Recently we have evaluated three successive generations of a family with the diagnosis of positive angle kappa and Wagner's vitreoretinal degeneration. This family is being reported because of the apparent autosomal dominant pattern of inheritance of the positive angle kappa that has not been reported previously. Wagner's disease is known to be an autosomal dominant disorder but. has not been associated with the positive angle kappa.
Patient No. 1
The family propositus is a 5-year-old male seen initially for evaluation of amblyopia. Visual acuity was 20/80 OD and 20/25 OS. Motility examination showed an esotropia of 10 prism diopters. Refractive error was piano +3.00 OD and piano +1 .50 OS. The fundus showed a grandular macula and peripheral vitreous detachment OU, Amblyopia treatment was done with the visual acuity becoming equal. There was a positive angle kappa that measured 10 degrees (Fig. 1a).
Patient No. 2
This is the 1 1/2-year-old brother who was examined without complaints and was found to have a normal ocular examination with the exception of the vitreous. There were several fine bands running through the periphery. He also showed a large positive angle kappa (Fig. 1b).
Patient No. 3
This is the 27 -year-old mother who on examination was rioted to have a large positive angle kappa (Fig. 1c) and peripheral cortical spoking of each lens. Vitreous and retinal examination showed increased vitreous bands and peripheral degenerative retinal changes.
Patient No. 4
This is the 28-year-old maternal uncle whose ocular findings were remarkable only in the presence of a large positive angle kappa and mild myopic astigmatism (Fig. 2).
Patient No. 5
This is the 52-year-old maternal grandfather who gave a history of poor vision in the right eye since childhood and bilateral cataract extractions at age 34. Figure 3 is a copy of a picture of the grandfather taken at age 4. Notice the large positive angle kappa that was present. Present visual acuity is no light perception OD and 6/6 OS. The patient demonstrated a large positive angle kappa by fixation OS. The right eye showed band keratopathy, elevated intraocular pressure, exotropia, and extensive vitreoretinal degeneration. The left eye also showed marked vitreoretinal changes.
Patient No. 6
This isthe70-year-old maternal great grandmother who gave a history of myopia as a child and cataract development in her 20s. Cataract extraction was done OD in her 30s but due to the postoperative complications she never had good vision. Shortly thereafter, she lost her vision in her OS before any operative procedure was performed. She also reported that her mot her went blind early in life and had attended a blind school. Her examination showed phthesis bulbi OU.
The angle kappa is defined as the angle formed by the primary line of sight and a line perpendicular to the center of the pupil. A positive angle is when the line of sight is nasal to the perpendicular.1 Of those individuals with no manifest strabismus, 37% have a positive angle kappa, 29% zero angle kappa, and 34% a negative angle kappa. :
Fig. 1. 1a) Patient No. ha S-year-old maie; !b) Patient No. 2. his 1 1 /2-year-old brother; (c) Patient No. 3, the 27-year-old mother of Patient Nos. 1 and 2.
Wagner's hereditary vitreoretinal degeneration is a bilateral, autosomal dominant disorder with 100% penetrance. At birth, affected infants may show a normal fundus with slight tessellation or excessive choroidal pigment. Most children develop a myopia of the magnitude of 1-5 diopters. As a child grows older, tessellation becomes more prominent and the choroidal vessels become atrophic. Choroiretinal pigment migrates along the retinal vessels that become sheathed. Vitreous changes are also seen early in life and consist of liquifaction, fibrous condensation, and preretina! membranes. Electrophysiologic studies have found the electroretinogram to be subnormal. Retinal breaks are seen in about 75% of the patients with retinal detachmentsformed in approximately 50%.
Cataract formation is seen after adolescence in more than 60% of the individuals. The cataracts characteristically are of the posterior subcapsular or posterior capsular type. The cataracts are often mature by the age of 40.'
The pattern of inheritance of -the positive angle kappa in three successive generations is evidence for autosomal dominant inheritance in this family. Such a Mendelian model of inheritance has not been previously reported.
The strong association of two ocular conditions of apparent autosomal dominant inheritance can suggest either that they are closely linked or a chance association in this particular family. Future observations may help to separate the two possibilities.
Fig. 2. Patient No. 4, the 28-year-old maternal uncle.
Fig. 3. The maternal grandfather at age 4.
Three successive generations of a family with a diagnosis of positive angle kappa and Wagner's vitreoretinal degeneration are presented. This is the first known report of a family with an apparent autosomal dominant pattern of inheritance of a positive angle kappa.
1. Duke-Elder S: Pseudostrabismus. In von Noorden: Atlas of Strabismus, ed 3. Saint Louis, CV Mosby, 1977, ? 32.
2. Scott WE, Mash AJ: Kappa angle measures of strabismic and non-strabismic individuals. Arch Ophthalmol 89:18-20, 1973.
3. Tolentino, Schepends, Freeman: Vitreoretinal Disorders, Diagnosis and Management, chapt 13, pp 242-247, 1976.
4. Hegman JP, Mash AJ, Spivey BE: Genetic analysis of human visual parameters in population with varying incidences of strabismus. Am J Hum Genet 26(5):549-562, 1974.