PubMed Health⌕ Search

Biomedical subjects

W Sekundo

Publications and source records attributed to W Sekundo.

31 records · Page 2Linked to original sources
PubMed1996

Effects of allopurinol and steroids on inflammation and oxidative tissue damage in experimental lens induced uveitis: a biochemical and morphological study.

AIMS: To evaluate the effects of allopurinol in lens induced uveitis (LIU) by morphological methods and to compare these effects with those of steroids and a combination of both drugs biochemically and morphologically. METHODS: Lipid peroxides (LPO) of the retinal tissue were determined by two different methods (thiobarbituric acid assay (TBA) and high performance liquid chromatography expressed as malondialdehyde-like substances). Myeloperoxidase (MPO) activity in the iris/ciliary body complex was analysed spectrophotometrically. Histological changes on three morphological levels of LIU eyes were evaluated. RESULTS: Both allopurinol and the combination of allopurinol/prednisolone led to a significant reduction in the increaed retinal LPO values. Prednisolone only revealed significant effects on retinal LPO when being measured with the TBA method. MPO activity in iris and ciliary body was significantly reduced in all therapy groups. The morphological evaluation of the sections by two masked investigators revealed a significant reduction (p < 0.05) in the inflammation score in all therapy groups. Morphometric studies using the QUANTIMED system (Leica, Cambridge) showed significantly reduced values (p < 0.05) in the allopurinol group and in the group receiving prednisolone and allopurinol. Prednisolone alone did not lead to a significant reduction in the values. CONCLUSIONS: The findings show that both allopurinol and steroids exert positive effects on the variables determined in LIU. The effects of steroids are believed to be mostly due to their direct action on inflammatory cells. The recently reported scavenging effects of methylprednisolone should play a minor role in this disease model. Allopurinol and oxypurinol act as direct scavengers of free radicals and hypochlorous acid, which is produced via MPO catalysis, thus leading to a reduction in tissue inflammation and tissue damage.

Allopurinol↗
PubMed1996

Monoclonal corneal gammopathy: topographic considerations.

Desposition of immunoglobulins in the cornea occasionally occurs in benign and malignant lymphoproliferative conditions. A 52-year-old woman with recently discovered monoclonal gammopathy of undetermined significance (MGUS) was referred to our hospital. Slit-lamp and ultrasound biomicroscopy revealed bilateral deposits within all corneal layers. The precipitates were organized in a circle, leaving a perilimbal zone and the axial cornea clear. Light microscopy of a biopsy disclosed confluent subepithelial deposits and defects in Bowman's layer. Immunoperoxidase reaction was positive only for IgG and IgG-kappa. Transmission electron microscopy confirmed the presence of extracellular rectangular and arcuate immunoglobulin crystalloids with a 10-nm periodicity but a non-crystalline defraction pattern. A review of the literature showed that the circumferential pattern of immunoglobulin deposition is associated with short-term visual symptoms and good visual acuity. The present report supports a hypothesis of immunoglobulin deposition via the limbal arcade and contradicts the "tear theory."

Biopsy↗
PubMed1995

[Traumatic wound dehiscence and corneal rupture 3 1/2 years after radial keratotomy].

BACKGROUND: Severe complications such as a traumatic wound dehiscence have been described very rarely after radial keratotomy. The following case demonstrates for the first time that wound healing is not completed even 31/2 years postoperatively and that therefore an ocular blunt trauma may still cause a dehiscence of the radial incisions. CASE REPORT: A 22-year-old patient presented in July 1993 to our emergency unit because of a corneal perforation in his right eye after a blunt trauma. His past medical history was significant for radial keratotomy surgery performed in January 1990 to correct a bilateral low-degree myopia (OD = -3.25 D; OS = -3.75 D). At surgery a horizontal rupture running through the entire cornea and including the two radial keratotomies at the 3 and 9 o'clock position was evident. The whole iris and lens were missing. The retina was completely detached. The corneal laceration was sutured. Twelve days later the retina was reattached with an encircling band, vitrectomy, endolaser and cryocoagulation, as well as silicone oil fill. Finally, a penetrating keratoplasty was performed 6 months after the accident. Thereafter, visual acuity improved to 0.1. The histologic examination of the corneal button showed that the wound healing of the incisions that had remained intact was not completed yet. Epithelial plugs of various size were still filling the somewhat dehiscent wound margins. Fibroblastic activity was detected in the surrounding stroma. CONCLUSION: Even several years after surgery, blunt traumas represent a definite risk for eyes undergoing radial keratotomy.

Adult↗
PubMed1994

Immuno-electron labelling of matrix components in congenital hereditary endothelial dystrophy.

