Eyelid Disorders in Ophthalmology Practice: Results from a Large International Epidemiological Study in Eleven Countries

Purpose

Anecdotal evidence suggests that eyelid disorders are common, although estimates of prevalence vary. The current study determines the prevalence of eyelid disorders, meibomian gland dysfunction (MGD) and related diseases (specifically ocular surface disease) in a population of patients presenting for routine ophthalmologic consultations.

Methods

This cross-sectional epidemiologic survey evaluated patients presenting for routine ophthalmic visits. During the consultation an ophthalmologist completed a questionnaire, and each patient underwent an ophthalmic examination and completed a quality of life questionnaire.

Results

Three hundred forty-nine ophthalmologists, recruited from 11 countries, provided data on 6525 patients. Patients were predominantly females (61.6%). The mean age of the study population was 57.0 ± 17.6 years. Eyelid disorders were diagnosed in 5109 (78.3%) patients and were statistically associated with: atopic dermatitis, seborrheic dermatitis, dry eye, age-related macular degeneration, diabetes, cataract, allergy and MGD (P < 0.05, all associations). Eyelid abnormalities were identified in 59.6% of patients; conjunctival or corneal abnormalities were observed in 64.9% and 28.1% of patients, respectively. MGD was diagnosed in 54.3% patients and was statistically significantly associated with the presence of eyelid disorders and eyelid margin abnormalities (P < 0.001, both comparisons). Dry eye was diagnosed in 61.8% of patients. Concurrent dry eye and MGD were present in 67.6% of patients. Most patients reported some degree of impaired vision and daily/work activities related to dry eye. Impact on contact lens usage, emotions and quality of sleep was also reported. The effects on daily life were associated with the presence of MGD.

Conclusion

In conclusion, eyelid disorders were highly prevalent in this ‘real-world’ population of patients from ophthalmology clinics. Routine ophthalmologic consultations provide an opportunity to improve patient quality of life and to modify topical therapy in patients who may be predisposed to eyelid disorders.

The physical properties of generic latanoprost ophthalmic solutions are not identical

PURPOSE

To compare various characteristics of Xalatan^® and five generic latanoprost ophthalmic solutions.

METHODS

Drop size, volume, pH values, buffer capacity, viscosity, hardness of bottles and costs were determined. Drop sizes were measured in triplicates by micropipettes, and the number of drops counted in three separate bottles of each generic product was determined. pH values were measured in triplicates by a calibrated pH meter. Buffer capacity was exploited by titrating known quantities of strong base into 2.5 ml of each brand and interpolated to neutral pH. Kinematic viscosity was determined by linear regression of timed gravity flow from a vertical syringe through a 21-G cannula. The hardness of the bottles was evaluated by gradually increasing tension on a hook placed around each bottle until a drop was expelled reading the tension on an attached spring scale.

RESULTS

Drop sizes and the number of drops in the bottles varied significantly between the generic drugs. The control value of pH in the brand version (Xalatan^® ) was markedly lower compared to the generic latanoprost products. Titration of Xalatan^® to neutrality required substantially more NaOH compared to the generic latanoprost products. Finally, the viscosity revealed a significant variability between brands. Remarkable differences were found in bottle shapes, bottle hardness and costs of the latanoprost generics.

CONCLUSION

Generic latanoprost eye drops should not be considered identical to the original brand version as regards to drop size, volumes, pH values, buffer capacity, viscosity, hardness of bottles and costs. It is likely that these issues affect compliance and intraocular pressure (IOP)-lowering effect. Therefore, re-evaluation of the requirements for introducing generic eye drops seems reasonable.

Oxcabazepine (®Trileptal) in Anti-epileptic Polytherapy

The anti-epileptic activity of oxcarbazepine (OXC) was compared with that of carbamazepine (CBZ) and the primary active metabolite of OXC, a monohydroxy derivative (MHD). Altogether 255 patients receiving either OXC or MHD (192 and 63 patients respectively) were included in the analysis of efficacy. Out of these 255 patients a total of 40 were children. The duration of treatment varied between 8 and 24weeks. The daily dose of OXC or MHD varied between 600 and 5400 mg (in children 600-2400 mg). Out of five studies two were double-blind controlled studies (including a total of 105 patients) whereas the remaining three were open studies.The results of these studies indicate that, in adults with epilepsy, there is no statistically significant difference in overall seizure frequency between CBZ and OXC. In one double-blind study the number of generalized tonic-clonic seizures was significantly less frequent during treatment with OXC than with CBZ. No statistically significant difference with regard to side-effects was observed between OXC and CBZ.The results in children with epilepsy show a statistically significant difference in seizure frequency in favour of OXC, in comparison with CBZ.Overall, the polytherapy studies in adults and children support the effectiveness and safety of oxcarbazepine.

