topiramate is a sulfamate - substituted monosaccharide , used in the treatment of epilepsy , depression , migraine , and neuropathic pain .
secondary angle closure glaucoma due to topiramate is well recognized and has been related to supraciliary effusions and forward rotation of ciliary processes .
furthermore , the medication is associated with drug - induced myopia , due to anterior displacement of the iris - lens diaphragm . in most cases
, this secondary angle closure glaucoma and myopic shift resolves rapidly with discontinuation of the medication and management of intraocular pressure ( iop ) with topical therapy .
a 36-year - old caucasian female presented to the emergency department with a one - day history of severe headache , abdominal pain , and decreased vision in the left eye ( os ) .
the patient reported that she had been suffering from headaches for the past 11 months , for which she was being treated by a neurologist . during previous headache episodes , she experienced decreased vision in either eye and a frontal headache centered around or behind the affected eye lasting 810 hours .
her medical history was significant for crohn s disease , migraines , erosive gastritis , and kidney stones .
her medications included mesalamine , sumatriptan , topiramate ( prescribed 10 months prior by neurologist ) , dexlansoprazole , oxycodone / acetaminophen , ondansetron , and promethazine . on examination ,
visual acuity was 20/30 in the right eye ( od ) and count fingers at 6 inches os .
iop via tono - pen ( tono - pen avia tonometer , reichert technologies , depew , ny , usa ) was 31 mmhg od , and 53 mmhg os .
anterior segment examination os revealed mild conjunctival injection , diffuse microcystic edema of the cornea , and a narrow anterior chamber with 12 + pigmented cells .
gonioscopy revealed appositionally closed angles bilaterally , which did not open with goniocompression os , and opened with a plateau iris configuration ( double hump sign ) od .
undilated funduscopic examination findings were asymmetric with a cup - disc ratio of 0.3 od , and 0.7 os .
topical therapy was initiated with brimonidine / timolol and dorzolamide ophthalmic drops . while iop od improved to 18 mmhg
the patient had a history of kidney stones , therefore oral and intravenous carbonic anhydrase inhibitors were avoided .
the patient was also advised to discontinue use of topiramate . while the mechanism of acute angle closure was thought to be secondary to topiramate use , underlying chronic angle closure
could not be ruled out given the history of repeated episodes of vision loss during headaches , even prior to initiation of topiramate and the advanced cupping of the optic nerve os .
ultrasound biomicroscopy was not available , therefore , based on the clinical examination ( gonioscopy ) , plateau iris angle closure was suspected while recognizing that secondary angle closure from ciliary body effusion may also be a factor .
therefore , in addition to advising discontinuation of topiramate , a laser peripheral iridotomy ( pi ) was performed os with reduction in iop to 22 mmhg os .
twelve hours later , visual acuity was 20/30 od , and 20/70 os with iop of 09 mmhg od , and 34 mmhg os , despite the discontinuation of topiramate and the use of topical bimatoprost and brimonidine / timolol .
gonioscopy revealed plateau iris configuration with patent iridotomies and an open angle od , but peripheral anterior synechiae with a closed angle despite goniocompression os . at this time
because the patient was visiting from out of state and had to return home immediately , follow - up with a glaucoma specialist was arranged . at the patient s initial consultation with the glaucoma specialist 2 days later , visual acuity was 20/20 od , and 20/40 os with an iop of 12 mmhg od , and 50 mmhg os .
the plan was to proceed with a trabeculectomy the following day , however , this was postponed as the patient was admitted to the hospital for a flare - up of her crohn s disease . throughout her hospitalization , iop remained well controlled in the range of 1012 mmhg ou without topical medications od , and on topical bimatoprost , brimonidine / timolol and dorzolamide os .
one day after the patient was discharged from the hospital , she was found to have elevated iop 53 mmhg os with a patent iridotomy .
the following day , the iop was elevated again to 51 mmhg os and the patient underwent an urgent trabeculectomy with mitomycin c os .
postoperatively , the patient s visual acuity os returned to 20/20 and iop os was controlled with trabeculectomy in the range of 0910 mmhg .
banta et al1 , sanka et al2 , and rhee et al3 were among the first to report cases of secondary angle closure glaucoma associated with the use of topiramate in 2001 .
they described uveal effusions , ciliary process swelling , and forward displacement of the iris - lens diaphragm leading to myopic shift and secondary angle closure glaucoma . by 2003 ,
they found that 85% of cases of topiramate associated secondary angle closure glaucoma occurred within the first 2 weeks of treatment .
there were 17 reports of acute bilateral myopia ( up to 8.75 diopters ) , and vision returned to normal within a few days to a few weeks of discontinuation of topiramate .
