Corneal transplantation, also known as corneal grafting, is a surgical procedure where a damaged or diseased cornea is replaced by donated corneal tissue (the graft) in its entirety (penetrating keratoplasty) or in part (lamellar keratoplasty). (Keratoplasty is surgery to the cornea.) The graft is taken from a recently deceased individual with no known diseases or other factors that may affect the viability of the donated tissue or the health of the recipient. The cornea is the transparent front part of the eye that covers the iris, pupil and anterior chamber. The corneal transplantation is performed when medicines, keratoconus conservative surgery and cross-linking cannot heal the cornea anymore.
Keratoconjunctivitis sicca (KCS), also called dry eye syndrome (DES) or keratitis sicca, is an eye disease caused by eye dryness, which, in turn, is caused by either decreased tear production or increased tear film evaporation. It is found in humans and some animals. KCS is the most common eye disease, affecting 5 – 6% of the population. Prevalence rises to 6 – 9.8% in postmenopausal women, and as high as 34% in the elderly. The phrase “keratoconjunctivitis sicca” is Latin, and its translation is “dry [inflammation] of the cornea and conjunctiva”. A variety of approaches can be taken to treatment. These can be summarized as: avoidance of exacerbating factors, tear stimulation and supplementation, increasing tear retention, and eyelid cleansing and treatment of eye inflammation.
Pterygium (Surfer’s Eye) most often refers to a benign growth of the conjunctiva. A pterygium commonly grows from the nasal side of the sclera. It is usually present in the palpebral fissure. It is associated with and thought to be caused by ultraviolet-light exposure (e.g., sunlight), low humidity, and dust. Growth has been known to be preceded with scleral trauma around the Palpebral comissure. The predominance of pterygia on the nasal side is possibly a result of the sun’s rays passing laterally through the cornea, where it undergoes refraction and becomes focused on the limbic area. Sunlight passes unobstructed from the lateral side of the eye, focusing on the medial limbus after passing through the cornea. On the contralateral (medial) side, however, the shadow of the nose medially reduces the intensity of sunlight focused on the lateral/temporal limbus.
A cataract is a clouding of the lens inside the eye which leads to a decrease in vision. It is the most common cause of blindness and is conventionally treated with surgery. Visual loss occurs because opacification of the lens obstructs light from passing and being focused on the retina at the back of the eye. It is most commonly due to aging, but has many other causes. Over time, yellow-brown pigment is deposited in the lens, and this, together with disruption of the lens fibers, reduces the transmission of light and leads to visual problems. Those with cataracts often experience difficulty in appreciating colors and changes in contrast, driving, reading, recognizing faces, and coping with glare from bright lights.
Multifocal Lens Implant
An intraocular lens (IOL) is a lens implanted in the eye used to treat cataracts or myopia. The most common type of IOL is the pseudophakic IOL. These are implanted during cataract surgery, after the cloudy crystalline lens (otherwise known as a cataract) has been removed. The pseudophakic IOL replaces the original crystalline lens, and provides the light focusing function originally undertaken by the crystalline lens. The second type of IOL, more commonly known as a phakic intraocular lens (PIOL), is a lens which is placed over the existing natural lens, and is used in refractive surgery to change the eye’s optical power as a treatment for myopia or nearsightedness. IOLs usually consist of a small plastic lens with plastic side struts, called haptics, to hold the lens in place within the capsular bag inside the eye. IOLs were traditionally made of an inflexible material (PMMA), although this has largely been superseded by the use of flexible materials. Most IOLs fitted today are fixed monofocal lenses matched to distance vision. However, other types are available, such as multifocal IOLs which provide the patient with multiple-focused vision at far and reading distance, and adaptive IOLs which provide the patient with limited visual accommodation.
