Evaluation of Eyelid Malpositions

A thorough eyelid examination should be included in the documentation of any eyelid malposition. Accurate diagnosis of eyelid dystopia including some determination of its etiology is essential prior to consideration of surgical or nonsurgical correction.

HISTORY

An adequate history can provide useful clues to the cause of the eyelid malposition and may suggest the need for further evaluation. In some cases the history may make immediate surgical intervention unwise.

The time of onset of the malpositioned lid may be congenital or acquired. In the case of ptosis, a careful birth history will uncover the possible use of forceps during delivery, or the occurrence of other birth trauma. Abnormal eyelids in other family members should alert the observer to the possibility of a familial disorder such as blepharophimosis syndrome or cran-iosynostosis syndrome. The presence of other congenital anatomical deformities or especially neurologic deficiencies may indicate a more serious genetic syndrome, congenital oculomotor nerve palsy, or a central mechanism for the eyelid disorder.

Rapidity of onset should be questioned in all patients. An acute-onset ptosis in an adult may be the result of a metabolic disturbance or compressive lesion. Hemorrhage into a preexisting, unsuspected eyelid or orbital mass can result in a sudden-onset ptosis especially in children, often associated with some degree of proptosis or motility disturbance. A history of recent trauma with new onset eyelid malposition should raise suspicion not only of scarring and/or levator transection, but also for retained foreign body. Trauma without eyelid laceration is more likely to result in a contusive injury to the levator muscle or its nerve, with a high likelihood of spontaneous recovery. Orbital fractures can be associated with eyelid malpositions; a ptosis that evolves over several days following eyelid trauma may indicate an enlarging hematoma or abscess.

Gradual-onset of an eyelid malposition is more typical of involutional disease, but may occur with a paralytic or cicatricial process. Eyelid changes occurring with other extraocular muscle dysfunction or loss of vision demands investigation of the orbital apex and cavernous sinus. A history of decreased facial movement with associated ocular surface irritation, tearing, or blurred vision may accompany lagophthalmos or paralytic ectropion. A history of changes in the eyelid skin might suggest a chronic inflammatory process, infection, or dermatosis that has led to cicatricial changes in the anterior lamella. Chronic ocular surface disease may result in posterior lamellar scarring (tarsus or conjunctiva), contraction of the conjunctival fornices, or sympblepharon formation.

A history of slow progression is not uncommon with most involutional eyelid changes, but this usually occurs over several years. Almost all patients with ptosis or dermatochalasis will report some increase in droopiness late in the day or when tired; this does not usually indicate myasthenia gravis. The occurrence of an eyelid malposition with orbital pain is always worrisome and demands investigation to rule out neoplasm or pseudotumor. Any such association requires radiographic study.

A history of previous eye surgery is important. Eyelid malpositions are not uncommon sequelae of retinal detachment surgery, strabismus surgery or cataract extraction. Ptosis is reported to occur following cataract surgery in 7-8% of cases. Other surgery, especially intracranial or thoracic procedures, may result in central third nerve palsy or Horner's syndrome respectively.

The patient should be questioned carefully about previous episodes of eyelid edema, as with allergic angioneurotic edema or blepharochalasis which can affect eyelid position. This is particularly true in younger patients. A past or present history of systemic diseases that commonly affect the eyelid and orbit such as thyroid ophthalmopathy should be noted. Symptoms of thyroid hormone imbalance should be reviewed since the eyelid manifestations of Graves' disease may precede diagnosis of systemic thyroid dysfunction.

A thorough ocular history should be obtained to attempt to uncover the presence of chronic conjunctivitis or uveitis, or a past or present history of cicatricial diseases such as ocular pemphigoid or Stevens-Johnson syndrome. A history of morning ocular irritation and spontaneous eyelid eversion during sleep, particularly in an obese male, should lead to careful examination of the conjunctiva for papillary conjunctivitis, and of the tarsus for possible floppy eyelid syndrome.

Any prior malignancy should raise the possibility of a mechanical etiology for a malposi-tioned eyelid from metastatic disease. Previous excision of an eyelid or periocular tumor should alert the observer to the possibility of deep orbital recurrence resulting in distortion of eyelid position.

