Definition/Introduction

Amsler sign, also known as Amsler-Verrey sign, is present in Fuchs heterochromic uveitis. This sign is characterized by hemorrhage in the anterior chamber (hyphema) following anterior chamber paracentesis or entry with the microvitreoretinal blade during anterior segment surgeries, including cataract surgery or minor trauma. This hemorrhage is due to fine, fragile vessels in the anterior chamber angle. The sign derives its name from Dr Marc Amsler and Dr Florian Verrey, who described it in 1946.[1]

Dr Marc Amsler (1891-1968) was a Swiss ophthalmologist and a great teacher. He was a student of Jules Gonin (1870-1935) at the University of Lausanne and a strong supporter of Gonin's ideas on the repair of rhegmatogenous retinal detachments. Dr Amsler was known as Le marcheur de l'operation de Gonin ("The seller of Gonin's surgical procedure").[2] He later became the chief of the Zurich Eye Clinic. His contributions to ophthalmology include the Amsler grid and the Amsler-Dubois chart.

• Amsler grid is a 10 cm × 10 cm square-shaped chart with 7 variants. The chart is a valuable and affordable tool for monitoring metamorphopsia and scotoma in various macular diseases, particularly in cases of wet age-related macular degeneration.[3]
• The Amsler-Dubois chart is essential for documenting posterior segment lesions, including retinal detachment.

Dr Amsler's research focused on macular function, aqueous humor in uveitis, and keratoconus. He invented a mirror for retinal examination using a monocular indirect ophthalmoscope.[2] 

Dr Florian Verrey (1911-1976) was a Swiss ophthalmologist who worked with Dr Amsler at the University of Lausanne and later at the Zurich Eye Clinic. His research primarily focused on uveitis and aqueous humor.

Fuchs heterochromic uveitis gets its name from Ernst Fuchs (1851-1930), an Austrian ophthalmologist who was the clinical director of the Second Vienna Eye Hospital.[4] His Textbook of Ophthalmology was considered one of the best textbooks on the subject at that time. Fuchs endothelial corneal dystrophy and Fuchs spot in myopia are named in his honor.

Fuchs heterochromic uveitis is characterized by unilateral heterochromia, cataract, glaucoma, and the absence of posterior synechia.[4] Typically, Fuchs heterochromic uveitis has fine stellate keratic precipitates that are present diffusely over the endothelium and involve both the superior and inferior parts of the cornea. The iris typically loses detail on the surface (featureless iris) due to atrophy compared to the other eye, and iris nodules may be noted at the pupillary margin (Koeppe nodules). However, frank heterochromia may be absent, especially in patients with heavily pigmented iris. Typically, anterior chamber reaction, if present, is mild. Vitreous may show some debris, and retrolental cells may be noted on slit-lamp examination.

Issues of Concern

Pathophysiology

Gonioscopy in Fuchs heterochromic uveitis reveals the following findings: [5][6]

• Small twig-like vessels in the angle that likely give rise to the Amsler-Verrey sign
• The visibility of large vessels at the peripheral iris is likely due to the atrophy of the iris
• Loss of the details in the anterior chamber angle, appearing dull or covered with a felt-like texture
• Small, irregular areas of non-confluent goniosynechiae

The fine vessels in the anterior chamber angle are fragile and prone to rupture after trivial trauma. The exact nature of these vessels is unknown; they may represent abnormal vasculature or new vessels. There is no clear correlation between the hyphema and abnormal angle vessels.[7] The hemorrhage in the anterior chamber originates from the angle in a filiform appearance and then may settle inferiorly when the patient is upright. There are claims that the Amsler-Verrey sign is a diagnostic sign in FHI, especially in Europe.[7]

In FHI, the angular vessels can be injured during diagnostic procedures using a 30-gauge needle inserted through the limbus or during paracentesis with a blade in cataract surgery. This damage can result in a micro-hyphema known as the Amsler sign. The hyphema may occur from the anterior chamber angle, away from the entry site. This occurrence is due to sudden decompression of the anterior chamber and hypotony, leading to hemorrhage from the anterior chamber angle vessels.

However, similar anterior chamber hemorrhage after paracentesis may also present in other conditions, including:

• Neovascular glaucoma
• Neovascularization of the anterior chamber angle
• Sudden hypotony or shallowing of the anterior chamber during anterior segment surgery
• Patients on anticoagulant therapy or with bleeding disorders

Despite these possibilities, the presence of this sign should raise a strong suspicion of Fuchs heterochromic uveitis.  