management of topiramate induced secondary angle closure glaucoma based on fraunfelder et al4 included : 1 ) prompt discontinuation of topiramate , as iop decreases rapidly after the medication is stopped ; 2 ) maximal medical therapy ( oral medications and aqueous suppressants ) , and avoiding topical miotics in order to avoid relative pupillary block .
furthermore , laser pi was not found to be beneficial if glaucoma was only associated with topiramate .
topiramate induced secondary angle closure glaucoma has been found to resolve within 2448 hours of discontinuation of the mediation , while the myopia resolves within 12 weeks.5 we present the case of a 36-year - old caucasian female with plateau iris configuration , acute onset angle closure , and acute angle closure superimposed on chronic angle closure in the setting of topiramate use . while it is difficult to prove the exact etiology of her angle closure without ultrasound biomicroscopy , which we did not have the luxury of obtaining during this patient s acute attack , it is presumed that her topiramate use may have contributed to the acute attack .
her acute change in vision in a previous emmetropic eye and improvement in visual acuity with discontinuation of the medication support this assumption .
regardless of the mechanism , this case raises a few notable points : 1 ) the multifactorial etiology of some forms of angle closure ; 2 ) the prescription of topiramate in eyes with underlying narrow angles ; and 3 ) the possibility of delayed secondary angle closure with topiramate use .
our patient did not have a prior ophthalmology examination diagnosis of narrow angles or angle closure glaucoma , but had clinical symptoms of angle closure which preceded the topiramate use , and clinical findings including narrow angles ( plateau iris od ) and chronic angle closure os , which suggests multiple etiologies as an underlying mechanism for angle closure .
follow - up examination od revealed a more open , narrow , non - occludable angle with a patent pi off topiramate but with a plateau iris configuration , which could explain the presenting angle closure od , while the 360 degree peripheral anterior synechiae os ( likely from chronic intermittent angle closure episodes ) explains the persistent elevated iop and permanently closed angle os .
finally , topiramate use could have further contributed to the angle closure precipitating the attack by a ciliary body effusion that led the patient to present to our emergency department . of note , this patient was on other systemic medications with anticholinergic properties which could further contribute to her risk of angle closure .
her case highlights the often multifactorial nature of angle closure glaucoma that can indicate multiple therapeutic interventions . in this patient
s case , while topiramate induced secondary angle closure was one suspected mechanism , a peripheral iridotomy was also warranted based on other clinical findings ( plateau iris ) and to help rule out aqueous misdirection once the topiramate was discontinued .
furthermore , when plateau iris is identified on gonioscopy but the patient is asymptomatic with a normal iop , we typically attempt laser pi first . we find that this will often open up the angle and resolve the occludability . if , however , the peripheral iridotomy fails to open up the angle or the patient is symptomatic or develops elevated iop , we would then perform peripheral iridoplasty .
the multifactorial nature of this patient s angle closure also raises the question of whether this patient was a suitable candidate for topiramate therapy and whether her underlying narrow occludable angles should have been a relative contraindication to this drug .
it suggests that perhaps , baseline ophthalmic examination with gonioscopy should be performed on all individuals being considered for topiramate therapy .
finally , our patient had been receiving topiramate therapy for roughly 10 months , far longer than the average timeframe of 2 weeks post - initiation of therapy to induce secondary angle closure glaucoma , and by taking into account her history we suspect the patient was having angle closure symptoms prior to commencing topiramate .
only one such report exists by czyz et al7 who reported a delayed onset of topiramate induced angle closure glaucoma , 262 days after initiation of therapy , which resolved with topical aqueous suppressants and discontinuation of topiramate .
this finding suggests that patients on topiramate should be monitored and counseled regarding angle closure beyond the initial 24 weeks after initiation of therapy .
while angle closure secondary to topiramate therapy has been widely recognized as a potential side effect of this medication , our report suggests that perhaps baseline ophthalmic examination should be performed prior to initiation of therapy , and that findings of narrow occludable angles should be a relative contraindication to treatment with this medication .
patients with angle closure symptoms could be mistaken by non - ophthalmologists as suffering from migraines .
further analysis of combined - mechanism angle closure is warranted to elucidate whether exclusion of patients with narrow angle glaucoma from topiramate treatment would reduce the occurrence of this side effect .
 this is a case report describing recurrent intermittent acute angle closure episodes in the setting of topiramate use in a female suffering from migraines . despite laser peripheral iridotomy placement for the pupillary block component , and the discontinuation of topiramate 
 , the acute angle closure did not resolve in the left eye with chronic angle closure and the patient required urgent trabeculectomy . 
 the right eye responded to laser peripheral iridotomy immediately and further improved after the cessation of topiramate . 
 while secondary angle closure glaucoma due to topiramate use has been widely reported , its effects in patients with underlying primary angle closure glaucoma have not been discussed . 
 our report highlights the importance of recognizing the often multifactorial etiology of angle closure glaucoma to help guide clinical management . 