OBSERVATION

While taking the history the surgeon should observe the patient's eyes and face. It should be noted whether the eyelid position is unilateral or bilateral, and whether there is any associated disorder affecting the brows and midface. The position of the eyelids, canthal angles, and eyelash orientation should be noted (Fig. 1). The presence of concurrent anatomical deformities, such as brow ptosis, diffuse facial laxity, skeletal abnormalities, clefting disorders, or stigmata of Down's syndrome or other genetic disorders should be recorded. Any abnormal eyelid movements with extraocular muscle contraction or with jaw movement should be carefully documented. These may sometimes be quite subtle. A head turn or tilt should lead to careful evaluation of ocular motility to rule out the presence of associated strabismus.

EXAMINATION

For all patients with eyelid malpositions a complete ophthalmic examination is mandatory. Visual acuity with a current refraction is recorded, and especially in children presenting with upper eyelid ptosis, the presence of amblyopia must be ruled-out. In any patient unexplained decrease in vision requires comprehensive investigation. Pupil size and reactivity should be measured, and any asymmetry noted. Corneal examination must evaluate the presence of keratopathy secondary to corneal exposure as a result of the malpositioned eyelid.

A slit lamp examination should include a magnified evaluation of the conjunctiva and eyelid margin (Fig. 2). Thickening of the lid margin or injection of the conjunctiva may represent inflammation or infiltrating neoplasm. Malpositions or misalignments of the eyelashes should be noted.

A Schirmer's test is essential in all older adults to establish the adequacy of tear production (Fig. 3). Ptosis repair or blepharoplasty in a patient over 40 or 50 years with borderline tear function can push them into a symptomatic dry eye syndrome. Some inflammatory diseases or those that involve the lacrimal gland can also be associated with dry eye syndrome.

Extraocular motility is examined in all patients and the presence of an adequate Bell's phenomenon noted. The absence of Bell's phenomenon should lead the surgeon to be more cautious in consideration of elevating the eyelid in patients where lagophthalmos might result. Hypertropia may be responsible for a pseudoptosis, and strabismus surgery may be more

Figure 1 Major features of the normal Figure 2 Slit lamp examination of the eyelid. a. Eyelid margin with cilia; b. upper anterior segment of the eye and the eyelid eyelid crease; c. medial canthus; d. lateral margins. canthus; e. caruncle; f. plica; g. brow.

Figure 1 Major features of the normal Figure 2 Slit lamp examination of the eyelid. a. Eyelid margin with cilia; b. upper anterior segment of the eye and the eyelid eyelid crease; c. medial canthus; d. lateral margins. canthus; e. caruncle; f. plica; g. brow.

appropriate here than ptosis repair. The lack of spontaneous eye or eyelid movements may suggest progressive external ophthalmoplegia.

A pupillary examination should be recorded. The presence of anisocoria should raise the possibility of Horner's syndrome, third nerve palsy, or ocular trauma.

Palpation of the eyelid and anterior orbit may reveal a mass lesion or deep scar responsible for the eyelid malpositon. The upper eyelid should be everted to examine the tarsal plate and palpebral conjunctiva for any irritative lesions or sympblepharon formation that could influence the eyelid position. The bulbar conjunctiva should also be examined up to the superior fornix using an eyelid retractor if necessary.

A thorough orbital examination should be recorded and actual or relative proptosis evaluated by Hertel exophthalmometry (Fig. 4). A relatively proptotic globe may give the illusion of eyelid retraction while an enophthalmic globe may give the impression of ptosis. Some eyelid diseases can extend posterior to the orbital septum to involve the orbit. If there are any orbital signs such as proptosis, motility disturbance, palpable masses, or vascular congestion, orbital imaging with CT or MRI should be ordered (Fig. 5).

Simple observation will reveal the presence of entropion or ectropion. If not immediately obvious, asking the patient to squeeze the eyelids closed may trigger spontaneous entropion formation. The snap-back test (pulling outward on the eyelid and observing for spontaneous reapposition to the globe) will often demonstrate excessive eyelid laxity or subtle ectropion (Fig. 6). The eyelids normally maintain enough elasticity to reappose the globe in less than 2 seconds.

