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Biomedical subjects

L J Blanksma

Publications and source records attributed to L J Blanksma.

At least 19 recordsLinked to original sources
PubMed2006

Scintigraphic evaluation for tear drainage, after dacryocystorhino- stomy, in relation to patient satisfaction.

AIM: To measure the degree of physiological patency of the tear drainage system using dacryoscintigraphy before and after external dacryocystorhinostomy (EDCR) in relation to patient complaints. METHODS: Prospective evaluation of 29 eyes of 24 patients with primary acquired nasolacrimal duct obstruction (PANDO) who underwent EDCR. The epiphora complaints were measured subjectively. Dacryoscintigraphy was performed in all eyes preoperatively, and was repeated 6 months after DCR together with the complaints score. For evaluation of dacryoscintigraphy, we determined T1 (percentage of administered dose still present after 1 min) and linear clearance rate (LCR), defined as: 100%(T1-T15)/T1) from the tracer disappearance curve. Dacryoscintigraphy findings were compared with the results of 20 eyes of normal volunteers without any symptoms. Scintigraphic findings were compared before and after the operation, with the change in patient complaints score as well as with normal values. RESULTS: Significant improvement occurred after the operation in the complaints score, T1 and LCR. However, despite absence of complaints (score=0) postoperative scintigraphic values were still abnormal as compared to normal individuals. CONCLUSION: Despite almost complete remission of epiphora complaints, DCR does not result in normalization of the tear drainage system.

Adult↗
PubMed2005

Clinical value of dacryoscintigraphy using a simplified analysis.

PURPOSE: To study the discriminatory ability of dacryoscintigraphy in differentiating between patients with epiphora and volunteers using a simple method. METHODS: Twenty eyes in ten volunteers and 66 eyes in 55 patients with severe epiphora were studied. Dacryoscintigraphy (15 frames of 1 min) was performed after administration of 4 MBq (99m)Tc-pertechnetate (10 mul) in both eyes. By mapping a single region of interest (ROI) over the conjunctival sac we determined T1 (%dose in first minute) and linear clearance rate (LCR, defined as [see text] from the tracer disappearance curve. Reproducibility was determined in volunteers. Conjunctival resorption was determined from completely obstructed systems. Sensitivity and specificity were calculated and receiver operating characteristics (ROC) analysis was conducted. RESULTS: In volunteers mean T1 was 52.8+/-11.9% (95% CI 47.1-58.4%), and LCR was 74.2+/-11.1% (95% CI 69.0-79.4%). Reproducibility was good (mean difference 4.1+/-13.3% for T1 and 0.7+/-17% for LCR). Epiphora patients had clearly higher T1 (82.1+/-15.2%, P<0.0001) and lower LCR (38.9+/-22.5%, P<0.0001) values. Tracer resorption was 24%. Based on ROC analysis 70% for T1 and 50% for LCR were considered optimal cut-off levels to separate patients from volunteers. Sensitivity/specificity were 77/95% for T1 and 71/100% for LCR. T1 and LCR values did not correlate with symptom scores or Anel test results. CONCLUSION: Dacryoscintigraphy, using LCR and T1 as parameters, is a reliable and objective method to detect tear-flow abnormalities.

Adult↗
PubMed1995

Measurement of visual acuity with two different charts; a comparison of results and repeatability in patients with cataract.

PURPOSE: To compare two different optotypes to measure visual acuity. METHODS: Experiment 1: Fifty patients with moderate cataracts were asked to read a chart consisting of letters of the alphabet (Sloan letters) first and a chart comprising Landolt's broken rings afterwards. Experiment 2: Half of patients were instructed to repeat the reading with a second letter chart, the other half was instructed to read the chart with the broken rings again. RESULTS AND CONCLUSIONS: Experiment 1: It was found that with the letter chart more optotypes (two to four) were recognized than with the broken ring chart. The different result of visual acuity measurement with the two optotypes is irrespective of the visual acuity. Experiment 2: The re-read instruction revealed that the measurements were reproduced equally for both charts.

Cataract↗
PubMed1991

Lens reflectometry with a CCD video camera and computer image analysis.

Lens reflectometry is a useful method of determining the back scatter of light from the cataractous lens. Making use of normal programmes, the personal computer can be used for the quantitative determination of the lens reflex, as seen in the slit-lamp image. If three different images of the same eye are compared, it appears that the mean variation in the back-scatter readings made by our method is 8.3%.

Aged↗
PubMed1991

Concentration of timolol in aqueous humour.

Two groups of twenty patients who were to undergo a routine e.c.c.e. applied eye-drops containing timolol 0.1% or 0.5% twice daily during the week preceding their operation. A third group of twenty patients, using placebo drops, served as control. During the cataract surgery a sample of aqueous was collected. The samples from the timolol 0.1% patient group contained a significantly lower concentration of timolol than those from the timolol 0.5% patient group, but there was considerable overlap.

Administration, Topical↗
PubMed1990

Clinical and physical measurements of the cataractous lens.

In connection with the clinical trial of an anti-cataract drug (Bendazac lysine) a number of examination methods were used to assess the progress of the cataract: slitlamp examination, visual acuity determination, and the measurement of the contrast sensitivity, light scatter in the eye and the autofluorescence and transmission of the lens. In this article the measurements of 43 patients (43 eyes) are presented, taken at the time that medication was started. In this way we can get an impression of the value of these measurements for the study of cataractous lenses. The contrast sensitivity of the cataractous eye is lowered for all spatial frequencies as compared with the normal population. Light scatter is greatly increased. The autofluorescent profile of the lens with nuclear cataract differs markedly from that of the lens with cortical cataract.