Bilateral optic neuropathy in a patient with familial amyloidotic polyneuropathy

Amyloidogenic transthyretin (ATTR)-related familial amyloidotic polyneuropathy (FAP) is an autosomal-dominant hereditary disease characterised by slowly progressive peripheral sensorimotor and autonomic neuropathy and tissue involvement of the heart, kidneys and central nervous system. Secondary glaucoma has been reported following intraocular surgery, but optic nerve involvement unrelated to glaucoma has not previously been described. We reported a male patient in his late 40s when deceased, who previously had a liver transplant in order to reduce the abnormal protein synthesis underlying his FAP ATTR Val30Met mutation. After 11 years of ophthalmic follow-up best-corrected visual acuity was 20/100 in his seeing eye, which further had visual field findings suggestive of optic neuropathy. This was also the diagnosis underlying the preceding insidious full loss of vision in the fellow eye, with colour Doppler imaging to support an ischaemic aetiology. To our knowledge, this is the first report of ischaemic optic neuropathy in this familial amyloid disorder.

A new risk-based screening criterion for treatment-demanding retinopathy of prematurity in Denmark

OBJECTIVE

The aim of this study was to uncover the most effective and safe criterion to implement for retinopathy of prematurity screening in Denmark.

METHODS

This retrospective national cohort study is based on data from 3 national registers. These registers provided on infants treated for retinopathy of prematurity, infants in need of treatment but missed by the present screening program, and the candidate neonates for advanced retinopathy of prematurity development A nonlinear logistic regression model was fitted to the data, and various screening criteria were evaluated.

RESULTS

During the study period (2002-2006), 116 infants were treated for retinopathy of prematurity, no treatment-demanding retinopathy of prematurity infants were missed by the screening program, and 182 premature infants were candidates for developing treatment-demanding retinopathy of prematurity. Screening criteria combining gestational age at delivery and birth weight limits and new risk-based criteria were compared with regards to their effectiveness. The risk-based criteria were the most effective. Use of the 0.13% risk-based criterion to define the population to be screened resulted in the detection of all treated infants in the study period and 17.4% fewer infants to screen. The model predicted this criterion to result in 1 missed case of treatment-demanding retinopathy of prematurity every 11 years and 1 case of blindness every 18 years in Denmark.

CONCLUSIONS

Screening criteria based on risk estimates of developing treatment-demanding retinopathy of prematurity are the most effective for retinopathy-of-prematurity screening. The risk-based criterion of 0.13% can safely be implemented for future retinopathy-of-prematurity screening in Denmark.

Ultrasonographic three-dimensional scanning for determination of intraocular tumour volume

Important prognostic information may be gained from knowing the volume and the rate of growth of intraocular tumours, such as choroidal melanomas. An ultrasonographic 3-D scanning system based on rotation of a commercial sector scanning transducer applied directly onto a closed eyelid was designed to measure such volume. Control of movement, data acquisition, and image analysis are accomplished by means of a microcomputer and application-specific software. The elapsed time for scanning and digitizing 20 cross-sectional images is about 1 sec. Outlines of specific structures are traced manually. The system var tested through repeated measurements of known volumes of meat. The mean variation coefficient of these measurements was 2.8%. The traced volumes were linearly dependent on gain setting of the system requiring a fixed setting for accurate estimates. The procedures of scanning and tracing contributed about equally to the total variance. This method allows repeatable, reliable, and easily generated quantitative measurements of volume with a great potential for use in the diagnosis of malignant tumours and control of the effectiveness of radiotherapy.

Treatment for retinopathy of prematurity in Denmark in a ten-year period (1996 2005): is the incidence increasing?

OBJECTIVE

The objective of this study was to analyze the population incidence of retinopathy of prematurity treatment in Denmark in the 10-year period from 1996 to 2005.

METHODS

Patient charts of infants treated for retinopathy of prematurity and the national birth registry provide information about neonatal parameters. These parameters, along with birth in the latter half of the period (2001-2005), were analyzed as risk factors for retinopathy of prematurity. The national registry for blind and visually impaired children was accessed to obtain information about visual impairment attributable to retinopathy of prematurity in both treated and untreated infants.

RESULTS

The study population consisted of 5467 Danish preterm infants born in 1996 to 2005, with a gestational age of < 32 weeks, who survived for > or = 5 postnatal weeks; 2616 were born in 1996 to 2000, and 2851 were born in 2001 to 2005. The incidence of treated retinopathy of prematurity cases increased significantly from 1.3% in 1996 to 2000 to 3.5% in 2001 to 2005. Significant risk factors for retinopathy of prematurity treatment were low gestational age, small for gestational age, male gender, and multiple birth. Other, yet unknown factors contributed to the increased incidence in the latter half of the period. Of the study population, 0.6% were registered as visually impaired because of retinopathy of prematurity within 2 years after birth (early-detected visual impairment). The incidences were not significantly different between 1996 to 2000 and 2001 to 2005. Of all of the early-detected, visually impaired children, 16% had not been treated for retinopathy of prematurity and were considered screening failures.

CONCLUSIONS

The incidence of retinopathy of prematurity treatment in Denmark has more than doubled during the past half-decade. This increase could not be fully explained by increased survival rates for the infants or by changes in the investigated neonatal risk factors.

Automatic Retinal Oximetry

PURPOSE

To measure hemoglobin oxygen saturation (SO(2)) in retinal vessels and to test the reproducibility and sensitivity of an automatic spectrophotometric oximeter.

