23^rdEdition of Advancements in Ophthalmology: Clinical & Surgical Practices

Glaucoma results in raised intraocular pressure and vision loss over time. Unfortunately, surgery for glaucoma cannot reverse this vision loss. However, surgery can reduce the intraocular pressure when medication is not a sufficient solution. If necessary, glaucoma surgery can be performed multiple times with low risk.

There are two kind of common glaucoma surgery: Laser Surgery – During laser surgery, a laser is used to make a small opening in the eye’s drainage system to help increase fluid drainage out of the eye. When laser surgery unable to solve the condition & condition re-emerges, the ophthalmologist may refer for conventional surgery. Conventional Surgery – During conventional surgery, a new drainage canal is created that allows intraocular fluid to flow out of the eye.

Lid repair may be shown for both cosmetic and functional reasons. Lid repair is most generally used to treat ptosis, also called as droopy eyelids. This has become an extremely famous surgery as the condition can cosmetically age the patient, obstruct vision, or make a visual incongruence between the eyelids.

Surgeries for ptosis can incorporate blepharoplasty (ptosis resulting from aging), Fasanella-Servat and Müller’s muscle-conjunctival resection (for mild to moderate ptosis), and frontalis suspension (for more extreme congenital cases).

Orbital eye surgery is demonstrated for conditions for example anopthalmia, enucleation, and evisceration. These types of surgeries are indicated for individuals with: congenital defects resulting in absent eyes, large eye tumors, or when the eye cannot be preserved due to trauma.

Surgical methodologies incorporate introducing an orbital implant for example the Orbital Tissue Expander, and bioceramic or silicone orbital implants. The Orbital Tissue Expander helps the preserve the congruency of facial structure in congenital cases where maintaining pressure on the surrounding structures is imperative to proper growth.

Orbital implants are utilized to protect the regular structure of the eye orbit and provide support for the placement of an artificial eye. Recent advancements in orbital implants have aided in improving implant motility and allowing for the natural movement of artificial eyes. Stable materials that are biocompatible, bioinert, nontoxic, and non-allergenic provide a lower rate of migration and rejection in patients.

Strabismus is a vision problem in which both eyes do not focus at the same object at the same time. Strabismus most often begins in early childhood. It is sometimes called crossed-eyes, walleye, or squint.

Normally, the muscles attached to each eye work together to move both eyes in the same direction at the same time. Strabismus occurs when the eye muscles don't work accurately to control eye movement. When the eye muscles don't work as they should, the eyes may become misaligned and the brain may not be able to merge what one eye sees with what the other eye sees.

The most common treatments for strabismus are:

Glasses. Wearing glasses sometimes correct mild strabismus.

A temporary eye patch over the stronger eye. This can make the weak eye stronger, which may help in aligning the eyes. Your child may have to wear the patch some or all of the time for a few weeks or months.

Surgery on the eye muscles. This is the only way to improve vision and for betterment in alignment of the eyes. It may take more than one surgery, and your child may still need to wear glasses.

Vitrectomy is a surgery to remove the vitreous gel from the center of the eye. It may be done when there is a retinal detachment or if blood in the vitreous gel (vitreous discharge) does not clear on its own. Removing the vitreous gel gives your eye specialist better access to the back of the eye. Vitrectomy is done by an eye doctor (ophthalmologist) who has special training in treating problems of the retina.

During surgery, the doctor uses small devices to remove the vitreous gel. Then the specialist may treat other eye issues, for example a retinal detachment, vitreous drain, scar tissue on the retina, or tears or holes in the macula.

At the end of the surgery, the specialist may inject an oil or gas bubble into the eye. This gently presses the retina against the wall of the eye. If an oil bubble is used, the doctor will need to evacuate/remove the oil after the eye has healed.

Refractive surgery is used to correct common eye disorders such as nearsightedness, farsightedness, and astigmatism. Refractive surgery is designed to alter the shape of the cornea in order to improve the patient’s vision.

For people who are myopia, some refractive surgery techniques will minimize the curvature of a cornea that is too steep so that the eye's focusing power is lessened. Images that are focused in front of the retina, due to a longer eye or steep corneal curve, are pushed closer to or directly onto the retina following surgery.

Hyperopia people will have refractive surgery procedures that achieve a steeper cornea to increase the eye's focusing power. Images that are focused beyond the retina, due to a short eye or flat cornea, will be pulled closer to or directly onto the retina after surgery.

Astigmatism can be treated with refractive surgery techniques that selectively reshape part of an irregular cornea to make it smooth and symmetrical. The result is that images focus clearly on the retina rather than being distorted due to light scattering through an irregularly shaped cornea.

