Robert Marcus Gunn

Robert Marcus Gunn (1850 – 1909)

Robert Marcus Gunn (1850 – 1909) was a Scottish Ophthalmologist.



  • Born 1850 Culgower, Scotland
  • 1868-1873 Studied at Edinburgh and St Andrews Universities. MA (1871); MB CM (1873); MRCS (1873)
  • 1882 – FRCS Edinburgh
  • 1907 – President of the Ophthalmological Society
  • Died 29 November 1909 Surrey, England

Medical Eponyms

Marcus Gunn pupilary phenomenon (1902)

[aka relative afferent pupillary defect or RAPD] A pupil that responds by constricting more to an indirect than to a direct light, seen with unilateral optic nerve or retinal disease

Other eponyms
  • Marin Amat syndrome (reverse Marcus Gunn syndrome)
  • Marcus Gunn phenomenon (Gunn jaw winking syndrome): congenital syndrome (autosomal dominant) present in 5% of neonates with congenital ptosis. Widening of the ptosis when the patient opens their jaw or chews – secondary to a pathological synkinesis between the pterygoids and elevator palpebrae.
  • Gunn’s dots: nonpathologic small, glistening, white/yellow dots on the retina adjacent to the macula
  • Gunn’s sign: Described the retinal signs of arterial sclerosis
    • (1) A tendency to tortuosity of the arteries, especially the smaller vessels.
    • (2) Variation in the calibre of the vessels, especially sudden diminution for a short length passing again into normal size. The calibre is apparently sometimes narrowed by nodules in the vessel walls, imparting to the vessels a beaded appearance.
    • (3) Alteration of the normal light streak. This becomes very much brighter and very much more sharply defined.
    • (4) Indentation of veins, either by supra-pressure of the artery crossing above the vein, or infra-pressure from crossing below. When there is considerable indentation there is great obstruction followed by all the sequela of back pressure, viz., stasis, thrombosis, oedema, and haemorrhages into the surrounding tissues.

Major Publications


eponymictionary CTA 2


the person behind the name

Emergency physician MA (Oxon) MBChB (Edin) FACEM FFSEM with a passion for rugby; medical history; medical education; and asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books |

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