METHODS

Specialized software automatically identifies the retinal blood vessels on fundus images, which are obtained with four different wavelengths of light. The software calculates optical density ratios (ODRs) for each vessel. The reproducibility was evaluated by analyzing five repeated measurements of the same vessels. A linear relationship between SO(2) and ODR was assumed and a linear model derived. After calibration, reproducibility and sensitivity were calculated in terms of SO(2). Systemic hyperoxia (n = 16) was induced in healthy volunteers by changing the O(2) concentration in inhaled air from 21% to 100%.

RESULTS

The automatic software enhanced reproducibility, and the mean SD for repeated measurements was 3.7% for arterioles and 5.3% venules, in terms of percentage of SO(2) (five repeats, 10 individuals). The model derived for calibration was SO(2) = 125 - 142 . ODR. The arterial SO(2) measured 96% +/- 9% (mean +/- SD) during normoxia and 101% +/- 8% during hyperoxia (n = 16). The difference between normoxia and hyperoxia was significant (P = 0.0027, paired t-test). Corresponding numbers for venules were 55% +/- 14% and 78% +/- 15% (P < 0.0001). SO(2) is displayed as a pseudocolor map drawn on fundus images.

CONCLUSIONS

The retinal oximeter is reliable, easy to use, and sensitive to changes in SO(2) when concentration of O(2) in inhaled air is changed.

Determinants of Bleb Morphology in Minimally Invasive, Clear-Cornea Micropenetrating Glaucoma Surgery with Mitomycin C

PURPOSE

Antimetabolites, especially mitomycin C (MMC), increase the incidence of late bleb-related endophthalmitis in trabeculectomy. This is related to a higher incidence of avascular, thin, cystic, translucent blebs, which may be caused by a toxic effect on conjunctival tissue. An MMC dose-response study was carried out focusing on bleb morphology and function.

PATIENTS AND METHODS

In a retrospective, comparative case series study, 2 successive groups of patients with complicated glaucoma were compared 2 years after a special, minimally invasive, filtering procedure (intrastromal holmium laser keratostomy). Preoperative local subconjunctival injections of a fixed MMC dose (4 microg) were used in group A, and lower MMC doses, calculated individually (1 or 2 microg), were used in group B. Bleb vascularity and morphology were evaluated by masked grading of photomicrographs. Bleb function was evaluated by intraocular pressure (IOP).

RESULTS

Total bleb avascularity occurred in 63% of the blebs in group A and 0% in group B (P < 0.01). In eyes with IOP < or = 20 mmHg without medical treatment, the mean IOP was significantly lower in group 1 (8 vs 15 mm Hg, P < 0.002). A translucent cystic bleb without conjunctival stroma was observed in only 1 eye in group A. An optimal spongy stromal bleb was observed in all other eyes (96%) despite the different MMC doses. The numbers of complications in the 2 groups were nearly equal.

CONCLUSIONS

Bleb avascularity after 4 microg MMC could be avoided by the use of 1 or 2 microg MMC on the basis of preoperative prognosticators for failure, but at the expense of some of the IOP-lowering effect. This indicates that the therapeutic index (clinical safety margin) of MMC seems to be narrow. An MMC dose-response relation was not observed for the thin, cystic, and translucent bleb. The low incidence of this bleb (4%) indicates that the operative technique, apart from the vascularity, may be the most essential determinant of bleb morphology.

Optic nerve oxygenation

The oxygen tension of the optic nerve is regulated by the intraocular pressure and systemic blood pressure, the resistance in the blood vessels and oxygen consumption of the tissue. The oxygen tension is autoregulated and moderate changes in intraocular pressure or blood pressure do not affect the optic nerve oxygen tension. If the intraocular pressure is increased above 40 mmHg or the ocular perfusion pressure decreased below 50 mmHg the autoregulation is overwhelmed and the optic nerve becomes hypoxic. A disturbance in oxidative metabolism in the cytochromes of the optic nerve can be seen at similar levels of perfusion pressure. The levels of perfusion pressure that lead to optic nerve hypoxia in the laboratory correspond remarkably well to the levels that increase the risk of glaucomatous optic nerve atrophy in human glaucoma patients. The risk for progressive optic nerve atrophy in human glaucoma patients is six times higher at a perfusion pressure of 30 mmHg, which corresponds to a level where the optic nerve is hypoxic in experimental animals, as compared to perfusion pressure levels above 50 mmHg where the optic nerve is normoxic. Medical intervention can affect optic nerve oxygen tension. Lowering the intraocular pressure tends to increase the optic nerve oxygen tension, even though this effect may be masked by the autoregulation when the optic nerve oxygen tension and perfusion pressure is in the normal range. Carbonic anhydrase inhibitors increase the optic nerve oxygen tension through a mechanism of vasodilatation and lowering of the intraocular pressure. Carbonic anhydrase inhibition reduces the removal of CO2 from the tissue and the CO2 accumulation induces vasodilatation resulting in increased blood flow and improved oxygen supply. This effect is inhibited by the cyclo-oxygenase inhibitor, indomethacin, which indicates that prostaglandin metabolism plays a role. Laboratory studies suggest that carbonic anhydrase inhibitors might be useful for medical treatment of optic nerve and retinal ischemia, potentially in diseases such as glaucoma and diabetic retinopathy. However, clinical trials and needed to test this hypotheses.