The cornea is the clear outer lens on the front of the eye. The cornea is made of layers of cells. These layers work together to protect your eye and provide clear vision.

Your cornea must be clear, smooth and healthy for good vision. If it is swollen, scarred or damaged, light is not focused accurately into the eye. As a result, your vision is blurry or you see glare. A cornea transplant replaces diseased or scarred corneal tissue with healthy tissue from an organ donor.

There are two main kinds of cornea transplants: traditional, full thickness cornea transplant (also known as penetrating keratoplasty, or PK) and back layer/ Partial-thickness cornea transplant (also known as endothelial keratoplasty, or EK).

A graft replaces central corneal tissue, damaged due to disease or eye injury, with healthy corneal tissue donated from a local eye bank. An affected cornea affects your vision by scattering or distorting light and causing glare and blurred vision. A cornea transplant may be necessary to restore your functional vision.

Corneal eye disease is the fourth most common cause of blindness (after cataracts, glaucoma and age-related macular degeneration) and affects more than 10 million people worldwide.

Oculoplastic surgeons are ophthalmologists (eye doctors) who have specialized in eyelid and facial plastic surgery. Oculoplastic surgery is a general term used to represent a variety of procedures that involve the orbit, eyelids, & tear ducts. Ocular reconstructive surgery, aesthetic eyelid surgery, facial plastic surgery, and cosmetic procedures fall into this category.

Some types of oculoplastic surgery are considered both medically necessary and cosmetic. For instance, certain eyelid and periocular issues can affect a person’s appearance as well as their vision, eye comfort, and eye health.

Retinal separation/detachment is a serious condition of the eye in which the retina stops receiving oxygen. Your retina is the part of your eye that sends images through your optic nerve to the brain. Your retina contains millions of cells that detect light like a camera. It is part of the very back of your eyeball and is essential to your vision.

Retinal detachment occurs when the retina pulls away from the back of the eye and the blood supply. Without a blood supply, the retinal cells will start to die. This can make changeless harm to your vision. If the macula begins to loosen, your vision may be permanently damaged. If  macula completely detaches, you may lose your vision entirely. Reattaching the retina quickly is essential to prevent such a serious complication.

Retinal detachment happens because the vitreous fluid of the eye drawn back from the back of the eye, pulling the retina and tearing it. Some causes and risk factors of retinal detachment include glaucoma, severe trauma, nearsightedness, previous cataract surgery, previous retinal detachment in your other eye, or family history of retinal detachment. Symptoms of a retinal detachment include frightening. Objects might appear to float in front of your eye, or a gray veil may move across your field of vision. If not treated quickly, a retinal detachment can cause you to lose your vision. Retinal detachment repair is a surgery used to restore circulation to the retina and restore vision.

Advanced diagnostic and therapeutic decisions reside on the outcomes of imaging technologies have become a common practice in every ophthalmic subspecialty. New devices and tools for evaluating the retina and optic nerve head, such as scanning laser polarimetry and spectral-domain optical coherence tomography (OCT), are widely used in clinical practice. These technologies provide objective quantitative measurements and in vivo real-time images of ocular structures. The performance of imaging devices is continuously being improved, and thus knowledge of their applications, advantages, and limitations must also be continuously updated to optimize their management by clinicians. A spectral-domain optical coherence tomography (SD-OCT) device in pediatric ophthalmology practice, this mode of imaging has become a standard diagnostic tool. Also known as fourier-domain OCT, the technology has a much higher quality of image than the previous standard of care, time-domain OCT. These new machines scan 65 or more times faster than the older OCT images.

Macular Degeneration is the most common cause of vision loss, affecting more than 10 million Americans – more than cataracts and glaucoma combined.

At present, Macular Degeneration is considered an incurable eye disease.

The macula is made up of millions of light-sensing cells that provide sharp, central vision. Macular Degeneration happened due to the damage of the central portion of the retina, the inside back layer of the eye that records the images we see and sends them via the optic nerve from the eye to the brain, and it controls our ability to read, drive a car, recognize faces or colors, and see objects in fine detail.

There are two common types of Macular Degeneration: “dry” and “wet.” Approximately 85% to 90% of the cases of Macular Degeneration are the “dry” (atrophic) type, while 10-15% is the “wet” (exudative) type.

Stages of Macular Degeneration

There are three steps of Age-related Macular Degeneration (AMD).

Early AMD – Most population do not experience vision loss in the early stage of AMD, which is why regular eye exams are important, particularly if you have more than one risk factor (see below). Early AMD is diagnosed by the presence of medium-sized drusen (yellow deposits underneath the retina).

