A drooping upper eyelid, medically known as ptosis, is a common condition. While it can occur at birth or due to various medical conditions, a specific type, known as involutional ptosis, is often seen with aging. This age-related drooping can impact vision.
What is Involutional Ptosis?
Involutional ptosis is the drooping of one or both upper eyelids due to age-related changes. The degree of drooping can vary, ranging from barely noticeable to severe enough to obstruct the pupil. When the eyelid sags significantly, it can impede vision, particularly the superior (upper) and peripheral (side) visual fields.
Individuals with involutional ptosis often report symptoms. They may experience difficulty reading, a feeling of eye strain, or a persistent tired appearance. To compensate for the obstructed vision, some people unconsciously tilt their heads back or repeatedly raise their eyebrows, which can lead to discomfort in the head and neck. This condition can impact daily activities like driving or reading.
Why Does It Happen?
Involutional ptosis primarily arises from age-related changes to the levator aponeurosis, a thin, tendon-like structure that connects the levator palpebrae superioris muscle to the eyelid’s tarsal plate. This muscle is responsible for lifting the upper eyelid. Over time, the levator aponeurosis can stretch, thin, or even detach from the tarsal plate, reducing its ability to transmit the lifting force effectively.
While the levator aponeurosis is the primary factor, the Müller’s muscle, a smaller smooth muscle also involved in eyelid elevation, can contribute to involutional ptosis. Changes in its structure or sympathetic innervation may also play a role. Repetitive traction on the eyelid, such as from frequent eye rubbing or long-term contact lens use, can also contribute to the attenuation of the levator aponeurosis.
How is it Diagnosed?
Diagnosing involutional ptosis involves a comprehensive evaluation by an eye care professional. A thorough medical history is taken, inquiring about onset, progression, and any associated symptoms like blurred vision, headaches, or double vision. Information about past eye surgeries, injuries, or long-term contact lens use is also gathered.
A physical examination of the eyes and eyelids is performed, which includes measuring the eyelid height and assessing the function of the levator muscle. A common measurement is the marginal reflex distance 1 (MRD1), which is the distance from the center of the pupil to the upper eyelid margin; a normal MRD1 is typically 4 to 5 mm. Visual field testing is often conducted to quantify vision impairment caused by the drooping eyelid. This may involve comparing visual fields with the eyelid in its natural position and then taped up to simulate post-surgical results.
Treatment Approaches
Treatment for involutional ptosis aims to improve vision and address cosmetic concerns. Surgical intervention is a common approach. One common procedure is levator aponeurosis advancement or reattachment, where the stretched or detached tendon is shortened or reconnected to the tarsal plate, allowing the levator muscle to lift the eyelid more effectively. Another surgical option is Müller’s muscle conjunctival resection, sometimes referred to as the Fasanella-Servat procedure, which involves removing a small portion of the Müller’s muscle and conjunctiva to elevate the eyelid. If there is also drooping of the eyebrow, a brow lift may be performed concurrently to achieve a more comprehensive correction.
For patients with mild to moderate ptosis, a non-surgical option is available: prescription eye drops like oxymetazoline hydrochloride (Upneeq). This medication works by stimulating the Müller’s muscle, providing a temporary lift to the eyelid that typically lasts for about six to eight hours.
Understanding Different Types of Ptosis
While involutional ptosis is a common age-related condition, it is just one of several types of eyelid drooping. Congenital ptosis is present from birth, usually due to underdeveloped levator muscles. Neurogenic ptosis results from nerve pathway issues affecting eyelid muscle control, seen in conditions like Horner’s Syndrome or oculomotor nerve palsy. Mechanical ptosis occurs when the eyelid is weighed down by excess skin, a tumor, or swelling, physically impeding its movement. Traumatic ptosis is directly caused by an injury to the eyelid muscles or nerves.