Overview of Lower Eyelid Laxity Examination
The lower eyelid is important for the look of your face and the function of your eye. It helps in protecting the front part of your eye, known as the cornea, and helps maintain the tear drainage system. Before doing any procedures on the lower eyelids for beauty or medical reasons, doctors need to understand different ways to check the position and tightness or looseness (laxity) of the lower eyelid. Accurate analysis and diagnosis are very important before doing any lower eyelid surgery.
There are certain conditions when testing the tightness or looseness of the lower eyelid is especially important. Some of these conditions are before certain beautification surgeries, after an injury to the lower eyelid and the area around the eye, when checking the lower eyelid for skin cancer or tumors, dry or watery eyes (Dry eye or Epiphora), inability to fully close the eye (Lagophthalmos), damage to the cornea due to exposure (Exposure keratopathy), eye disease related to thyroid problems (Thyroid orbitopathy), and facial paralysis (Facial palsy).
Anatomy and Physiology of Lower Eyelid Laxity Examination
The lower eyelid’s structure is important to understand for safe and effective cosmetic or reconstructive surgery. The lower eyelid is made up of two layers: an anterior layer, which includes the skin and the muscle around the eye known as the orbicularis oculi muscle, and a posterior layer, made up of the eyelid retractors, tarsal plate, and conjunctiva – a thin layer covering the front of the eye. Between these two layers is the septum and some fat, often referred to as the middle layer.
The lower eyelid sits snugly against the eyeball, with the rim of the eyelid lining up with the bottom of the eye. The distance between the top and bottom eyelids is about 10mm vertically and 30mm horizontally. The skin on the lower eyelid is less than 1mm thick and doesn’t contain any layer of fat underneath. It’s attached to the underlying muscle by delicate connective tissue.
The orbicularis oculi muscle, the muscle around the eye, is divided into a thicker part around the orbit of the eye and a thinner part near the eyelid. This muscle is responsible for the tight position of the lower eyelid. The skin around the eye, where crow’s feet wrinkles typically develop, is connected to this muscle.
The orbital septum, a membrane underneath the eyelid muscles, separates the outer and inner layers of the eyelid. Behind this septum is the orbital fat, distributed in three compartments within the eye socket. The main nerve supply to the lower eyelid comes from the infraorbital nerve, with additional supply from the infratrochlear and zygomaticofacial nerves.
As we age, the structure of the lower eyelid changes. This can take different forms in different people, but typically involves a deflation and lowering of the facial soft tissues. This can lead to changes like excess skin, protrusion of fat, loosening of the muscles and tendons, and changes in muscle tone. Aging can affect the lower eyelid’s position and the shape of the eye opening.
Changes due to aging can lead to various symptoms, including excess skin on the lower eyelid, protrusion of orbital fat, weakening of the eye’s supporting structures, and changes in the tone of the orbicularis oculi muscle. These changes can affect the shape of the eye and lead to issues like improper closure of the eye, eye tearing, and changes in the appearance of the eye opening. Age-related changes in the midface area, like tear trough deformity, midface folds, and malar festoons, are also important to consider before any lower eyelid surgery.
Equipment used for Lower Eyelid Laxity Examination
Before undergoing a procedure related to your lower eyelid, your doctor usually checks how loose or flexible your lower eyelid is. This is part of the process that helps your doctor gather all the necessary information before surgery. A few tools help with these assessments:
A Snellen chart is a tool that helps measure how sharp your eyesight is. Hertel’s exophthalmometer is a special instrument used to evaluate the position of your eye. The Schirmer test kit is used to check for dry eye syndrome by measuring how wet your eyes are. Lastly, the slit-lamp ophthalmoscopy allows your doctor to get a closer look at different parts of your eye, particularly the cornea, which is the transparent front surface of your eye.
Who is needed to perform Lower Eyelid Laxity Examination?
Surgeons who specialize in facial or eye plastic surgery should have a deep understanding of how to examine the lower eyelid’s looseness. This knowledge is also important for other doctors who treat conditions of the lower eyelid, for example, skin cancers in that area. It’s crucial for them to know about the direction and force of the tension and how to assess the eyelid’s looseness. This can help prevent the lower eyelid from being in the wrong position after surgery.
Preparing for Lower Eyelid Laxity Examination
If you’re going to have a surgery on your lower eyelid, your doctor needs to perform a thorough check-up to assess whether you are in the right condition to have the operation. This includes looking at your overall health, specific medical conditions and a careful examination of the eyelid.
Before going ahead with the procedure, your doctor will need to make sure that you’re healthy enough to have the surgery. They’ll ask about your medical history to find out about any serious health problems that could affect your ability to handle anesthesia. For example, patients with multiple health conditions may not be suitable for general anesthesia – the kind that puts you completely to sleep. They’ll take note of important details like if you frequently use a machine called a CPAP (continuous positive airway pressure) machine for sleep apnea, as this can lead to swelling in the cheek area after surgery.
