Kerala Journal of Ophthalmology

CASE REPORT
Year
: 2022  |  Volume : 34  |  Issue : 2  |  Page : 167--170

Vision “wipe-out” phenomena following a nonincisional laser procedure in the management of narrow-angle glaucoma


Irshad Ahamed Subhan1, Ismail A Bantan1, Waleed M Alkhuraimi1, Taha Alaidaroos1, Ahmed M Abdelaal2,  
1 Ophthalmology Center, Department of Glaucoma, King Abdullah Medical City, Makkah, Kingdom of Saudi Arabia
2 King Saud Bin Abdulaziz University for Health Sciences, Kingdom of Saudi Arabia

Correspondence Address:
Dr. Irshad Ahamed Subhan
Department of Ophthalmology, King Abdullah Medical City, Makkah
Kingdom of Saudi Arabia

Abstract

The “Wipe-out” or “Snuff-out” phenomenon refers to a permanent and severe loss of vision without an identifiable cause and is considered a rare but dreaded consequence of incisional ocular surgery. It is believed to occur in patients with advanced glaucoma who demonstrate a residual central island of vision. A 42-year-old female patient presented to the general ophthalmology clinic with complaints of painless blurring of vision of the left eye for 8 months. Best-corrected visual acuity (BCVA) was 20/30 and 20/40 and intraocular pressure (IOP) was 26 mmHg and 28 mmHg in the right and left eyes, respectively. Relative afferent pupillary defect was noted in the left eye. Anterior segment examination showed peripherally shallow anterior chamber and gonioscopy revealed appositionally closed angles (Shaffer-<20 Deg) in both eyes. Fundus examination showed advanced glaucomatous optic neuropathy of the left eye. Generalized depression in the right eye and inferior arcuate scotoma with a superior nasal step, and split fixation in the left eye was seen on Humphreys 30-2 visual fields. A diagnosis of chronic primary angle closure glaucoma was made and the patient was offered Nd: Yag Laser Peripheral Iridotomy (LPI). LPI was completed for the right eye and Argon Laser Iridoplasty was performed in the left eye as Iridotomy was not possible due to the proximity of the iris to the cornea as the pupil was mid-dilated. After the procedure, the patient was prescribed topical antiglaucoma medications with topical steroids at 1 week follow-up, the patient had BCVA of 20/30 in the right eye and hand motion in the left eye, IOPs were well controlled on topical anti-glaucoma medication. A thorough examination including a dilated fundus examination, B-Scan ultrasound, and fundus fluorescein angiography were unremarkable. Magnetic resonance imaging scan of the brain and orbits was normal. “Wipeout” phenomenon is a rare but notorious complication associated with incisional surgeries in patients with advanced glaucoma. It is also reported to occur following cataract and retinal incisional surgeries. There are no reports of a wipe-out after a commonly performed laser procedure.



How to cite this article:
Subhan IA, Bantan IA, Alkhuraimi WM, Alaidaroos T, Abdelaal AM. Vision “wipe-out” phenomena following a nonincisional laser procedure in the management of narrow-angle glaucoma.Kerala J Ophthalmol 2022;34:167-170


How to cite this URL:
Subhan IA, Bantan IA, Alkhuraimi WM, Alaidaroos T, Abdelaal AM. Vision “wipe-out” phenomena following a nonincisional laser procedure in the management of narrow-angle glaucoma. Kerala J Ophthalmol [serial online] 2022 [cited 2022 Nov 29 ];34:167-170
Available from: http://www.kjophthal.com/text.asp?2022/34/2/167/355044


Full Text



 Introduction



The “Wipe-out” phenomenon also known as the “Snuff-out” phenomenon refers to an unexplained permanent and severe loss of central vision and is considered a rare and dreaded consequence of incisional ocular surgery in patients with advanced glaucoma.[1],[2] It is a complication believed to affect patients with advanced visual field loss and with only residual Central Island of vision.[3],[4],[5] This incidence is reported in between 1.9% and 7.7% with higher incidences reported in studies with relatively smaller sample sizes.[6],[7],[8],[9]

 Case Report



A 42-year-old female with uncontrolled epilepsy on oral carbamazepine presented to the general ophthalmology clinic of our center with the complaint of painless blurring of vision in her left eye since 6–8 months. Examination showed best-corrected visual acuity (BCVA) to be 20/30 and 20/40 and intraocular pressure (IOP) 26 mm of Hg and 28 mm of Hg in the right and left eye, respectively. Afferent pupillary defect (RAPD) was noted in the left eye. Anterior segment examination of the left eye showed shallow anterior chamber (Von Herrick's Grade 1) and appositionally closed angles on Gonioscopy (Shaffer-< 20 Deg). Fundus examination was remarkable for glaucomatous optic neuropathy of the right eye with a vertical cup to disc ratio of 0.7 with the presence of an inferotemporal notch and advanced glaucomatous optic neuropathy of the left eye with a vertical cup to disc ratio of 0.9–0.95 with diffuse neuro-retinal rim loss.

