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initial management of bleb dysesthesia involves the use of lubrication.1 if medical management fails , sutureless excision of overhanging blebs,2 neodymium : yag laser to the bleb surface,3 and external compression sutures have been used.4 various methods for conjunctival closure have been used should bleb excision be required , including direct closure and free graft.15 a large conjunctival defect or glaucoma surgery in the fellow eye precludes the use of these methods , as does the need to preserve conjunctiva for future glaucoma surgery .
we describe the use of a rotational conjunctival flap in the closure of a large defect following bleb excision .
a 68-year - old white male who had undergone a limbus - based trabeculectomy with an anti - fibrotic 12 years prior in the left eye presented to our institution complaining of persistent , disabling bleb dysesthesia despite frequent lubrication .
examination revealed an avascular bleb superonasally [ figure 1a ] , with a well - controlled intraocular pressure ( iop ) in the mid - to upper single digits .
( a ) this pre - operative photograph demonstrates a large avascular bleb superonasally in the patient s left eye , ( b ) this photograph taken 8 months post - operatively demonstrates a thick - walled diffuse bleb superonasally anesthesia was achieved via retrobulbar block .
the vannas scissors were then used to excise the bleb , which measured 3 mm in its largest anteroposterior dimension .
minimal leakage of the aqueous through the old scleral flap with well - maintained anterior chamber was noted , obviating the need to add tectonic support .
due to the previous conjunctival incision for a limbus - based trabeculectomy , the remaining conjunctiva retracted , leaving a large conjunctival defect measuring 8 mm by 8 mm [ figure 2a ] .
blunt dissection of the surrounding conjunctiva was performed using a westcott scissors but still did not allow for direct wound closure .
an alternative surgical technique , a rotational conjunctival flap , was then employed . in brief , the limbal side of the large conjunctival defect was measured by a caliper distance between points a and b , figure 3a ) .
an equal - sized limbal peritomy was created ( distance between points b and c = distance between points a and b , figure 3a ) .
a relaxing incision ( distance between points c and d ) was created to facilitate the extension of the conjunctival flap for the closure .
the prepared conjunctival flap was then rotated to cover the large defect [ figure 3b ] .
figure 3c demonstrates the resultant closure . the proximal edge of the flap ( point a )
was sutured to the nasal aspect of the conjunctiva remaining after excision of the bleb ( point b ) and the resulting linear tangential defect closed in a running fashion using 9 - 0 polyglactin .
the flap was secured at the 12 oclock limbus using 9 - 0 polyglactin , and the temporal linear defect was also sutured in a running fashion .
two horizontal mattress sutures of 9 - 0 polyglactin were placed through the conjunctiva at the limbus to prevent corneal migration of the conjunctival edge .
( a ) this intraoperative photograph demonstrates an 8 mm by 8 mm conjunctival defect superonasally following excision of the avascular bleb , ( b ) this intraoperative photograph demonstrates subconjunctival and subtenon s dissection in preparation for creation of a rotational flap diagrammatic representation of rotational conjunctival flap creation .
( a ) an equal size of peritomy ( distance b to c = a to b ) and a relaxing incision ( point c to d ) were made , ( b ) the conjunctiva at point ( b ) has been rotated to cover the conjunctival defect ( a ) .
the prepared conjunctival flap can be then rotated to cover to defect ( from points d  c  b a ) , ( c ) the incisions can be closed with running polyglactin sutures on post - operative day 1 , the patient demonstrated a small thick - walled bleb with iop of 12 mm hg .
one week post - operatively , the patient had a formed bleb with iop of 10 mm hg , with a small slow leak along the nasal running closure .
iop measured 17 mm hg . during the 3 post - operative week , a large bleb was observed .
one month post - operatively , iop measured 22 mm hg , decreasing to 15 mm hg with massage .
approximately 2 weeks later , a large bleb was observed , and iop measured 15 mm hg and 10 mm hg after massage . a second subconjunctival 5-fluorouracil injection was given . at 2 months post - operatively ,
a large bleb was present , with iop measuring 16 mm hg and 9 mm hg after massage .
seven months post - operatively , the patient demonstrates a large thick - walled bleb , and iop measures 10 mmhg [ figure 1b ] .
palmberg and zacchei4 reported an 80% success rate in reduction of bleb dysesthesia with placement of external compression sutures through the bleb using 9 - 0 or 10 - 0 nylon .
anis et al.2 describe a technique for sutureless trimming of overhanging blebs in six patients , whereby the overhanging portion is dissected from the cornea and trimmed at the junction of the cornea and limbus with a vannas scissors .
one patient continued to experience dysesthesia , while one patient required suturing of a persistent leak .
tabet et al.6 describe a  bleb window-pexy technique in which a conjunctival window is created in the bleb and the cut edges of conjunctiva and tenon capsule are glued to the underlying bare sclera with fibrin glue .
regarding surgical bleb reduction , la borwit et al.5 describe bleb reduction in 11 patients for large , symptomatic blebs .
ten of 11 of these eyes underwent excision of excess bleb tissue with primary closure of the remaining tissue , while one eye required a conjunctival allograft .
all patients achieved their target iop at last follow - up ; further bleb revision was required in five patients . in their retrospective study of surgical revision of dysfunctional blebs that included one case of dysesthesia , lee and holcombe7 report the use of a sliding conjunctival flap and fibrin glue .
lloyd et al.8 describe the use of modified conjunctivoplasty and subconjunctival scar tissue excision within the palpebral fissure to treat bleb dysesthesia .
all 13 eyes had improvement in their symptoms and adequate iop control , with three eyes requiring adjunctive topical glaucoma treatment .
other authors have reported in general the use of conjunctival flaps for bleb revision ; however , preparation of the conjunctival flap has not been well described .
we illustrate in detail a specific technique for the closure of a large conjunctival defect using a rotational conjunctival flap following excision of a dysesthetic bleb .
specific advantages include preservation of the limbal border and the grafting of viable , vascularized tissue to avoid retraction and scarring that may be seen with forced direct closure or devitalized free conjunctival autografts . by measuring exact flap length
[ figure 3a , distance b to c = a to b ] , the rotational autograft can be closed with minimal tension as long as sufficient subconjunctival dissection [ figure 3a , points b to c to d ] has been performed .
the patient has had resolution of dysesthesia and is maintaining good iop on two topical agents .
this technique could be useful in eyes where excision of the bleb creates a defect too large for primary closure and in patients with glaucoma drainage procedures in both eyes or in patients who may require future glaucoma surgery in the fellow eye , limiting the use of a free conjunctival autograft .
bleb dysesthesia is a common but under recognized late complication of trabeculectomy , sometimes requiring surgical revision if conservative measures fail . 
 we describe in detail a surgical technique for closure of a large conjunctival defect following bleb excision for refractory dysesthesia . 
 two subconjunctival 5-fluorouracil injections were given to improve bleb function . 
 eight months post - operatively , the intraocular pressure is well controlled on two agents , and the patient has had resolution of dysesthesia .