Duke Elder Ophthalmology Exam PDF - Cataract Questions

9”x6” b4144   300 MCQs for the Duke Elder Ophthalmology Exam 15 Chapter Cataract Questions 2 1) Epidemiologically, cataracts are: A. More prevalent in men than women B. Entirely an age-r...

9”x6” b4144   300 MCQs for the Duke Elder Ophthalmology Exam 15 Chapter Cataract Questions 2 1) Epidemiologically, cataracts are: A. More prevalent in men than women B. Entirely an age-related process C. The most common cause of reversible blindness D. Not a congenital condition 2) Cataracts are associated with the following systemic diseases: A. Marfan syndrome B. Osler-Weber-Rendu syndrome C. Tuberous sclerosis D. Multiple sclerosis 3) Which of the following is NOT a symptom arising from the formation of cataracts? A. Poor night vision B. Reduced contrast sensitivity C. Blurred vision for both near and distance D. Photophobia 4) Which one of the following types of cataracts is NOT age-related? A. Nuclear sclerotic B. Posterior polar C. Cortical D. Posterior subcapsular 5) Which of the following is TRUE — with age, the lens: A. Becomes increasingly curved and has increasing refractive power B. Becomes less curved and has decreasing refractive power C. Becomes increasingly curved and has decreasing refractive power D. Becomes less curved and has increasing refractive power b4144_Ch-02.indd 15 19-04-2021 11.32.19 AM  9”x6” b4144   300 MCQs for the Duke Elder Ophthalmology Exam 1 6 3 00 M CQ s F O R T H E D U K E E L D E R O P H T H A L M O LO G Y E X A M 6) Which of the following is FALSE regarding the anatomy of lens? A. The lens is biconcave B. The lens is avascular C. The lens has no neural innervation D. The lens is held in place by zonular fibres 7) The contraction of the ciliary muscle ring is related to the shape of the lens via the following mechanism: A. Ciliary muscle ring contracts, the ring diameter is reduced and the zonular fibres relax, resulting in the lens becoming rounder B. Ciliary muscle ring contracts, the ring diameter is increased and the zonular fibres relax, resulting in the lens becoming rounder C. Ciliary muscle ring contracts, the ring diameter is increased and the zonular fibres contract, resulting in the lens becoming flatter D. Ciliary muscle ring contracts, the ring diameter is reduced and the zonular fibres relax, resulting in the lens becoming flatter 8) Which of the following is FALSE regarding the “pump-leak theory”? A. Potassium and amino acids are actively pumped into the anterior portion of the lens via the lens epithelium B. All ion movement into the lens is mediated by active transport C. Potassium is concentrated in the anterior lens, meanwhile sodium is concentrated in the posterior lens D. Intercellular gap junctions facilitate passive diffusion throughout the lens 9) Which of the following is NOT a feature of terminal differentiation? A. Epithelial cells elongate into lens fibres B. There is a loss of cell organelles, including nuclei, ribosomes and mitochondria C. The mass of cellular proteins in each cell increases D. The cells become less dependent on glycolysis for energy b4144_Ch-02.indd 16 19-04-2021 11.32.19 AM  9”x6” b4144   300 MCQs for the Duke Elder Ophthalmology Exam Ca t arac t Q uesti o n s 17 10) Which of the following refers to a Morgagnian cataract? A. A cataract where the lens is completely opacified B. A cataract where the lens is partially opacified, but the nucleus has some transparent proteins C. Due to the leakage of water from the lens, the cataract has a shrunken anterior capsule D. There is cortical liquefaction resulting in the nucleus sinking inferiorly 11) Which one of the following systemic diseases results in the formation of fine, needle-like opacities that resemble a Christmas tree cataract? A. Diabetes mellitus B. Myotonic dystrophy C. Atopic dermatitis D. Neurofibromatosis type 2 12) Which one of the following is associated with the formation of snowflake cataracts? A. Diabetes mellitus B. Neurofibromatosis type 2 C. Tuberous sclerosis D. Von Hippel-Lindau syndrome 13) Which of the following is FALSE? A. Myopia is associated with the formation of nuclear sclerotic cataract B. A nuclear sclerotic cataract can worsen a myopic refractive error C. Acute close angle glaucoma