Intermediate AMD – At this stage, there may be little vision loss, but there still may not be noticeable symptoms. A comprehensive eye exam with specific tests will look for larger drusen and/or pigment changes in the retina.

Late AMD – At this stage, vision loss has become noticeable.

Tumors can arise in almost any part of the eye. Some eye tumors can be quite serious, while others need no treatment.

Ocular Surface Tumors, Tumors may occur on the surface of the eye due to overexposure to the sun and other causes.

Uveal Melanoma, Melanoma of the uveal tract is an uncommon, but serious, condition that requires careful diagnosis and follow-up.

Orbital Tumors and Inflammation, The orbit is comprised of the bones of the eye socket, the eyeball, the eye muscles, the optic nerve and the surrounding fat. Any of these structures may form a tumor in adults and children.

Retinoblastoma, Tumors of the retina, in the back of the eye, are uncommon and are mostly found in young children, although they can develop at any age.

Ocular tumors including intraocular tumor resection, as well as laser, radiation therapy, and chemotherapy treatments for the eye, eyelid, orbit and conjunctiva, as needed.

The structure of your face shields your eyes from injury. Still, wounds can damage your eye, sometimes severely enough that you could lose your vision. Most eye wounds are preventable.

Injuries to the eye and encompassing structures can be caused by blunt trauma from sport balls, fists, or airsoft/pellet/paintball guns; sharp trauma for example a stick, knives; or chemical trauma for example splash from a caustic substance like a cleaning material or pool supplies.  Safety glasses should be worn at all times while playing with airsoft/pellet/paintball guns and these should never be pointed at anybody faces.

The broadest type of injury occurs when something tease the outer surface of your eye. Certain jobs such as industrial jobs or hobbies such as carpentry make this type of injury more likely. It's also more likely if you wear contact lenses. Chemicals or heat can burn your eyes. 

Whenever possible eye misalignment treated conservatively. In many children who are farsighted, crossing of the eyes can be treated with glasses in place of surgery. In many adults, symptoms of double vision can be controlled with prisms instead of surgery. Children born with ptosis have what is called congenital ptosis. This can be due to problems with the muscle that lifts the eyelid. However, there are some eye misalignment problems that conservative measures cannot help, and in these cases eye muscle surgery is necessary.

A pediatric ophthalmologist is an ophthalmologist who has training in order to better understand and serve the eyes and developing visual system of infants and children. The Pediatric Ophthalmology Service offers primary care of common children's eye problems as well as comprehensive evaluations, inpatient consultations, and follow-up for children with simple or complex eye and vision disorders. Children presenting with amblyopia, lacrimal disorders, strabismus, pediatric glaucoma, ocular cancers, inherited eye disease, and other eye conditions receive not only short-term treatment of the immediate problem, but also long-term rehabilitative care and monitoring of their visual development.

Machines that are able of making exact operations inside the human eye will make it conceivable to perform altogether new procedures. Tiny surgical robots "are revolutionizing eye surgery," said Simon Parkin at Technology Review. The Robotic Retinal Dissection Device, known as R2D2, enables specialists to produce miniscule incisions,

move membranes as small as a hundredth of a millimeter thick, and perform other staggeringly precise maneuvers on patients' eyes utilizing "a joystick and a camera feed."

Unlike the skin covering the rest of the body, the ocular surface is secured only by a thin layer of tear film. A steady tear film present when the eye is open is the key system to keep up the ocular surface healthy. Ocular surface disorder are disorders of the surface of the cornea—the transparent layer that forms the structure in front of the eye. These disorder incorporates dry eye syndrome, meibomian gland dysfunction, rosaceous, scarring from glaucoma medications, allergies, chemical burns, thermal burns, and immunological conditions such as Mucous Membrane Pemphigoid and Sjogren’s Syndrome.

Ocular surface diseases can extremely affect eyesight and quality of life. Symptoms may include blurry vision, discomfort or pain, redness and itching, and in severe cases, blindness due to corneal scarring.

Unfortunately, cases often go undiagnosed and undertreated, because of a lack of understanding of symptoms and inaccurate evaluation. And, as people are living longer, these disorders are becoming more prevalent.

Uveitis is swelling and irritation of the uvea. The uvea is the center layer of the eye. The uvea gives a large portion of the blood supply to the retina. Uveitis is a general term describing a gathering of inflammatory disorders that produces swelling and destroys eye tissues. These disorders can slightly decreased vision or lead to extreme vision loss.

