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 Table of Contents  
Year : 2023  |  Volume : 3  |  Issue : 2  |  Page : 368-371

An unusual presentation of Urrets-Zavalia syndrome after minimally invasive glaucoma surgery in a case of pigmentary glaucoma

1 Medical Officer, Department of Glaucoma and Research, Mahathma Eye Hospital Private Limited, Trichy, Tamil Nadu, India
2 Medical Officer, Department of Cataract and Refractive Surgery, Mahathma Eye Hospital Private Limited, Trichy, Tamil Nadu, India

Date of Submission29-Dec-2022
Date of Acceptance09-Feb-2023
Date of Web Publication28-Apr-2023

Correspondence Address:
Prasanna Venkatesh Ramesh
Mahathma Eye Hospital Private Limited, No. 6, Seshapuram, Tennur, Trichy - 620 017, Tamil Nadu
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/IJO.IJO_3394_22

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Urrets-Zavalia syndrome (UZS) is a rare post-operative condition characterized by a fixed and dilated pupil after ophthalmic surgery. UZS syndrome was first appreciated by Castroviejo and was later published in 1963 by Alberto Urrets-Zavalia in patients who underwent penetrating keratoplasty (PKP). Though there are many risk factors for UZS, the most widely accepted theories are ischemia of the iris and acute rise in intraocular pressure (IOP), with possible spontaneous partial recovery expected in some of them. Contrastingly, permanent UZS was also rarely reported in the literature by Mocan et al. among the pigment dispersion syndrome (PDS) population. In this manuscript, we have reported an unusual presentation of UZS after iStent implantation (Glaukos Corporation, United States) with the following two possible risk factors, namely, acute post-operative IOP spike and pre-existing pigmentary dispersion syndrome condition, which, accordingly to our knowledge, has never been reported in the literature before.

Keywords: iStent, MIGS, Pigmentary Glaucoma, Urrets-Zavalia Syndrome

How to cite this article:
Ramesh PV, Ramesh SV, Varsha V. An unusual presentation of Urrets-Zavalia syndrome after minimally invasive glaucoma surgery in a case of pigmentary glaucoma. Indian J Ophthalmol Case Rep 2023;3:368-71

How to cite this URL:
Ramesh PV, Ramesh SV, Varsha V. An unusual presentation of Urrets-Zavalia syndrome after minimally invasive glaucoma surgery in a case of pigmentary glaucoma. Indian J Ophthalmol Case Rep [serial online] 2023 [cited 2023 Jun 2];3:368-71. Available from: https://www.ijoreports.in/text.asp?2023/3/2/368/375046

Historically, Urrets-Zavalia syndrome (UZS) has been defined as a post-operative condition characterized by a fixed and dilated pupil following penetrating keratoplasty (PKP) in keratoconus patients who received mydriatics. With time, UZS has also been reported in various ocular surgeries such as trabeculectomy, goniotomy and iridoplasty, PKP, deep anterior lamellar keratoplasty (DALK), Descemet stripping endothelial keratoplasty (DSAEK), cataract surgery, phakic intraocular lens (IOL), and intracameral gas injection [Table 1].[6] In this manuscript, we have reported an unusual presentation of UZS after minimally invasive glaucoma surgery (MIGS) in a case of pigmentary glaucoma.
Table 1: The table shows the lists of cases that reported Urrets-Zavalia syndrome (UZS) following glaucoma surgeries with its salient features