Snap Back EyelidBasal Cell Carcinoma Eyelid
Figure 5 Basal cell carcinoma with extension into the anterior orbit. a. Lesion of the left brow; b. corresponding CT scan.

Excessive upper or lower eyelid skin and fat herniation (steatoblepharon) should be noted. Hooding of skin over the lashes should be noted and if associated ptosis is suspected this redundant tissue should carefully be lifted to evaluate the position of the upper eyelid margin relative to the pupil.

The interpalpebral fissures are measured vertically with a millimeter ruler at the level of the pupil with eyes in primary position (Fig. 7). The degree to which the eyelid margin covers the superior corneal limbus is also recorded. Additionally, the distance between the upper eyelid margin and the central pupillary reflex, known as the margin to reflex distance (MRD1) is a useful measurement, since total vertical fissure distance may be unreliable in the presence of lower eyelid retraction. The distance between the lower eyelid margin and the central pupillary reflex is sometimes recorded as the MRD2.

Next, the patient is asked to gently close the eyes. Any residual lagophthalmos is measured and recorded. Presence or absence of an eyelid crease gives some indication of the status of the levator aponeurosis and its position above the eyelid margin should be measured. Care must be taken to measure the true crease which may be covered by redundant skin. The absence of a definitive eyelid crease, or a very high position (more than 10 mm), suggests redundancy or dis-insertion of the levator aponeurosis, but is also seen in poor to absent-function myopathic ptosis.

Eyelid Laxity
Figure 6 Lower eyelid laxity determined with the snap-back test. a. The lid in normal position after a blink; b. the lid is pulled forward away from the eye; c. before another blink the lax lid fails to snap back against the eye indicating significant laxity.
Snap Back Eyelid

Levator muscle function is perhaps the single most important measurement made during the preoperative evaluation, and is most predictive of the surgical outcome for ptosis repair following any particular surgical procedure. It must be performed with great care. Function is recorded as maximum eyelid excursion from extreme downgaze (without closing the eyes), to extreme upgaze position. A millimeter ruler is placed in front of the eyelids with the patient looking down as far as possible, and the position of the upper eyelid margin noted against the scale. The patient is asked to look up as far as possible and the eyelid margin position on the scale is again noted (Fig. 8). The difference between the two readings is the total excursion and is recorded as levator function. Contraction of the frontalis muscle can elevate the eyelid by up to 3 to 4 mm so that the examiner must be certain to eliminate any possible contribution form this source. This is done properly by placing a thumb firmly over the brow to immobilize it against the supraorbital rim during measurement. This procedure is critical in patients with poor levator function, since a difference of only 1 or 2 mm in function may influence the choice of a surgical procedure.

All cases of ptosis or eyelid retraction should be tested for a Hering's phenomenon. Because central innervation of the levator muscles is bilaterally equal, an asymmetry in eyelid height may

Muscles The Eyelid

result in a central compensatory increase or decrease in motor output to the levator muscles, thus masking an abnormal position of the contralateral eyelid. For example, a patient with bilateral but asymmetric ptosis may have a centrally mediated unconscious increased eyelid height in order to improve visual field. The more ptotic lid still appears ptotic but the less ptotic lid may appear normal. Correction of the apparently unilateral ptosis could uncover the ptosis in the opposite lid requiring additional surgery. In some patients this can be uncovered preoperatively by manually elevating the ptotic lid and seeing the "normal" lid drop (Fig. 9). Conversely, the "normal" lid might actually be retracted, and a decrease in central output might result in both lids being lower, with the contralateral lid now appearing ptotic. In this case depressing the "normal" lid downward could result in the ptotic lid coming up. This so-called Hering's phenomenon is sometimes useful in predicting the results of surgery. However, the results of this test are not always reliable in predicting the behavior of the eyelids after surgical correction.

In congenital myogenic ptosis levator function is usually reduced because of levator fibro-sis, with deficient stretching as well as impaired contraction. Typically, the eyelid is ptotic in primary gaze, more ptotic in upgaze, but less ptotic or even relatively retracted in downgaze (Fig. 10). This contrasts with acquired ptosis where the eyelid characteristically shows the same degree of ptosis in all positions of gaze.

