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   Table of Contents      
Year : 2019  |  Volume : 67  |  Issue : 1  |  Page : 126-127

Transcorneal tube extrusion: Anterior segment optical coherence tomography–aided management

Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India

Date of Submission13-Apr-2018
Date of Acceptance17-Aug-2018
Date of Web Publication21-Dec-2018

Correspondence Address:
Dr. Shikha Gupta
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi - 110 029
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijo.IJO_416_18

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Keywords: Ahmed glaucoma valve tube, corneal perforation, tube extrusion

How to cite this article:
Gupta S, Saluja G, Chaurasia AK, Behera AK, Gupta V. Transcorneal tube extrusion: Anterior segment optical coherence tomography–aided management. Indian J Ophthalmol 2019;67:126-7

How to cite this URL:
Gupta S, Saluja G, Chaurasia AK, Behera AK, Gupta V. Transcorneal tube extrusion: Anterior segment optical coherence tomography–aided management. Indian J Ophthalmol [serial online] 2019 [cited 2020 Jul 4];67:126-7. Available from: http://www.ijo.in/text.asp?2019/67/1/126/248144

  Case Report Top

A 40-year-old female with iridocorneal endothelial syndrome was referred after Ahmed glaucoma valve (AGV) implantation 3 months ago. The patient was on oral acetazolamide 250 mg tds, topical timolol 0.5% bd, and brimonidine 0.2% bd with intraocular pressure 40 mmHg in the right eye (RE) and 16 mmHg in the left eye (LE). The patient's visual acuity was 1/60 RE and 6/6 in LE with a relative afferent pupillary defect in RE. Anterior segment biomicroscopy revealed supracorneal AGV tube lying within pseudocorneal groove in RE and iridocorneal adhesions just beneath corneal perforation [Figure 1]a. Seidel's test was negative. Fundus RE could not be appreciated and ultrasound B scan was anechoic.
Figure 1: (a) Corneal photograph showing tube lying exposed in the corneal gutter with formation of corneoiridic adhesions immediately beneath the tube. (b) Postoperative appearance of pseudocornea formation with vascularization over the site of previous tube

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Anterior segment spectral domain optical coherence tomography (Spectralis, Heidelberg Engineering, Inc., USA; [Figure 2]) showed self-sealed corneal perforation with thick pseudocornea formation encircling the overlying tube. Blood investigations showed normal blood counts, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP).
Figure 2: Anterior segment optical coherence tomography showing the tube embedded within the corneal stroma (solid arrow), with pseudoepithelialization (white arrow) and pseudocornea formation at bed of the tube (arrowhead)

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Exposed supracorneal AGV tube was simply excised with a Vannas scissors after exerting a stretch on the tube to maximize trimmed tube length leaving behind the plate in situ. No conjunctival dissection was done since the extrusion was primarily transcorneal. The tube was not reinserted after cutting as there was a risk of intraocular infection introduction. Anterior chamber remained deep with no aqueous leakage from either tube entry site or the corneal wound due to pseudocornea formation; hence, corneal patch graft was not required for defect repair. Inferior 180° diode laser cyclophotocoagulation was done for intraocular pressure (IOP) control. Postoperatively, the patient was administered topical antibiotic–steroid combination along with antiglaucoma medications. Bacterial and fungal cultures from tube bed were sterile.

After 6 months, the patient maintains visual acuity and IOP of 21 mmHg on three topical medications. Healing with localized scar and superficial vascularization was observed in the region of melt [Figure 1]b.

  Discussion Top

Glaucoma drainage devices (GDDs) have been associated with complications such as tube exposure,[1] corneal decompensation,[2] and endophthalmitis.[3] However, transcorneal melt following GDD implantation is rare and more often seen in children associated with conjunctival extrusion.[4],[5] The peculiarity in our case was primarily extensive transcorneal extrusion without conjunctival exposure and use of anterior segment optical coherence tomography (ASOCT) in diagnosis and management of the case. Localized corneal melt could have been due to an anterior limbal tube entry, causing prolonged tube–corneal contact with subsequent pressure-induced corneal perforation and healing by pseudocornea formation. Absence of adjacent corneal opacity/scarring in addition to sterile corneal cultures ruled out infective etiology. Collagen vascular disease could cause corneal melt; however, it was ruled out by normal ESR and CRP. Tube-induced corneal melt could have been avoided by making a more posterior scleral entry, or by early tube repositioning.

  Conclusion Top

ASOCT is a good modality to look for corneal integrity in cases of tube-induced melt and decide appropriate management plan.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Levinson JD, Giangiacomo AL, Beck AD, Pruett PB, Superak HM, Lynn MJ, et al. Glaucoma drainage devices: Risk of exposure and infection. Am J Ophthalmol 2015;160:516-21.  Back to cited text no. 1
Topouzis F, Coleman AL, Choplin N, Bethlem MM, Hill R, Yu F, et al. Follow-up of the original cohort with the Ahmed glaucoma valve implant. Am J Ophthalmol 1999;128:198-204.  Back to cited text no. 2
Al-Torbak AA, Al-Shahwan S, Al-Jadaan I, Al-Hommadi A, Edward DP. Endophthalmitis associated with the Ahmed glaucoma valve implant. Br J Ophthalmol 2005;89:454-8.  Back to cited text no. 3
Al-Shahwan S. Transcorneal tube erosion of an Ahmed valve implant in an adult. Middle East Afr J Ophthalmol 2010;17:377-8.  Back to cited text no. 4
[PUBMED]  [Full text]  
Al-Torbak A, Edward DP. Transcorneal tube erosion of an Ahmed valve implant in a child. Arch Ophthalmol 2001; 119:1558-9.  Back to cited text no. 5


  [Figure 1], [Figure 2]


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