The expression “uveitis” is utilized because the disorder often affects a part of the eye called the uvea. In any case, uveitis is not limited to the uvea. These diseases also affect the lens, retina, optic nerve, and vitreous, producing reduced vision or blindness. Uveitis may be occured by irritation or disorders occurring in the eye or it can be part of an inflammatory disease affecting other parts of the body. Uveitis can last for a short (acute) or a long (chronic) time. The severest forms of uveitis reoccur commonly.

Eye care professionals may depict the disorder more specifically as:

Anterior uveitis

Intermediate uveitis

Posterior uveitis

Panuveitis uveitis

Eye care professionals may also depict the disease as infectious or noninfectious uveitis.

Ocular inflammation has become a hot topic in ophthalmology, involving also several areas of medicine: internal medicine, surgery, basic research, physiology, pharmacology, microbiology, immunology, rheumatology, pharmacology, or laboratory. There are many ocular inflammatory diseases in different locations, including orbit, ocular adnexa, ocular surface, conjunctiva, cornea, sclera, uvea, retinal vessels, and optic nerve.

Ocular inflammatory disease is an extremely common issue that challenges ophthalmologists in a number of ways. The ocular surface, made up of many important components, can suffer from a wide variety of inflammatory issues.

It can be caused by many different things; some of the most common include allergic, bacterial, chemical or viral conjunctivitis, blepharitis, keratitis sicca, sub-conjunctival hematomas and corneal abrasion. These patients need to be treated quickly and efficiently, because the small percentage of emergency visits resulting from much more serious ocular emergencies such as endophthalmitis and bacterial keratitis require more immediate and intensive care.

Implantable Lenses (Visian ICL and Verisyse), like contact lenses, first got FDA endorsement in 2004. These surgically embedded lenses basically are viewed as proper for more elevated amounts of myopia. At the point when implantable lenses are utilized, your eye's regular focal point is left set up. Both of these lenses have a long reputation of utilization, including over 15 years in Europe.

Refractive Lens Exchange is another non-laser, interior eye methodology. RLE is much similar to waterfall surgery. Be that as it may, rather than expelling the eye's common focal point that has developed shady because of waterfall arrangement, RLE includes evacuating a reasonable characteristic focal point and supplanting it with a simulated focal point of an alternate shape, for the most part to decrease or take out high degrees of farsightedness. 

Gene therapy implies the delivery of genes to somatic tissues for therapeutic purposes.  The eye is an attractive target for gene therapy because of its accessibility and its immune privilege. One of the most stringent tests of a gene therapy would be to replace the function of a defective ocular gene, since this requires the introduction and long term expression of a functional copy into many, if not a majority of, target cells. In the case of the retina, for example, specific genetic defects have been found in 20 of the 87 mapped genes causing genetic eye disorder. Most of these disorders result from single gene defects which are both highly disabling and potentially correctable. As an alternative, transferred genes expressing growth factors may be therapeutic in some of the degenerative disorders.⁷ These aspects of gene therapy have therefore attracted a growing body of researchers bent on revolutionising their treatment.

·         Gene therapy in corneal dystrophy

·         Gene therapy in Keratococonus

·         Gene therapy in Glaucoma

·         Gene therapy in Cataract

·         Genetic therapy in ADM

·         Gene therapy in RP

·         Gene therapy for Retinoblastoma

"IVFA" (Intravenous Fluorescein Angiography) gives a definite examination of the blood stream of the retina and choroid. It utilizes a vegetable based dye, not at all like the iodine color utilized for CT checks, and a camera to photo the color in the vessels in the back of the eye

Pneumatic retinopexy (PR) is an office-based nonincisional strategy that has turned into an all around acknowledged contrasting option to scleral clasping and vitrectomy for the repair of chose instances of rhegmatogenous retinal separation. Pneumatic retinopexy is a 2-step methodology. In the initial step, a growing gas bubble is infused into the vitreous cavity and the patient is situated with the goal that the air pocket shuts the retinal break, allowing resorption of subretinal liquid. The second step involves acceptance of a chorioretinal attachment around every single retinal break with cryopexy, laser, or both.

An optical instrument either processes light waves that can enhance an image for viewing, or analyzes light waves that regulate one of a number of characteristic properties. Telescope is the first optical instruments were used for magnification of distant images, and microscopes used for magnifying very tiny images. These instruments have been greatly improved and stretched into other portions of the electromagnetic spectrum. The binocular device is generally a compact instrument for both eyes designed for mobile use. Ophthalmic instruments like Toric Marker and Pre-chopper are used to mark and chop the lens before implantation. Capsulotomy forceps are used to to tear the anterior capsule of the lens during cataract surgery. Camera could be considered AS optical instrument, with the pinhole camera and camera obscura being very simple examples of such devices.