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  Case Reoprt Top

A 36-year-old male patient with pigmentary glaucoma was referred to our center for glaucoma management. His best corrected visual acuity with the Snellen visual acuity chart was 6/6 in both eyes (OU) for distance, with N6 for near vision. Anterior segment examination revealed the classic triad of pigment dispersion syndrome (PDS) comprising dense trabecular meshwork pigmentation, mid-peripheral iris transillumination defects, and pigment deposition (Krukenberg spindle) on the posterior surface of the central cornea OU with an otherwise normal anterior segment. Fundus examination right eye (OD) revealed 0.5 vertical cupping, and the left eye (OS) revealed 0.5 vertical cupping with an arcuate retinal nerve fiber layer defect inferiorly [Figure 1]. His intraocular pressure (IOP) was 24 mm Hg in OD and 22 mm Hg in OS. He was advised latanoprost 0.005% at bedtime (HS) to achieve control of IOPs. Three weeks after initiating therapy, his IOP was reduced to 15 mm Hg in OD and 16 mm Hg in OS. Despite achieving the target IOP, he was persistent in undergoing surgery for glaucoma due to compliance/convenience issues. A stand-alone MIGS without cataract extraction was planned topically in OS, with iStent (generation one) implant (Glaukos Corporation, United States). Under topical anesthesia, the angle was visualized using a gonioprism iprism® SX (Glaukos Corporation, United States), and a preloaded iStent was implanted into the nasal region of the Schlemm's canal through a clear corneal temporal incision [Video Clip 1][Additional file 1].
Figure 1: Fundus photograph of the left eye showing a cup-disc ratio of 0.5 with an arcuate retinal nerve fiber layer defect inferiorly

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On post-operative day 1, the patient had visual acuity of 6/60 with corneal edema due to an IOP spike of about 29 mm Hg. His pupils were fixed and dilated, with no direct or consensual response to light, despite no mydriatics being added preoperatively as it was a stand-alone MIGS procedure. With medical management involving dorzolamide hydrochloride 2% and timolol maleate 0.5%, the IOP dropped to 18 mm Hg in the first post-operative week. Subsequently, the IOP-lowering drugs were tapered and stopped. His IOP was 14 mm Hg in OS without any hypotensive medications during the final follow-up at a 1-month post-operative period. The patient's pupil, however, has still not recovered [Figure 2], with no direct or consensual response to light and no constriction to accommodation. Gonioscopy, ultrasound biomicroscopy (UBM), and Anterion (AS-OCT) revealed open angles in all quadrants with iStent in situ [Figure 3] and [Figure 4] along with the IOP in low teens revealing an optimally functioning iStent.
Figure 2: The slit lamp biomicroscopy image shows dilated pupil after iStent implantation on post-operative day 30

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Figure 3: The gonioscopy image reveals open angles in all quadrants with iStent (red arrow) implanted in the nasal quadrant during the final follow-up of post-operative day 30

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Figure 4: Post-operative day 30. (a) The Anterion (AS-OCT) images show hyporeflective space (red arrow) in the trabecular meshwork region, depicting the region where the iStent was placed. (b) The ultrasound biomicroscopy (UBM) image reveals an open-angle and a space (red arrow), depicting a defect in the trabecular meshwork region where iStent was placed

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  Discussion Top

UZS has been reported following various anterior segment surgeries, with incidence ranging from 0% to 17.7%; it usually occurs unilaterally despite bilateral surgery. In this case report, we intend to report the first case of UZS after MIGS, which has never been reported in the literature.

Multifactorial pathogenesis

The pathogenesis of UZS has been poorly understood and is probably multifactorial. There are many risk factors for UZS, such as increased IOP during or after surgery, the use of atropine or other mydriatic agents, the presence of keratoconus, direct iris injury by the toxic effect of the viscoelastic material left in the eye, genetic predisposition, PDS, and anterior chamber inflammatory reaction in the post-operative period.[7],[8],[9],[10] Though there are many risk factors, one of the most widely accepted theory is an acute rise in IOP, which was seen in this case also, subsequent to iStent implantation; incidentally, this patient also had another pre-existing risk factor (i.e. pigmentary dispersion syndrome/pigmentary glaucoma).

Timing of the pupillary dilatation and recovery

In this case, the possible cause of the dilated pupil could have been iris ischemia secondary to the rise in IOP during post-operative day 1. The raised IOP probably could have caused the occlusion of the iris vessels, leading to secondary iris sphincter atrophy and mydriasis.[11] Literature supports this school of thought by highlighting that UZS will present in the first two post-operative days in almost 80.9% of cases. However, UZS was also reported to occur up to 5 months postoperatively, and the reported recovery of the pupil size was seen only among 4.8%.[11] One-third to two-thirds of patients with UZS will recover some form of pupil reactivity within 1 to 18 weeks, with some patients regaining normal pupil size. However, in our case, it is too early to comment on pupil recovery (as the last follow-up period is only one month). With subsequent follow-up, more clarity can arrive on whether there is a chance for spontaneous recovery in this case. The possibility of permanent mydriasis cannot be ruled out, as they have been reported in PDS cases.

