forceps or cotton swab to stabilize the eye (or nothing at all).

• Avoid conjunctival blood vessels

• Keep 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 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 (Shorstein, Ophthalmology 2024; Kalina, Arch Oph 1969) 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 should be followed postoperatively until the steroid depot is no longer substantially visible. Injecting 4 mg of Triamcinolone 10 mg/mL generally produces deposits that are no longer visible between 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.