Biomedical subjects

I Lehto

Publications and source records attributed to I Lehto.

14 recordsLinked to original sources

PubMed1999

Prospective evaluation of external ocular microbial growth and aqueous humor contamination during cataract surgery.

PURPOSE: To analyze the route of aqueous humor contamination leading to the development of postoperative endophthalmitis. SETTING: Department of Ophthalmology, University of Helsinki, Finland. METHODS: Forty-nine eyes of 49 patients (31 having phacoemulsification and 18 extracapsular cataract extraction [ECCE]) participated in the study. Four bacterial cultures were taken: preoperative conjunctival swab, lid margin culture, intraoperative lacrimal lake sample, and immediate postoperative anterior chamber fluid sample. RESULTS: Preoperative lid margin cultures were positive in 59.2% of eyes, conjunctival cultures in 69.4%, and lacrimal lake cultures in 24.9%. Four aqueous humor samples (8.2%) showed bacterial growth in the anterior chamber aspirate: 3 in the phacoemulsification and 1 in the ECCE group. The bacteria isolated in this study, Staphylococcus epidermidis and Propionibacterium acnes (2 positive isolates each) were sensitive to the preoperative topical antibiotics used. No aqueous humor sample or any from other locations showed gram-negative microbe growth. The most frequently recovered microbes in all samples collected from the 3 other sources were S epidermidis and other coagulase-negative staphylococcus species, followed by P acnes and other propionibacterium species. Staphylococcus aureus, and diptheroids. CONCLUSION: The ocular surface significantly contributed to the transmission of microbes into the eye during cataract surgery. These microbes could not be eradicated by topical preoperative antibiotics. However, no patient developed postoperative endophthalmitis. Natural defense mechanisms appear to fend off a minor inoculum with these microbes of relatively low pathogenicity.

Anti-Bacterial Agents↗

PubMed1998

Cellular and plasma fibronectin in the aqueous humour of primary open-angle glaucoma, exfoliative glaucoma and cataract patients.

PURPOSE: To compare the concentrations of cellular fibronectin (cFN), plasma fibronectin (pFN), tenascin and calcitonin gene-related peptide (CGRP) in the aqueous humour in primary open-angle glaucoma (POAG), exfoliative glaucoma (EXFG) or cataract (control group). METHODS: The concentrations were determined by enzyme-linked immunoassays in the aqueous humour of patients with EXFG (n = 26), POAG (n = 29) or cataract (control group, n = 13). RESULTS: The pFN concentrations of the three patient groups differed significantly from each other (p = 0.0004 in a non-parametric analysis of variance). In multiple comparisons EXFG patients showed significantly higher pFN levels than POAG patients (p < 0.05) or cataract patients (p < 0.01). the cFN level was also significantly higher in EXGF patients than in POAG patients (p < 0.05) or cataract patients (p < 0.05). The pFN or cFN concentrations of the POAG group did not differ from those of the control group. Neither tenascin nor CGRP was detected in the aqueous humour of any of our patients. CONCLUSIONS: The significantly higher aqueous humour pFN concentration in exfoliative glaucoma may be a consequence of disruption of the blood-aqueous barrier and may further add to an increased outflow resistance.

Aged↗

PubMed1998

Diagnosis and management of pigmentary glaucoma.

Pigment dispersion syndrome and pigmentary glaucoma affect typically young, myopic persons. Iridozonular contact causes pigment dispersion and obstruction of the trabecular meshwork. Accumulation of pigment may result in transient elevation of intraocular pressure or irreparable damage to the meshwork accompanied by uncontrolled glaucoma. In the reviewed publications the transition from pigment dispersion syndrome to pigmentary glaucoma was found to be 20%. The main risk factors for the transition were ocular hypertension and myopia. Dapiprazole, an alpha-adrenergic blocking agent, was found to be effective in treating pigmentary glaucoma and in preventing pressure spikes after exercise. Dapiprazole causes miosis without affecting accommodation. Yttrium aluminum garnet laser iridotomy reduced the incidence of ocular hypertension in pigment dispersion syndrome, although the effect was less pronounced in persons older than 40 years of age. Lattice degeneration was found in 33.3% of the eyes with pigment dispersion syndrome.

Adrenergic alpha-Antagonists↗

PubMed1994

Magnetization transfer imaging of lumbar disc degeneration. Correlation of relaxation parameters with biochemistry.

OBJECTIVES: The authors attempted to find out if magnetization transfer (MT) imaging with magnetic resonance imaging (MRI) provides new information of disc degeneration. SUMMARY OF BACKGROUND DATA: Magnetization transfer technique improves soft-tissue contrast and characterization. It measures the cross-relaxation and chemical exchange processes between free and macromolecule-bound water protons in tissues. METHODS: The lumbar MRI and MT of four living subjects and six cadaveric spines were performed at 0.1 T. Disc water, protein, proteoglycan, and collagen contents of cadaveric samples were correlated to MT parameters. RESULTS: The rate of magnetization transfer between free-water protons and the macromolecule-bound protons was elevated in degenerated discs. A positive correlation was found between disc collagen and total protein concentration and the rate of transfer. The contrast of normal and degenerated discs on MT images was not altered much. CONCLUSIONS: More studies are needed to fully establish the importance of MT processes in the disc.