A comparison of colour micrographs obtained with a charged couple device (CCD) camera and a 35-mm camera

PURPOSE

The purpose of this study was to determine if micrographs produced with a colour charged couple device (CCD) camera were comparable in quality to micrographs obtained with a 35-mm colour film camera. The Axiocam (Zeiss, Jena, Germany) CCD camera produced images of 3900 x 3090 pixels.

METHODS

Each picture in a series of 50 pairs of film and digital micrographs was rated independently by each of three observers on the categories of colour, detail and overall impression. A total of 28 of the 50 pairs of micrographs were discarded due to colour differences.

RESULTS

Digital micrographs were rated lower on colour and higher on detail compared to film micrographs. The film and digital micrographs were rated equally on overall impression. The difference in colour between film and digital micrographs can be compensated for using image processing software on the digital image. However, such manipulation was not carried out as part of the present study. The study originally included 50 digital micrographs and 50 film micrographs. The micrographs were paired and 22 of the 50 pairs of micrographs were assessed. Thus 28 pairs were not evaluated due to colour differences in the non-manipulated pictures. The interobserver difference on colour in the remaining 22 pairs given as mean square +/- standard error of the mean was - 0.27 +/- 0.10, 0.62 +/- 0.10 and 0.90 +/- 0.11. The interobserver difference on detail was - 0.48 +/- 0.10, 0.95 +/- 0.10 and 1.43 +/- 0.10. The interobserver difference on overall impression was - 0.70 +/- 0.10, 0.57 +/- 0.10 and 1.27 +/- 0.10. All the results differed significantly (p < 0.001).

CONCLUSION

Digital micrographs are sufficient in detail, colour and overall impression to replace the traditional 35-mm film recordings for use in histopathology.

Carbonic anhydrase inhibition increases retinal oxygen tension and dilates retinal vessels

BACKGROUND

Carbonic anhydrase inhibitors (CAIs) increase blood flow in the brain and probably also in the optic nerve and retina. Additionally they elevate the oxygen tension in the optic nerve in the pig. We propose that they also raise the oxygen tension in the retina. We studied the oxygen tension in the pig retina and optic nerve before and after dorzolamide injection. Also the retinal vessel diameters during carbonic anhydrase inhibition were studied.

METHODS

A polarographic oxygen electrode was placed transvitreally immediately over the retina or the optic disc in anaesthetised pigs. The oxygen tension was recorded continually and 500 mg dorzolamide was injected intravenously. Retinal vessel diameters were analysed from monochromatic fundus photographs taken before and after injection of dorzolamide.

RESULTS

Baseline retinal oxygen tension (RPO2) was 3.34+/-0.50 kPa (mean +/- SD, n=6) and baseline optic nerve oxygen tension (ONPO2) was 3.63+/-1.00 kPa. RPO2 was increased by 0.36+/-0.11 kPa (n=6, P=0.025) and ONPO2 by 0.73+/-0.34 kPa (n=6, P=0.003) 30 min after dorzolamide administration. The retinal arterioles was significantly dilated by 13+/-7% (n=5, P=0.016) and the retinal venules by 12+/-8% (n=5, P=0.030) 30 min after injection of dorzolamide.

CONCLUSION

Retinal and optic nerve oxygen tension increased with systemic administration of dorzolamide. The retinal vessels dilated, probably causing increased blood flow inducing the observed increase in RPO2. The increased oxygenation of retina by CAI may offer therapeutic possibilities in ischaemic diseases of the retina and optic nerve.

Is there an association between bacteriological drinking water quality and childhood diarrhoea in developing countries?

To investigate the association between bacteriological drinking water quality and incidence of diarrhoea, we conducted a 1-year prospective study in the southern Punjab, Pakistan. Diarrhoea episodes, drinking water sources and drinking water quality were monitored weekly among children younger than 5 years in 200 households. We found no association between the incidence of childhood diarrhoea and the number of Escherichia coli in the drinking water sources (the public domain). A possible trend was seen relating the number of E. coli in the household storage containers (the domestic domain) and diarrhoea incidence, but this did not reach statistical significance. Faecal contamination levels in household water containers were generally high even when the source water was of good quality. Under conditions such as this, it is questionable whether public water treatment will have a significant impact on the incidence of endemic childhood diarrhoea.

Indomethacin lowers optic nerve oxygen tension and reduces the effect of carbonic anhydrase inhibition and carbon dioxide breathing

BACKGROUND/AIMS

Prostaglandins are important in blood flow regulation. Carbon dioxide (CO(2)) breathing and carbonic anhydrase inhibition increase the oxygen tension in the retina and optic nerve. To study the mechanism of this effect and the role of cyclo-oxygenase in the regulation of optic nerve oxygen tension (ONPO(2)), the authors investigated how indomethacin affects ONPO(2) and the ONPO(2) increases caused by CO(2) breathing and carbonic anhydrase inhibition in the pig.

METHODS

Optic nerve oxygen tension was measured in 11 pigs with a polarographic oxygen electrode. The tip of the electrode was placed 0.5 mm above the optic disc. The effects of indomethacin, CO(2) breathing (3%) before and after indomethacin treatment, and carbonic anhydrase inhibition with or without indomethacin treatment were investigated.

