Histopathologic Findings After Experimental Penetrating Keratoplasty Using Expanded Polytetrafluoroethylene(Gore-Tex(R))in Rabbits: Treatment of Corneal Perforation Using Synthetic Materials. Report I

Although there had been many studies for evaluating an usefulness of expanded polytetrafluoroethylene(Gore-Tex(R)) as a temporary treatment of corneal perforation and a supporting skirt of keratoprosthesis, complications and instability of graft had limited the clinical applications. To find histopathologic factors that can contribute to the instability of graft and to try to modify the surgical methods with models of graft, serial examinations including biomicroscopy and histopathology were performed. According to the results, we were able to divide the causes of instability into two categories as a function of time. Epithelial down growth into the interface between graft and cornea with absence of epithelial coverage over the graft may cause leakage from anterior chamber in early period. Absence of fibrovascular invasion into Gore-Tex(R) resulting no cohesion between graft and cornea might be a factor of instability in late period. Based on these results, modification of surgical techniique and models of graft are needed. Several methods of modificiation are suggested in this report.

Histopathologic study of Dacron Graft following Experimental Fun-thickness Scleral Resection in Rabbits

To evaluate the possibility of Dacron patch for artificial sclera. Dacron(polyethylene terephthalate) which is readily available, biocompatable, safe, and inert synthetic material was implanted in the area of full-thickness scleral defect in rabbits. The histopathologic examinations showed that fibrovascular tissue invested into all interstices of Dacron filaments and fibroconnective tissue encapsulation around Dacron patch had strong connection with collagen fibers of recipient sclera at 4 weeks after graft There were no adverse reactions such as retinal detachment and fibrous proliferation into the vitreous cavity except mild inflammatory response of surrounding tissue at the early postoperative stage. As a result, Dacron graft showed successful firm adhesion to the recipient sclera without serious complications. Thus, We think that Dacron could possibly be used, instead of donor sclera, as artificial scleral graft material for the surgical treatment of perforating scleral diseases.

Histopathologic Findings after Experimental Penetrating Keratoplasty using Dacron-Gore-Tex(R) Combined Graft in Rabbits: Treatment of Corneal Perforation using Synthetic Materials. Report II

The purpose of this study is to evaluate the histopathologic findings after experimental penetrating keratoplasty using Dacron-Gore-Tex(R) combined graft in rabbits and the clinical efficacy of the treatment of corneal perforation using synthetic materials. Type A which used end to end fixation showed better results than that of type B which used intralamellar fixation and, however, complications and instability of graft occured in most eyes of both types. Type C which modified type B and reduced the thickness of intralamellar portion of graft showed relatively good results compared with type A and B, but there was still instability. Leakage from anterior chamber in early postoperative period prior to fiibrovascular invasion into graft was considered as the main cause of instability of graft. Therefore we performed type D which emphasized on preventing leakage, and well-maintained anterior chamber without extrusion of graft, that is, the best result among all 4 types was observed until 6 weeks postoperatively. Although further study is needed, we think that Dacron-Gore-Tex(R) combined graft can be a good substitute for the management of corneal perforation.

Histopathologic Comparison of Vascularization between Dacron and Donor Sclera as Wrapping Material in Hydroxyapatite Implantation

Recently, a hydroxyapatite sphere has been increasingly used as a buried integrated orbital implant for the great improved motility of the prosthesis after enucleation. To allow more rapid ascess of vasculature into the hydroxyapatite implant, Dacron as a new synthetic wrapping material of the implant for anophthalmic sockets had been used and compared histologically with donor sclera in rabbits. At 4 weeks after implantation, fibrovascular ingrowth was found mainly near the scleral windows, where fibrosis extended 2 mm centrally in scleral-wrapped implants. In Contrast, in Dacron-wrapped implants, there was extensive fibrovascular infiltration through Dacron filaments and windows as well, making the hydroxyapatite sphere completely invested with fibrovascular tissue to the center within 4 weeks of implantation. Thus, Dacron as a new wrapping material appears to allow a more rapid vascularization into the hydroxyapatite implant than other collagen material without any serious complications, resulting in early rehabilitation with an artificial eye.