Insertion of an intraocular lens for the treatment of cataracts is the most commonly performed eye surgical procedure. Surgeons annually implant more than 6 million lenses The procedure can be done under local anesthesia with the patient awake throughout the operation. The use of a flexible IOL enables the lens to be rolled for insertion into the capsule through a very small incision, thus avoiding the need for stitches, and this procedure usually takes less than 30 minutes in the hands of an experienced ophthalmologist. The recovery period is about 2–3 weeks. After surgery, patients should avoid strenuous exercise or anything else that significantly increases blood pressure. They should also visit their ophthalmologists regularly for several months so as to monitor the implants.
IOL implantation carries several risks associated with eye surgeries, such as infection, loosening of the lens, lens rotation, inflammation and night time halos, but a systematic review of studies has determined that the procedure is safer than conventional laser eye treatment. Though IOLs enable many patients to have reduced dependence on glasses, most patients still rely on glasses for certain activities, such as reading.
Toric Lens Implant
Toric Lens Implants are a type of Lens Implant that can correct astigmatism. Astigmatism is an optical aberration that is caused by the cornea being shaped more like a football, than spherical like a baseball. For Cataract patients who have astigmatism, and who do not wish to wear eyeglasses to see clearly at a distance, choosing a Toric Lens Implant can help them be independent of glasses for tasks such as driving, that require clear distance vision. In addition, for those who desire the clarity provided by an Aspheric Lens Implant (IOL), there is an Aspheric Toric IOL that offers an enhanced aspheric optical zone that improves image quality and increases contrast sensitivity for Cataract patients with astigmatism.
Diabetic Screening and Treatment of Diabetic Diseases of the Eye
If you have diabetes, your blood glucose, or blood sugar, levels are too high. Over time, this can damage your eyes. The most common problem is diabetic retinopathy. It is a leading cause of blindness in American adults. Your retina is the light-sensitive tissue at the back of your eye. You need a healthy retina to see clearly. Diabetic retinopathy damages the tiny blood vessels inside your retina. You may not notice it at first. Symptoms can include:
Blurry or double vision
Rings, flashing lights, or blank spots
Dark or floating spots
Pain or pressure in one or both of your eyes
Trouble seeing things out of the corners of your eyes
Treatment often includes laser treatment or surgery, with follow-up care.
Oculoplastics, or oculoplastic surgery, includes a wide variety of surgical procedures that deal with the orbit (eye socket), eyelids, tear ducts, and the face. It also deals with the reconstruction of the eye and associated structures. Oculoplastic surgeons perform procedures such as the repair of droopy eyelids (blepharoplasty), repair of tear duct obstructions, orbital fracture repairs, removal of tumors in and around the eyes, eyelid reconstruction.
Neuro-ophthalmology is an academically-oriented subspecialty that merges the fields of neurology and ophthalmology, often dealing with complex systemic diseases that have manifestations in the visual system. Common pathology referred to a neuro-ophthalmologist includes afferent visual system disorders (e.g. optic neuritis, optic neuropathy, papilledema, brain tumors or strokes) and efferent visual system disorders (e.g. anisocoria, diplopia, ophthalmoplegia, ptosis, nystagmus, blepharospasm and hemifacial spasm).
Glaucoma is a term describing a group of ocular (eye) disorders resulting in optic nerve damage or loss to the field of vision, in many patients caused by a clinically characterized pressure buildup in regards to the fluid of the eye (intraocular pressure-associated optic neuropathy). In a large number of glaucoma patients, however, the intraocular pressure (IOP) is normal, i.e. below 20 mm Hg. These patients display the same signs of glaucomatous damage as those with an elevated IOP; their condition is thus called normal tension glaucoma. The disorders can be roughly divided into two main categories, “open-angle” and “closed-angle” (or “angle closure”) glaucoma. The angle refers to the area between the iris and cornea, through which fluid must flow to escape via the trabecular meshwork, an area of tissue in the eye located around the base of the cornea. Closed-angle glaucoma can appear suddenly and is often painful; visual loss can progress quickly, but the discomfort often leads patients to seek medical attention before permanent damage occurs. Open-angle, chronic glaucoma tends to progress at a slower rate and patients may not notice they have lost vision until the disease has progressed significantly.