RESULTS

Administration of 300 mg indomethacin decreased optic nerve oxygen tension significantly. Carbonic anhydrase inhibition and CO(2) breathing increased ONPO(2) significantly. After indomethacin had been given, the rise in ONPO(2) caused by CO(2) breathing and carbonic anhydrase inhibition was significantly reduced.

CONCLUSION

Systemic administration of indomethacin decreases the optic nerve oxygen tension; this is probably the result of decreased blood flow through vasoconstriction of vessels in the optic nerve. Additionally, indomethacin diminishes the ONPO(2) increasing effect of CO(2) breathing and carbonic anhydrase inhibition, thus affecting the reactivity of vessels in the optic nerve.

Diameter variations of retinal blood vessels during and after treatment with hyperbaric oxygen

AIMS

To quantify retinal vascular change during and after hyperbaric oxygenation (HO) for 6x5 weekly 90 minute treatments.

METHODS

Fundus photographs were taken before, during, and after HO at 2.5 atmospheres absolute pressure (ATA) on days 1, 2, 3, 10, 20, 29, and 30 of treatment on three patients using a specially developed hand held ophthalmoscope with a digital colour camera. Blood vessel diameter was estimated on red free retinal images. The mean of three measurements of arterioles and venoles close to the optic disc was calculated. Consistency and repeatability of the method was verified by estimating the diameter of the vessels by three measurements in each of seven images taken within 70 seconds on the same person. Analysis of variance with Bonferroni correction for multiple comparisons was conducted to ascertain whether significant intergroup differences existed.

RESULTS

Breathing 100% oxygen at 2.5 ATA constricts retinal arterioles by 9.6% (standard deviation 0.3%) and venoles by 20.6% (SD 0.3%) of their size in air at ambient pressure. Constriction escalates during treatment. Ten minutes after the HO, arterioles dilate to 94.5% (SD 0.3%) and venoles to 89.0% (SD 0.3%) of their primary size. This pattern is the same for each day of measurement. Heart frequency falls continually during HO. Systolic, diastolic, and mean arterial pressures stay constant.

CONCLUSION

Exposure to hyperbaric oxygen causes constriction of the retinal vessels. It is found that this constriction is constant through the series of treatments. This suggests that oxygen or products thereof are responsible for the vascular changes during and after hyperbaric oxygenation probably through autoregulation of the retinal vessels.

Optic nerve oxygen tension: the effects of timolol and dorzolamide

BACKGROUND/AIMS

The authors have previously reported that carbonic anhydrase inhibitors such as acetazolamide and dorzolamide raise optic nerve oxygen tension (ONPO(2)) in pigs. The purpose of the present study was to investigate whether timolol, which belongs to another group of glaucoma drugs called beta blockers, has a similar effect. In addition, the effect of dorzolamide and timolol in combination was studied.

METHODS

Polarographic oxygen electrodes were placed transvitreally over the optic disc in anaesthetised pigs and ONPO(2) was recorded continually. Drugs were administered intravenously either as 100 mg timolol followed by 500 mg dorzolamide (n = 5), 500 mg dorzolamide followed by 100 mg timolol (n = 5), or 100 mg timolol and 500 mg dorzolamide given simultaneously (n = 5). Arterial blood pressure, blood gasses, and heart rate were recorded.

RESULTS

ONPO(2) was unaffected by administration of 100 mg timolol as an intravenous injection (n = 5). Administration of 500 mg dorzolamide by itself significantly increased ONPO(2) from 2.96 (SD 0.62) kPa to 3.69 (SD 0.88) kPa (n = 4, p = 0.035). The dorzolamide induced ONPO(2) increase was not significantly different from the ONPO(2) increases were seen when dorzolamide was administered simultaneous with (n = 5) or 35 minutes (n = 5) after 100 mg timolol.

CONCLUSION

Systemic administration of timolol does not affect the optic nerve oxygen tension despite its lowering effect on the intraocular pressure. Additionally, timolol does not affect the ONPO(2) increasing effect of dorzolamide.

Uveal effusion and ultrasonic imaging: a clinical series

PURPOSE

To establish the diagnostic role of imaging by ultrasound for the diagnosis of uveal effusion syndrome.

METHODS

Using ultrasonic imaging features as the main criteria for evaluation, the recorded data from 16 patients with presumed uveal effusion seen between 1994 and 2000 were reviewed and analysed for clinical manifestations and current diagnostic suggestions. Eventually, as cumulating experience suggested that ultrasound is capable of indicating uveal effusion, the study set-up became in part more prospective.

RESULTS

The two main ultrasonic features found were: (1) extended multi-layered detachment patterns by B-scan, often kinetically mobile; (2) a spongy oedematous ciliary body region, often with interstitial lacunae, as demonstrated by high-resolution ultrasound biomicroscopy (50 Mhz).

CONCLUSIONS

In patients with visual loss and ambiguous detachment-like fundus pathology, ultrasonic features are often of practical guidance for diagnosing uveal effusion syndrome.

