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Biomedical subjects

B Seitz

Publications and source records attributed to B Seitz.

At least 127 records · Page 7Linked to original sources
PubMed1997

Multiplex sequencing of 1.5 Mb of the Mycobacterium leprae genome.

The nucleotide sequence of 1.5 Mb of genomic DNA from Mycobacterium leprae was determined using computer-assisted multiplex sequencing technology. This brings the 2.8-Mb M. leprae genome sequence to approximately 66% completion. The sequences, derived from 43 recombinant cosmids, contain 1046 putative protein-coding genes, 44 repetitive regions, 3 tRNAs, and 15 tRNAs. The gene density of one per 1.4 kb is slightly lower than that of Mycoplasma (1.2 kb). Of the protein coding genes, 44% have significant matches to genes with well-defined functions. Comparison of 1157 M. leprae and 1564 Mycobacterium tuberculosis proteins shows a complex mosaic of homologous genomic blocks with up to 22 adjacent proteins in conserved map order. Matches to known enzymatic, antigenic, membrane, cell wall, cell division, multidrug resistance, and virulence proteins suggest therapeutic and vaccine targets. Unusual features of the M. leprae genome include large polyketide synthase (pks) operons, inteins, and highly fragmented pseudogenes.

Amino Acid Sequence↗
PubMed1997

Can zinc prevent apoptosis of anterior keratocytes after superficial keratectomy?

OBJECTIVE: To determine whether zinc, which blocks apoptosis in many systems, including in leukemic cells and possibly in retinal dystrophies, can prevent the unwanted loss of anterior stromal keratocytes after superficial keratectomy. METHODS: After mechanical central corneal epithelial debridement, the left eyes of nine New Zealand white rabbits were treated with 25 mM zinc chloride (ZnCl2) in Earle's salts minimal essential medium (MEM) either every 30 min (n = 3), every 2 h (n = 3), or every 4 h (n = 3). The left eyes of nine additional animals, divided into three equal groups, were deepithelialized, and each received pure culture medium at one of the same three frequencies. One eye of each of another six rabbits was deepithelialized but received no drops. After 24 h, all 24 animals were sacrificed and the globes were enucleated. The corneas were processed and sections were stained with hematoxylin and eosin. RESULTS: The cell count of MEM-treated corneas exceeded that of untreated corneas (p = 0.03, analysis of variance [ANOVA]), but there was no difference among eyes that received the different frequencies of MEM application (p = 0.36, ANOVA). Cell counts increased with frequency of zinc application, but the differences were not statistically significant (p = 0.09, ANOVA). Only in the group receiving the most frequent zinc applications were superficial keratocytes retained. This group also possessed a greater number of stromal keratocytes than untreated controls and MEM-treated corneas (p = 0.01). CONCLUSIONS: At a significantly high dosage, zinc can prevent loss of superficial keratocytes to a greater extent than culture medium alone can. Moreover, zinc has the advantage of preserving the most anterior layer of keratocytes. Retention of these cells may prevent the reactive overproliferation that constitutes haze after photorefractive surgery.

Administration, Topical↗
PubMed1996

Corneal sensitivity and burning sensation. Comparing topical ketorolac and diclofenac.

OBJECTIVES: To compare the effect of topical 0.5% ketorolac tromethamine and 0.1% diclofenac sodium on human corneal sensitivity and to assess the intensity of burning sensation at specific intervals after drop instillation. DESIGN AND SETTING: Double-masked parallel clinical study. PATIENTS: Eleven women and 4 men (8 white, 4 Hispanic, 3 Asian), 22 to 60 years of age (mean [ +/- SD], 34 +/- 10 years). INTERVENTIONS: Repeated instillation of either ketorolac and placebo or diclofenac and placebo at 5-minute intervals. MAIN OUTCOME MEASURES: Assessment of corneal sensitivity before instillation, immediately after instillation, and after termination of drop application; and subjective evaluation of burning sensation by asking participants to rate burning on a scale ranging from 0 (none) to 3 (severe) after each drop application. RESULTS: Both diclofenac (P < .01) and ketorolac (P < .01) decreased corneal sensitivity significantly, while the placebo had no measurable effect. After administration of additional drops over time, the effect of diclofenac and ketorolac increased. After termination of the drug instillation, corneal sensitivity returned to baseline significantly slower (P < .01) in participants receiving diclofenac than in those receiving ketorolac. Ketorolac (P = .01) and diclofenac (P < .05) were significantly more effective in whites than in nonwhites. Mean burning sensation was mild, and there was no statistically significant difference between the 2 drugs on this measure (P = .12). CONCLUSIONS: The decrease in corneal sensitivity in normal human corneas is more pronounced and longer lasting with diclofenac than with ketorolac. Both drugs are well tolerated topically and may be useful for pain reduction after refractive corneal surgery.

