NBME 23 Answers : Block 2 : #43 = A 2-week-old girl is brought to the physician ...

+34
submitted by hayayah(990),

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oCboomal is na yee liaayornmbt atht orccsu rofeeb t.ihrb e'yherT ingisms pieecs of isteus in tseutsrcur atht ofmr eth ee.y

mabooClos ffecitagn het ri,is wchih lesurt in a ""oheylke aecpaenpar of het ,lppiu nalyleerg do tno elad ot siovin lso.s
aooCsoblm lovvnnigi het nirate esrlut in iosvin ossl ni ipscfeic tapsr of het liauvs f.deli
gerLa tneiarl lcsaoobom ro ehtso gifectnaf eth topci evern nac suaec owl niivso, cihhw nmase isoniv slso htat ncnoat be eyclmeltpo erdrcecto itwh lsasges ro tnccaot n.slees

mousie thanks for this explanation! +

macrohphage95 can any one explain to me why not lens ? +

krewfoo99 @macrophage95 Lens are an interal part of the refractive power of the eye. Without the lens the image would not be formed on the retina, thus leading to visual loss +4

qfever Do anyone know why not choroid? +1

adong @qfever, no choroid would also be more detrimental to vision since it supplies blood to the retina +2

irgunner That random zanki card with colobomas associated with a failure of the choroid fissure to close messed me up +7

mnemonicsfordayz Seems like the key to this question is in what is omitted from the question stem: there is no mention of vision loss. If we assume there is no vision loss, then we can eliminate things associated with visual acuity (weird to think of in 2 week old but whatever): C, D, E, F. Also, by @hayayah 's reasoning, we eliminate E & F. If you reconsider the "asymmetric left pupil" then the only likely answer between A & B is B, Iris because the iris' central opening forms the pupil. I mistakenly put A because I was thinking of the choroid fissure and I read the question incorrectly - but it's a poorly worded question IMO. +

mamed Key here is that it doesn't affect vision- the only thing would be the iris. All others are used in vision. Don't have to know what a coloboma actually is. +1

azibird The extra section of that Zanki card specifically says that a coloboma "can be seen in the iris, retina, choroid, or optic disc." Don't you dare talk trash about Zanki! +1

testready https://aapos.org/glossary/coloboma +