27.1 Patient History Leading to the Specific Problem

A normal eye fissure has visible sclera on either side of the cornea, known as the medial and lateral scleral triangles. Round eye deformity is present when the lateral scleral triangle becomes rounder and distorted due to loss of integrity or strength of the lateral canthal tendon. Round eye deformity can be primary due to aging and laxity of the lateral canthus, or secondary to stretching, damaging, or scarring of the lateral canthal tendon due to surgery or trauma.

Patients with round eye deformity usually present with the following symptoms:

• 
  

  Poor blinking mechanism leading to chronic dry eyes that do not subside with continuous use of eye drops or eye lubricants.

  
  
• 
  

  Tearing of the eyes.

  
  
• 
  

  Unpleasing aesthetic shape of the eyes or complaints of “small eyes” after eyelid surgery.

  
  
• 
  

  Fishmouthing syndrome during blinking.

  
  
• 
  

  Lack of complete eyelid closure.

  
  
• 
  

  Nonspecific symptoms related to abnormal eye position or lubrication.

  
  
• 
  

  Scleral show and/or lower lid retraction.

The patient shown in Fig. 27-1 presented with round eye deformity after a previous four-lid blepharoplasty performed elsewhere. The major complaints were unpleasing eyelid shape, lack of eyelid closure, and excessive tearing due to poor blinking mechanics. On examination, she presented with unpleasing eye shape, rounding of the lateral scleral triangle, scleral show, and poor eyelid closure.

The patient shown in Fig. 27-2 also presented with round eye deformity after a previous four-lid blepharoplasty elsewhere. The major complaints were unpleasing eyelid shape and lack of eyelid closure. On examination, she presented with distortion of the lateral scleral triangle, mild scleral show, and poor eyelid closure. She also had concomitant eyelid ptosis.

27.2 Anatomic Description of the Patient’s Current Status

In both cases, the distortion of the lateral scleral triangle is very clear. The normal pointy shape of the most lateral angle of the lateral scleral triangle is blunt, rounded, and displaced inferiorly. The rounding of the lateral scleral triangle makes the eye fissure look unnatural with loss of the natural almond shape of the eyes. This is particularly visible at rest and can be more severe in patients with deep-set eyes. Other problems such as poor eyelid closure and scleral show are also present.

A dynamic distortion often happens in the round eye deformity. During blinking, the lateral canthus is more easily displaced nasally and this abnormal blinking biomechanics causes incomplete eyelid closure with gapping of the eyelids. Patients with round eye deformity can also present with a phenomenon called fishmouthing syndrome. Fishmouthing syndrome is a dynamic deformity of the eyelid during blinking that resembles the concentric movement of a fish mouth. The normal eye blinking happens due to the contracture of the inner canthal orbicularis oculi muscle, a very powerful muscle group. When this strong medial contraction finds lateral resistance or counterpull at the lateral canthus, the eyelids close in a vertical vector. When there is laxity or dehiscence at the level of the lateral canthal tendon, the contraction of the inner orbicularis oculi muscle during blinking causes a strong pull of the eyelids toward the nose, creating a rounded and weak approximation of the eyelids instead (Fig. 27-3).

Fishmouthing syndrome also produces medial and downward displacement of the upper lid lashes due lateral canthal tendon weakness. This eyelash deformity is called “cow lashes” deformity and is a sign of the fishmouthing syndrome: straight upper eyelashes pointing nasally and downward (Fig. 27-4). This deformity can be seen at rest and is intensified during blinking.