Pterygium Surgery
Despite the fact that pterygium surgery has been around for thousands of years, we still don't have a consensus on the optimal surgical technique. Most of the available literature is non-comparative, and many of your mentors (myself included) draw from habit and anecdotal experience.
This is a summary of my current technique, which incorporates elements I learned from residency, fellowship, literature, conferences, and personal experience. Your goal in training should be to broaden your skillset by seeking exposure to different approaches and philosophies in preparation of refining your technique in practice.
Dissection
Head-to-tail? Tail-to-head? It probably doesn't make a big difference for the overall safety and efficacy of the surgery, but I like to start at the limbus (Figure a) for a couple reasons:
-
Establishes the correct tissue plane for anterior dissection
-
Prevents over-aggressive posterior dissection
The conjunctiva will always retract, resulting in a larger-than-expected defect (Figure d). This requires a bigger graft, with associated discomfort and poor cosmesis.
Rather than an extensive conjunctival excision, I like to undermine healthy conjunctiva to perform a wider dissection of Tenon's capsule (Figure b).
Harvesting the conjunctival autograft is one of the more challenging and frustrating steps for beginner surgeons, but I think it's one of the most important building blocks for ophthalmic surgery.
One trick is to use hydrodissection, rather than manual dissection, to separate conjunctiva from Tenon's capsule. Once you establish a fluid pocket in the correct tissue plane (Figure c), you can push the fluid across with a cannula or muscle hook, then excise your graft with scissors.
If you harvest only conjunctiva and leave behind Tenon's, the defect will fill in quickly with minimal scarring.
a
b
c
d
Adjuvants
Loosely interpreted from Kaufman et al (2013) and Clearfield et al (2016)
There are numerous studies looking at adjuvant therapies intended to reduce pterygium recurrence. Unfortunately there are few randomized controlled trials, and comparing results from different series with different endpoints is probably not very useful.
In general, the literature suggests that conjunctival autograft is superior to amniotic membrane, both of which are better than bare sclera. Mitomycin C, either intra-operatively or post-operatively, reduces recurrence rate, but can be associated with serious complications.
In your practice, you will need to choose adjuvant treatments based on the resources in your practice setting, your patient population, and your risk tolerance. I personally favor conjunctival autograft without mitomycin C for the vast majority of pterygium surgeries I perform.
Fixation
Your last decision is about how to attach your graft. In my residency, we would use about twenty interrupted 7-0 polygalactin (Vicryl) sutures so we could get plenty of suturing practice. Unfortunately, the recurrence rate was high because those thick dissolvable sutures are pro-inflammatory.
Alternatively, you could use thinner 10-0 polygalactin or nylon sutures, both of which induce much less inflammation. Some surgeons even forego sutures altogether in favor of tissue glue. It gives me peace of mind to have at least two limbal anchoring sutures on my grafts in addition to glue.