Also, figuring out if you have a bleeding condition or take any medicines that can impact how your blood clots is crucial. This can help lessen the possible risk of bleeding behind the eyeball and losing sight after surgery. As a safety measure, it’s usually advised to stop taking anti-inflammatory drugs two weeks before surgery, and medicines like warfarin need to be stopped three days to allow for normal blood clotting.
Moreover, it’s very important to ensure that if you have high blood pressure, it is well-managed for at least two weeks before your surgery.
Dry eyes are a normal side effect after this kind of surgery since the procedure may temporarily affect how often you blink and close your eyes. Your doctor will ask about any frequent tearing, discomfort, a gritty sensation in your eyes, and excessive blinking. If you have these symptoms, more tests may be required to find out the cause, which could be anything from an allergy, certain diseases like Sjögren syndrome or Graves disease, or an incomplete recovery from paralysis of the facial nerve. A particular test named the Schirmer test can help doctors measure how dry your eyes are.
How is Lower Eyelid Laxity Examination performed
To check if your lower eyelid is loose (a condition known as lower eyelid laxity), doctors perform a systematic check-up. They look at the skin around the eye, the actual position of the lower eyelid, if there is excess fat around the eye, how tight the muscles and ligaments around your eye are, and the area in the middle of your face.
Skin
The doctor will examine the skin of your lower eyelid and the area around your eyes. They will check for signs of sun damage, wrinkles, looseness, swelling, pouch-like structures called ‘festoons’, and any related conditions, like yellowish cholesterol-filled deposits under your skin known as ‘xanthelasma’. To assess how loose your skin is, you’ll be asked to look up and open your mouth. The doctor will then pinch your skin slightly to see if there is any surplus skin that perhaps needs to be removed. If you have swelling in your cheeks before the operation, your doctor will let you know that there could be swelling after the surgery as well.
Lower Eyelid Position
The doctor will determine the position of your lower eyelid, which should be at the same level or slightly above the bottom of your cornea. They will measure it in millimeters. If your eyelid is lower than it should be, perhaps due to a previous operation, a thyroid eye disease, or a past facial burn, these factors will be considered in the analysis. The doctor will also check if your eye moves upwards when you try to close your eyes while your eyelids are being held open. This is called ‘Bell’s phenomenon’.
Fat Compartments
There are three fat compartments around the eye — lateral (the outer side), central, and medial (the inner side). The doctor will see if any of these are prominent or bulging and document it with before-operation photography. They will photograph you in sitting and standing positions, close-ups of your eyes when closed and open, while you are looking upwards and to the sides. Your doctor will also touch the lower rim of your orbit (the bone that forms the eye socket). If they feel that your orbital rim is quite prominent, they might need to be cautious about removing fat during the operation to avoid a “sunken-eye” look after the operation.
Muscle and Ligament looseness
There are certain tests that your doctor might do to assess this. One is to pull your lower eyelid gently and see how quickly it goes back into position. There are four grades to determine this, from grade 0, which is normal, taking less than seconds to spring back to the eye, to grade IV, which means the eyelid never returns to its normal position.
Another test they might do is called the lid retraction test. This is to estimate the tone of your lower eyelid and the stability of the corners of your eyes. This can be done by a gentle downward pull of the lower eyelid towards the inferior orbital rim (bottom part of the eye socket) and observing the position of the puncta (small openings in the inner part of your upper and lower eyelids) and lateral canthus (outer corner of your eye). If they observe any movement of more than 2 mm of the puncta from the medial canthus (inner corner of your eye), it would indicate looseness of the canthal tendon, a tendon that connects your upper and lower eyelids to the bone at the corners of your eye sockets.
This approach is similar to how to ascertain the looseness of the medial canthal tendon (the inner corner of your eye), and lateral canthal corner (outer corner of your eye), by the amount the lower eyelid moves when pulled gently. It can also fall within a range of four grades.
An examination with a slit lamp is useful to check the status of your cornea (the clear, dome-shaped surface that covers the front of the eye) and see if there’s any dryness or tearing. The doctor can also use it to measure the distance from your upper eyelid to the reflective part of your cornea, and similarly for the lower eyelid, which should usually measure between 3 to 5 mm. Checking your visual acuity, or how sharp your eyesight is, with a Snellen chart (a chart with lines of letters decreasing in size) is another crucial part of the examination.
Midface
The doctor will also examine your midface. If the surface of your cornea is at the same level as your cheekbone (a negative vector or negative malar angle), there’s a higher risk of postoperative eyelid malposition (your eyelid not returning to its normal position), and so the doctor will need to provide a supportive structure at the outer corner of your eye when performing the surgery. They will also look to see if there are any signs of an aging midface, such as dips or lines under your eye/inner cheek, and deepening of the crease from the side of your nose to the corner of your mouth.
What Else Should I Know About Lower Eyelid Laxity Examination?
If you’re having any issues with your eyelids, it’s essential that your doctor understands how the aging process can affect the structure of your lower eyelid and the surrounding areas. This is particularly important when they are evaluating if your lower eyelid is loose or sagging.
Before any procedure, they’ll closely check your overall health and examine the front, middle, and back layers of your eyelid. This careful evaluation helps your doctor make a safe and effective plan to restore a youthful look to your lower eyelid.