Evaluating patients’ eyelids before cataract and refractive surgery is crucial, as ptosis can create unwanted adverse effects and alter outcomes.
When evaluating patients, including considerations for refractive and cataract surgery, remember to look at the lids for both pathology and position. This can be especially important in patients preparing for refractive or cataract surgery. Lid ptosis can induce unwanted adverse effects and affect measurements, thus altering outcomes.
Acquired blepharoptosis can occur unilaterally or bilaterally and is defined by abnormal drooping of the upper eyelid while in primary gaze. This is most commonly caused by the stretching or disinsertion of the levator muscle in relation to age, known as aponeurotic ptosis.1 Ptosis also can have other etiologies, including neurogenic, traumatic, mechanical, or myogenic dysfunction.1
When evaluating patients, be cautious if the ptosis is new onset, unilateral, accompanied by diplopia or reduction in extraocular muscle function, or abnormal pupillary function. These may indicate that the ptosis is a sign of serious underlying neurological disease requiring immediate attention.1,2
Patients also may present with the appearance of ptosis, but upon further evaluation, clinicians may determine that it is caused by dermatochalasis, microphthalmos, brow ptosis, hemifacial spasm, or even a superior sulcus deformity.2 Prevalence of ptosis is estimated, depending on region and study, to affect 4.7% to 13.5% of adults.1
Ptosis can be induced during routine intraocular surgery with an incidence ranging from 7.3% to 21% after cataract surgery.3
Results of one study showed that 44.4% of patients who had cataract surgery had ptosis at 6 weeks post surgery, and a majority resolved without treatment.4,5
In those patients where the ptosis does not resolve, the underlying etiology is believed to be caused by dehiscence of the levator palpebrae superioris from a combination of lid edema, bridle sutures, and the lid speculum.3
Not surprisingly, ptosis can cause significant changes in vision, the most well-established being the effect on the visual field. Results of numerous studies have shown loss of superior visual field greater than 12° or up to 24%.6-8
Percentage of superior visual field loss is inversely correlated to marginal reflex distance –1 (MRD-1), with anything less than 4 mm resulting in impairment.6-8 With an MRD-1 of 2 mm, there is a resulting 24% to 30% field loss correlating to 12° to 15° degrees of superior visual field loss.6
Functionality and safety are major considerations with loss of visual, as each 10% of visual field loss corresponds to an 8% higher risk of falls in patients 65 years and older.6
In regard to contrast sensitivity, improvement has been noted with repositioning the upper lid in patients with both ptosis and dermatochalasis.9-11
Lid position and pressure create an impact on higher order aberrations (HOA).7,8 Ptotic eyes have been shown to create significant changes in both anterior and posterior corneal HOAs, leading to significant degradation in visual quality.9,12
Study results also have also that upper lid changes affect induction of astigmatism. One study looked at 58 patients with both age-related ptosis (AP) and contact lens–related (CLP) ptosis who underwent blepharoplasty.13
Against-the-rule astigmatism was common in AP, whereas with-the-rule astigmatism was found in those with CLP.13
One month after upper lid repositioning, 41% of patients with AP and 13% of patients with CLP had a shift in the astigmatism severity and type.13 This is important in regard to refractive and cataract surgery because it could affect measurements as well as surgical outcomes.
Because surgery can induce ptosis, and that ptosis can affect both measurements and outcomes, it is important to take the lids into consideration when discussing both refractive and cataract surgery. Traditionally, the only treatment for ptosis was surgery. But in these cases, is it better to do ptosis surgery before or after refractive or cataract surgery? The concern is that it may be exacerbated or regress post surgically.
Another option is to use topical ocular oxymetazoline hydrocholoride 0.1% solution, which has had positive outcomes with improvement in superior visual field loss in patients with acquired ptosis and was well tolerated.8 This could be used prior to refractive and cataract surgery for measurements needed for calculations, as well as to determine if postoperative complications are second to ptosis. In patients with visual HOA and contrast sensitivity complaints, using this may help decide if they would benefit from lens exchange versus ptosis repair.
In evaluating patients for surgical referral or postsurgical outcomes, don’t forget to start with the lids. Ptosis can have a much more significant effect on patients beyond esthetics and should not be ignored in even the milder cases that traditionally aren’t considered significant enough for surgery.