Administration, Topical↗
PubMed1996

Effect of diclofenac, ketorolac, and fluorometholone on arachidonic acid metabolites following excimer laser corneal surgery.

OBJECTIVE: To compare the ability of several topical anti-inflammatory agents to modulate the production of prostaglandin E2 after excimer laser ablation in rabbit cornea. METHODS: Adult New Zealand white rabbits were subjected to phototherapeutic keratectomy with a commercially available excimer laser. Prostaglandin E2 and leukotriene B4 were detected by enzyme-linked immunoassay, and leukocyte infiltration was determined histologically. RESULTS: Prostaglandin E2 and leukocyte infiltration increased in the cornea after excimer ablation. Treatment with topical fluorometholone and diclofenac sodium significantly reduced prostaglandin E2 levels. Corneas treated with diclofenac had significantly higher levels of leukocyte infiltration than those treated with ketorolac tromethamine. No changes in leukotriene B4 levels were detected in this model. CONCLUSIONS: As a group, topical anti-inflammatory medications tend to lower prostaglandin E2 levels in rabbit corneas subjected to excimer ablation, but differ in their ability to reduce polymorphonuclear leukocyte infiltration. Further work is needed in this model to understand how these drugs alter leukocyte infiltration of the remaining stromal bed.

Administration, Topical↗
PubMed1996

Thermal effects in excimer laser trephination of the cornea.

BACKGROUND: Excimer laser trephination, as an alternative to mechanical trephination of the cornea in penetrating keratoplasty, is expected to reduce long-term postkeratoplasty astigmatism. Trephination with high energy densities may induce thermal epithelial alterations when metal aperture masks are used. METHODS: Ninety porcine eyes fixed in an artificial anterior chamber (20 mmHg) were trephined with a 193-nm excimer laser in order to study the effect of the temperature on the cornea and the aperture mask during and after termination of the laser exposure. Energy levels tested were in the range used in patients. A pyroelectric infrared sensor connected to a PC via an analog-digital converter was used. With a high-speed sampling routine written in C+2 it was possible to monitor on line the temperature in a focus 0.8 mm in diameter. RESULTS: In donor trephination the maximum temperature increase of the metal mask was 11 K (donor tissue 6.1 K, repetition rate 30/s). During recipient trephination the maximum temperature increase of the mask was 9.4 K (7.5 K on the cornea). An increase in the repetition rate and a decrease in the rotation speed resulted in greater temperature increase of the exposed cornea or metal mask. CONCLUSIONS: Online monitoring of cornea and mask surface temperatures during excimer laser trephination is possible using high-speed sampling equipment. Appropriate adjustment of repetition rate and rotation speed may reduce thermal effects, especially in donor trephination.

Animals↗
PubMed1996

[Juvenile open angle glaucoma with microcornea in oculo-dento-digital dysplasia (Meyer-Schwickerath-Weyers syndrome)].

HISTORY: An 8-year boy underwent bilateral repeat trabeculectomies with iridectomies at age 4 and 5 and cyclocryocoagulation of the right eye at age seven for glaucoma. FINDINGS: The first examination in our department revealed a visual acuity of OD light perception, OS 0.2. The right eye was exotropic and hypotropic. The intraocular pressure was 30 mm Hg in both eyes. The corneal diameters were OD 9.0 x 7.0 and OS 8.5 x 6.5 mm, while the axial length was OD 25.3 and OS 23.6 mm. Both eyes had slightly prominent filter blebs with uveal incarceration. The chamber angles were open in both eyes and partly covered with uveal tissue, the E/P ratio was OD 1.0, OS 0.9. Extraocular changes were: dysplastic teeth, dental enamel hypoplasia, thickened jaw, small nose with pronounced nose bridge. Both hands showed shortening of the metacarpals and of the IVth digits as compared to the IInd and IIIrd digits. Syndactylic digits IV and V had been surgically separated earlier. DIAGNOSIS: Our diagnosis was juvenile open-angle glaucoma in oculo-dento-digital dysplasia. THERAPY: After trabeculotomy and cyclocryocoagulation IOP remained around 10 mm Hg. CONCLUSIONS: Despite small corneal diameters, congenital glaucoma needs to be ruled out early in patients with oculo-dento-digital dysplasia. These patients should be treated in close cooperation with pediatric neurologists, orthopedic surgeons, dentists and otorhinolaryngologists.

