Robert Marcus Gunn

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

• FAMOUS FOR

Biography

• 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 pupillary 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

• Marcus Gunn R. Congenital ptosis with peculiar associated movements of the affected lid. Transactions of the Ophthalmological Societies of the United Kingdom. 1883; 3: 283-287. [Marcus Gunn phenomenon]
• Marcus Gunn R. Peculiar appearance in the retina in the vicinity of the optic disc occuring in several members of the same family. Transactions of the Ophthalmological Societies of the United Kingdom. 1883; 3: 110-113. [Gunn’s dots]
• Gunn RM. Functional or hysterical amblyopia. The Ophthalmic review 1902;21:271-80. [Marcus Gunn pupil]
• Gunn RM. On ophthalmoscopic evidence of general arterial disease. Transactions of the Ophthalmological Societies of the United Kingdom. 1887; 18: 356-381. [Gunn’s sign of retinal arterial sclerosis]

References

• In Memoriam: Robert Marcus Gunn. Br Med J. 1909 Dec 11; 2(2554): 1719–1721
• Biography: Gunn, Robert Marcus (1850 – 1909). Plarr’s Lives of the Fellows Online. Royal College of Surgeons of England.
• Beighton G, Wiedemann HR. The Person Behind the Syndrome. Springer. 1997 pp 74-76
• Marin Amat M. Sur le syndrome ou phenomen de Marcus Gunn. Annales d’oculistique, Paris, 1919, 156: 513-528.
• Bardsley PC. The Retinal Signs of Arteriosclerosis compared with those due simply to Increased Blood-pressure. Proc R Soc Med. 1917; 10(Sect Ophthalmol): 34–42.