Bietti's crystalline dystrophy. A clinicopathologic correlative study

We report the clinical and electrophysiologic findings in three patients with Bietti's crystalline corneal-retinal dystrophy. The initial evaluation in one patient demonstrated diffuse disease involving retinal pigment epithelium and choriocapillaris with severe widespread disturbance of retinal function. The patient's disease progressed greatly from the age of 36 to 47 years. Two brothers had regional involvement of the posterior pole with disturbances of retinal function attributable to localized disease, and there was only mild progression in these patients. A corneal biopsy specimen from the more severely affected patient and biopsy specimens from a patient whose case had been previously reported demonstrated crystals resembling cholesterol or cholesterol ester and complex lipid inclusions in corneal and conjunctival fibroblasts. Similar inclusions were present in circulating lymphocytes, suggesting that Bietti's crystalline corneal-retinal dystrophy may be due to a systemic abnormality of lipid metabolism.

Endothelial function and aqueous humor flow rate in patients with Fuchs' dystrophy

Using a two-dimensional scanning fluorophotometer, we studied 50 subjects with symmetric ocular involvement of Fuchs' dystrophy without epithelial edema. Twenty-six subjects with confluent or nearly confluent cornea gutata with increased corneal thickness and 24 subjects with mild to moderate cornea guttata with normal corneal thickness were compared to normal control subjects. There were no statistically significant differences in endothelial permeability between the three groups. Corneal thickness was significantly increased in the subjects with confluent to nearly confluent guttae, however. These results suggest that endothelial pump function may be affected in subjects with advanced cornea guttata with stromal edema.

[Quantitative control of the function of the corneal endothelium by fluorophotometry in the anterior eye segment]

Whereas specular microscopy yields mostly qualitative information, fluorophotometry furnishes quantitative data of endothelial cell function. Determination of fluorescein permeability of the endothelial cell layer reflects the function of the endothelial barrier. Following topical application of fluorescein, the time-dependent change in the fluorescein concentration in corneal stroma and aqueous yields the transfer coefficient (Kc) of the corneal endothelium. With the Fluorotron Master, Kc was 3.77 +/- 0.57 X 10(-3)/min. for normal eyes; patients with cornea guttata or Fuchs's dystrophy had a significantly higher transfer coefficient (Kc = 7.9 +/- 2.88 X 10(-3)/min.). Normal Kc values were found 6-63 months (average 33.5 months) after phacoemulsification with implantation of a posterior chamber lens.

Superficial reticular degeneration of Koby

Koby in 1927 described a progressive, superficial corneal degeneration in a middle-aged woman that led to a painless loss of vision. This condition was characterized by the appearance of a central, fine, white reticulum at the level of Bowman's layer. The epithelium was thickened and bedewed, giving a faint brownish opalescence and providing a striking contrast to the white reticulum. We evaluated a patient with this rare corneal degeneration, and present clinical findings as well as the results of a superficial corneal biopsy. The biopsy was evaluated by light and electron microscopy and provides the initial documentation of this entity as an atypical form of band keratopathy.

Polymorphic corneal abnormalities

Alterations of the deep corneal layers, which are manifest primarily as Hassall-Henle bodies in older patients, are a relatively frequent finding in the normal population. Changes which occur in Descemet's membrane and the endothelium earlier in life can be ascribed to various causes, including dystrophy, herpetic infections, and birth trauma. Six cases in which clear vesicles and scalloped lesions were found exclusively at the level of Descemet's membrane and the endothelium are reported. Although the polymorphic changes were in some cases extensive, visual acuity and, apparently, corneal physiology remained normal. The etiology for all cases was uncertain, but the evidence suggested a dystrophic origin or the occurrence of posterior corneal vesicles of a nonfamilial variety.

Lattice corneal dystrophy: a source of confusion

Published descriptions of families with lattice dystrophy of the cornea reveal a much more varied clinical course and a more pleomorphic corneal picture than the rather stereotyped textbook descriptions would suggest. This report describes a family with lattice dystrophy of unusually late onset with retention of useful vision into the 7th decade. Herpes simplex keratitis was misdiagnosed in 5 members of the family by different ophthalmologists, probably because the typical lattice lines were fine and visible only by retroillumination.

C-reactive protein in human lattice corneal dystrophy

Lattice corneal dystrophy (LCD), an autosomal dominantly inherited disease, is characterized by a branching network of subepithelial and stromal amyloid deposits (1). Due to their small size and close association with stromal components and epithelial cells, their chemical composition is as yet undetermined. Amyloid deposits in other types of diseases have been found to contain amyloid P protein (AP). Serum amyloid P component (SAP) and C-reactive protein (CRP) resemble each other in molecular structure and amino acid sequence, but appear to be antigenically distinct (2-6). A humoral mediator most likely stimulates CRP release by hepatocytes and could be related to Interleukin-I synthesis from macrophages (4-6). Rabbit corneal epithelial cells also produced an Interleukin-I-like activity and contain a thymocyte activating cytokine (7). In this study, corneas from normal controls, primary LCD and recurrent LCD were fixed in formalin with lmM CaCl2 and tested with antibodies to CRP, AP and AA (non-immunoamyloid), using the immunoperoxidase technique. The stroma of LCD and normal corneas did not stain with antibodies to AP, AA or CRP. However, we now report that antibodies to CRP show immunospecific binding to the corneal epithelium in primary and recurrent LCD.