Adult↗

PubMed1994

Diurnal fluid changes of lumbar discs measured indirectly by magnetic resonance imaging.

The feasibility of magnetic resonance imaging and the magnetization transfer technique for measurement of diurnal fluid changes in lumbar discs was studied with the use of 13 healthy subjects. The diurnal height loss of the subjects ranged from 13 to 21 mm. The disc signal in T2-weighted magnetic resonance imaging increased as much as 25% after overnight bed rest, presumably due to the enhanced influx of water. The change in magnetization transfer parameters also suggested increased hydration of the disc after bed rest. Magnetic resonance imaging techniques can be used for indirect measurement of the changes in fluid content and the interaction of water with macromolecules in the disc.

Adult↗

PubMed1994

A randomized, prospective study on the use of sodium hyaluronate (Healon) in trabeculectomy.

The effect of injecting sodium hyaluronate (Healon) before fistulization in trabeculectomy was investigated in a prospective, randomized study of 107 consecutive eyes. Fifty-two eyes were operated on with the viscoelastic and 55 without. An early postoperative intraocular pressure (IOP) peak of 21 mm Hg or more occurred in 27% of the study eyes versus 17% of the control eyes, an insignificant difference. The mean peak IOPs of the study and the control eyes did not differ significantly (29.8 +/- 9.0 mm Hg versus 32.7 +/- 10.2 mm Hg), nor did the mean IOPs and the need for glaucoma medications 1 month after surgery. Shallow/flat anterior chamber and choroidal detachment were equally frequent in both groups, but hyphema occurred significantly more often in the study group (40%) than in the control group (18%).

Aged↗

PubMed1992

Side effects of topical treatment in pigmentary glaucoma.

A series of 35 patients with pigmentary glaucoma were asked to report possible side effects of topical glaucoma medication using a multiple-choice questionnaire. Of the 31 patients (89%) returning the forms, 22 (71%) were men and 9 (29%) women with a mean age of 45.1 years, range 23 to 72 years. The mean follow-up time of their glaucoma was 10.7 years, range 2 to 30 years. A mild burning feeling (in 50% in all treatment groups) and redness of the eyes (in 42% treated with timolol alone and in 50% with timolol combined with dipivephrine, pilocarpine or both) were the main complaints, followed by a slight reduction of vision (in 17% in the timolol group and in 56% with combined treatment) and mild watering of the eyes (in 42% of the timolol and in 31% of the combined treatment groups). Twenty-three percent of the patients did not have any side effects from their topical medication. Patients who admitted defaulting their topical treatment once a month amounted to 43% and once a week to 17%. Patients who admitted to never having missed a drop amounted to 40% of the sample; forgetfulness and haste were the main reasons for not applying the drops.

Administration, Topical↗

PubMed1992

Long-term follow up of argon laser trabeculoplasty in pigmentary glaucoma.

Nine eyes in nine patients with pigmentary glaucoma were treated with argon laser trabeculoplasty (ALT). The mean age of the patients at the time of treatment was 35 years (range, 25 to 46 years); the mean follow up after treatment was 5.5 years. The initial pressure-lowering effect of ALT was 53% (15.3 mm Hg), ie, from a preoperative mean of 29.0 mm Hg to a postoperative mean of 13.7 mm Hg the day after ALT. However, the initial response to ALT wore off in 3 months, after which the intraocular pressure settled at a level 14% (4 mm Hg) lower than before treatment. The rate of failure (ie, unstable glaucoma after treatment) was 11%.

Adult↗

PubMed1991

Long-term prognosis of pigmentary glaucoma.

Outcome, prognosis and course of pigmentary glaucoma were studied in 38 patients (75 eyes). The mean age of the subjects at the time of diagnosis was 34.0 years and at the time of the study 44.1 years. The follow-up time ranged from 2 to 30 years with a mean follow-up time of 10.1 years. At the time of the study eighty-nine percent of the eyes had normal vision (0.7 or better), 3% slight impairment of vision (0.6-0.3), 5% low vision (0.2-0.05) and 3% were blind. Visual field defects were mild in 78%, moderate in 13% and severe in 8% of the eyes. One eye (1%) had normal fields. In 8 patients the stage of the field defects was asymmetrical between the two eyes. All were able to read at least monocularly with glasses. No one was blind, retired early or professionally limited because of pigmentary glaucoma. Thirty-nine eyes were on topical treatment. Fifteen eyes had additionally been treated with laser trabeculoplasty when the glaucoma could not be stabilized with topical treatment combined with systemic acetazolamide. Further twenty eyes had undergone trabeculectomy, 18 of them when medical treatment had failed and 2 following LTP. The non-involved eye of a patient suffering from a monocular disease was without treatment. The mean intraocular pressure at the time of the diagnosis was 33.5 mmHg (SD 10.4 mmHg) and at the final visit 17.5 mmHg (SD 3.4 mmHg). Four eyes were operated for cataracts and one for retinal detachment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Corneal endothelium in pigmentary glaucoma and pigment dispersion syndrome.

