Post-trabeculectomy early bleb localization mimicking a 'ring of steel'S Choudhary, M Kaur, SS Pandav, S Kaushik
Department of Ophthalmology, Advanced Eye Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
Correspondence Address: Source of Support: None, Conflict of Interest: None DOI: 10.4103/jpgm.jpgm_738_21
Source of Support: None, Conflict of Interest: None
Keywords: Bleb needling, ring of steel, tenon cyst
Successful trabeculectomy surgery is the product of the surgery itself and, more importantly, of a proper nurturing of the bleb. The fibrous reaction at the surgical site in the post-operative period can limit the scope of the aqueous's posterior drainage, resulting in a cystic bleb surrounded by a ring of fibrous or scar tissue commonly known as the “ring of steel.” This obstruction to posterior drainage can lead to an overhanging bleb due to the push faced by the limbal conjunctiva, ultimately putting the bleb at risk of failure. If left unrecognized or untreated in its early course, a ring of steel will inevitably require a bleb revision with conjunctival advancement surgery.
A 54-years old male patient presented with raised intraocular pressure in both eyes. On clinical examination, his best-corrected visual acuity was 6/9 in both the eyes, and intraocular pressure (IOP) on the Goldmann applanation tonometer was 32 mmHg in the right eye and 24 mmHg in the left eye on topical brinzolamide (1.0% w/v), timolol (0.5% w/v), travoprost (0.004%) and brimonidine (0.2% w/v) along with systemic tablet acetazolamide 250 mg thrice a day. On gonioscopy examination, prominent iris processes with high iris insertion and concave iris configuration were found with total cupping in both the eyes. He was diagnosed as a case of juvenile open-angle glaucoma and underwent right eye trabeculectomy augmented with intra-operative mitomycin-C (sponges soaked in 0.02% solution and applied for 2 minutes in the subtenon's space).
The patient developed an elevated, well-circumscribed, and thin-walled bleb with fibrosis around the bleb margin at three weeks follow-up, giving it a typical “ring of steel” appearance [arrow, [Figure 1]a]. The sub-conjunctival fluid indicated a localized bleb [star, [Figure 1]a].
What to do next?
The appearance of a “ring of steel” in the post-operative period indicates intense scar tissue around the bleb, limiting the posterior drainage of the aqueous and thus resulting in an elevated and well-circumscribed bleb. It is vital to intervene surgically at this stage to rescue and nurture the bleb. A bleb revision surgery with conjunctival advancement surgery is a commonly thought of procedure in such cases. Still, in the present case, bleb needling was done at slit lamp through subconjunctival space to break the early fibrosis around the bleb. A diffuse bleb was formed at the end of needling. Subconjunctival 0.1 mL of injection 5-fluorouracil (250 mg/5 mL) was injected to prevent extensive fibrosis at the end of the procedure. An IOP of 6 mmHg was noted immediately after needling. A diffuse well formed bleb was noted on follow-up visit [Figure 1]b. Extensive fibrosis can be the cause of failure of trabeculectomy, and injection 5-fluorouracil is helpful in preventing it.
The post-procedure IOP at two weeks follow-up was noted to be 8.0 mmHg without anti-glaucoma medications. The “ring of steel” phenomenon, if recognized in time, can be well managed by early needling.
Method of bleb needling on slit lamp
Take home message
“Ring of steel” is a cause of bleb failure, necessitating careful examination and management to prevent bleb failure after trabeculectomy. Early recognition and intervention might help save patients from undergoing a repeat major surgical procedure.
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There are no conflicts of interest.