Transient (incomplete) versus permanent (complete) UZS

In the transient/incomplete form of UZS, pupil size reduction is possible over time. Clinical features pointing to transient form in this case, as supported by literature, are diffuse atrophy of the anterior layers of the iris and pigmentary granules on the corneal endothelium and the anterior lens capsule.[6] However, it could be counter-argued that these findings can also be due to PDS.

Contrastingly, patients with the permanent/complete form will have marked atrophy of both the anterior and posterior layers of the iris, making the mydriasis irreversible, thus bringing the iris close to the trabecular meshwork, causing adhesions leading to secondary angle-closure glaucoma; along with posterior synechiae and glaukomflecken.[11] However, none of the above features were present in this case.

  Conclusion Top

MIGS is associated with fewer complications and is expected to have lesser recovery time with a better safety profile than conventional procedures.[12],[13],[14] Rarely, UZS can be encountered following surgery, especially in a patient with pigmentary glaucoma.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published, and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Klezlova A, Liebezeit S, Prokosch-Willing V, Gericke A, Pfeiffer N, Hoffmann E. Urrets-Zavalia syndrome after combined trabeculotomy-trabeculectomy surgery. J Glaucoma 2018;27:e80-3.  Back to cited text no. 1
Gharbiya M, Colica C, Campagna O, De Vico U, Cruciani F. Urrets-Zavalia syndrome after glaucoma filtration device implantation. Clin Ter 2013;164:e381-2.  Back to cited text no. 2
Chelnis JG, Sieminski SF, Reynolds JD. Urrets-Zavalia syndrome following goniotomy in a child. J AAPOS 2012;16:312-3.  Back to cited text no. 3
Jain R, Assi A, Murdoch I. Urrets-Zavalia syndrome following trabeculectomy. Br J Ophthalmol 2000;84:338-9.  Back to cited text no. 4
Espana EM, Ioannidis A, Tello C, Liebmann JM, Foster P, Ritch R. Urrets-Zavalia syndrome as a complication of argon laser peripheral iridoplasty. Br J Ophthalmol 2007;91:427-9.  Back to cited text no. 5
Urrets-Zavalia Syndrome-EyeWiki. Available from: https://eyewiki.aao.org/Urrets-Zavalia_Syndrome. [Accessed on 2022 Dec 09].  Back to cited text no. 6
Magalhães OA, Kronbauer CL, Müller EG, Sanvicente CT. Update and review of Urrets-Zavalia syndrome. Arq Bras Oftalmol 2016;79:202-4.  Back to cited text no. 7
Silva LRE, Gonçalves MM, Kappel GM, Gomes JAP. Iris ischemia following penetrating keratoplasty for keratoconus (Urrets-Zavalia syndrome). Cornea 1995;14:618-22.  Back to cited text no. 8
Nizamani NB, Bhutto IA, Talpur KI. Cluster of Urrets-Zavalia syndrome: A sequel of toxic anterior segment syndrome. Br J Ophthalmol 2013;97:976-9.  Back to cited text no. 9
Bowden B. Keratoconus, keratoplasty and iris atrophy. Trans Ophthalmol Soc Aust 1966;25:20-2.  Back to cited text no. 10
Tuft SJ, Buckley RJ. Iris ischaemia following penetrating keratoplasty for keratoconus (Urrets-Zavalia syndrome). Cornea 1997;6:120.  Back to cited text no. 11
Jastaneiah S, Al Towerki A-E, Al Assiri A. Fixed dilated pupil after penetrating keratoplasty for macular corneal dystrophy and keratoconus. Am J Ophthalmol 2005;140:484-9.  Back to cited text no. 12
Lagoutte F, Thienpont P, Comte P. Proposition de traitment du syndrome d Urrets-Zavalia. A propos d'un cas reversible [Proposed treatment of the Urrets-Zavalia syndrome. A propos of one reversible case]. J Fr Ophthalmol 1983;6:291-4.  Back to cited text no. 13
Mathew DJ, Buys YM. Minimally invasive glaucoma surgery: A critical appraisal of the literature. Ann Rev Vis Sci 2020;6:47-89.  Back to cited text no. 14


  [Figure 1], [Figure 2], [Figure 3], [Figure 4]

  [Table 1]


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