The increased intraocular pressure can permanently damage vision in the affected eye(s) and lead to blindness if left untreated. It is normally associated with increased fluid pressure in the eye (aqueous humour). The term “ocular hypertension” is used for people with consistently raised intraocular pressure (IOP) without any associated optic nerve damage. Conversely, the term ‘normal tension’ or ‘low tension’ glaucoma is used for those with optic nerve damage and associated visual field loss, but normal or low intraocular pressure.
The nerve damage involves loss of retinal ganglion cells in a characteristic pattern. The many different subtypes of glaucoma can all be considered to be a type of optic neuropathy. Raised intraocular pressure (above 21 mmHg or 2.8 kPa) is the most important and only modifiable risk factor for glaucoma. However, some may have high eye pressure for years and never develop damage, while others can develop nerve damage at a relatively low pressure. Untreated glaucoma can lead to permanent damage of the optic nerve and resultant visual field loss, which over time can progress to blindness.
Pediatric ophthalmologists focus on the development of the visual system and the various diseases that disrupt visual development in children. Pediatric ophthalmologists also have expertise in managing the various ocular diseases that affect children. Pediatric ophthalmologists are qualified to perform complex eye surgery as well as to manage children’s eye problems using glasses and medications. Many ophthalmologists and other physicians refer pediatric patients to a pediatric ophthalmologist for examination and management of ocular problems due to children’s unique needs. In addition to children with obvious vision problems, children with head turns, head tilts, squinting of the eyes, or preferred head postures (torticollis) are typically referred to a pediatric ophthalmologist for evaluation. Pediatric ophthalmologists typically also manage adults with eye movement disorders (such as nystagmus or strabismus) due to their familiarity with strabismus conditions.
Macular degeneration, often age-related macular degeneration (AMD or ARMD), is a medical condition that usually affects older adults and results in a loss of vision in the center of the visual field (the macula) because of damage to the retina. It occurs in “dry” and “wet” forms. It is a major cause of blindness and visual impairment in older adults (>50 years). Macular degeneration can make it difficult or impossible to read or recognize faces, although enough peripheral vision remains to allow other activities of daily life. Although some macular dystrophies affecting younger individuals are sometimes referred to as macular degeneration, the term generally refers to age-related macular degeneration (AMD or ARMD). The retina is a network of visual receptors and nerves. It lies on the choroid, a network of blood vessels which supplies the retina with blood. In the dry (nonexudative) form, cellular debris called drusen accumulates between the retina and the choroid, and the retina can become detached. In the wet (exudative) form, which is more severe, blood vessels grow up from the choroid behind the retina, and the retina can also become detached. It can be treated with laser coagulation, and with medication that stops and sometimes reverses the growth of blood vessels.
Uveitis is, broadly, inflammation of the uvea. The uvea consists of the middle, pigmented vascular structures of the eye and includes the iris, ciliary body, and choroid. Uveitis requires an urgent referral and thorough examination by an optometrist or ophthalmologist and urgent treatment to control the inflammation. Prior to the twentieth century, uveitis was typically referred to in English as “ophthalmia.” Uveitis is classified anatomically into anterior, intermediate, posterior, and panuveitic forms—based on the part of the eye primarily affected.
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 or broad, but without rapid treatment the entire retina may detach, leading to vision loss and blindness. It is almost always classified as a medical emergency. Permanent damage may occur if the detachment is not repaired.
The retina is a thin layer of light sensitive tissue on the back wall of the eye. The optical system of the eye focuses light on the retina much like light is focused on the film or sensor in a camera. The retina translates that focused image into neural impulses and sends them to the brain via the optic nerve. Occasionally, posterior vitreous detachment, injury or trauma to the eye or head may cause a small tear in the retina. The tear allows vitreous fluid to seep through it under the retina, and peel it away like a bubble in wallpaper.