can result in subcapsular or capsular opacities D. Chronic anterior uveitis is not associated with cataract formation 14) Which of the following drugs is associated with intraoperative floppy iris syndrome? A. Atropine B. Tamsulosin C. Haloperidol D. Timolol b4144_Ch-02.indd 17 19-04-2021 11.32.19 AM  9”x6” b4144   300 MCQs for the Duke Elder Ophthalmology Exam 18 3 00 M CQ s F O R T H E D U K E E L D E R O P H T H A L M O LO G Y E X A M 15) Which of the following regarding a preoperative ophthalmic assessment is FALSE? A. A shallow anterior chamber heralds a difficult cataract surgery B. Nuclear cataracts tend to require lower ultrasonic energy during phacoemulsification C. Ectropion and entropion may increase the likelihood of postoperative endophthalmitis D. Trypan blue can be used to overcome a poor red reflex when creating a capsulorrhexis 16) Which of the following is NOT an intraocular lens (IOL) power calculation formula? A. SRK-T B. Hoffer Q C. Javal-Schiotz D. Holladay 1 17) Which one of the following surgical steps refers to the separation of the lens nucleus and cortex from the capsule? A. “Phaco-chop” B. “Divide and conquer” C. Capsulorrhexis D. Hydrodissection 18) Which of the following is NOT a sign of posterior lens capsule rupture? A. Pupillary dilation and shallowing of anterior chamber B. The phaco tip is unable to approach the nucleus as it moves posteriorly C. Increased rate of aspiration as vitreous is aspirated by the phaco probe tip D. The vitreous gel can be visualised 19) Which of the following perioperative measure is established as the most effective preventative measure for endophthalmitis prophylaxis? A. Topical administration of 5% povidone-iodine a few minutes prior to surgery B. Topical fluroquinolone in the days leading up to the surgery C. Reducing the duration of the surgery D. Early suturing of leaking wounds during operation b4144_Ch-02.indd 18 19-04-2021 11.32.19 AM  9”x6” b4144   300 MCQs for the Duke Elder Ophthalmology Exam Ca t arac t Q uesti o n s 19 20) Which of the following is NOT a risk factor for cystoid macular oedema? A. Poorly controlled diabetes mellitus B. Topical NSAIDs C. Posterior capsule rupture D. Vitreous loss 21) Which one of the following statements regarding posterior capsular opacification (PCO) is FALSE? A. PCO is the most common early complication of cataract surgery B. Its causative mechanism involves the proliferation of remnant lens epithelial cells C. Capsulorrhexis openings that are in contact with the intraocular lens reduce the incidence of PCO D. Epidemiological studies suggest that approximately 50% of all eye patients will eventually develop PCO after cataract surgery 22) Which of the following morphologies is NOT seen in congenital cataract? A. Blue dot opacities B. Central “oil droplet” opacities C. Lamellar opacities D. Snowflake opacities 23) A 45-year-old lady presents with a history of increasing difficulty in reading books and newspapers, especially under bright lights. You are told her sole ocular pathology is cataracts. Which one of the following cataract is she MOST likely to have? A. Posterior polar B. Anterior polar C. Nuclear sclerotic D. Posterior subscapular 24) Which of the following is NOT a type of congenital cataract? A. Zonular B. Fusiform C. Punctate D. Cortical b4144_Ch-02.indd 19 19-04-2021 11.32.19 AM  9”x6” b4144   300 MCQs for the Duke Elder Ophthalmology Exam 2 0 3 00 M CQ s F O R T H E D U K E E L D E R O P H T H A L M O LO G Y E X A M 25) Which of the following is the MOST common lens protein? A. Alpha crystallin B. Beta crystallin C. Gamma crystallin D. Insoluble albuminoid b4144_Ch-02.indd 20 19-04-2021 11.32.19 AM  9”x6” b4144   300 MCQs for the Duke Elder Ophthalmology Exam 21 Chapter Cataract Answers 2 1) C Cataracts may be age-related, congenital or traumatic in their aetiology. They can also be associated with other intraocular diseases. Ionizing radiation and pharmaceutical agents such as steroids can also cause cataracts. There are more common but not exclusive in the elderly. Epidemiological studies point to an increased prevalence among women. It remains the world’s leading cause of reversible blindness. 