Abnormalities, Multiple↗
PubMed1996

[Regularity of corneal topography after penetrating keratoplasty--comparison between non-mechanical (excimer laser 193 nm) and mechanical trepanation].

BACKGROUND: "Vertical tilt" of the graft caused by incongruent cut angles, "horizontal torsion" caused by a asymmetric suturing and decentration of the wound seem to be the most important reasons for high and/or irregular postoperative astigmatism and deterioration of visual outcome after penetrating keratoplasty. We studied the time course of qualitative and quantitative topographic criteria after nonmechanical and mechanical trephination in correlation with visual outcome. PATIENTS AND METHODS: Fifty patients each (30 keratconus, 20 Fuchs' dystrophies) underwent nonmechanical trephination (excimer laser MEL60, Aesculap-Meditec, Heroldsberg) and mechanical motor-trephination in penetrating keratoplasty. All procedures (7.5 mm trephination diameter in Fuchs, 8.0 mm in keratoconus, double-running 10-0 nylon suture) were done by one surgeon. Pre-, intra- and postoperative treatment were identical. At the follow-up examinations, the keratometric astigmatism, qualitative and quantitative criteria of the automatic videokeratography, visual acuity and refraction were assessed. In addition, vector-corrected astigmatism (Jaffe-model) was evaluated in the postoperative time course, particularly after suture removal. RESULTS: After a mean follow-up of 1.1 +/- 0.8 years, keratometric net astigmatism was 4.0 and 4.2 diopters after nonmechanical and mechanical trephination. Corneal topography analysis showed a higher orthogonality of the bowtie shape and less asymmetry between opposite hemimeridians. Vector-corrected changes of corneal astigmatism were less after complete suture removal in nonmechanical trephination. After nonmechanical trephination, visual acuity was 2 decimal lines better. DISCUSSION: Nonmechanical trephination with the excimer laser 193 nm has the potential to improve the visual outcome by creating smooth and congruent cut edges parallel to the optical axis and the application of "orientation teeth". Since corneal net astigmatism does not differ significantly, a higher regularity of corneal topography after excimer laser trephination is supposed to be a main reason for this finding.

Adolescent↗
PubMed1996

In vitro effects of aminoglycosides and fluoroquinolones on keratocytes.

PURPOSE: Commonly used fluoroquinolones are reported to have less of an effect than aminoglycosides on corneal epithelial cells. The purpose of this study was to assess the effects of these antibiotics on stromal keratocytes in vitro. METHODS: Cultured rabbit keratocytes were incubated with various concentrations of gentamicin, tobramycin, ofloxacin, norfloxacin, and ciprofloxacin. Evaluations were performed by means of phase-contrast microscopy and [3H]thymidine uptake assay after 24 hours and 48 hours of incubation with the drug (concentrations from 3 to 0.003 mg/ml). RESULTS: At a concentration of 3 mg/ml, all three fluoroquinolones inhibited keratocyte proliferation significantly more than either aminoglycoside after 24 hours (P<0.001) and after 48 hours (P<0.001). In contrast to the aminoglycosides, all three fluoroquinolones induced a dose- dependent inhibition of proliferation after 24 hours. Even at the lowest concentration (0.003 mg/ml), ofloxacin and norfloxacin inhibited keratocyte proliferation significantly (P=0.001) compared to control after 24 hours. Concentrations of fluoroquinolones ranging from 0.09 to 0.24 mg/ml produced a 50% inhibition of proliferation, a level of inhibition not observed with any tested concentration of aminoglycosides. After 24 hours, all three fluoroquinolones, but neither of the aminoglycosides, showed moderate to severe signs of cytotoxicity at a concentration of 3 mg/ml. CONCLUSIONS: Relative effects of fluoroquinolones and aminoglycosides on epithelial cells and stromal keratocytes appear to be different. This might have an impact on choosing the optimal antibiotic drug to be applied prophylactically in clinical situations in which the epithelium is absent, such as after photorefractive keratectomy or chemical burn.

