Chapter 16 Ophthalmic Surgery

The correct answer is Globe because the question asks for the part of the eye that is being referred to in its entirety. The retina, cornea, and sclera are all parts of the eye, but the globe refers to the entire eyeball itself, including all of these parts.

Cataract is the correct answer because it is a condition characterized by the clouding or opacity of the crystalline lens in the eye. This clouding can occur due to age or trauma, leading to a loss of vision or blurred vision. A cataract can be caused by various factors such as aging, injury, certain medications, or underlying medical conditions. It can be treated through surgical removal of the cloudy lens and replacement with an artificial lens.

Intraocular lenses are small prescription lenses that are placed inside the eye. These lenses are used to replace the natural lens of the eye during cataract surgery or to correct vision problems such as nearsightedness, farsightedness, or astigmatism. By implanting intraocular lenses, the vision can be restored or improved, allowing the person to see clearly without the need for glasses or contact lenses.

A chalazion is a small lump that forms on the inner or outer surface of the eyelid. It is typically caused by a blockage in one of the small oil glands of the eyelid. Chalazions are usually painless and may appear as a red, swollen bump. They can sometimes resolve on their own, but may require treatment such as warm compresses or medication.

Strabismus refers to the misalignment or deviation of the eyes that normally work together to track visual objects. This condition can cause one eye to turn inwards, outwards, upwards, or downwards, while the other eye remains straight. Strabismus can lead to problems with depth perception and can affect a person's ability to focus and coordinate their eyes. Treatment options for strabismus include eyeglasses, eye patches, and in some cases, surgery.

Balanced Salt Solution is the most commonly used irrigating fluid in the eye. It is a sterile, isotonic solution that closely resembles the natural fluids found in the eye. It helps to maintain the health and integrity of the ocular tissues during surgical procedures or when flushing the eye is necessary. It provides a balanced electrolyte composition, which helps to prevent damage or irritation to the eye. Additionally, it has a pH level that is compatible with the eye, further ensuring its safety and effectiveness.

The lacrimal gland is responsible for secreting tears that keep the conjunctiva moist. Tears are essential for maintaining the health and lubrication of the eyes. The lacrimal gland produces tears, which are then spread across the surface of the eye by blinking. This helps to prevent dryness and irritation of the conjunctiva, ensuring clear vision and protecting the eye from foreign particles and infections. The lacrimal gland is located above the outer corner of the eye and is connected to the tear ducts, which drain the excess tears into the nasal cavity.

Glaucoma is a condition characterized by increased pressure within the eye, which can lead to damage of the optic nerve and vision loss. The explanation for the given correct answer is that glaucoma occurs when the aqueous fluid, which normally circulates within the eye, is unable to exit due to blockage by the iris. This blockage causes a buildup of fluid and increased pressure, leading to the development of glaucoma.

Rods are photoreceptor cells located in the retina of the eye that are responsible for vision in low light conditions. They are more sensitive to light than cones, but are not able to perceive color. In dim light, the rods are activated and allow us to see shades of gray and distinguish general shapes or outlines. Therefore, the presence of rods is the most likely explanation for being able to see shades of gray in dim light.

Mydriatics are drugs used to dilate the pupil for examination of the retina. They work by relaxing the muscles in the iris, allowing the pupil to open wider. This dilation of the pupil enables better visualization of the retina and helps in diagnosing various eye conditions. Viscoelastic agents are substances used during eye surgeries to maintain space and protect the delicate structures of the eye. Balanced Salt Solution is a sterile solution used for irrigation and rinsing during eye procedures. Miotics, on the other hand, are drugs that constrict the pupil and are used to treat conditions like glaucoma.

Cones are photoreceptor cells in the retina that are responsible for color vision and sharp image perception in bright light. Unlike rods, which are more sensitive to dim light and provide black and white vision, cones are specialized for detecting different wavelengths of light and allow us to see a wide range of colors. Therefore, cones are the correct answer for providing color vision in bright light and seeing sharp images.

Ptosis refers to the drooping of the upper eyelid, which can be either congenital or acquired. This condition can occur due to the weakness of the muscles responsible for lifting the eyelid or damage to the nerves controlling these muscles. It can affect one or both eyes and may cause vision obstruction. Ptosis can be a result of age, trauma, neurological disorders, or certain medical conditions. Treatment options for ptosis include surgery to repair the muscle or lift the eyelid, depending on the severity of the condition.