Neuronal cell death in the visual cortex is a prominent feature of the X-linked recessive mitochondrial deafness-dystonia syndrome caused by mutations in the TIMM8a gene

The Mohr-Tranebjaerg syndrome (MIM 304700) and the Jensen syndrome (MIM 311150) were previously reported as separate X-linked recessive deafness syndromes associated with progressive visual deterioration, dystonia, dementia, and psychiatric abnormalities. In the most extensively studied Norwegian family, the Mohr-Tranebjaerg syndrome was reported to be caused by a one-basepair deletion (151delT) in the deafness/dystonia peptide (DDP) gene at Xq22. This gene has been renamed TIMM8a. We identified a stop mutation (E24X) in the TIMM8a gene segregating with the disease in the original Danish family with the Jensen syndrome, which confirms that the two disorders are allelic conditions. We also report abnormal VEP examinations and neuropathological abnormalities in affected males from the two unrelated families with different mutations. The findings included neuronal cell loss in the optic nerve, retina, striate cortex, basal ganglia, and dorsal roots of the spinal cord. The demonstration of mitochondrial abnormalities in skeletal muscle biopsies in some patients is compatible with the suggestion from recent research that the TIMM8a protein is the human counterpart of an intermembrane mitochondrial transport protein, Tim8p, recently characterized in yeast. The clinical and neuropathological abnormalities associated with mutations in the TIMM8a gene support that this X-linked deafness-dystonia-optic neuropathy syndrome is an example of progressive neurodegeneration due to mutations in a nuclear gene necessary for some, yet unknown mitochondrial transport function. We recommend sequencing the TIMM8a gene, thorough ophthalmological examination, and measuring visual evoked potentials in clinically suspected male patients with either progressive hearing impairment, dystonia, or visual disability in order to establish an early diagnosis and provide appropriate genetic counselling.

[The molecular genetic background of hereditary craniosynostoses and chondrodysplasias]

Fibroblast growth factors are structurally related proteins associated with cell growth, differentiation, migration, wound healing, angiogenesis, and oncogenesis. At the cellular level, their function is mediated by transmembrane tyrosinekinase receptors, fibroblast growth factor receptors. Four genes encoding fibroblast growth factor receptors have been identified, and mutations in three of these, FGFR1, FGFR2, and FGFR3, can cause different congenital, autosomal dominant disorders affecting the craniofacial and skeletal development: craniosynostosis and chondrodysplasias. The craniosynostosis syndromes: Apert syndrome, Beare-Stevenson syndrome, Crouzon syndrome, Jackson-Weiss syndrome, Muenke syndrome, Pfeiffer syndrome and Saethre-Chotzen syndrome can be caused by mutation in either FGFR1, FGFR2, or FGFR3. Saethre-Chotzen syndrome can also be caused by mutation in a functionally related gene, ACS. The same mutation can cause different syndromes, and the same syndrome can be caused by mutations in different genes. The chondrodysplasias: achondroplasia, hypochondroplasia, and thanatophoric dysplasia are all caused by mutations in FGFR3.

Basicity of the amino groups of the aminoglycoside amikacin using capillary electrophoresis and coupled CE-MS-MS techniques

This paper describes the use of capillary electrophoresis (CE), and coupled CE and mass spectrometric techniques, to measure the values of the pKa of the amino groups of the aminoglycoside antibiotic amikacin and of its acetylated derivatives. These values of pKa (8.4, 6.7, 9.7, 8.4) were determined by measuring the electrophoretic mobilities of the molecules as a function of pH; they are within 0.7 unit of certain values reported in the literature (by 13C and 15N NMR spectroscopies) but resolved ambiguities left by these earlier studies. The range of values of pKa of amino groups also indicates the complex dependence of the acidity of a functional group (and thus the extent of ionization at a specified value of pH) on the molecular environment of that group.

Exercise and iris concavity in healthy eyes

PURPOSE

To study the effect of exercise on the configuration of the anterior chamber angle in healthy persons.

METHODS

Both eyes of 22 healthy persons were scanned by Ultrasound Biomicroscopy. Before and after 10 minutes of exercise the anterior chamber angle and the area of the peripheral anterior chamber were measured on the scannings.

RESULTS

After exercise the anterior chamber angle/peripheral area increases in all eyes due to changes in the iris configuration. The myopic group shows the largest change.

CONCLUSION

Reverse pupillary block (iris concavity) is not pathognomonic in pigmentary glaucoma, it occurs in all normal eyes after exercise, most pronounced in myopics. Consequently, the difference between physiological and pathological reverse pupillary block has to be clarified.

Specificity for field enumeration of Escherichia coli in tropical surface waters

In remote rural areas in developing countries, bacteriological monitoring often depends on the use of commercial field media. This paper evaluates a commercial field medium used for the enumeration of Escherichia coli in different surface waters under primitive field conditions in rural Pakistan. In order to verify the field kit, 117 presumptive E. coli isolates have been tested, finding a specificity of only 40%. By excluding some strains based on colony colours, the calculated specificity could be increased to 65%. Thus, it is suggested that prior to use in a tropical environment, the specificity of any commercial medium used should be tested with representative tropical isolates, in order to increase the specificity.