The origin of amyloid in gelatinous drop-like corneal dystrophy

The origin of amyloid in gelatinous drop-like corneal dystrophy, one of the primary corneal amyloidoses, was studied by light and electron microscopy. Milky-white granules over the corneal surface are the first clinical findings. In the initial stage, the amyloid substance exists between the basal cell of the corneal epithelium and the basal lamina of the cell. The basal lamina, Bowman's membrane and the stroma remained intact. Numerous filaments, about 7nm in width, were seen in the normal basal cells. In addition, many fibrils, about 10nm in width, were observed in the damaged basal cells. With progressing of the disease, the amyloid increased in amount and Bowman's membrane disappeared. Our results suggest that the basal cell of the corneal epithelium may produce and secreted the amyloid substance and gelatinous drop-like corneal dystrophy occurred.

Penetrating keratoplasty for pseudophakic bullous keratopathy. Visual results

Thirty-six patients with pseudophakic bullous keratopathy had penetrating keratoplasties with one immediate graft failure and two subsequent rejections. Fifty-four percent of the patients saw 20/40 or better, and 79% saw 20/80 or better. These results are much better than reported for aphakic bullous keratopathy. Endothelial counts in the other eyes showed that 17% of these patients have unexpectedly very low cell counts, which were not appreciated on slitlamp examination and were probably a contributing factor to their corneal decompensation.

The basement membrane complex of the human corneal epithelium

The present report reviews the fine structure of the basement membrane zone or complex in the normal human cornea and describes its alterations in cases of early and acute keratoconus. In normal human cornea the basement membrane zone is formed by a basal lamina (with a lamina lucida and a lamina densa), "special fibrils", collagen fibrils and assemblies of filaments. These components are less evident in the central region of the cornea than in its periphery. In early stages of keratoconus the basement membrane zone is thickened and the lamina densa displays an irregular course. In acute keratoconus, the basement membrane zone is also thickened and includes a large number of "special fibrils" as well as bundles of "microfibrils" (oxytalan fibers). The conclusion that the basement membrane complex of the corneal epithelium is equivalent to the epidermal-dermal junction of the skin is discussed.

Protein AA and lattice corneal dystrophy

A 73-year-old woman underwent corneal transplantation because of lattice dystrophy. Histopathologic examination of the excised host cornea disclosed eosinophilic deposits that stained positively with Congo red and showed green birefringence with polarized light. Immunofluorescent examination showed protein AA and protein AP in the stromal deposits. To the best of our knowledge, this is the first report of protein AA and protein AP in the amyloid deposits of lattice corneal dystrophy.

Eye problems of the elderly

The most frequent changes of the anterior eye observed in senescence include changes in refraction which may be toward the hyperopic or the myopic side and a diminished tear secretion which may lead to the sicca syndrome. The corneal endothelium often shows degenerative changes which may lead to a decompensation of the cornea and corneal edema. A senile cataract is a frequent finding in older people as is chronic open angle glaucoma. One of the most serious senile changes in macular degeneration which may lead to extremely poor central vision though the peripheral vision may still be satisfactory. A similar effect has the less frequently seen anterior ischemic optic neuropathy.

Familial amyloidosis with cranial neuropathy and corneal lattice dystrophy

Five siblings of a Danish family with slowly progressive involvement of the trigeminal, facial, glossopharyngeal, accessory, and hypoglossal nerves beginning at the age of 55-65 years were examined. All had asymptomatic corneal lattice dystrophy. Clinical and electrophysiological investigations also showed evidence of slight neurogenic involvement of the limbs. Conduction velocity along sensory nerves was normal but amplitude of sensory potentials was severely reduced suggesting an axonal affection which was confirmed by sural nerve biopsy. The neuropathy was secondary to amyloidosis revealed by skin and sural nerve biopsies.

[Reduced production of aqueous humor in Fuch's corneal dystrophy]

Fuchs' corneal dystrophy is associated with a reduced production of the aqueous humor, as can be established via tonography. The trophopathy and cornea guttata caused thereby are prerequisites for the production of Fuchs' corneal dystrophy. The aqueous humor production should be examined before keratoplasty, since the prognosis is questionable if the production is low. If no improvement of visual acuity can be excepted, keratoplasty should not be performed, since pain has also been relieved by means of intracorneal acrylate implantates.

[Observations on the pathogenesis of essential progressive iris atrophy with corneal dystrophy and secondary glaucoma (author's transl)]

A report is given of a case of a unilateral condition of this type in a 30-year-old woman, who was observed and repeatedly photographed for more as 7 years.

[On the so-called inferior, sickle-shaped edematous corneal dystrophy (author's transl)]

The inferior, sickle-shaped, edematous corneal dystrophy described by Bietti has not been further reported in the literature. A similar corneal lesion in a 44-year-old patient provided the stimulus to express some thoughts as to the etiology and pathogenesis of this form of dystrophy.

Secondary anterior crocodile shagreen of Vogt

The clincopathological features and pathogenesis of secondary mosaic degeneration of the cornea (anterior crocodile shagreen of Vogt) are described. The structural basis for the normal anterior corneal mosaic pattern seems to lie in the particular arrangement of many prominent collagen lamellae of the anterior stroma that thake an oblique course to gain insertion into Bowman's layer. Since, at normal intraocular pressure, Bowman's layer is under tension, when viewed from the anterior surface the cornea appears smooth. By releasing the tension, however, a reproducible polygonal ridge pattern becomes manifest. It is suggested that a prolonged phthisical state of the eye is one condition wherein the mosaic pattern may become permanent and that, as a secondary event, this is followed by irregular calcification of Bowman's layer which particularly involves the ridges projecting into the epithelium. Biomicroscopically these ridges corresponded to the branching reticular arrangement of the mosaic opacities.