Aged↗
PubMed1990

Periorbital necrotising fasciitis due to Cryptococcus neoformans in a healthy young man.

A case report is presented of a healthy 25-year-old man who developed a periorbital necrotising fasciitis after a trivial trauma with a wooden splinter. Necrotising fasciitis of the eyelids occurs rarely. Cryptococcus neoformans is not described as a causative factor of necrotizing fasciitis. Cryptococcus neoformans usually infects patients with immunodeficiencies, diabetes mellitus or steroid therapy. This patient was healthy and developed a periorbital necrotising fasciitis due to Cryptococcus neoformans.

Adult↗
PubMed1989

Intra-ocular light scatter in pseudophakia.

In 22 patients (23 eyes), who had undergone an uncomplicated cataract extraction with implantation of a posterior chamber lens in otherwise normal eyes 11 to 44 weeks previously, the intra-ocular light scatter was measured with an IOI stray light meter. All the eyes examined had little or no after-cataract. A regression curve for stray light values in normal eyes as function of age was used as reference. The measurements show that the intra-ocular light scatter in pseudophakic eyes with little or no after-cataract increases by a factor 2. This increase must be caused by the combination implant lens-posterior capsule.

Adolescent↗
PubMed1986

Xeroderma pigmentosum and keratoconus.

Two XP patients are presented. A corneal perforation in the left eye of the first patient necessitated an at-random transplantation à chaud. The graft was remarkably well tolerated, which is possibly explained by UV-light-induced suppression of the cellular immune response in the patient. The right eye of this patient and both eyes of the second patient had a keratoconus. Keratoconus in XP may be the result of disturbances in the cell differentiation and the function of epithelial cells and keratocytes, due to UV-light-induced deficient DNA repair synthesis.

Adult↗
PubMed1986

An unusual complication of perforating wounds of the eye.

In two patients, after a perforating wound of the eye, a cilium was found in the vitreous. In the first patient one end of a cilium was stuck in the retina, the other end floated freely in the vitreous of the right eye. During a 5-year follow-up no inflammatory signs were observed. Visual acuity remained 1.0. In the second patient a large metal foreign body was removed from the vitreous of the left eye immediately after the injury. A week later, while parsplana vitrectomy was being performed for a vitreous haemorrhage caused by the trauma, an eyelash was discovered in the vitreous, but it could not be removed. During the follow-up period, which included the removal of a traumatic cataract, the eyelash caused no inflammatory reaction. A year later the visual acuity of the left eye was 1.0. In the literature 17 reports were found of cases with one or more eyelashes in the posterior segment of the eye. In 5 cases this was discovered on clinical examination. Once the eyelash was spontaneously extruded from the bulbus, once panophthalmia developed after the injury. In 3 cases the eye could be saved, twice with useful visual acuity, in spite of retention of the eyelash.

Adolescent↗
PubMed1986

Membrane formation and endothelial cell growth on an intra-ocular lens in the human eye, a SEM study.

In this study we have demonstrated the formation of an acellular and a cellular membrane on the surface of an explanted intra-ocular lens by scanning electron microscopy. The acellular membrane is considered to be the result of a physiological process, whereas the cellular membrane is looked upon as a pathological endothelial membrane formed as the result of intermittent touch between the implant and the endothelium.

Aged↗
PubMed1986

Mechanical and biochemical effects of man-made fibres and metals in the human eye, a SEM-study.

Prolene, perlon, supramid and titanium, either used as sutures, 'Strampelli' sutures or artificial lens loops, were compared after remaining in the human eye for at least one year. For comparison, non-implanted samples of each of the materials were used as blanks. Prolene and Perlon in particular showed severe biodegradation after a given period; Supramid showed much less degradation of its surface. Titanium showed a rather rough outer surface (even in the non-implanted samples), particularly as bends in the lens loop, which facilitated the adherence of cells, fibres and microorganisms.

Azepines↗
PubMed1983

Fluoro-photometry in myotonic dystrophy.

We found pigment alterations in the anterior segments of the eyes of patients with myotonic dystrophy. We therefore performed fluoro-photometry in a group of ten myotonic patients and the results were compared with those of a group of normal persons. The fluorescence levels in the aqueous and vitreous of the myotonic eyes appeared to be two or three times higher than in the normal eyes. This brings us to the conclusion that myotonic eyes have a defect in the blood-ocular barriers.

Aqueous Humor↗
PubMed1983

Clinical applications of fluorometry.

An instrument has been developed that measures in ten seconds the level of fluorescein along a scanning line from the retina to the cornea. With spatial resolving power of 1.1 mm in the eye, concentrations of 1 X 10(-8) gr/ml fluorescein and higher are detectable. In this way an indication of the integrity of the blood-ocular barriers is achieved. In uveitis the dysfunction is mainly localised at the blood-aqueous barrier while in diabetic retinopathy the blood-retinal barrier is predominantly affected. Sources of error are discussed.

Adult↗
PubMed1983

Retinopathy and intraocular pressure in diabetic children.

40 diabetic children, ranging in age from 7 to 18 years, were examined with fluorescein angiography. 31 of them also underwent applanation tonometry. In 45% of the children a diabetic retinopathy was demonstrated on the angiograms. This retinopathy appeared to be progressive during a follow-up period of 1-3 years. The diabetic children without retinopathy had an intraocular pressure which was equal to that of a control group of 25 nondiabetic children. However, the diabetic children who developed retinopathy had a significant (p less than 0.01) elevation of their intraocular pressure.

Adolescent↗