The cornea is the transparent, dome-shaped front part of the eye that covers the iris, pupil, and anterior chamber. It is responsible for refracting light and focusing it onto the retina, which then transmits the visual information to the brain. The cornea plays a crucial role in vision by helping to bend light rays so that they can properly focus on the retina.

The retina is the layer of tissue at the back of the eye that contains cells called photoreceptors, which detect light and convert it into electrical signals that can be interpreted by the brain. This explanation fits with the statement "Makes up the inner tunic, images are received," as the retina is responsible for receiving and processing visual information. The other options, such as the pupil, lens, and iris, are not directly involved in receiving images.

The sclera is the correct answer because it is the tough, white outer layer of the eye that helps to maintain the shape and protect the delicate inner structures. It forms the majority of the external tunic of the eye and provides support and attachment points for the muscles that control eye movement. The sclera is also involved in maintaining the pressure within the eye and plays a role in vision by reflecting light back out of the eye.

Miotics are pupil constricting agents that act on the sphincter of the iris. They are used to treat conditions such as glaucoma, where the pupil needs to be constricted to reduce intraocular pressure. Balanced Salt Solution is a sterile solution used for irrigation and rinsing of the eye. Mydriatics are drugs that dilate the pupil and are used in eye examinations. Tetracaine is a local anesthetic used to numb the eye before certain procedures. Therefore, out of the given options, miotics are the correct answer as they specifically constrict the pupil.

Vitrectomy is a microsurgical procedure used to repair retinal disorders. It involves the use of specialized microinstruments and techniques to remove the gel-like substance (vitreous) from the eye and replace it with a saline solution. This procedure is commonly performed to treat conditions such as retinal detachment, macular hole, and diabetic retinopathy. By removing the vitreous, the surgeon is able to access and repair the underlying retinal issue, improving vision and preventing further damage to the eye.

The correct answer is Conjunctiva. The conjunctiva is a mucous membrane that covers the front surface of the eye and lines the inside of the eyelids. It helps to protect the eye from foreign particles and lubricates the surface of the eye, keeping it moist. The conjunctiva is transparent and allows light to pass through to the cornea, which is the clear outer layer of the eye.

Pterygium is a condition where conjunctiva, the thin transparent layer covering the white part of the eye, grows onto the cornea, the clear front surface of the eye. This growth can cause symptoms such as redness, irritation, and blurred vision. Dacryocystitis is an infection of the tear duct, Chalazion is a blocked oil gland in the eyelid, and Cataract is a clouding of the lens inside the eye. Therefore, Pterygium is the most appropriate answer as it specifically describes the growth of conjunctiva onto the cornea.

Entropin is the correct answer because it refers to a condition that affects the lower eyelid. Entropin is a medical condition in which the eyelid turns inward, causing the eyelashes and skin to rub against the eye surface. This can lead to discomfort, irritation, and potential damage to the cornea. It is commonly caused by muscle weakness or age-related changes in the eyelid. Treatment options for entropion include lubricating eye drops, eyelid taping, and surgical correction.

The superior rectus muscle is responsible for rotating the eye upward and toward the midline. This muscle helps in elevating the eye and also helps in adduction, which is the movement of the eye toward the midline of the face. The other muscles listed, such as the inferior rectus, medial rectus, and lateral rectus, have different functions and are not responsible for the specific movement described in the question.

The pupils are responsible for allowing the transmission of light into the eye. The pupils are the black circular openings in the center of the iris, which is the colored part of the eye. When the pupils dilate, they become larger, allowing more light to enter the eye. Conversely, when the pupils constrict, they become smaller, reducing the amount of light that enters the eye. This adjustment in the size of the pupils helps regulate the amount of light that reaches the retina, the light-sensitive tissue at the back of the eye.

The superior oblique muscle is responsible for rotating the eye downward and away from the midline. This muscle helps to move the eye in a diagonal direction, specifically rotating it downward and outward. It works in conjunction with other muscles to control eye movements and maintain proper alignment.

The lacrimal sac is the correct answer because it is the structure that collects tears from the nasolacrimal duct and drains them into the nasal cavity. The nasolacrimal duct carries tears from the lacrimal gland to the lacrimal sac, which then leads to the nasal cavity. The other options mentioned (palate, canaliculi) are not involved in the drainage of tears.