A Scleral Homograft on Pseudomonal Scleral Abscess after Pterygium Excision

Pseudomonas scleral abscess is characterized by acute onset and rapid progression to scleral perforation, and has a subsequent risk of endophthalmitis. After control of infection with appropriate antibiotics, graft surgery should be performed for reinforcing the defected sclera. We performed a scleral homograft on the eye with large necrotic sclera caused by Pseudomonas aeruginosa infection after pterygium excisIon. And the results were remarkably good.

Foveomacular Vitelliform Dystrophy, Adult Type

Vitelliform macular dystrophy, adult type, is a type of pattern dystrophies of the pigment epithelium characterized by autosomal daminant inheritance, mid-life onset and small, round or oval, yellow deposits located at the level of the pigment epithelium. The authors report a case of this dystrophy which showed small yellow round lesion measuring 1/4-1/3 D.D. within the macula, normal electroretinogram, subnormal electrooculogram light-peak/dark-traugh ratio. typical irregular ring-like transmitted fluorescence surrounding the central non-fluorescent Iesion and leakage from perifoveal capillaries on fluorescent angiogram.

Comparison of the SRK and SRKII Formulas with Revision of Constant A in Intraocular Lens Power Calculation

The predictive accuracy of the SRK and SRKII formulas were compared in 113 pseudophakic eyes who had extracapsular cataract extraction with implantation of same type of posterior chamber IOL from Feburary 1990 to March 1991. These patients were folio we red up for at least 2 months postoperatively. Their best corrected visual acuities were above 0.5 and their astigmatisms were below 3 diopters by spectacles correction at the time of the last refraction. The results were as follows. 1. Overall, there were no significant differences in predictive accuracy between SRK and SRKII formulas. 2. The revised constant A for same type of implatnts, which constant A was 118.8. was 117.4 The SRK and SRKII formulas with revised constant A were more accurate than conventional formulas(p<0.001). 3. Our results suggested the constant A was to be revised appropriately according to the surgeon's individual regression analysis when using SRK or SRKII formulas for the calculation of intraocular lens power in Koreans.

A Clinical Study on Transscleral Suture Fixation of Posterior Chamber Intraocular Lens

Posterior chamber intraocular lenses were implanted into 40 eyes with inadequate capsular or zonular support by securing both haptics of the lenses to the sclera at ciliary sulcus with 10-0 prolene sutures. Our follow-up of 36 eyes with scleral fixated posterior chamber intraocular lenses ranged from 2 months to 8 months(average 4.6 months). At the last follow-up visit. 31 eyes(86%) had a vision of 0.5 or better. Mean refractive error was -1.15 +/- 1.13D. which was -0.67 +/- 0.99D more myopic than predicted (p0.05). Additionally, the difference of postoperative axial length between two groups was not statistically significant(23.39 +/- 0.87mm, 23.42 +/- 0.75mm, respectively). In 4 eyes(ll %), minor intraoperative bleeding oceured but was absorbed spontaneously without any sequelae. One eye(3%) of minimal decentration of PCL, one eye(3%) of subluxation of PCL, and one eye(3%) of exposed scleral fixation suture were noted, but no serious postoperative complication, such as corneal edema, glaucoma, persistent uveitis, or retinal detachment was detected.

A Case Report of Takayaeu's Arteritis Associated with, a Retinopathy

The authors have experienced a case of Takayasu's arteritis associated with Takayasu's retinopathy which is confirmed by aortography and fluorescent angiography in a 14 year old female.

A Case of Optic Atrophy following Methanol Poisoning

Methanol poisoning is a rare disease but may cause blindness and, in severe cases, results in death. It may develop lesions in optic nerve and retina, which may be accompanied with permanent visual damage. We report a case of Methanol poisoning in a 20 year-old male patient, which is followed by optic atrophy and loss of vision.

The Anticollagenase Effect of Serum in Alkali-burned Cornea in Rabbit

The possible role of collagenase in the development of corneal ulcers has been intensively studied and collagenase inhibitors have been successfully used to control some corneal ulcers. They are cysteine, EDTA, proteoglycan, serum, and medroxyprogesteron, However, most of them are limited in clinical use because of their toxicity and instability except serum, which is not toxic to the host. We carried out an experiment with serum upon alkali-burned rabbit cornea. Serum has potent anticollagenase effect, and prevents corneal ulceration.

