Sagging Eye Syndrome

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Original article contributed by: Luai T. Eldweik, MD
All contributors: Luai T. Eldweik, MD
Assigned editor:
Review: Not reviewed


Introduction

Sagging eye syndrome (SES) was first described by Rutar and Demer in 2009, as a potential leading cause of strabismus in older adult population as a combination of horizontal and/or vertical strabismus in addition to bilateral blepharoptosis and deep sulci.[1] SES should be differentiated from heavy eye syndrome (HES) which is an association of axial high myopia, esotropia, and hypotropia.[2]

Anatomy of pulleys system

Extraocular muscle (EOM) paths are constrained by connective tissue pulleys serving as functional origins. The mechanical properties of pulleys are critical for the support and rotational properties of the eye.

Histologic studies showed that each rectus pulley consists of an encircling ring of collagen located near the globe equator in tenon fascia, coupled to the orbital wall, adjacent EOMs, and equatorial Tenon fascia by bands containing densely woven collagen, elastin, and smooth muscle.[3] The pulleys inflect rectus and inferior oblique paths by the exact same way that the trochlea inflects the path of the superior oblique (SO) tendon. The global layer of each rectus EOM, passes through the pulley and becomes contiguous with tendon to insert on the globe. The orbital layer, inserts on the pulley, not on the globe.[3]

A dense band was present from the medial rectus to the inferior pulleys (MR–IR band) and from the medial rectus to the superior rectus pulleys (MR–SR band). Similarly, another dense band was present from the Superior rectus to the lateral rectus pulleys (LR–SR band). The inferior oblique muscle was present between the inferior rectus and lateral rectus pulleys.[3]

Pathophysiology

Degeneration of one of the ligaments interconnecting the extraocular muscle pulleys is the lateral rectus (LR)-superior rectus (SR) band, the LR-SR band vertically supports the LR pulley against the downward force of the inferior oblique muscle to maintain the LR pulley’s vertical position and the degeneration permits inferior sag of the LR pulley, causing esotropia, or cyclovertical strabismus, or both.[4]

Age Related Distance Esotropia (ARDE)[5] Cyclovertical Strabismus (CVS)[5]
  • Results from bilateral inferior shift of the LR pulleys
  • Characterized by esotropia at distance fixation, orthotropia or esophoria at near fixation
  • Normal horizontal duction range, and normal horizontal saccadic velocities
  • Results from asymmetrical inferior shift of the LR pulley
  • Characteristically by hypotropia and excyclotortion of the lower eye

History

The typical presentation in an older individual is one of gradual or subacute onset of diplopia. Initially, most patients only notice intermittent binocular diplopia at long distances, such as in the theater or while driving. Over a period of several months, the diplopia becomes more constant and is noticed while driving, watching television, and in other long-distance vision situations. Typically, patients note that they do not have any diplopia at near. The remainder of the neurological examination should be normal, without any cranial neuropathies or abduction deficits. In addition to that patients usually either have blephroptosis or had a history of eyelid surgery or face lifting.[5]

Physical examination

External features

Retraction of the upper eyelid into the superior orbit (superior sulcus deformity), aponeurotic blepharoptosis and high upper eyelid crease[1][4].

Sensorimotor exam[4]

  1. ARDE only: incomitant esotropia worse in distance and in side gaze with no strabismus or small phoria for near and no vertical deviation
  2. ARDE and CVS: incomitant esotropia with a small hypotropia in one side
  3. CVS only: hypotropia with no horizontal deviation
  4. Supdraduciton deficit
  5. Normal horizontal duction range, and normal horizontal saccadic velocities

Magnetic Resonance Imaging (MRI)

Chaudhuri and Demer used MRI to evaluate rectus EOMs, pulleys, and the LR-superior rectus (SR) band ligament in SES. Magnetic resonance imaging resolution showed superotemporal bowing of the LR-SR band in milder cases and abrupt termination of an attenuated band remnant in the superolateral orbit in more severe cases.[4] The ligament was ruptured in 64% of orbits with DPE and 91% of orbits with CVS.  Also found significant displacement of all four rectus pulleys away from the orbital center, lateral displacement of the inferior rectus pulley and obliquely angulated lateral rectus pulley.[4]

