| Conjunctivochalasis | |
|---|---|
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| An eye with conjunctivochalasis. | |
| Specialty | Ophthalmology  |
Conjunctivochalasis, also known as mechanical dry eye (MDE), is a common eye surface condition characterized by the presence of excess folds of the conjunctiva located between the globe of the eye and the eyelid margin. [1]
Symptoms range from dry eye, epiphora and irritation to localized pain, foreign body sensation, subconjunctival hemorrhage and ulceration. Symptoms are often made worse by vigorous blinking.
Most conjunctivochalasis is thought to be caused by both a gradual thinning and stretching of the conjunctiva that accompanies age and a loss of adhesion between the conjunctiva and underlying sclera as the result of dissolution of Tenon's capsule. The resulting loose, excess conjunctiva may mechanically irritate the eye and disrupt the tear film and its outflow, leading to dry eye and excess tearing. [2] A correlation may also exist between inflammation in the eye and conjunctivochalasis, though it is unclear whether this correlation is causal. [3] [4] Conjunctivochalasis may be associated with previous surgery, blepharitis, meibomian gland disorder (MGD), Ehlers-Danlos Syndrome and aqueous tear deficiency.
Because the disorder often occurs in people with typical dry eye symptoms, it can be difficult to readily distinguish the discomfort caused by the dry eye from that directly related to the redundant conjunctiva.
Mechanical dry eye should not be confused with aqueous tear deficiency dry eye or delayed tear clearance. [5] Mechanical dry eye patients complain of blurry vision and pain that tend to be worse when looking down such as while reading. Dryness in aqueous tear deficiency dry eye patients tends to be worse as the day progresses due to progressive exposure. Frequent blinking exacerbates mechanical dry eye symptoms, while increasing blinking improves symptoms of aqueous tear deficiency dry eye.
Diagnosis can be further made under a slit lamp upon the observation of redundant conjunctival folds. These folds can be made more apparent by staining with fluorescein dye and by applying gentle upward pressure with a finger to the eyeball through the lower lid. In pure aqueous tear deficiency dry eye patients, fluorescein stains in the interpalpebral exposure zone. In mechanical dry eye patients, fluorescein staining can be seen by pulling down the lower lid spread to the non-exposure zone. A tear-clearance test can also detect irregularities in the tear film. [6]
Diagnosis can also be made by measuring the replenishment of the tear meniscus. The test can be done as follows: Apply 5 μl of fluorescein to the base of the inferior fornix, maximally deplete the lower tear meniscus by a capillary tube or Weckcel sponge, and then monitor the recovery of the tear meniscus height with or without blinking. [7] Patients with mechanical dry eye detectable within 3–8 seconds without blinking or within 0.5-1.5 seconds with blinking.
Mild conjunctivochalasis can be asymptomatic and in such cases does not require treatment. Lubricating eye drops may be tried but are often ineffective. [8]
If discomfort persists after standard dry eye treatment and anti-inflammatory therapy, surgery may be undertaken to remove the conjunctival folds and restore a smooth tear film. This conjunctivoplasty surgery to correct conjunctivochalasis typically involves resection of an ellipse-shaped segment of conjunctiva just inferior to the lower lid margin, and is usually followed either by suturing or amniotic membrane graft transplantation to close the wound. [9]
Further techniques have been developed, such as reservoir restoration, which aim to replace the degenerated Tenon’s, deepen the inferior fornix to restore the normal anatomy and physiology, and facilitate restoration of the normal tear film [10] . In this surgical procedure, a crescent-shaped area of the conjunctiva is recessed along a limbal peritomy with a maximum anterior-posterior width no more than 3 mm. Diseased and dissolved Tenon’s are undermined leaving a large bare scleral defect. Cryopreserved amniotic membrane is slid over the scleral bed with fibrin glue and tucked under the conjunctiva to recreate the fornix. Immediately postop, the surgeon should note an improved anatomical definition and deepening of the inferior fornix.
A pterygium of the eye is a pinkish, roughly triangular tissue growth of the conjunctiva onto the cornea of the eye. It typically starts on the cornea near the nose. It may slowly grow but rarely grows so large that it covers the pupil and impairs vision. Often both eyes are involved.
Blepharitis, sometimes known as "granulated eyelids," is one of the most common ocular conditions characterized by inflammation, scaling, reddening, and crusting of the eyelid. This condition may also cause swelling, burning, itching, or a grainy sensation when introducing foreign objects or substances to the eye. Although blepharitis by itself is not sight-threatening, it can lead to permanent alterations of the eyelid margin. The primary cause is bacteria and inflammation from congested meibomian oil glands at the base of each eyelash. Other conditions may give rise to blepharitis, whether they be infectious or noninfectious, including, but not limited to, bacterial infections or allergies.
An eyelid is a thin fold of skin that covers and protects an eye. The levator palpebrae superioris muscle retracts the eyelid, exposing the cornea to the outside, giving vision. This can be either voluntarily or involuntarily. "Palpebral" means relating to the eyelids. Its key function is to regularly spread the tears and other secretions on the eye surface to keep it moist, since the cornea must be continuously moist. They keep the eyes from drying out when asleep. Moreover, the blink reflex protects the eye from foreign bodies. A set of specialized hairs known as lashes grow from the upper and lower eyelid margins to further protect the eye from dust and debris.
Dry eye syndrome, also known as keratoconjunctivitis sicca, is the condition of having dry eyes. Symptoms include dryness in the eye, irritation, redness, discharge, blurred vision, and easily fatigued eyes. Symptoms range from mild and occasional to severe and continuous. Dry eye syndrome can lead to blurred vision, instability of the tear film, increased risk of damage to the ocular surface such as scarring of the cornea, and changes in the eye including the neurosensory system.