The case was referred to Glaucoma services. A 30-2 Humphrey visual field test was requested. Right eye visual fields showed generalized depression, and left eye showed an incomplete inferior arcuate scotoma extending into a superior nasal step and demonstrating split fixation on the numerical plot with absent pattern deviation plot because of severely depressed fields [Figure 1] and [Figure 2]. A diagnosis of chronic primary angle-closure glaucoma was made, and the patient was offered Nd: Yag laser peripheral iridotomy (LPI) for both eyes. LPI was performed in the right eye. However, due to the mid-dilated pupil in the left eye, LPI was not possible. Hence, Argon laser iridoplasty (LPI) was performed. Argon laser light was delivered using an Abraham iridotomy lens, with a spot size of 400 microns for 0.5s. The treatment was initiated at 300 mW pf power and increased till contraction of the iris tissue was seen. The beam was aimed as peripheral as possible onto the iris surface in the anterior chamber angle. Both the procedures were performed under antiglaucoma medications. Following the laser procedures, the patient was advised to start topical anti-glaucoma medications in the form of a beta-blocker and carbonic anhydrase inhibitor and a short course of topical steroids.{Figure 1}{Figure 2}

The patient's BCVA after 1 week was 20/20 in the right eye and hand motion in the left eye, with well-controlled IOP on topical anti-glaucoma medications. A thorough ocular examination was done including dilated fundus examination [Figure 3], B-Scan ultrasound [Figure 4] and fundus fluorescein angiography [Figure 5], and optical coherence tomography was performed to identify the cause of sudden loss of vision. Anterior segment photography was done to demonstrate patent PI in the right eye and iris atrophic patches at the site of attempted LPI [Figure 6]. A magnetic resonance imaging scan of the brain and orbit was requested to rule out intracranial pathology. All the investigations were normal, ruling out contribution to the loss of vision.{Figure 3}{Figure 4}{Figure 5}{Figure 6}

 Discussion



Unexplained vision loss, known as “Wipe-out” or “Snuff-out” phenomenon is a rare but feared complication associated with incisional surgeries in patients with advanced glaucoma.[1],[2],[3] Theories have been suggested including disc hemorrhages occurring in association with surgical opening of the eye, perioperative cardiovascular insufficiency and nutritional instability, sudden hypotony induced by surgery, and as an unforeseen complication of retro-bulbar anesthesia.[3],[4],[5] A more recent small case series suggests an association between a significant loss of vision after glaucoma filtering surgery and progressive macular thinning observed on optical coherence tomography, advocating progressive retinal ganglion cell loss as a cause of vision loss after uncomplicated glaucoma surgery.[10]

Historical reports based on studies with a high variation in sample size show the incidence of unexplained central vision loss following trabeculectomy in patients with advanced glaucoma to range between 0% and 7%, underlying the concern many glaucoma specialists have regarding the unexplained vision loss following ocular surgery.[6],[7],[8] Recently, studies based on newer trabeculectomy techniques and standards show lower occurrence rates of the “Wipe-out” phenomenon ranging between 0% and 2%.[1],[2] Yet routine counseling of patients with advanced glaucoma to the risk of unexplained central vision loss after different incisional ocular surgeries is widely practiced. The general consensus is despite the risk of the wipeout phenomenon as a complication, its occurrence is sufficiently rare that it should not supplant performing interventions when potential benefits outweigh risks.[4] This argument is particularly important when dealing with advanced glaucoma where inevitable vision loss and blindness may ensue if the disease progression is allowed to continue without necessary intervention.[11]

Studies have suggested the wipeout phenomenon to occur following trabeculectomy with and without antimetabolites and possibly cataract surgery as well. Risk factors found to be associated with the “Wipe-out” phenomenon include advanced age, preoperative split fixation on visual fields, as well as postoperative hypotony and choroidal effusions.[1]

Our patient who presented with chronic primary angle-closure Glaucoma of the left eye had advanced glaucomatous optic neuropathy with a cup to disc ratio of 0.9–0.95 and a visual field showing glaucomatous defects and split fixation on visual fields [Figure 1] and [Figure 2]. The first step in her management following diagnosis was to address the appositional angle closure with Nd: Yag LPI to both eyes. Due to the inability to successfully perform, a LPI in the left eye argon laser Iridoplasty was performed. A week following nonincisional laser procedure which is commonly performed in the ambulatory care setting, the patient had developed unexplained loss of central vision and profound decline in visual acuity.

After utilizing reasonable and available investigations, we could only attribute this case of unexplained loss of central vision to the “Wipe-out” phenomenon. To the best of our knowledge, this presents the first case reported following an outpatient laser procedure. We wish to increase awareness and caution about this complication to ophthalmologists. We recommend adequate counseling of patients with advanced glaucoma who are undergoing routine outpatient procedures such as LPI or Argon laser iridoplasty of the potential risk of unexplained vision loss.

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 initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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