2) A Cataracts’ association with systemic diseases can be categorised by syndrome aetiologies: Metabolic Diabetes, Lowe syndrome, McCune-Albright Disorder syndrome, Wilson disease, Fabry disease Renal Disease Alport syndrome, Lowe syndrome Dermatological Atopic dermatitis, ectodermal dysplasia Connective Myotonic dystrophy, Marfan syndrome, skeletal Tissue/Skeletal dysplasia Central Nervous Neurofibromatosis type 2 System Although there are literature publications on the association of cataracts and tuberous sclerosis, this is only anecdotal and based on only a few cases series. 3) D Patients with cataracts may report glare or haloes and streaks sur- rounding lights and reduced acuity in the presence of bright lights — but this is not photophobia. b4144_Ch-02.indd 21 19-04-2021 11.32.20 AM  9”x6” b4144   300 MCQs for the Duke Elder Ophthalmology Exam 2 2 3 00 M CQ s F O R T H E D U K E E L D E R O P H T H A L M O LO G Y E X A M Blurred vision, glare, poor night vision, reduced contrast sensitivity and reduced colour sensitivity can be reported symptoms. 4) B Age-related cataracts are by far the most common cataracts. These can be subdivided by their origin: Nuclear Typically causes a myopic shift resulting from the Sclerotic yellowing and hardening of the lens nucleus. Cortical Opacification of the lens fibres surrounding the central nucleus with glare being a predominant symptom. Posterior Opacification of the posterior cortical layer adjacent Subscapular to the posterior capsule of the lens. Typically seen in younger patients and associated with diabetes and steroid use. Glare is also a predominant symptom. Posterior Typically congenital and inherited in an autosomal Polar dominant pattern. They project forward from the centre of the posterior capsule to penetrate the lens cortex. 5) A The ageing lens becomes increasing curved with time, resulting in an increase in its refractive power. 6) A The lens is a biconvex structure that is avascular and non-innervated. It is held in place by zonular fibres that arise from the ciliary body and attach to the equatorial region of the lens. The lens is suspended poste- riorly to the iris. It divides the eye into posterior and anterior segments. It is comprised of three layers that include, from central to peripheral, the nucleus, cortex and capsule. 7) A The ciliary muscle is a ring that is attached to the lens by zonular fibres. Upon contraction, the diameter of the ring counterintuitively reduces. Therefore the zonular fibres are relaxed and the tension force on the lens is also reduced, resulting in the lens becoming rounder. b4144_Ch-02.indd 22 19-04-2021 11.32.20 AM  9”x6” b4144   300 MCQs for the Duke Elder Ophthalmology Exam Ca t arac t A n swers 23 Given this, the ciliary muscles play an important role in accommodation and adjusting the focusing of the light reflecting from the objects to land on the fovea. Contraction is mediated by the parasympathetic activation of M3 muscarinic receptors. 8) B The “pump-leak” theory refers to the combination of active and passive transport of ions in and out of the lens. The theory stipulates that potas- sium and other molecules are pumped into the lens via ATPase and exchange pumps located in the epithelium of the lens anteriorly. These then diffuse to the posterior lens via passive diffusion and leave the lens due to membrane permeability in the back of the lens. Conversely, sodium passively flows in through the posterior lens down the concentration and electrochemical gradient and is actively exchanged with potassium in the anterior lens via Na+/K+-ATPase exchangers. 9) D Terminal differentiation refers to the process by which the lens epithelial cells lose their organelles and elongate into lens fibres. There is an increase in the intracellular protein mass, even as these cells lose their organelles. In doing so, they form a homogenous cytoplasm that is opti- cally advantageous. However, in losing their mitochondria, the cells switch from oxida- tive phosphorylation and increasingly rely on glycolysis, the hexose monophosphotase shunt and aldose reductase pathway for energy. 