Ocular anatomy
          It is important the ocular anatomy in details as the multiple choice questions can cover any ocular structures. The following are some of the facts which the candidates may think unimportant but have appeared in previous papers. The Snell's Anatomy of Ophthalmology should be read thoroughly.
           
                Structures                    Volume (ml) in adult
                orbit                                               30
                vitreous cavity                                4.5
                anterior chamber                           0.2
                posterior chamber                          0.06
                 

                Cornea
                thinnest in center                0.5 - 0.6 mm
                thickest in periphery                1.2 mm
                vertical diameter                     10.6 mm
                horizontal diameter                11.7 mm
                radius of curvature                   7.8 mm (anterior)
                                                                      6.5 mm (posterior)
                stroma  thickness                     90% of cornea
                endothelium at birth                one million cells or

                                                         4000 cells per square mm
                Lacrimal system
                tear production                    0.9 to 2.2 ul/minute
                tear thickness                       9 um
                tear overflow                        if > 100ul / minute secretion
                upper punctum lateral to lower punctum
                nasolacrimal duct narrowest midway
                nasolacrimal duct runs downward, backward and laterally

                Sclera
                thickest                                around optic disc (1mm)
                thinnest                                 behind recti insertion (0.3mm)
                anterior ciliary artery penetrates sclera 4 mm from limbus
                vortex vein exists sclera 4 mm behind the equator

                Retina
                retinal pigment epithelium        1 million cells
                rods                                       120 millions
                cones                                         6 millions
                ganglion cells                               1 million
                 

                                            X cells                            Y cells
                size                    smaller cells                           larger cells
                field                   small                                         large
                pathway             parvocellular                          magnocellular
                function            colour & sharp image           moving object
                                                                                                & flicker
                 

                Lateral geniculate body
                layer 1 and 2               magnocellular pathway
                layer 3 to 6                  parvocellular pathway
                layers 1,4 & 6            contralateral nasal retina
                layers 2, 3 & 5           ipsilateral temporal retina
                 

                Extraocular muscles
                longest rectus                                      superior rectus
                rectus with longest tendon                 lateral rectus
                shortest rectus                                     inferior rectus
                rectus with the shortest tendon         medial rectus
                all recti receive two anterior ciliary artery except lateral rectus which has one
                all recti arise from tendinous ring but lateral recti also has origin from the greater wing of sphenoid
                 

                Click for anatomy review questions
                 
                 

          Embryology
          Most candidates find embryology difficult because of the amount of facts they need to remember. The embryology section in Fundamentals and Principles of Ophthalmology by American Academy of Ophthalmology give adequate information for examination purposes and should be well read. To facilitate memory, it is useful to draw up tables for:
          • cells of origin for various ocular structures
          • when does each ocular structure first appear and when does it mature or reabsorb?

          Anatomy of head and neck
          The section on head and neck in Snell's Textbook of Anatomy is the recommended reading. In addition , MCQs on head and neck found in many anatomy and primary FRCS books provide good practice. The following topics relate to central nervous system which many candidates forget to revise

          • cranial nerves
          • structures passing through foramina at the base of the skull
          • cerebrospinal fluid and the ventricular system (lateral, third and fourth ventricles)
          • blood supply of the brain: carotid artery, circle of Willis, basilar artery
          • cerebellum
          • midbrain
          • pons
          • medulla
          • spinal cord: pathways for various sensation


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