MRI measurements of horizontal EOM lengths in SES were approximately 40%, or 14 mm, longer than the EOMs of nonstrabismic younger and older controls.[4]

Differential diagnosis

Differentiating sagging eye syndrome (SES) from other causes of strabismus is not always a straight forward task given that patients with SES may have risk factors for strokes or tumors. Usually the sensorimotor exam is helpful as in SES the misalignment does not map similar to cranial nerve palsies or skew deviation and in addition to that patients with SES usually have normal horizontal saccades and normal horizontal ductions. The differential includes:

  • Cranial nerve palsy (Third, Fourth or Sixth nerves)
  • Skew deviation
  • Thyroid eye disease
  • Myasthenia gravis
  • Decompensated phoria
  • Heavy Eye Syndrome

Management

Observation

Since most of the patients have good fusional capacities they do not experience double vision for near with that said these patient can likely manage without the need for intervention.

Prism

In spectacle dependent patients a temporary fresnel prism or permanent ground in prism are usually helpful in managing the double vision for distance without inducing diplopia for near given their strong near fusional capacities as mentioned before.

Surgery

Patients with sagging eye syndrome can be treated surgically if they do not respond to or do not desire prism therapy. Different surgical approaches were described when dealing with the components of sagging eye syndrome including divergence insufficiency esotropia and cyclovertical strabismus.

Age Related Distance Esotropia (ARDE)

  • Lateral Rectus Resection

In 2005 Thacker NM et al. published a case series of longterm follow up for 29 patients with divergence insufficiency esotropia underwent lateral rectus resection. Their patients all had satisfactory results, with no patients initially over-corrected or requiring additional prisms. However, they had a recurrence rate of almost 7% over their mean follow-up period of 39 months.[6]  In 2013, Stager et al. reported a series of 57 patients underwent unilateral lateral rectus resection for distance esotropia deviations of 5–30Δ with 96.5 % did not require further surgery. [7]

  • Medial Rectus Recession

Bothun and Archer reported a series of 8 patients who underwent bilateral medial rectus recessions for distance esotropias of 12–35Δ; 5 patients had satisfactory results with collapse of the distance-near deviation from 15Δ pre-operatively to 5Δ postoperatively. [8] Later Chaudhuri and Demer reported 24 patients and compared the results of those undergoing lateral rectus resection (n = 8) to those undergoing medial rectus recession (n = 16). They concluded that medial rectus recession is as effective as lateral rectus resection and suggested that double the distance angle of esotropia should be used as the surgical target.[9] In their case series patients with lateral incomitance, the adjustable suture was generally placed on the MR opposite the horizontal direction of the greatest ET.

Cyclovertical Strabismus (CVS)

  • Selective tenotomy and plication

Chang MY et al. reported a case series of Of 9 patients with vertical strabismus incomitant in horizontal gaze positions and cyclotorsion who underwent Adjustable small-incision selective tenotomy and plication. 8 (89%) had successful with postoperative vertical alignment and 4 (50%) were successfully corrected, with <5° of cyclotorsion postoperatively. They concluded that these surgeries are less effective for correcting cyclotorsion in patients with restriction or prior strabismus surgery.[10]

  • Graded Vertical Rectus Tenotomy (GVRT)

 In 2015 Chaudhuri and Demer published a retrospective observational study about utilizing Graded Vertical Rectus Tenotomy (GVRT) for treating incomitant vertical misalignment. The procedure is performed under topical anesthesia in the presence of an anesthesiologist. Initial tenotomy 30% of tendon width to avoid intraoperative overcorrection. Surgical effect was assessed immediately by setting the patient up and repeating the measurements at near and distance. If hypertropia persisted, further 5%–10% increments of GVRT up to a maximum of 90% were added with monitoring of alignment. The inferior rectus (IR) was chosen when hypertropia was vertically concomitant or greatest in infraversion. The SR was chosen when hypertropia was greatest in sursumversion or absent in infraversion. Temporal GVRT was chosen for the IR and nasal GVRT for the SR. They concluded that GVRT performed with intraoperative monitoring under topical anaesthesia, precise correction of hypertropia up to 10Δ can be achievable.[11]