Retinal detachment is a disorder of the eye in which the retina peels away from its underlying layer of support tissue. Initial detachment may be localized, but without rapid treatment the entire retina may detach, leading to vision loss and blindness. It is a surgical emergency.
In the anatomy of the eye, the conjunctiva is a thin mucous membrane that lines the inside of the eyelids and covers the sclera. It is composed of non-keratinized, stratified squamous epithelium with goblet cells, stratified columnar epithelium and stratified cuboidal epithelium. The conjunctiva is highly vascularised, with many microvessels easily accessible for imaging studies.
Schirmer's test determines whether the eye produces enough tears to keep it moist. This test is used when a person experiences very dry eyes or excessive watering of the eyes. It can cause damage to the cornea. A negative test result is normal. Both eyes normally secrete the same amount of tears.
Xerophthalmia is a medical condition in which the eye fails to produce tears. It may be caused by vitamin A deficiency, which is sometimes used to describe that condition, although there may be other causes.
Artificial tears are lubricating eye drops used to relieve dryness and irritation of the ocular surface. Dry eye syndrome is a common ocular surface disorder and is characterized by disruption of the tear film and increased inflammation.
A glaucoma valve is a medical shunt used in the treatment of glaucoma to reduce the eye's intraocular pressure (IOP).
Trabeculectomy is a surgical procedure used in the treatment of glaucoma to relieve intraocular pressure by removing part of the eye's trabecular meshwork and adjacent structures. It is the most common glaucoma surgery performed and allows drainage of aqueous humor from within the eye to underneath the conjunctiva where it is absorbed. This outpatient procedure was most commonly performed under monitored anesthesia care using a retrobulbar block or peribulbar block or a combination of topical and subtenon anesthesia. Due to the higher risks associated with bulbar blocks, topical analgesia with mild sedation is becoming more common. Rarely general anesthesia will be used, in patients with an inability to cooperate during surgery.
An ocular prosthesis, artificial eye or glass eye is a type of craniofacial prosthesis that replaces an absent natural eye following an enucleation, evisceration, or orbital exenteration. The prosthesis fits over an orbital implant and under the eyelids. Though often referred to as a glass eye, the ocular prosthesis roughly takes the shape of a convex shell and is made of medical grade plastic acrylic. A few ocular prostheses today are made of cryolite glass. A variant of the ocular prosthesis is a very thin hard shell known as a scleral shell which can be worn over a damaged or eviscerated eye. Makers of ocular prosthetics are known as ocularists. An ocular prosthesis does not provide vision; this would be a visual prosthesis. Someone with an ocular prosthesis is altogether blind on the affected side and has monocular vision.
Corneal ulcer, also called keratitis, is an inflammatory or, more seriously, infective condition of the cornea involving disruption of its epithelial layer with involvement of the corneal stroma. It is a common condition in humans particularly in the tropics and in farming. In developing countries, children afflicted by vitamin A deficiency are at high risk for corneal ulcer and may become blind in both eyes persisting throughout life. In ophthalmology, a corneal ulcer usually refers to having an infection, while the term corneal abrasion refers more to a scratch injury.
A pterygium is any wing-like triangular membrane occurring in the neck, eyes, knees, elbows, ankles or digits.
Scleral reinforcement is a surgical procedure used to reduce or stop further macular damage caused by high myopia, which can be degenerative.
Intraocular lens scaffold, or IOL scaffold technique, is a surgical procedure in ophthalmology. In cases where the posterior lens capsule is ruptured and the cataract is present, an intraocular lens (IOL) can be inserted under the cataract. The IOL acts as a scaffold, and prevents the cataract pieces from falling to the back of the eye. The cataract can then be safely removed by emulsifying it with ultrasound and aspiration. This technique is called IOL scaffold, and was initiated by Amar Agarwal at Dr. Agarwal's Eye Hospital in Chennai, India.
Krause's glands and Wolfring's glands are the accessory lacrimal glands of the lacrimal system of human eye. These glands are structurally and histologically similar to the main lacrimal gland. Glands of Krause are located in the stroma of the conjunctival fornix, and the glands of Wolfring are located along the orbital border of the tarsal plate. These glands are oval and display numerous acini. The acini are surrounded, sometimes incompletely, by a row of myoepithelial cells. Animal studies suggest that the ducts of Wolfring glands have a tortuous course and open onto the palpebral conjunctiva. Like the main lacrimal gland, the accessory lacrimal glands are also densely innervated, but they lack parasympathetic innervation. These glands are exocrine glands, responsible for the basal (unstimulated) secretion of the middle aqueous layer of the tear film. 20 to 40 glands of Krause are found in the upper fornix, and 6-8 glands appear in the lower fornix. There are usually 2 to 5 Ciaccio's glands, and are found along the superior tarsal border of the upper eyelid. Popov’s glands are located within the substance of the caruncle.
Tear break-up time (TBUT) also known as tear film break-up time (TFBUT) is the time taken for the first dry spot to appear on the cornea after a complete blink. TFBUT measurement is an easy and fast method used to assess the stability of tear film. It is a standard diagnostic procedure in the dry eye clinics. The volume of tear in the eye depends on two factors, drainage through the lacrimal passages and evaporation. Factors like decreased tear production, increased evaporation rate, tearfilm instability, tear hyperosmolarity, inflammations, ocular surface damages etc. can cause dryness to the eyes.
Exposure keratopathy is medical condition affecting the cornea of eyes. It can lead to corneal ulceration and permanent loss of vision due to corneal opacity.
Hypotony maculopathy is maculopathy due to very low intraocular pressure known as ocular hypotony. Maculopathy occurs either due to increased outflow of aqueous humor through angle of anterior chamber or less commonly, due to decreased aqueous humor secretion by ciliary body.