10) D Cataract maturity can be classified as: Immature There are still some transparent proteins and the lens is only partially opaque. Mature All of the proteins in the lens are now opaque. Hypermature There is a leakage of water from the lens resulting in a shrunken, withered appearance of the anterior capsule. Morgagnian A type of hypermature cataract where there is liquefaction of the cortex and subsequent settle- ment of the nucleus inferiorly. b4144_Ch-02.indd 23 19-04-2021 11.32.20 AM  9”x6” b4144   300 MCQs for the Duke Elder Ophthalmology Exam 24 3 00 M CQ s F O R T H E D U K E E L D E R O P H T H A L M O LO G Y E X A M 11) B Patients with myotonic dystrophy typically present with cortical opaci- ties that tend to resemble a Christmas tree cataract due to their iridescence and fine, needle-like morphology. This is seen in almost 90% of patients with myotonic dystrophy and typically presents at the age of 30–40 years. With time, these fine opacities develop into wedge-shaped cortical and sometimes subcapsular cataracts. In this phase, they are often likened to a star shape. 12) A Patient with poorly controlled diabetes may have a hyperglycaemic aqueous humour, which results in a diffusion of glucose into the lens. Its subsequent metabolisation and accumulation in the form of sorbitol result in an increased oncotic pressure, driving water into the lens. This can lead to limited and temporary change in the shape of the lens and its refractory index, which fluctuates with the corresponding rise or fall in plasma glucose levels. It can also, albeit rarely, cause the formation of snowflake cataracts in young patients. These are pathogno- monic of diabetes. Incidentally, age-related cataract formation takes place from an earlier age in patients with diabetes. 13) D Chronic anterior uveitis remains one of the most common causes of secondary cataracts. There is a close association with the degree and duration of inflammation. Unfortunately, the use of topical steroids, whilst indicated as treatment, may exacerbate cataract formation. High-grade myopia is associated with the formation of posterior capsular and nuclear sclerosis cataracts, both of which can induce or exacerbate a myopic refractive error. 14) B The intraoperative floppy iris syndrome (IFIS) refers to a triad of: · A “floppy” iris that transverses the incision site · Iris prolapse · Pupillary constriction during the operation Tamsulosin increases the risk of IFIS, although suspending it preopera- tively has not been shown to be effective in reducing IFIS. Newer b4144_Ch-02.indd 24 19-04-2021 11.32.20 AM  9”x6” b4144   300 MCQs for the Duke Elder Ophthalmology Exam Ca t arac t A n swers 25 generations of antipsychotic medications such as risperidone can also increase the risk of IFIS. 15) B In creating a capsulorrhexis, the operating surgeon creates an opening in the anterior capsule, allowing them access to the cortex and nucleus. A poor red reflex can make it difficult for capsulorrhexis creation, but this can be overcome to good effect by using Trypan blue. With a shallow anterior chamber, performing a capsulorrhexis is difficult due to poor manoeuvrability and the lack of flattening of the anterior lens capsule. Nuclear cataracts tend to be harder than cortical or posterior subcap- sular cataracts. Hence, higher phacoemulsification energy may be required. Ectropion and entropion may increase the likelihood of postopera- tive endophthalmitis, as can chronic conjunctivitis, dacryocystitis, blepharitis and tear film abnormalities. 16) C Postoperative refractive outcomes are predetermined using biometry and power calculation to determine the desired intraocular lenses power. Many such formulae exist and common examples include SRK-T, Haigis and Holladay 1 and 2. Some are used more than others in certain situations (e.g., Hoffer Q for those with very short eyes). 17) D Hydrodissection refers to the injection of fluid via a blunt cannula to separate the lens cortex and nucleus from the capsule. Meanwhile, “divide and conquer” and “phaco-chop” both refer to lens disassembly techniques in which the nucleus is emulsified and aspirated. As stated above, capsulorrhexis refers to the opening in the anterior capsule, allowing access to the cortex and nucleus. 