A Case of Cerebrotendinous Xanthomatosis

Cerebrotendinous xanthomatosis(CTX) is a rare familial, autosomal disease which seems to be inherited as a Mendelian recessive. It was first described by van Bogaert et al, in 1937 and only about 30 cases have been reported in the literature. CTX is characterized by tendon xanthomas, bilateral juvenile cataracts, progressive dementia and cerebella ataxia. And deposition of cholestanol appears to be the primary lesion in this disease. We experienced a patient, 43-year-old man who sbowed bilateral cataracts, mold cerebellar dysfunction and multiple xanthomas, the tendinous xanthomatosis was confirmed pathologically and the brain CT scan abnormalities were correlated with neuropathologic findings of CTX. We performed extracapsular cataract extraction on both eyes with a significant improvement in corrected vision.

A Case of Cerebrotendinous Xanthomatosis

Cerebrotendinous xanthomatosis(CTX) is a rare familial, autosomal disease which seems to be inherited as a Mendelian recessive. It was first described by van Bogaert et al, in 1937 and only about 30 cases have been reported in the literature. CTX is characterized by tendon xanthomas, bilateral juvenile cataracts, progressive dementia and cerebella ataxia. And deposition of cholestanol appears to be the primary lesion in this disease. We experienced a patient, 43-year-old man who sbowed bilateral cataracts, mold cerebellar dysfunction and multiple xanthomas, the tendinous xanthomatosis was confirmed pathologically and the brain CT scan abnormalities were correlated with neuropathologic findings of CTX. We performed extracapsular cataract extraction on both eyes with a significant improvement in corrected vision.

Five Cases of Hereditary Congenital Cataracts in One Family

The congenital cataract is the relatively common cause of the blindness in childhood, and its etiology is multiple but most of etiology is unknown. The inheritance is the largest single category of cause of congenital cataract. The modes of the inheritance are autosomal dominant, autosomal recessive and X-linked. The autosomal dominant inheritance is the most common type. We experienced hereditary congenital cataract, which transmitted with autosomal dominant inheritance. So we reported this patients with review of literatures.

A Case of Osseous Choristoma Involving Both Eyes

The authors experienced the bilateral osseous choristoma in 19 year-old female. Osseous choristoma is rare isolated bony nodule occurring in the conjunctival or episcleral connective tissues in eyes which are otherwise normal. They are present at birth and frequently have a history of increasing in size. There are no known associations with disorders of metabolism of with systemic osteogenic abnormalities.

A Seasonal Variation of Central Serous Chorioretinopathy

Central serous chorioretinopathy was defined as an isolated serous elevation of macular retina unassociated with subretinal blood, optic nerve head pathology, or evidence of other retinochoroidal or systemic disease. A review of 259 consecutive cases of patients under the age of 40 years with central serous chorioretinopathy seen between 1976 and 1985 was performed in order to define temporal patterns of occurrence. Although an increased number of cases were seen in June and July, a statistical trend analysis failed to confirm a defini te seasonal variation(p>0.1).

Surgical Effect of Transposition for Double Elevation Paralysis

The authors have experienced a case of double elevation paralysis with mild degree of hypophoria and exophoria in 10 year-old primary school girl. This case is congenital in origin. Transposition of the insertion of medial and lateral rectus muscle placing the new inserti ons immediately adjacent to the insertion of the superior rectus muscle was performed. After the operation, the subjective symptoms such as diplopia, dizziness, headache were improved even though this does not produce normal elevation beyond the midline level. Double elevation paralysis is caused often by unilateral supranuclear lesion than peripheral congenital lesion.

Clinical Study for Pupillary Membrane

Persistent remnants of the pupillary membrane are extremely common, but well-formed membrane which was covering almost entire pupil is very rare. We experienced one case a 15 year-old boy who had extensive dense persistent pupillary membrane with visual disturbance in left eye and optical iridectomy was performed with improvement of vision.

Two Cases of Marfan's Syndrome

The Marfan's syndrome is a collagenous hereditary disorder affected by the long bone, heart and eyes. Two cases of Marfan's syndrome are presented. Both two cases showed upward dislocation of lenses. We performed extraction of lenses on 4 eyes among the two cases by means of Cryo-extractor. The results of surgical treatment are described.

Clinical Study of Midline Surgery

The authors performed midline operation upon esotropia with abducens nerve paralysis and diplopia for 6 months following head trauma. Eye ball was straight without diplopia, but there was no improvement of lateral gaze in the paralytic eye.