Reactions 1871, p262 - 4 Sep 2021
Mitomycin S
Trans-conjunctival erosion of Preserflo microshunt: case report
An approximately 63-year-old man developed trans-conjunctival erosion of Preserflo microshunt during treatment with mitomycin.
The man, who had a longstanding history of type 1 diabetes mellitus, was referred for the management of bilateral and progressive secondary glaucoma (at the age of 62 years). His medical history was also significant for proliferative diabetic retinopathy for 15 years, which included bilateral combined phacoemulsification and pars plana vitrectomy with retinal laser for non-resolving vitreous haemorrhages. Subsequently, the proliferative diabetic retinopathy was controlled without resultant iris or angle neovascularisation. However, he developed bilateral persistently raised intraocular pressure (IOP) and subsequent early glaucomatous optic neuropathy (GON). On presentation, after considering various surgical options, a decision was made for Preserflo implantation. He therefore underwent successive right and then left Preserflo implantation with mitomycin [mitomycin C]
with a 10 week interval between surgeries. The surgery was performed under local anaesthesia. He received mitomycin in the right eye at a concentration of 0.4 mg/mL for 2.5 minutes and in the left eye at a concentration of 0.2 mg/mL for 2 minutes. The mitomycin was applied using three overlapping corneal sponge/light shields placed in a fornix-based sub-tenon’s pocket distal to the implant’
draining tip. The surgery was completed with administration of unspecified steroid and antibacterials [antibiotic]. Postoperatively, he received atropine and an unspecified antibacterial along with an unspecified steroid. Postoperatively, both eyes had excellent initial outcomes with well-positioned implants, diffuse posterior blebs and well-controlled IOP. Due to COVID-19 pandemic evolved, his next follow-up visit was postponed over a year from the original surgery date. At this time (approximately at the age of 63 years), he was found to have a non-functioning right implant with a flat bleb and a significantly encapsulated bleb on the left. The distal portions of both shunts were found to be undisplaced. Therefore, he underwent right Preserflo revision and left bleb needling, both augmented with mitomycin. He was found to have extensive fibrosis over the distal tip of the implant with multiple fibrotic layers occluding the distal lumen. Subsequently, a second Preserflo was inserted. A further application of mitomycin at a concentration of 0.2 mg/mL for 2 minutes using two corneal sponges was applied distal to the second implant followed once again by copious irrigation with balanced salt solution. The conjunctival/tenon’s bilayer was found to be healthy without surgical button- holes or defects. He also underwent bleb needling of the left eye, which was followed by ophthalmic (sub-tenon’s injection) of mitomycin 0.2 mg/mL across the distal drainage site. Surgery was completed bilaterally with administration of unspecified steroid and antibacterials, and he was discharged with a bilateral post-operative drop regimen of atropine and unspecified antibacterial and steroids to be weaned slowly over the following weeks. One week after the revision surgery, best-corrected visual acuity (BCVA) was found to be 0.24 logMAR in both eyes with diffuse, posterior and non-leaking blebs and stable and controlled IOP. After one month, he returned to the clinic and was found to have conjunctival erosion of the original Preserflo microshunt implant in the right eye, despite being completely asymptomatic. The trans-conjunctival erosion of Preserflo microshunt was attributed to the mitomycin therapy.
The man was admitted to the hospital and underwent urgent further revision for removal of the extruding device. The surgery was performed under local anaesthesia with a more localised conjunctival peritomy. The extruding Preserflo, which had no flow from the tip, was removed with forceps and the original scleral tunnel was sutured. The localised area of thin conjunctiva was excised with healthier conjunctival and tenon’s tissue. He was treated with unspecified steroid and antibacterial. On follow-up 3 months post- operatively, right BCVA and IOP were found to be 0.22 logMAR and 17mm Hg, respectively on latanoprost therapy.
Michaels L, et al. Trans-conjunctival Erosion of a Novel SIBS Microshunt after Revision Surgery Using Mitomycin C. Journal of Glaucoma 30: E349-E351, No. 7, Jul 2021.
Available from: URL: http://doi.org/10.1097/IJG.0000000000001848 803592329
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Reactions 4 Sep 2021 No. 1871 0114-9954/21/1871-0001/$14.95 Adis © 2021 Springer Nature Switzerland AG. All rights reserved
