Letter to the Editor Ab interno bleb needling revision: a new approach Graham A Lee MD FRANZCO,1,2,3 Desirée Murray FRCOphth4 and Peter Shah FRCOphth3,5,6 1. City Eye Centre, Brisbane, Queensland, Australia 2. University of Queensland, Brisbane, Queensland, Australia 3. Birmingham Institute for Glaucoma Research, Institute for Translational Medicine, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom 4. University of the West Indies, St. Augustine, Trinidad and Tobago. 5. Institute of Ophthalmology, University College London, United Kingdom 6. Centre for Health & Social Care Improvement, University of Wolverhampton, United Kingdom Correspondence: Associate Professor Graham Lee, 10/135 Wickham Terrace, Spring Hill, QLD, Australia Email: eye@cityeye.com.au Received 9 October 2016; accepted 17 October 2016 Conflict of interest: None Funding sources: None This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1111/ceo.12869 This article is protected by copyright. All rights reserved. There are numerous needling techniques combined with anti-fibrotic agents to revive the failing trabeculectomy bleb. Most involve insertion of a needle into the superior conjunctiva high in the fornix, then tunnelling under the conjunctiva to perforate the fibrotic wall of the encysted bleb. The scleral flap if visualised can be lifted and the anterior chamber entered. Potential complications of this technique include subconjunctival haemorrhage, hypotony and bleb leak from the perforation site. This case presents an alternative approach via the anterior chamber, utilising an anterior chamber maintainer. A 71 year old male with a history of sarcoidosis underwent a right trabeculectomy with mitomycin C (0.02% for 1 minute). The conjunctiva was noted to be very thin so the anti-fibrotic agent was placed under the scleral flap only. Post-operatively the bleb drained well and by month 3 the intraocular pressure was 11mmHg with a diffuse bleb. Guttae prednisolone acetate 1% QID was continued. At month 6, he presented with an intraocular pressure of 29mmHg. He was also on rivaroxaban 20mg daily for atrial fibrillation. A bleb needling with 5-fluorouracil 5% was undertaken resulting in an extensive subconjunctival haemorrhage (Figure 1.). The intraocular pressure was initially low, however gradually increased over the next month, despite regular self-massage and further 5-fluoruracil 5% injection. A further needling was undertaken in the operating theatre, ceasing the rivaroxaban one week prior. Under peribulbar block, a 7/0 vicryl traction suture on a spatulated 3/8 needle (Ethicon, Somerville, USA) was inserted into the mid peripheral cornea anterior to the scleral trapdoor. A Lewicky self-retaining anterior chamber maintainer (BD Visitec, Warks, UK) was used to infuse balanced salt solution in a controlled fashion utilising the irrigation-aspiration mode on the phacoemulsification machine. A 23G needle bent at 90 degrees, bevel upwards was inserted opposite to the scleral trapdoor of the trabeculectomy just behind the limbus, anterior to the iris plane. The traction suture was used to infraduct the eye whilst the 23G needle was passed across the anterior chamber avoiding the corneal endothelium, iris and intraocular lens. The needle tip was inserted into the sclerostomy, under the scleral flap to elevate the scleral flap edge and advanced further to the wall of the Tenons cyst where the bevel-up tip was used to multiply perforate the fibrous tissue (Figure 2). Subconjunctival 5-fluorouracil 5% was injected via a 30G needle high in the This article is protected by copyright. All rights reserved. superior fornix, avoiding haemorrhage as well as subconjunctival dexamethasone 0.1% into the inferior fornix. Post-operatively, guttae prednisolone acetate 1% and chloramphenicol 0.5% was prescribed six times a day in a tapering dose. Post- needling, the bleb drained well and the intraocular pressure was 6mm Hg at 3 months. A recent bleb needling technique has been described by Wilson et al utilising continuous infusion performed in the operating room.1 The balanced salt solution keeps the anterior chamber formed and avoids the need for ophthalmic viscosurgical device. The ab interno technique requires careful passing of the needle across the anterior chamber to avoid collateral damage to intraocular structures, particularly if the patient is phakic. In such cases, the iris can be pharmacologically constricted and the needle passed obliquely across the anterior chamber to avoid the pupil opening. It would be an advantage to directly visualise the sclerostomy with a surgical gonioprism, however the superior quadrant is difficult to access and prevents the use of the corneal traction suture. The scleral trapdoor needs to be visible to perform this technique to enable the needle tip to be precisely manipulated in order to avoid the potential risk of conjunctival perforation. Transconjunctival scleral flap sutures have been used in conjunction with bleb needling to avoid postoperative hypotony and may be a useful if there is intra-operative overdrainage and anterior chamber collapse.2 Needling ab interno can be utilised for routine bleb needling, but is particularly useful if there is risk of significant conjunctival bleeding, poor access to the superior conjunctiva and if there is thin or scarred tissues prone to buttonhole. It does need to be performed in the operating theatre, where the anterior chamber can be controlled with continuous infusion, precise manipulation of the eye with the traction suture and remedial measures undertaken if bleb perforation or overdrainage from the flap occurs intraoperatively. This article is protected by copyright. All rights reserved. REFERENCES 1. Wilson ME , Gupta P, Tran KV, et al. Results From a Modified bleb needling procedure with continuous infusion performed in the operating room. J Glaucoma. 2016;25:720-6. 2. Laspas P , Culmann PD , Grus FH, et al. A new method for revision of encapsulated blebs after trabeculectomy: combination of standard bleb needling with transconjunctival scleral flap sutures prevents early postoperative hypotony. PLoS One 2016;11:e0157320. This article is protected by copyright. All rights reserved. Figure 1: Extensive sub-conjunctival haemorrhage post-needling. This article is protected by copyright. All rights reserved. Figure 2: Intra-operative needling ab interno with 23G needle showing (A) corneal traction suture infraducting eye, entry of needle just behind limbus opposite to the the scleral flap and anterior chamber maintainer in situ; (B) the needle passed across the anterior chamber, out the sclerostomy with the tip of the needle at the posterior lip of the scleral trapdoor; (C) the tip of the needle puncturing the wall of the Tenons cyst and resulting elevation of the bleb and (D) formation of a diffuse superior bleb and subconjunctival injection of 5-fluorouracil 5% high in the superior fornix. This article is protected by copyright. All rights reserved.