Aminoglycosides↗
PubMed1996

Morphological response to UV-B irradiation after excimer-laser photorefractive keratectomy.

The purpose of this study was to evaluate the morphological effects of UV-B exposure on the outcome of photorefractive keratectomy (PRK). A total of 42 pigmented rabbits were used in the study. In all, 1 eye of 12 rabbits received a 193-nm and 45-micron-deep (-5.0-D) excimer-laser PRK, 1 eye of 12 rabbits received a 135-micron-deep (-15.0-D) excimer-laser PRK and 1 eye of 12 rabbits received a 270-micron-deep (-30.0-D) excimer-laser PRK. At 21 days after PRK, six of the laser-treated eyes from each group were exposed to 100 mJ/cm2 UV-B (280-320 nm) light by placement of the rabbits in a standard clinically used "dermatological chamber" for 7 min. One eye of six rabbits received only UV-B light, serving as a control. The other six rabbits from the PRK groups received no further treatment. Subepithelial "haze" was evaluated before and after UV irradiation. Corneal morphology was assessed at 4, 8 and 12 weeks after UV-B exposure by light microscope and transmission electron microscope techniques (TEM). Eyes exposed to 100 mJ/cm2 UV-B light exhibited only keratitis for 2 days but showed no haze and were histologically normal at all time points. The PRK-treated, UV-B-irradiated rabbit eyes exhibited a significant increase in stromal haze as compared with the eyes receiving PRK alone; this phenomenon correlated with the depth of photoablation. Histologically, the main difference observed between the UV-B-irradiated and nonirradiated post-PRK eyes was the presence of anterior stromal extracellular vacuolization in the UV-B-exposed eyes. The vacuolated foci were confined to the PRK treatment area, contained increased numbers of keratocytes and showed a disorganization of normal collagen lamellae. TEM revealed activated keratocytes containing abundant rough endoplasmic reticulum, prominent Golgi zones and extracellular vacuoles filled with amorphous material. The haze and morphological changes showed a tendency towards incomplete resolution over a period of 12 weeks. UV-B exposure during post-PRK stromal healing exacerbates and prolongs clinical symptoms and the stromal healing response in rabbits, which is manifested biomicroscopically by augmentation of subepithelial haze. The findings suggest that excessive ocular UV-B exposure should be avoided during the period of post-PRK stromal repair (at least 3 months) and that UV-B light may modulate the response of tissues to 193-nm excimer and, perhaps, other laser energy in general.

Animals↗
PubMed1995

[Endothelial keratopathy in pseudoexfoliation syndrome: quantitative and qualitative morphometry using automated video image analysis].

UNLABELLED: This prospective study intended to quantify and classify morphological changes of the corneal endothelium in pseudoexfoliation syndrome (PSX) after having tested reproducibility and validity of a new automated technique for analysing corneal endothelium. PATIENTS AND METHODS: We used a contact specular microscope combined with a video camera (Tomey EM-1000) and a computer (IBM compatible PC, 486DX33) with suitable software (Tomey EM-1100, version 0.94). Video images of corneal endothelium (area: 0.312 mm2) are passed directly into the computer input by means of a frame grabber and are automatically processed. Missing or falsely recognized cell borders are corrected using the mouse. We examined 85 eyes with PSX and 33 healthy control eyes. At first, retest-stability and validity of the cell density measurements were assessed in the PSX-eyes. A qualitative analysis of the corneal endothelium followed. RESULTS: The cell density measurements showed a high retest-stability (reliability coefficient r = 0.974). The values of the automated method (2040 +/- 285 cells/mm2) and those of manual cell counting (2041 +/- 275 cells/mm2) did not differ significantly (p = 0.441). The mean difference was 3.1 +/- 2.4%. Comparing the 85 PSX-eyes (2052 +/- 264 cells/mm2) to the 33 control eyes (2372 +/- 276 cells/mm2), there was a significant reduction of cell density (p < 0.001). The cell density of the 69 PSX-eyes with glaucoma (2014 +/- 254 cells/mm2) was significantly lower than that of the 16 PSX-eyes without glaucoma (2214 +/- 251 cells/mm2) (p = 0.008). Eighty-five percent of the 85 PSX-eyes showed polymegalism, 77% pleomorphism; 68% had white deposits and 42% guttae. White deposits and guttae were significantly more frequent and more intensive in PSX-eyes than in control eyes. PSX-eyes with and those without glaucoma showed no significant differences concerning the four qualitative parameters. CONCLUSION: The automated method for analysing corneal endothelium quickly provides reproducible and valid results using the correction mode of the software. Semiquantitative analysis of qualitative parameters permits a more differentiated assessment of keratopathy in pseudoexfoliation syndrome than does mere consideration of endothelial cell density. Both evaluations are recommended to assess the risk of a diffuse endothelial decompensation before intraocular surgery.