Rapid quantitative measurements of proteomes by Fourier transform ion cyclotron resonance mass spectrometry

The patterns of gene expression, post-translational modifications, protein/biomolecular interactions, and how these may be affected by changes in the environment, cannot be accurately predicted from DNA sequences. Approaches for proteome characterization are generally based upon mass spectrometric analysis of in-gel digested two dimensional polyacrylamide gel electrophoresis (2-D PAGE) separated proteins, allowing relatively rapid protein identification compared to conventional approaches. This technique, however, is constrained by the speed of the 2-D PAGE separations, the sensitivity limits intrinsic to staining necessary for protein visualization, the speed and sensitivity of subsequent mass spectrometric analyses for identification, and the limited ability for accurate quantitative measurements based on differences in spot intensity. We are presently developing alternative approaches for proteomics based upon the combination of fast capillary electrophoresis, or other suitable chromatographic separations, and the high mass accuracy and sensitivity obtainable with unique Fourier transform ion cyclotron resonance (FTICR) mass spectrometers available at our laboratory. Several approaches are presently being pursued; one based upon the analysis of intact proteins and the second upon approaches for global protein digestion and accurate peptide mass analysis. Quantitation of protein/peptide levels are based on using two or more stable-isotope labeled versions of proteomes which are combined to obtain precise quantitation of relative protein abundances. We describe the status of our efforts towards the development of a high-throughput proteomics capability and present initial results for application to several microorganisms and discuss our efforts for extending the developed capability to mammalian proteomes.

Irrigation water as a source of drinking water: is safe use possible?

BACKGROUND

In arid and semi-arid countries there are often large areas where groundwater is brackish and where people have to obtain water from irrigation canals for all uses, including domestic ones. An alternative to drawing drinking water directly from irrigation canals or village water reservoirs is to use the water that has seeped from the irrigation canals and irrigated fields and that has formed a small layer of fresh water on top of the brackish groundwater. The objective of this study was to assess whether use of irrigation seepage water for drinking results in less diarrhoea than direct use of irrigation water and how irrigation water management would impact on health.

METHODS

The study was undertaken in an irrigated area in the southern Punjab, Pakistan. Over a one-year period, drinking water sources used and diarrhoea episodes were recorded each day for all individuals of 200 households in 10 villages. Separate surveys were undertaken to collect information on hygiene behaviour, sanitary facilities, and socio-economic status.

RESULTS

Seepage water was of much better quality than surface water, but this did not translate into less diarrhoea. This could only be partially explained by the generally poor quality of water in the in-house storage vessels, reflecting considerable in-house contamination of drinking water. Risk factors for diarrhoea were absence of a water connection and water storage facility, lack of a toilet, low standard of hygiene, and low socio-economic status. The association between water quality and diarrhoea varied by the level of water availability and the presence or absence of a toilet. Among people having a high quantity of water available and a toilet, the incidence rate of diarrhoea was higher when surface water was used for drinking than when seepage water was used (relative risk 1.68; 95% CI 1.31-2.15). For people with less water available the direction of the association between water quality and diarrhoea was different (relative risk 0.80; 95% CI 0.69-0.93). This indicates that good quality drinking water provides additional health benefits only when sufficient quantities of water and a toilet are available. In a multivariate analysis no association was found between water quality and diarrhoea but there was a significant effect of water quantity on diarrhoea which was to a large extent mediated through sanitation and hygiene behaviour.

CONCLUSIONS

Increasing the availability of water in the house by having a household connection and a storage facility is the most important factor associated with reduced diarrhoea in this area. Safe use of canal irrigation water seems possible if households can pump seepage water to a large storage tank in their house and have a continuous water supply for sanitation and hygiene. Irrigation water management clearly has an impact on health and bridging the gap between the irrigation and drinking water supply sectors could provide important health benefits by taking into account the domestic water availability when managing irrigation water.

Identification of human candidate genes for male infertility by digital differential display

Evidence for the importance of genetic factors in male fertility is accumulating. In the literature and the Mendelian Cytogenetics Network database, 265 cases of infertile males with balanced reciprocal translocations have been described. The candidacy for infertility of 14 testis-expressed transcripts (TETs) were examined by comparing their chromosomal mapping position to the position of balanced reciprocal translocation breakpoints found in the 265 infertile males. The 14 TETs were selected by using digital differential display (electronic subtraction) to search for apparently testis-specific transcripts in the TIGR database. The testis specificity of the 14 TETs was further examined by reverse transcription-polymerase chain reaction (RT-PCR) on adult and fetal tissues showing that four TETs (TET1 to TET4) were testis-expressed only, six TETs (TET5 to TET10) appeared to be differentially expressed and the remaining four TETs (TET11 to TET14) were ubiquitously expressed. Interestingly, the two tesis expressed-only transcripts, TET1 and TET2, mapped to chromosomal regions where seven and six translocation breakpoints have been reported in infertile males respectively. Furthermore, one ubiquitously, but predominantly testis-expressed, transcript, TET11, mapped to 1p32-33, where 13 translocation breakpoints have been found in infertile males. Interestingly, the mouse mutation, skeletal fusions with sterility, sks, maps to the syntenic region in the mouse genome. Another transcript, TET7, was the human homologue of rat Tpx-1, which functions in the specific interaction of spermatogenic cells with Sertoli cells. TPX-1 maps to 6p21 where three cases of chromosomal breakpoints in infertile males have been reported. Finally, TET8 was a novel transcript which in the fetal stage is testis-specific, but in the adult is expressed in multiple tissues, including testis. We named this novel transcript fetal and adult testis-expressed transcript (FATE).

