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Updated: May 28, 2026

An Alternative and Validated Injection Method for Accessing the Subretinal Space via a Transcleral Posterior Approach
Published on: December 7, 2016
Use of triamcinolone to judge needle depth in big-bubble deep anterior lamellar keratoplasty
Hamish D McKee1, Fiona M Carley, Vishal Jhanji
1Department of Ophthalmology, Manchester Royal Eye Hospital, Central Manchester University, NHS Foundation Trust, Manchester, UK. hamishmckee@gmail.com
Purpose:
To report a technique for judging needle depth in the corneal stroma during big-bubble deep anterior lamellar keratoplasty (DALK).
Methods:
With the anterior chamber full of air, a dilute suspension of washed triamcinolone crystals is injected to "wash" over the air bubble. Some crystals are trapped between air and endothelium, making the posterior limit of the cornea easier to identify. The needle is then inserted into deep stroma, and big-bubble DALK is performed in the usual manner.
Results:
This technique was used in 10 keratoconic eyes undergoing big-bubble DALK. No adverse effects of triamcinolone use were found in any eyes.
Conclusions:
This technique provides another option for surgeons who wish to accurately judge needle depth during big-bubble DALK.

