The Duke Elder Exam of Ophthalmology

A Comprehensive Guide for Success

Mostafa Khalil, Omar Kouli, Mostafa Khalil, Omar Kouli

• Publisher: CRC Press
• Year: 2019
• ISBN:
  9781000020588
• Edition: 1
• Topic: Medicine
• Subtopic: Medical Theory, Practice & Reference

The Duke Elder Exam of Ophthalmology – A Comprehensive Guide for Success is an indispensable resource for any student wishing to achieve the highest mark on the Duke Elder Exam and receive a prize.

With expert knowledge of students and doctors that have scored high on the exam, along with the supervision of well-regarded ophthalmologists and trainees, we believe this is the only resource you will need to achieve a high score on the exam.

Key Features

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• In-depth coverage of the Duke Elder Curriculum including the basic sciences, anatomy, optics and all subspecialties of ophthalmology

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• Full colour and easy to read with clinical photographs and diagrams to aid in the understanding of key topics

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• 180 SBAs, which accurately reflect the format and difficulty of the exam

1

Basic science, investigations and lasers

TAREK KHALIL, BILAL IBRAHIM, STEWART GILLAN AND OBAID KOUSHA

1.1Embryologic origins of eye structures

1.2Genetics

1.3Microbiology

1.4Immunology

1.5Drug mechanisms and side effects

1.6Investigations

1.7Lasers

1.8Miscellaneous

References

1.1 Embryologic origins of eye structures

Ocular structures are derived from the germ layers described in Table 1.1.

Table 1.1 Summary of ocular structures’ embryologic origins
Germ layer	Ocular structures
Surface ectoderm	Conjunctival and corneal epithelium Nasolacrimal duct Lens Lacrimal gland Eyelids
Neuroectoderm	Neurosensory retina Pigment epithelium of the retina, iris and ciliary body Pupillary sphincter and dilator muscles Optic nerve
Neural crest	Corneal endothelium Trabecular meshwork Stroma of cornea, iris and ciliary body Ciliary muscle Choroid Sclera Orbital cartilage and bone
Mesoderm	Extraocular muscles Blood vessels Schlemm’s canal endothelium Sclera (temporal portion)

1.2 Genetics

In this section, basic knowledge of chromosomes and types of inheritance are covered, along with examples of conditions and their associated inheritance (Table 1.2).

Table 1.2 Inheritance of ocular and systemic pathologies
Inheritance	Conditions
AD	Congenital cataracts Best disease Fuchs’ corneal dystrophy (also sporadic) Granular and lattice corneal dystrophies Marfan syndrome Neurofibromatosis Retinitis pigmentosa (also AR or XLR) Retinoblastoma (most commonly sporadic) Stickler syndrome Tuberous sclerosis Von Hippel-Lindau (VHL)
AR	Congenital glaucoma (most commonly sporadic) Oculocutaneous albinism Stargardt disease Retinitis pigmentosa-like conditions
XLR	Fabry disease Lowe syndrome Ocular albinism Retinoschisis
XLD	Alport syndrome (also AR)
Mitochondrial	Kearns-Sayre syndrome Leber hereditary optic neuropathy

1.2.1 Chromosomes

Eukaryotic cells differ from primitive cells with the presence of the nucleus. Deoxyribonucleic acid (DNA) is present in the nucleus and carries genetic information needed for cell production. The DNA molecules are packaged into structures called chromosomes.

Chromosomes have a short arm, denoted as ‘p’, and a long arm, denoted as ‘q’. Human cells contain 46 chromosomes: 22 identical pairs and a pair of sex chromosomes. Genetic information can be carried on any of these chromosomes, and hence inheritance can be autosomal or sex-linked (X-linked). Other forms of inheritance that...