Additional Resources

  1. Rutar T, Demer JL. “Heavy Eye” Syndrome in the Absence of High Myopia: A Connective Tissue Degeneration in Elderly Strabismic Patients. Journal of AAPOS : the official publication of the American Association for Pediatric Ophthalmology and Strabismus / American Association for Pediatric Ophthalmology and Strabismus. 2009;13(1):36-44. doi:10.1016/j.jaapos.2008.07.008.
  2. Demer JL. More respect for connective tissues. J AAPOS. 2008;12(1):5–6. 
  3. Chaudhuri Z, Demer JL. Sagging Eye Syndrome: Connective Tissue Involution as a Cause of Horizontal and Vertical Strabismus in Older Patients. JAMA ophthalmology. 2013;131(5):619-625. doi:10.1001/jamaophthalmol.2013.783.
  4. Bradley J. Katz, MD; Joseph L. Demer, MD, PhD; Robert A. Clark, MD: Sagging Eye Syndrome. Audio blog post. American Academy of Ophthalmology. 2016.

References

  1. 1.0 1.1 Rutar T, Demer JL. “Heavy Eye” Syndrome in the Absence of High Myopia: A Connective Tissue Degeneration in Elderly Strabismic Patients. Journal of AAPOS : the official publication of the American Association for Pediatric Ophthalmology and Strabismus / American Association for Pediatric Ophthalmology and Strabismus. 2009;13(1):36-44. doi:10.1016/j.jaapos.2008.07.008.
  2. Demer JL et al. Heavy eye syndrome versus sagging eye syndrome in high myopia. Journal of American Association for Pediatric Ophthalmology and Strabismus {JAAPOS} , Volume 19 , Issue 6 , 500 - 506
  3. 3.0 3.1 3.2 Demer JL. More respect for connective tissues. J AAPOS. 2008;12(1):5–6. 
  4. 4.0 4.1 4.2 4.3 4.4 4.5 Chaudhuri Z, Demer JL. Sagging Eye Syndrome: Connective Tissue Involution as a Cause of Horizontal and Vertical Strabismus in Older Patients. JAMA ophthalmology. 2013;131(5):619-625. doi:10.1001/jamaophthalmol.2013.783.
  5. 5.0 5.1 5.2 Bradley J. Katz, MD; Joseph L. Demer, MD, PhD; Robert A. Clark, MD: Sagging Eye Syndrome. Audio blog post. American Academy of Ophthalmology. 2016.
  6. Thacker NM, Velez FG, Bhola R, Britt MT, Rosenbaum AL. Lateral rectus resections in divergence palsy: Results of long-term follow-up. J AAPOS. 2005;9:7–11.
  7. Stager DR, Sr, Black T, Felius J. Unilateral lateral rectus resection for horizontal diplopia in adults with divergence insufficiency. Graefes Arch Clin Exp Ophthalmol. 2013;251:1641–1644.
  8. Bothun ED, Archer SM. Bilateral medial rectus muscle recession for divergence insufficiency pattern esotropia. J AAPOS. 2005;9:3–6.
  9. Chaudhuri Z, Demer JL. Medial rectus recession is as effective as lateral rectus resection in divergence paralysis esotropia. Arch Ophthalmol. 2012;130:1280–1284
  10. Chang MY, Pineles SL, Velez FG. Adjustable small-incision selective tenotomy and plication for correction of incomitant vertical strabismus and torsion. Journal of AAPOS : the official publication of the American Association for Pediatric Ophthalmology and Strabismus / American Association for Pediatric Ophthalmology and Strabismus. 2015;19(5):410-416. doi:10.1016/j.jaapos.2015.07.290.
  11. Gupta, Vinita, Sonali Gupta, and Zia Chaudhuri. "Diplopia in High Myopia." Expert Review of Ophthalmology just-accepted (2016).