Congenital anterior segment epithelialisation (case)

Posterior polymorphous endothelial dystrophy and iridocorneal endothelial syndrome share common specular microscopic findings, clinical course, and some histopathological features. Despite differences in inherited trait and severity of disease a common pathogenetic mechanism for the two diseases is suggested. This consists of congenital epithelialisation of the posterior corneal surface during embryogenesis with migration of these cells around the anterior segment uninhibited by surrounding normal endothelium.

Recurrence of macular corneal dystrophy within grafts

Two patients (a 41-year-old woman and a 40-year-old man) with macular corneal dystrophy developed significant visual impairment from recurrent disease within corneal grafts. One patient required regrafting 18 years after a penetrating keratoplasty, and the second patient underwent a penetrating graft 19 years after a lamellar corneal graft. In both cases the typical histochemical and electron-microscopic features of macular dystrophy were evident within donor tissue from the original grafts. The patient who originally underwent penetrating keratoplasty had recurrent disease in the corneal endothelium and within Descemet's membrane. Although the explanation of this observation is uncertain, endothelial cells of the recipient human cornea may resurface Descemet's membrane after penetrating keratoplasty, contrary to current belief. An alternative possibility is that involvement of both the corneal endothelium and Descemet's membrane in macular dystrophy is a secondary phenomenon, and that the abnormal storage product of this dystrophy is an abnormal metabolite rather than a normal compound with a defective catabolic enzyme as previously suspected.

Intermittent touch syndrome

Intermittent touch of a pseudophakos to the corneal endothelium is heralded by three signs: ciliary flush, (local) corneal dystrophy, and cystoid macular edema. This syndrome is often missed, and should be ruled out whenever any one of these three signs is detected. Once diagnosed, elimination of the touch should be accomplished promptly. If discovered early, the syndrome may be reversed.

The Barraquer experience with intraocular lenses. 20 years later

The Barraquer Clinic experience in lens implantation is briefly reviewed. About 500 lenses were implanted in a seven-year period, with excellent early results. Late disasters, particularly corneal dystrophy, required the removal of over 300 of these lenses. Recently an extensive analysis has been completed of 162 of the lenses removed. These included Ridley, Strampelli, Dannheim, Boberg-Ans, and Barraquer lenses. The examination of the lenses themselves, coupled with current knowledge of design requisites for intraocular lenses, permits a scientific analysis of these early implants and the problems associated with their use.

[Differential diagnosis of corneal changes in wearers of Hema lenses (author's transl)]

The authors report on a disease of the cornea resembling keratitis nummularis developed by patients wearing Hema lenses. The large disk-shaped subepithelial opacities are accompanied by pathologic changes in the endothelium of the peripheral parts of the cornea. Etiologically, it is believed that there is an immunologic process acting on components of the lenses and the solutions they are cleaned with and kept in. The differential diagnosis between Dimmer's nummular keratitis, epidemic keratoconjunctivitis and herpetic corneal diseases in discussed.

Onchocerciasis in Guatemala. Epidemiology in fincas with various intensities of infection

To provide quantitative information on the epidemiology of infection with Onchocerca volvulus and to define the association between indicators of infection and onchocercal eye disease, skin snips were obtained and skin and ocular examinations were performed on 892 persons living on seven Guatemalan coffee plantations. Skin-snip positivity and the density of microfilariae in the skin increased with age, reaching highest levels at 15-19 years, and both were greater in males than females. A history of nodulectomy was given by 67% of long-term residents and this percentage also increased with age. Over 90% of skin-snip positive subjects and 39% of skin-snip negative subjects had previous or present nodules. Microfilariae were detected in the cornea of 35.1% and in the anterior chamber of 18.9% of all persons examined and the frequencies increased with age, reaching peak levels at 10-19 years. Onchocercal eye lesions were found in 52 persons, causing bilateral blindness in six. Skin-snip positivity, microfilarial skin density, number of nodules, eye infection, and onchocercal eye lesions all correlated significantly with each other. Onchocercal blindness in one or both eyes was found only on fincas with a high prevalence (greater than 80%) and intensity of infection (greater than 22 microfilariae/mg skin).

Contact lens intolerance in association with epithelial dystrophy

Refractile changes in corneal transparency that are associated with epithelial basement membrane dystrophy have been detected in contact lens wearers who show a wide range of contact lens tolerance. In some of these cases, contact lens wear precipitates an episode of recurrent epithelial erosion. In other cases excellent contact lens tolerance is observed. The cases described indicate that pure bleb forms of epithelial basement membrane dystrophy may not be of benign significance when contact lenses are worn.

Long-term changes in corneal endothelium following intraocular lens implantation

To understand the long-term effects of intraocular lens implantation on corneal endothelium, 52 eyes with intraocular lens implantations and 35 eyes with simple cataract extractions were studied using clinical specular microscopy. Endothelial photographs were obtained preoperatively and at least four times in the postoperative period in each case. The postoperative period ranged from 16 to 43 months. Our observations demonstrated that intraocular implants produce a greater magnitude of endothelial cell damage and iris-supported lenses have a more deleterious effect on the corneal endothelium compared with anterior chamber lenses. Seventy-one percent of the eyes with intraocular implants demonstrated precipitates on the endothelium with 16% developing guttata-like areas. All these changes were progressive with time with no such phenomenon occurring in eyes with simple cataract extractions. The progressive endothelial cell damage may be a sequel of chronic, smoldering uveitis associated with intraocular implants.