Aged↗
PubMed1995

[Differential diagnosis and prognosis of 112 excised epibulbar epithelial tumors].

BACKGROUND: Epithelial tumors of the epibulbar conjunctiva are rare in northern Europe. There are no reliable clinical criteria to predict the histological nature of the lesion. Even histologically proven malignant tumors typically do not show ocular invasion or metastasis. PATIENTS AND METHODS: From 1980 to 1993, 112 epithelial epibulbar tumors were classified in our ophthalmopathological laboratory. Surgical management of 50 papillomas (mean age 46 +/- 18 years, 58% males), 49 conjunctival/corneal intraepithelial neoplasias (CIN) (28 mild, 21 severe) and 12 squamous cell carcinomas (mean age 63 +/- 13 years, 69% males) included excisional biopsy (61%), with additional lamellar keratectomy (14%), epithelial abrasion (10%), cauterisation (3%), cryotherapy (2%), excimer laser ablation (2%). Other management regimes were lamellar keratoplasty (2%), penetrating keratoplasty (2%), epithelial abrasion (2%). One eye with intraocular invasion of a mucoepidermoid carcinoma was enucleated. RESULTS: Fifty five per cent of the papillomas were located at the caruncle or semilunar fold. Seventy eight percent of the papillomas had a pedunculated appearance. Two lesions involved the epibulbar conjunctiva as well as the opposite tarsal conjunctiva ("kissing papilloma"). Eighty eight percent of CIN/carcinoma were located at the limbus. The clinical differential diagnoses of CIN/carcinoma were squamous cell carcinoma (26%), papilloma (18%), leukoplakia (10%), pinguecula/pterygium (10%), dysplasia (8%), malignant melanoma (5%), trachoma (3%), chronic keratoconjunctivitis with corneal pannus (2%), "granuloma" (2%), non-pigmented naevus (2%). After a mean follow-up of 6.3 +/- 3.5 years, 13% of the papillomas showed a local recurrence. After a mean follow-up of 4.8 +/- 3.7 years, there were 30% local recurrences of CIN/carcinoma (50% each in severe CIN and carcinoma, 9% in mild CIN). But there was no recurrence of CIN/carcinoma in patients who had received a complete tumor resection initially. If the surgical margins were involved, there was a 64% recurrence rate (80% each in severe CIN and carcinoma). Thirteen per cent of the patients with CIN/carcinoma showed an additional malignant tumor elsewhere in the body. CONCLUSIONS: Local recurrences after excision of CIN/carcinoma did occur only if the surgical margins where involved, and most often within the first year following surgery. Dedifferentiation of epithelial tumors in recurrences was not observed. The diagnosis of CIN/carcinoma of the conjunctiva requires the exclusion of an additional extraocular neoplasia. Histopathological classification and assessment of resection margins of epibulbar tumors is indispensable, especially in view of the more aggressive treatment necessary in mucoepidermoid carcinomas.

Adult↗
PubMed1995

[Mucoepidermoid carcinoma of the epibulbar connective tissue with diffuse intraocular epithelial invasion].