Two corneal buttons were obtained from a patient with congenital hereditary endothelial dystrophy (CHED) at the ages of 2.5 years (right eye) and 14 years (left eye) and were studied by light and electron microscopy including immunogold labelling for collagen types I-V and laminin. The posterior collagenous layer (PCL) of Descemet's membrane contained collagen types I, III-V, and laminin: the latter was also localised to fine-banded and granular material in the posterior non-banded zone (PNBZ). Comparison of the endothelium 2.5 years and 14 years revealed occasional dystrophic changes in the former and extensive dystrophic changes in the latter. The distribution of collagen types I, III and V within the PCL supports previous morphological observations of fibroblast-like change of the endothelium in CHED. Persisting endothelial properties were manifest as positive labelling of type IV collagen and laminin. An excessive amount of laminin found in PNBZ and PCL is another stress-related endothelial reaction.

Adolescent↗
PubMed1994

An ultrastructural investigation of an early manifestation of the posterior polymorphous dystrophy of the cornea.

BACKGROUND: Posterior polymorphous dystrophy of the cornea is an uncommon, but well-recognized, congenital disease affecting Descemet's membrane and endothelium. Visual impairment usually is minimal and slowly progressive. Edema develops in a small number of patients, necessitating a corneal graft in middle age. An early manifestation of posterior polymorphous dystrophy with corneal edema present at birth or soon thereafter is extremely rare; only a few ultrastructural reports are available. METHODS: The corneal button of a 5-month-old baby with posterior polymorphous dystrophy was examined by conventional light and electron microscopy. FINDINGS: The anterior banded zone of Descemet's membrane was thinned (2 microns) in the axial part of the cornea, contained defects in the paraxial part, and was absent at the periphery. Where present, the anterior banded zone was lined posteriorly by a fibrocellular layer (containing fibroblast-like spindle cells and striated collagen fibrils) and a fibrillar layer forming an abnormal posterior collagenous layer. This layer was lined posteriorly by degenerate overlapping endothelial cells, which also were in apposition to the stroma in regions with an absent anterior banded zone. The defects in Descemet's membrane were used by the abnormal keratocytes to migrate between the anterior banded zone and the posterior collagenous layer. At the periphery, a multilayer of spindle cells was present behind the stroma. CONCLUSIONS: Failure to produce a continuous anterior banded zone indicates an onset of the disease before the twelfth week of gestation. It appears that, in posterior polymorphous dystrophy, there is a mosaic of better preserved and dystrophic endothelial cells and that the presence or absence of the normal components of Descemet's membrane is determined by the proportion of dystrophic cells in the endothelial cell population.

Consanguinity↗
PubMed1994

Bilateral uveal melanoma presenting simultaneously.

A case of bilateral uveal melanoma in a 54-year-old man is described. On admission of the patient for a choroidal melanoma of the left eye, an asymptomatic ciliary-body tumour was detected in his right eye. A thorough general examination did not reveal any metastases. The left eye was enucleated and local excision of the tumour in the right eye was performed 2 months later. Histology confirmed the presence of malignant melanomas in both eyes. The tumours were of similar A/B spindle-cell type. The patient remained healthy, showing no sign of metastasis or local recurrence of melanoma 9 months after the date of diagnosis. The visual acuity in his remaining eye remained 6/6. Immunological assessment of the blood serum revealed abnormally high interleukin 1 beta (IL-1 beta) and IL-2 levels. Possible implications of these findings are discussed.

Choroid Neoplasms↗
PubMed1994

Multirecurrence of corneal posterior polymorphous dystrophy. An ultrastructural study.

Posterior polymorphous corneal dystrophy (PPD) is a rare bilateral, autosomal-dominant disease. The presence of the epitheliumlike endothelium and the thickening of Descemet's membrane by the posterior collagenous layer (PCL) has been reported in the majority of published cases. Reepithelialization of the posterior cornea in donor tissue has been reported only once. Therefore, to examine this process we examined, by light and electron microscopy, three corneal buttons (an original and two subsequent keratoplasties after 3 and 4 years, respectively) from the left eye of a patient with bilateral disease. Our study showed a repopulation of the posterior surface of the donor corneas by the host epitheliumlike endothelium, which was of identical morphology in each case. In contrast to the previously published work, a posterior collagenous layer in the failed grafts was absent from the axial cornea, where the epitheliumlike endothelium was in direct contact with donor Descemet's membrane. A PCL at the periphery in the failed transplants was of the fibrocellular type and differed from the fibrillar PCL in the first keratoplasty specimen. The fibroblastlike cells within the fibrocellular PCL were distinct from the underlying epithelial-like cells and contained numerous tertiary phagolysosomes. We suggest that the major contributor to the fibrocellular PCL in the repeat keratoplasties was a fibrous ingrowth from the host/graft junction and not the epitheliumlike endothelium. It appears that the synthetic capacity of the epitheliumlike endothelium was similar to that of the normal epithelium and was much lower than that of normal native endothelium.

Corneal Dystrophies, Hereditary↗
PubMedDate not supplied

Differences in the composition of inflammatory cell infiltrate in lens-induced uveitis under therapy with allopurinol or steroids.