Corneal endothelial cell density was determined in 64 eyes (32 patients) with pigmentary glaucoma and in 18 eyes (9 persons) with pigment dispersion syndrome without glaucoma. Twenty-eight healthy eyes served as controls. The glaucomas were stabilized with topical treatment or following laser trabeculoplasty or filtration surgery. The mean duration of the glaucoma was 7.6 years (SD 6.1 years) subsequent to diagnosis. Neither in the glaucomatous, nor in the pigment dispersion syndrome eyes, could any statistically significant difference in cell density be noted compared to the control series. Within the glaucoma group pressure level, topical treatment, laser trabeculoplasty and trabeculectomy did not have any statistically significant effect on cell counts. Distinct pleomorphism and polymegatism of the endothelial cells were observed in the study groups. The endothelial cell density decreased linearly with age.

Adult↗

PubMed1990

Immunohistochemical demonstration of tenascin in the normal human limbus with special reference to trabeculectomy.

Sections from the anterior segment of the fetal and adult human eye and from limbal tissue excised during standard trabeculectomies were studied immunohistochemically with monoclonal antibodies against human tenascin or monoclonal antibodies against cellular fibronectin (cFN). In the fetal eye, tenascin-like immunoreactivity (TEN-LI) was observed in the area of the developing limbus. In the adult eye TEN-LI was most intense at the corneoscleral margin in the stromal tissue and decreased towards the posterior sclera. No reaction was observed in the corneal stroma, but the epithelium showed moderate immunofluorescence. All tissues obtained during trabeculectomy showed similarly strong TEN-LI. The sections from trabecular specimens incubated with antibodies against cFN were negative.

Anterior Eye Segment↗

PubMed1990

The effect of naftidrofuryl on red blood cell aggregation detected in vitro with ultrasound.

Red blood cell aggregates are mainly responsible for the echogenicity of flowing blood. Thus, ultrasound can be used to observe the degree of red blood cell aggregation in slow flow conditions. We quantified blood echogenicity to study aggregation tendency of red blood cells in blood of patients with claudication, patients with suspected venous thrombosis, and normal volunteers without and with in vitro addition of naftidrofuryl (10(-6) M). Normal volunteers showed lower original echogenicity than any group of patients, and claudication patients showed the highest echogenicity. Naftidrofuryl caused a fall in mean echogenicity in all groups, and its effect was pronounced on blood samples with a high original echogenicity.

Aged↗

PubMed1985

Immune functions and the prognosis of patients with solid tumours.

The immune competence of 169 patients with solid malignant tumours was assessed before initiation of radiotherapy or chemotherapy and followed during the course of the disease. The data of years 1974-1984 were collected and subjected to an analysis in order to evaluate their prognostic significance. The number of leucocytes and lymphocytes in the peripheral blood, the percentage or absolute number of E-rosette forming cells or EAC-rosette forming cells or serum immunoglobulin levels did not show any association with the prognosis. Lymphocyte proliferative responses to PHA, Con A and PPD as studied before initiation of the treatment did not correlate with recurrence or final prognosis of the disease, except that the responses to PPD were slightly lower in patients with recurrence of gynaecological cancer, melanoma or gastrointestinal cancer than in their respective control patients. In the values observed after the first treatment course a low response to PPD was associated with poor prognosis in patients with melanoma or gastrointestinal cancer. At the time of recurrent disease the PPD response showed an association with a poor final outcome in patients with gastrointestinal malignancy. Of the responses assessed less than 3 months before death due to cancer, only in patients with breast cancer were low Con A responses seen; in all patient groups the PHA responses decreased in the terminal patients. The results do not support the idea that the methods currently available should be routinely used in the follow-up of cancer patients; rather, they indicate the need to seek new methods for this purpose.

Adolescent↗

PubMed1983

Laser trabeculoplasty in open angle glaucoma.

Laser trabeculoplasty was performed in 72 patients (81 eyes) with open angle glaucoma. A positive correlation between pre-laser pressure level and pressure reduction was found. In 23 eyes with POAG and an average pre-treatment pressure of 26.4 mmHg, post-laser IOP 6 months later was 21.6 (18% reduction) and 1 year later 21.8 mmHg (17% reduction). In 24 eyes with CG and an average pre-treatment pressure of 32.9 mmHg, post-laser IOP 6 months later was 23.8 mmHg (28% reduction) and 1 year later 22.8 mmHg (31% reduction). All eyes needed additional medical therapy for glaucoma control, and 8 eyes had to be operated. Three eyes had complications. One eye had a pressure rise on the 2nd post-operative day, and two eyes had a haemorrhage from the chamber angle.

Follow-Up Studies↗