PATIENT: A 55-year-old man was treated twice with local excision and crycoagulation for a recurrent limbal mass of the left eye. The original histologic diagnosis was squamous cell carcinoma. Three months after the last recurrence the globe was enucleated because of a spontaneous perforation at the corneoscleral limbus with iris prolapse. Histologic examination, including PAS and mucicarmine stains, revealed a mucoepidermoid carcinoma of the epibulbar conjunctiva with infiltration of the cornea, sclera, iris and ciliary body. CONCLUSIONS: Examination of specially stained sections (e.g. with mucicarmine) should be routinely performed for those conjuctival neoplasms that contain a squamous component. Aggressive surgical management, such as early enucleation including normal appearing tissue next to the globe, should be considered for treatment of primary mucoepidermoid carcinoma to avoid later exenteration or metastasis.

Carcinoma, Mucoepidermoid↗
PubMed1995

[Solitary retinal astrocytoma with "acoustic shadowing"].

PATIENT: A polycyclic lesion slightly prominent and yellowish in colour with a mulberry-like surface was incidentally detected in the left eye of a 69-year-old white female. It was located in the nasal horizontal sector of the fundus in a distance of about 5.5 mm from the optic disk. It was surrounded by a bright halo. Retinal arterioles penetrated the lesion superficially and more deeply. The vitreous body was unremarkable. Visual acuity was 0.8 to 1.0 p with a hyperopia of 3.5 dpt. Intraocular pressure was 116 mm Hg. In both eyes partially confluent drusen of the retinal pigment epithelium were present without a serous detachment of the retina. Ultrasound examination revealed an ovally shaped, 1.3-mm prominent solid tumor consisting of highly reflective granular internal echoes with acoustic shadowing behind. X-ray of the skull showed punctate calcifications in the medial orbit. The brain was unremarkable (incl. MRI). In fluorescein angiography the whole tumor was diffusely stained without signs of leakage or subretinal neovascularization. On red-free wide-angle photographs of the retinal nerve fiber layer no localized defects were detected. Neurological and dermatological examination were unremarkable without any hints for tuberous sclerosis or neurofibromatosis. All these findings led to the diagnosis of a solitary retinal astrocytoma. With no therapy performed, the functional and morphological status of the eye remained unchanged one year later. CONCLUSION: A retinal astrocytoma is a hamartoma that usually shows no tendency to grow and there is no need for treatment. It can rarely be the reason of a serous retinal detachment or vitreous hemorrhage. Especially solitary astrocytomas have sometimes been reported to show a tendency towards severe intraocular damage. Additional calcifications showing acoustic shadowing in ultrasound examination are important for the differential diagnosis of retinoblastoma.

Aged↗
PubMed1994

[Chronic unilateral keratoconjunctivitis in molluscum contagiosum of the upper eyelid margin].

PATIENT AND METHODS: Over a period of one year a 33-year-old married housewife, mother of two healthy children, complained of an initially recurrent, in the last 6 months persisting conjunctivitis, upper and lower lid edema, dacryorrhea and photophobia concerning the left eye. Neither topical derivates of cromoglycin acid, antibiotics nor steroids brought relief. Half a year ago the patient had noticed a "little nodule" of the lateral upper eyelid without tendency to grow. The visual acuity was 0.8 due to a punctate superficial keratopathy. In addition a marked follicular conjunctivitis was present. Our examination revealed a little whitish-rosy tumor with elevated edges and a central crater at the lateral margin of the upper lid. The right eye was completely normal. The tumor was totally excised preserving the lid margin. Our histopathological diagnosis was "molluscum contagiosum". Four weeks after surgery the keratoconjunctivitis had subsided without further medication. CONCLUSION: In persisting unilateral conjunctivitis without amelioration after any topical therapy the eyelids should be checked carefully for a tumor to be excised. In older patients a sebaceous gland carcinoma must be ruled out. Considering the patient's personal history a chlamydial infection should be kept in mind as a differential diagnosis.

Adult↗
PubMed1993

[193 excimer laser trepanation in perforating keratoplasty. Report of 70 patients].