Causes of Anterior Chamber Hemorrhage

Amsler and Verrey noted hyphema after paracentesis in FHI.[1][7] Other causes of the Amsler-Verrey sign include the following: [8][9]

• Spontaneous or possibly from trivial trauma such as rubbing the eyes
• Gonioscopy
• Applanation tonometry
• Pharmacological dilatation of the pupil
• Posterior capsulotomy
• Honan balloon before cataract surgery
• During cataract surgery
• Peribulbar anesthesia

Clinical Significance

The hyphema due to the Amsler sign is typically mild. Active bleeding from the anterior chamber angle may stop spontaneously. In cases with continuing intraoperative hemorrhage, forming the anterior chamber with a viscosurgical device or raising the intraocular pressure typically stops the bleeding. The hyphema typically does not worsen the visual outcomes, and most cases of Fuchs heterochromic uveitis have mild perioperative hemorrhage after cataract surgery. Hyphema may not be present on the first postoperative day. For postoperative mild hyphema, a medication regimen of antibiotics and steroid drops is typically sufficient to manage inflammation. In severe hyphema or postoperative inflammation, topical cycloplegics are necessary to prevent posterior synechia. Although posterior synechia is otherwise uncommon in Fuchs heterochromic uveitis, postoperative inflammation can lead to posterior synechia, necessitating treatment with both steroids and cycloplegics. Typically, the outcome of cataract surgery is good in Fuchs heterochromic uveitis with cataracts. However, some cases may have anterior chamber reaction, deposits on the intraocular lens, decentration of intraocular lens, glaucoma, vitreous inflammation/haze, posterior capsular opacification, cystoid macular edema, corneal edema, and macular hole.[10][11] 

Nursing, Allied Health, and Interprofessional Team Interventions

Amsler's sign is a vital clinical indicator that is typically innocuous. However, in all cases of intraoperative hyphema, the medical history should be reviewed specifically to rule out uncontrolled systemic diseases, including hypertension, clotting disorders, or anticoagulant therapy. Effective collaboration among the nursing team, physicians, and pharmacists is necessary to enhance patient care and achieve optimal ocular and systemic outcomes.

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References

1.

AMSLER M, VERREY F. [Fuchs heterochromia and vascular fragility]. Ophthalmologica. 1946 Feb-Mar;111(2-3):177-81. [PubMed: 20275799]

2.

Sampaolesi R. Prof. Marc Amsler and the Cantonal Hospital Eye Clinic, Zurich. Surv Ophthalmol. 1996 Mar-Apr;40(5):400-4. [PubMed: 8779087]

3.

Tripathy K, Salini B. StatPearls [Internet]. StatPearls Publishing; Treasure Island (FL): Aug 25, 2023. Amsler Grid. [PubMed: 30844168]

4.

Moshirfar M, Villarreal A, Ronquillo Y. StatPearls [Internet]. StatPearls Publishing; Treasure Island (FL): Feb 29, 2024. Fuchs Uveitis Syndrome. [PubMed: 32644574]

5.

Liesegang TJ. Clinical features and prognosis in Fuchs' uveitis syndrome. Arch Ophthalmol. 1982 Oct;100(10):1622-6. [PubMed: 6890339]

6.

FRANCESCHETTI A. Heterochromic cyclitis: Fuchs' syndrome. Am J Ophthalmol. 1955 Apr;39(4 Pt 2):50-8. [PubMed: 14361605]

7.

Jones NP. Fuchs' heterochromic uveitis: an update. Surv Ophthalmol. 1993 Jan-Feb;37(4):253-72. [PubMed: 8441952]

8.

Srinivasan S, Lyall D, Kiire C. Amsler-Verrey sign during cataract surgery in Fuchs heterochromic uveitis. BMJ Case Rep. 2010 Oct 10;2010 [PMC free article: PMC3038033] [PubMed: 22767537]

9.

Belfort R, Muccioli C. Hyphema after peribulbar anesthesia for cataract surgery in Fuchs' heterochromic iridocyclitis. Ocul Immunol Inflamm. 1998 Mar;6(1):57-8. [PubMed: 9798195]

10.

Tejwani S, Murthy S, Sangwan VS. Cataract extraction outcomes in patients with Fuchs' heterochromic cyclitis. J Cataract Refract Surg. 2006 Oct;32(10):1678-82. [PubMed: 17010867]

11.

Javadi MA, Jafarinasab MR, Araghi AA, Mohammadpour M, Yazdani S. Outcomes of phacoemulsification and in-the-bag intraocular lens implantation in Fuchs' heterochromic iridocyclitis. J Cataract Refract Surg. 2005 May;31(5):997-1001. [PubMed: 15975468]

Disclosure: Koushik Tripathy declares no relevant financial relationships with ineligible companies.

Disclosure: Baby Salini declares no relevant financial relationships with ineligible companies.