Ernst Pflüger

Biographical Timeline

• Born July 1, 1846 in Büren an der Aare, Canton Bern, Switzerland.
• 1870 – MD (Dr. med.), University of Bern; dissertation on ophthalmic tonometry
• 1870–1871 – Ophthalmology training under Henri Dor (1835–1912); study tour including Utrecht (F.C. Donders) and Vienna (C.F. Arlt).
• 1871–1876 – Practised as eye and ear physician in Lucerne (Luzern)
• 1876 – Appointed associate professor of ophthalmology at the University of Bern, succeeding Dor.
• 1879 – Became Ordinarius (full professor) of ophthalmology, University of Bern (held until death). Son Ernst Pflüger (1879–1954) born (later an ophthalmologist in Bern).
• 1880 – Published “Tafeln zur Bestimmung der Farbenblindheit” (colour-blindness plates) based on Florcontrast principles.
• 1882 – Developed an ophthalmoscope with corrective lenses (Refraktions-Ophthalmoskop). Published “Zur Ernährung Der Cornea” using fluorescein derivatives in animal experiments to visualise corneal uptake/flow and argue about sources of corneal nutrition
• 1882–1896 – Developed optotypes for vision testing (“Optotypi Pflüger”)
• 1886 – Published on myopia and education (Kurzsichtigkeit u. Erziehung).
• 1894 – Published on modern glaucoma operations (Operazioni moderne di glaucoma).
• 1899 – Published Suppression du cristallin transparent (clear lens removal). Campaigned for a new Bern eye clinic, which was completed only after his death.
• Died September 30, 1903 in Bern, Switzerland.

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Key Medical Contributions

Fluorescein contribution (1882) (cornea nutrition and stromal “flow” tracing)

1882 – In Zur Ernährung der Cornea, Pflüger provided an early example of fluorescein used as a physiological tracer, not merely a stain. He instilled succinylfluorescein into the conjunctival sac of rabbits and watched the cornea fluoresce. Then, by creating fine epithelial defects he produced sector- and “tongue”-like fluorescent patterns that advanced from the limbus toward the centre, which he interpreted as evidence of a centripetal stromal fluid stream. He used these observations to argue that corneal nutrition depends primarily on surrounding vascular tissues rather than chiefly on the aqueous humour.

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Refraction and diagnostic instrumentation (making optics measurable)

Pflüger began with a medical thesis on tonometry (IOP measurement), then focused heavily on refraction, promoting direct ophthalmoscopy as a refractive method and refining tools for retinoscopy and keratometry for practical clinical use.

Vision testing and colour vision (plates and optotypes)

Pflüger contributed to the “standardisation” of vision testing for both colour perception and visual acuity. He published “tables for determination of colour blindness” using a Florcontrast principle (letters/numbers seen through coloured “flor” papers), as an attempt to determine colour deficiency at the bedside. Later he designed visual acuity optotypes.

Surgical “solutions” for refractive extremes and glaucoma

Pflüger promoted removal of the clear crystalline lens for extreme myopia (a precursor to later refractive-lens strategies), and wrote on contemporary glaucoma operations and the public-health problem of myopia and schooling.

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Major Publications

• Pflüger E. Beiträge zur Ophthalmotonometrie: Inaugural-Dissertation. 1871
• Pflüger E. Augenklinik in Bern. 1879
• Pflüger E. Tafeln zur Bestimmung der Farbenblindheit. 1880
• Pflüger E. Zur Ernährung Der Cornea. Klinische Monatsblätter für Augenheilkunde, 1882; 20: 69–82.
• Pflüger E. A case of microcephalus with microphthalmus. 1885
• Pflüger E. Kurzsichtigkeit und Erziehung. 1887
• Pflüger E. Sehproben und Sehprufung, Optotypi Pflüger. 1896
• Pflüger E. Die operative Beseitigung der durchsichtigen Linse. 1900

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References

Biography

• Pflüger, Ernst. Deutsche Biographie.
• Streiff EB. The Genealogy of Ophthalmic Teaching in Switzerland. Hist. Ophthal. intern. 1982; 2: 407-430
• Koelbing, HM. Pflüger, Ernst in: Neue Deutsche Biographie 20 (2001), S. 356 f.