PURPOSE: The aim of this study was to compare the qualitative changes in the composition of inflammatory cell infiltrate in lens-induced uveitis (LIU) under treatment with allopurinol (Allo), methylprednisolone (Pred) or the two drugs combined (Allo/Pred). METHODS: Twenty male Wistar rats were sensitized with lens proteins for eight weeks. Intravenous (IV) therapy was started after anterior capsule disruption in one eye of each animal. Five rats were randomly assigned to each of the four groups: controls, Allo (50 mg/kg bw), Pred (7.5 mg/kg bw) and Allo/Pred (50 mg/7.5 mg per kg bw). Eyes were enucleated 24 hours later and fixed in paraformaldehyde/glutaraldehyde. Sections at three levels were stained with Giemsa and examined using a 0 to 4+ score for each type of inflammatory cell. Granulocytes were seen as neutrophils and eosinophils. Neutrophils were divided into polymorphs and "others", and graded with lymphocytes. RESULTS: In all therapy groups there was a significant reduction of polymorphs (p<0.05) in comparison to the control group. There was also a significant reduction in lymphocytes (p<0.05) in the Pred and Allo/Pred groups as compared to the control group and the Allo group. CONCLUSIONS: Single-dose IV allopurinol significantly reduced the overall number of polymorphonuclear leucocytes in LIU. Unlike methylprednisolone, allopurinol did not have any significant impact on lymphocytes.

Allopurinol↗
PubMedDate not supplied

Topical allopurinol or corticosteroids and acetylcysteine in the early treatment of experimental corneal alkali burns: a pilot study.

PURPOSE: To investigate the effect of topical allopurinol on experimental corneal burns and to compare this to established treatment modalities such as topical prednisolone and acetylcysteine. METHODS: Twenty Wistar rats were randomly assigned to four groups (n=5 each). The groups were controls (normal saline), allopurinol 0.4% eye drops, prednisolone acetate 1% eye drops and acetylcysteine 8% eyedrops. Corneal burn was induced using a 3 mm paper disc soaked in 1N NaOH for 60 seconds. Drops were instilled 6 times per day. In addition, one drop/day ofloxacine was given to prevent secondary infections. Eyes were enucleated 50 hours later and fixed in 4.5% formaldehyde. Three histological levels of each globe were stained with hematoxylin-eosin and examined by two independent masked investigators using a 0 to 4+ inflammatory score. All pair-wise multiple comparison procedures (Student-Newman-Keuls method) were applied for statistical work-up. RESULTS: All three substances significantly reduced the number of histologically visible inflammatory cells compared to the control group (p<0.05). CONCLUSIONS: In the present study, topical allopurinol was as effective as established drugs, namely steroids and acetylcysteine, in the early treatment of experimental alkali corneal burns.

Acetylcysteine↗
PubMedDate not supplied

Lidocaine-assisted xylocaine jelly anesthesia versus one quadrant sub-Tenon infiltration for self-sealing sclerocorneal incision routine phacoemulsification.

PURPOSE: To compare the effect of xylocaine jelly and intracameral lidocaine with one quadrant instant sub-Tenon infiltration for self-sealing sclerocorneal phacoemulsification. METHODS: One hundred patients were enrolled into a prospective randomized study, receiving either a combination of topical 2% xylocaine jelly and 0.5 ml of intracameral 1% lidocaine or sub-Tenon infiltration with 2 ml of 2% xylocaine on the operating table. All patients underwent a standard divide and conquer phacoemulsification procedure through a superior sclerocorneal frown incision followed by implantation of a polymethylmethacrylate intraocular lens. Intraoperative pain was indicated by the patient by squeezing the bedside nurse's hand, who allocated it to particular stages of surgery on a chart. After surgery, patients assessed the pain experienced using a 10-unit visual analogue scale. RESULTS: Pain was indicated on 31 occasions during the operation in the sub-Tenon group (mainly the injection itself) and 67 times in the topical group. The median overall subjective pain score was 3 in the jelly group and 0 in the sub-Tenon. Five eyes (10%) had to be converted to sub-Tenon during the surgery because of intolerable pain. CONCLUSIONS: Whereas lidocaine supported xylocaine jelly anesthesia provided acceptable analgesia for 90% of patients operated, sub-Tenon anesthesia proved to deliver better intraoperative comfort in all patients receiving sclerocorneal incision cataract surgery.

Aged↗
PubMedDate not supplied

Surgical treatment of keratoconus at the turn of the 20th century.

PURPOSE: This paper reviews surgical modalities for treatment of keratoconus at the threshold of the 20th century. METHODS: All ophthalmic literature from 1895 until 1925 in English and German, available at the library of the Institute of Ophthalmology, London, United Kingdom, was studied with respect to this topic. RESULTS: Three thermal procedures were described; galvanocauterization with perforation, without perforation, and a non-contact application of heat to the corneal apex. Radial extension of a thermal burn to correct the minus cylinder represented a further modification. Excision of the conical area was suggested either as a lamellar dissection or as a full thickness trephination. Incision of the cone appeared to be less popular. In staged procedures, a combination of galvanocauterization, splitting of the cornea, conjunctival flap, and a subsequent optical iridectomy were applied. CONCLUSION: The treatment of keratoconus 100 years ago used refractive surgery to improve visual function by modifying corneal shape.

Cornea↗