Genetics in ophthalmology / Arnold Sorsby.

  • Arnold Sorsby
Date:
1951
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Genetics in ophthalmology / Arnold Sorsby. Source: Wellcome Collection.

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    ABNORMALITIES IN TRANSPARENCY though Still within normal limits. The line of demarcation with the sclera is ill- defined, and the transparent part of the cornea tends to be horizontally oval. Frequently there are associated ocular anomalies, so that vision is poor. Cornea plana is probably inherited in a dominant manner (Fig. 84), though some pedigrees suggest a recessive mode of inheritance. Cornea plana together with bluish Fig. 84.—Cornea plana. Pedigree show¬ ing dominant inheritance. {After V. Lar sen and A. Erik sen (1949). Acta Ophthal., 27, 275.) m coloration of the sclera and xerosis of the conjunctiva has been observed once over two generations. Keratoconus In some pedigrees (Fig. 85 a) keratoconus and severe corneal astigmatism appear as alternative forms within the same family. Frequently, too, when there is kera¬ toconus in one eye there is a high degree of astigmatism in the other. This would suggest that high degrees of astigmatism are abortive forms of keratoconus, ? ? Í 5 5 i 1 iïi о oii ¿ ¿ ■ # Keratoconus. Ш 0 Astigmatism (at least 2 D). {a) (b) Fig. 85.—Keratoconus. (a) Pedigree over twogenerations showing keratoconus and severe astig¬ matism as alternative forms. (After J. Rumpf (1937). Contribution à Г étude de V hérédité du Keratocône, p. 65, Lausanne: Thesis.) (b) Pedigree suggestive of dominant inheritance. (After J. Stähli (1925). КНп. МЫ. Augenheilk., 75, 465.) and there is evidence that some, at any rate, tend to evolve into the fully developed type. The majority of records concern sibships only and would suggest recessiveness, but there are a substantial number of cases observed over two generations, and even three (Fig. 85 b). The interpretation of these pedigrees depends largely upon the significance attached to astigmatism as an abortive form of keratoconus. ABNORMALITIES IN TRANSPARENCY Congenital opacification of the cornea and corneal staphyloma Congenital opacification of the cornea presents considerable clinical complexities. It is not unlikely that many of the early records in the literature were partial observations on a variety of genetic affections ranging from embryotoxon to 101