BACKGROUND: In penetrating keratoplasty, trephination with the 193 nm excimer laser may help avoid the differences in the deformation of the donor and recipient wound margins which occur with the conventional procedure. By varying the shape of the "open metal mask", other cut configurations can be achieved besides circular. Thus, "vertical tilt" and "horizontal torsion", both potential reasons for persistent long-term astigmatism after PK, may be minimized. Following experimental studies, the authors present the results obtained in their first 70 consecutive patients. PATIENTS AND METHODS: 38 women and 32 men were treated (mean age 60.6 years, range 17 to 89 years). Indications were corneal processes without vascularization: Fuchs' dystrophy (n = 32), other stromal dystrophies (n = 5), secondary corneal endothelial decompensation (n = 6), keratoconus (n = 15), nonvascularized corneal scars (n = 4) and miscellaneous (n = 8 ). We used elliptical metal masks with/without orientation teeth and circular masks with four and eight orientation teeth, respectively. The HeNe aiming beam was manually controlled by a micromanipulator ("joystick"). The technical data of the laser were as follows: spot mode, 1.5 x 1.5 mm; repetition rate 30/sec and 25/sec, respectively; pulse energy 15-25 mJ; mean number of pulses 6407 (recipient) and 9150 (donor). With an elliptical outline, wound closure was usually achieved with single sutures. With a circular outline with orientation teeth, wound closure was most commonly achieved with a double running suture. Patients were prospectively documented using modified Erlangen record sheets. Follow-up ranged from 3 months to 3.4 years (mean 11.4 months). RESULTS: With two exceptions, penetration of the anterior chamber with the 193 nm excimer laser was accomplished without deformation of the cut edges. The elliptical outline facilitated fitting of the graft into the recipient wound bed, and the orientation teeth made fitting even easier. Initial intraoperative complications due to excessive laser energy densities included minor thermally induced corneal alterations caused by the heat of the metal mask and in a few cases minimal iris bleeding during corneal penetration. The median duration of re-epithelialization was two days. Wound healing was without complications. In particular, no primary graft insufficiency and no unexpected effects in donor or recipient corneas, iris, lens or posterior segments were observed. Postoperative complications were one corneal ulcer caused by premature fitting of an extended-wear contact lens and two immunologic graft reactions (3%). Mean astigmatism after suture removal was 4.6 D with an elliptical outline, and 3.9 D after trephination with orientation teeth and with the sutures in situ. CONCLUSION: Non-mechanical, "non-thermal" trephination with elliptical and circular metal masks with orientation teeth represents a viable alternative to knife trephination in penetrating keratoplasty. No unexpected complications such as disturbances of wound healing were seen. Further studies are needed to determine the effect on residual long-term astigmatism after suture removal.

Adolescent↗
PubMed1993

[Unilateral type III (Hida) lattice stromal corneal dystrophy].

BACKGROUND: All three types of lattice stromal dystrophy of the cornea use to appear bilaterally. We report on two patients with an unilateral manifestation of type III. PATIENTS: A 54 and a 87-years-old man presented a strictly unilateral atypical lattice dystrophy of the cornea and suffered from corneal erosion. Strikingly thickened lattice lines were predominantly orientated radially, almost reached to the corneoscleral limbus and were located in the anterior and midstroma. Both patients had no affected family members and there was no indication on general amyloidosis. RESULTS: After successful penetrating keratoplasty histological examination showed remarkably large amyloid deposits predominantly located close to Bowman's layer or in the midstroma and a discontinuous band of amorphous material beneath the intact Bowman's layer. Electron microscopy disclosed that the deposits were composed of typical amyloid fibrils. Four years later the younger of the two patients developed a corneal opacification being suggestive of early stage of lattice dystrophy in the other eye. CONCLUSIONS: Lattice corneal dystrophy type III, as described by Hida et al. in 1987, is easily diagnosed at the slit lamp. It may manifest itself unilaterally. In contrast to Meretoja's syndrome, there is no systemic involvement.

Aged↗
PubMed1993

[Medial canthus pilomatrixoma in an 80-year-old patient].

An 80-year-old lady noticed a painless "swelling" in the medial canthal region 3 months. The tumor showed a reddish color due to a recurrent superficial bleeding for 2 weeks. Clinically the tumor was supposed to be a super-infected keratoacanthoma. The differential diagnosis included an ulcerative basal cell carcinoma. Excisional biopsy and reconstruction using a free graft from the ipsilateral upper lid were performed. Histopathologically the lesion proved to be a "benign calcifying epithelioma Malherbe" (pilomatrixoma). Today, 8 years after surgery, there was no recurrence of the tumor. A circumscribed, subepidermal, movable reddish or livid tumor of the upper lid, eye brow or of the canthal region should be suggestive of pilomatrixoma, not only in young females.

Aged↗