18) C Rupture of the posterior lens capsule can result in vitreous loss and downward movement of the lens into the vitreous chamber. Intraoperative signs of this include: · The sudden deepening of the anterior chamber and pupil dilation · The nucleus will move posteriorly as the phaco tip approaches it b4144_Ch-02.indd 25 19-04-2021 11.32.20 AM  9”x6” b4144   300 MCQs for the Duke Elder Ophthalmology Exam 2 6 3 00 M CQ s F O R T H E D U K E E L D E R O P H T H A L M O LO G Y E X A M · As vitreous is aspirated into the tip, there may be a noticeable drop in aspiration · The vitreous may come in the line of sight Poorly managed posterior capsular rupture can result in retinal detach- ment, cystoid macular oedema, glaucoma and uveitis. 19) A Whilst (A), (C) and (D) are all correct, instillation of povidone-iodine 5% onto the ocular surface at least 3–5 minutes prior to surgery is recom- mended and has the highest quality evidence to support its efficacy. Preoperative antibiotic prophylaxis is given in some centres across the world, however, the evidence of its efficacy is lacking. 20) B Cystoid macular oedema (CMO) remains one of the most common causes of postoperative visual loss. Peri- and postoperative release of inflammatory mediators results in increased permeability in the foveal capillaries resulting in CMO. Topical NSAIDs can reduce postoperative inflammation and have been shown to be efficacious in reducing the incidence of CMO. Meanwhile, poorly controlled diabetes, vitreous loss and posterior capsule rupture are associated with an increased risk of CMO. 21) A PCO is one of the most common late complications of cataract surgery. Studies show that almost half of all patients will eventually develop PCO. Symptoms typically include a gradual blurring of vision and glare. In patients who have significant visual symptoms, a capsulotomy may be indicated where an opening is created in the posterior capsule. PCO is thought to be caused by the proliferation of epithelial cells that were left behind during cataract surgery. 22) D Snowflake opacities are seen in young diabetic patients, albeit rarely, and can be self-resolving. Blue dot opacities are common and innocuous as congenital opacities. Central “oil droplet” opacities are associated with galactosaemia. Lamellar opacities occur anteriorly and posteriorly in the lamella region of the lens and can have radial extensions. These can be b4144_Ch-02.indd 26 19-04-2021 11.32.20 AM  9”x6” b4144   300 MCQs for the Duke Elder Ophthalmology Exam Ca t arac t A n swers 27 hereditary, portraying an autosomal dominant inheritance pattern, in association with certain metabolic disorders and can also be associated with intrauterine infection during pregnancy. 23) D Posterior subscapular cataracts often result in difficulty with near vision and glare. They can be rapidly progressive and are often seen in a younger demographic compared to nuclear sclerotic or cortical cata- racts. Risk factors include steroid use, diabetes, uveitis and radiation. Nuclear sclerotic cataract may affect distance vision as opposed to near vision due to a myopic shift. A progressive loss of vision from ante- rior polar cataracts would not often be seen at someone of this age. Posterior polar cataracts are typically congenital, displaying an auto- somal dominant pattern of inheritance. However, given their rarity, they are not very well characterised. 24) D A cortical cataract is an age-related cataract. Zonular cataracts account for almost 50% of all congenital cataracts that are visually significant. They usually affect both eyes with the opacity usually showing a sharp demarcation. They tend to form just before or shortly after birth. Fusiform cataracts are spindle-shaped opacities. There is a strong genetic disposition, and they can often resemble a coral in their mor- phology and hence are often also referred to as coralliform. Punctate cataracts are also known as blue dot cataracts and are the most common type of congenital cataracts. The vast majority do not have any impact on vision. 25) B Eighty to 90 percent of soluble proteins in the lens are crystallins. The most common of which is beta (51%), followed by alpha (31%) and gamma (2%). With age, the concentration of both soluble and non-soluble pro- teins increases. This results in light scattering and contributes to the formation of cataracts. b4144_Ch-02.indd 27 19-04-2021 11.32.20 AM