Any patient with a history of significant worsening of ptosis late in the day or when tired should be suspected of having myasthenia gravis. This is especially true if the eyelid appears near normal in the morning, or the condition is associated with difficulty in swallowing, generalized weakness, or diplopia. A levator fatigue test can be performed easily without risk. The patient is asked to look upward for several minute without blinking. The position of the eyelid is measured before and immediately after the test. Any increase in ptosis with fatigue of the muscle is suggestive of myasthenia gravis. The definitive diagnostic procedure is the Tensilon test, which should be performed on all patients with a high suspicion of the disease.

Appropriate documentation of all eyelid malpositions with photographs and formal perimetry showing the relative impact of the eyelid on vision have become mandatory by third party payers prior to approval of any surgical intervention for an eyelid malady. A current refraction should be documented since any change in the height or tone of the eyelid can result in a postoperative change in corneal astigmatism. Finally, the patient's expectations for both visual and cosmetic improvement should be carefully elicited as this may impact the technique of surgical repair selected.

Once the nature and etiology of the eyelid malposition has been determined, the appropriate therapy must be selected. When the cause is determined to result from mechanical obstruction to eyelid movement, orbital disease, or ocular irritation initial therapy must be directed towards the source of the pathology. Frequently the malposition may resolve upon treatment of the inciting factor. Surgical correction of eyelid malpositions ranges from simple

Pseudoptosis

Figure 9 Positive Hering's phenomenon. The right eyelid shows a pseudoptosis resulting from retraction of the left upper lid a. When the left lid is held down, the right lid elevates due to Hering's law b.

Figure 9 Positive Hering's phenomenon. The right eyelid shows a pseudoptosis resulting from retraction of the left upper lid a. When the left lid is held down, the right lid elevates due to Hering's law b.

Figure 10 Congenital myogenic ptosis showing fibrosis of the levator muscle. a. In primary position the lid shows moderate ptosis; b. in upgaze the ptosis increases; c. in downgaze the ptosis decreases or even reverses.

to quite complex and may require specialized reconstructive techniques. A description of individual surgical techniques for various eyelid malpositions is beyond the scope of this text, but several generalities are true.

The success of ptosis repair depends a great deal on selecting the most appropriate procedure for each particular patient. In many cases this will be rather easy. All eyelid procedures can be performed on an outpatient basis under minimal intravenous sedation and local infiltrative anesthesia. Extensive reconstructive techniques requiring flaps and grafts may require a greater level of anesthetic control. When surgery is performed while the patient is conscious, it better enables the surgeon to predict the position of the eyelids postoperatively and minimizes the risk of postsurgical complications such as eyelid retraction, lagophthalmos, residual eyelid laxity, and excessive eyelid skin removal.

Perhaps the most dreaded complication of eyelid surgery is vision loss. With proper surgical technique this is an unlikely event. Unrecognized intraoperative or postoperative orbital hemorrhage can lead to compressive optic neuropathy. This risk is minimized by having the patient restrain from any medication that may inhibit the clotting mechanism and determining in advance any patient with a coagulation disorder. The cornea and sclera are at risk for laceration, particularly when laser, electrical, or radiofrequency devices are used by the inexperienced surgeon. Postoperative infection is rare, but severe infection of the orbit or ocular surface may lead to permanent vision loss.

REFERENCES

Dutton JJ. Atlas of Ophthalmic Surgery: Vol. II Oculoplastic, Lacrimal and Orbital Surgery. St. Louis: Mosby-Year Book, 1992.

Hosal BM, Tekli O, Gursel E. Eyelid malpositions after cataract surgery. Eur J Ophthalmol 1998; 8:12-15. Morax S, Hurbli T. The management of congenital malpositions of eyelids, eyes and orbits. Eye 1988; 2:207-219. Nowinski T, Anderson RL. Advances in eyelid malpositions. Ophthal Plast Reconstr Surg 1985; 1:145-148. Zucker JL. Eyelid disorders: recognizing pathologic changes in the older patient. Geriatrics 1993; 48:61-62.

How To Reduce Acne Scarring

How To Reduce Acne Scarring

Acne is a name that is famous in its own right, but for all of the wrong reasons. Most teenagers know, and dread, the very word, as it so prevalently wrecks havoc on their faces throughout their adolescent years.

Get My Free Ebook


Post a comment