Age-related changes in the cornea

The optometrist observes and must distinguish between physiologic and pathologic changes in the cornea. This paper deals with normal, physiologic age-related corneal changes. Age-related changes are those that occur over the entire life span, not merely in senescence. They include changes in corneal curvature, toricity, diameter, asphericity, thickness, tactile sensitivity, and a variety of senescent changes. The senescent changes of the cornea include a reduction in epithelial luster, dellen, microcystic dystrophy, the Hudson-Stahli line, crocodile shagreen, the white limbus girdle of Vogt, an increase in stromal relucency, cornea farinata, arcus senilis, Hassall-Henle warts, guttata, a reduction in endothelial cell count and Krukenberg's spindle.

Intraocular gas injection in the pseudophakic patient

Two patients underwent vitrectomy with the use of intraocular gas. In one patient the cornea decompensated because of lens-cornea contact and in the second patient a surgical technique devised to protect the cornea from lens contact was used successfully. The technique consisted of injecting a smaller gas bubble into the anterior chamber before the instillation of the posterior chamber gas.

Corneal dystrophy following lens implantation

Corneal dystrophy following lens implantation is a fairly frequent complication. In our material from the last 2 years (293 corneal grafts) we checked the number of cases of these iatrogenic dystrophies which we had treated. The causes of the dystrophy were investigated and the results with respect to the visual acuity after corneal grafting were reviewed. It appears that the most favourable results are obtained if the corneal graft is performed within 9 months of the onset of the dystrophy.

[Implantation of intraocular lens in keratoplasty with cataract extraction (author's transl)]

A combined operation a) keratoplasty; b) cataract extraction; c) iridocapsular implant must be advised when a corneal opacity and a cataract require both a surgical treatment. Six months after surgery, functional results are good in 4 cases/5.

Anterior membrane dystrophy following cataract extraction

This paper describes a patient with previously normal corneas who underwent bilateral cataract surgery. This was followed by acute dehiscence of the epithelium and the eventual appearance of fingerprint lines, microcysts, and map-like areas typical of Cogan's microcystic dystrophy. Light and electron microscopy showed the presence of epithelial microcysts and a seam of subepithelial material like basement membrane. It is suggested that this patient represents a rapid transition from apparent normality to an extensive anterior membrane dystrophy, precipitated by operation for cataract.

[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.

Review of the literature on intraocular lenses 1976--1977

This paper reviews the advantages, indications, and contraindications of intraocular lenses. The common complications of cystoid macular edema, endothelial corneal dystrophy, and pseudophakic pupillary block glaucoma are discussed. Advantages of inserting the intraocular lens some time after the cataract extraction are enumerated.

[Herpetiform bilateral epithelial corneal dystrophy caused by Tyrosinemia (Richner-Hanhart-Syndrome) (author's transl)]

Nutritional Tyrosinemia in animal experiments (Schweizer, Burns a. o.) caused an epithelial corneal dystrophy. The corresponding clinical picture is the Richner-Hanhart-Syndrome with herpetiform epithelial corneal dystrophy, palmo-plantar-keratosis and -- in some case -- a later developing oligophrenia. Goldsmith and coworkers suceeded to find out that all these symptoms are combined with tyrosinemia presumably caused ty one congenital enzyme defect. -- Personal clinical observations of such patients demonstrate that as well the corneal as the dermatological symptoms could be cured by diet, if the diagnosis is made in childhood. Corneal symptoms are still absent with a tyrosinemia as high as 10 mg%. Dietetic formula was found out to maintain this level, which is low enough to avoid the symptoms of Richner-Hanhart-Syndrome and certainly high enough to avoid symptoms of nutritional deficiency. One might expect that oligophrenia will not develop if this diet is used consequently. -- Since the first corneal symptoms develop already during the first years of life the ophthalmologist ought to know this etiology. The levels of tyrosinemia are so exorbitant (30--50 mg%) that the laboratory diagnosis is possible without any difficulty. If the diagnosis is only made in adult patients dietetic therapy is of limited value.

Scanning electron microscopy of intraocular lens and endothelial cell interaction

Scanning electron microscopic evaluation of two intraocular lenses removed at keratoplasty for pseudophakie bullous keratopathy demonstrated apparently viable endothelial cells adherent to their surfaces. These presumably adhered to the lens implants at the time of their insertion and confirm this as a mechanism for endothelial damage and subsequent corneal edema from intraocular lens implantation.

Corneal dellen following cataract extraction with lens implantation

Two cases of dellen following cataract extraction with implant insertion are described. Etiology may be based upon deprivation of nervous and vascular supplies, and possibly related to large corneal sections. Conservative therapy was found to be sufficient in restoring the corneal integrity.