Disease associated balanced chromosome rearrangements: a resource for large scale genotype-phenotype delineation in man

Disease associated balanced chromosomal rearrangements (DBCRs), which truncate, delete, or otherwise inactivate specific genes, have been instrumental for positional cloning of many disease genes. A network of cytogenetic laboratories, Mendelian Cytogenetics Network (MCN), has been established to facilitate the identification and mapping of DBCRs. To get an estimate of the potential of this approach, we surveyed all cytogenetic archives in Denmark and southern Sweden, with a population of approximately 6.6 million. The nine laboratories have performed 71 739 postnatal cytogenetic tests. Excluding Robertsonian translocations and chromosome 9 inversions, we identified 216 DBCRs ( approximately 0.3%), including a minimum estimate of 114 de novo reciprocal translocations (0.16%) and eight de novo inversions (0.01%). Altogether, this is six times more frequent than in the general population, suggesting a causal relationship with the traits involved in most of these cases. Of the identified cases, only 25 (12%) have been published, including 12 cases with known syndromes and 13 cases with unspecified mental retardation/congenital malformations. The remaining DBCRs were associated with a plethora of traits including mental retardation, dysmorphic features, major congenital malformations, autism, and male and female infertility. Several of the unpublished DBCRs defined candidate breakpoints for nail-patella, Prader-Willi, and Schmidt syndromes, ataxia, and ulna aplasia. The implication of the survey is apparent when compared with MCN; altogether, the 292 participating laboratories have performed >2.5 million postnatal analyses, with an estimated approximately 7500 DBCRs stored in their archives, of which more than half might be causative mutations. In addition, an estimated 450-500 novel cases should be detected each year. Our data illustrate that DBCRs and MCN are resources for large scale establishment of phenotype-genotype relationships in man.

Optic nerve oxygen tension: effects of intraocular pressure and dorzolamide

AIM

To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide.

METHODS

Domestic pigs were used as experimental animals. Oxygen tension was measured by means of a polarographic electrode in the vitreous 0.5 mm anterior to the optic disc. This entity is called the optic nerve oxygen tension. Intraocular pressure was controlled by a hypodermic needle inserted into the anterior chamber and connected to a saline reservoir.

RESULTS

When the intraocular pressure was clamped at 20 cm H2O optic nerve oxygen tension was 20 (5) mm Hg (n=8). Intravenous administration of dorzolamide caused an increase in optic nerve oxygen tension of 43 (8)% (n=6). Both before and after administration of dorzolamide optic nerve oxygen tension was unaffected by changes in intraocular pressure, as long as this pressure remained below 60 cm H2O. At intraocular pressures of 60 cm H(2)O and below, dorzolamide significantly increased optic nerve oxygen tension.

CONCLUSION

Intravenous administration of 500 mg dorzolamide increases the oxygen tension at the optic nerve head during acute increases in intraocular pressure.

High resolution comparative genomic hybridisation analysis reveals imbalances in dyschromosomal patients with normal or apparently balanced conventional karyotypes

A sensitive technique is needed for screening whole genome imbalances in dyschromosomal patients when G-banding shows normal karyotypes or apparently balanced translocations. In this study we performed highly sensitive comparative genomic hybridisation analysis on a number of such cases and revealed chromosomal imbalances in all.

Characterization of human alcohol dehydrogenase isoenzymes by capillary isoelectric focusing-mass spectrometry

The human liver alcohol dehydrogenase (ADH) isoenzymes are currently believed to play a major role in ethanol metabolism, accounting for most of the ethanol oxidized in the liver. They have similar molecular masses and similar isoelectric point (pI) values (the 13 possible isoenzymes having pIs in the range of 8.26-8.87), making their characterization a significant analytical challenge. Capillary isoelectric focusing (CIEF) coupled on-line with electrospray ionization - Fourier transform ion cyclotron resonance (ESI-FTICR) mass spectrometry was applied to separate and characterize mixtures of alphaalpha, beta1beta1 and beta3beta3 ADH isoenzymes. Seven different species were resolved by the separation in the pI 8.26-8.67 range. ESI-FTICR analysis of native ADHs revealed that each noncovalent ADH complex contains two monomeric protein units and four zinc atoms. The combination of CIEF separations with mass spectrometry appears well-suited for detailed characterization of ADH isozymes, and the attomole level sensitivity of FTICR should allow very small samples to be addressed.

Mass spectrometric detection for capillary isoelectric focusing separations of complex protein mixtures

Capillary isoelectric focusing (CIEF) can provide high-resolution separations of complex protein mixtures, but until recently it has primarily been used with conventional UV detection. This technique would be greatly enhanced by much more information-rich detection methods that can aid in protein characterization. We describe progress in the development of the combination of CIEF with Fourier transform ion cyclotron resonance (FTICR) mass spectrometry and its application to proteome characterization. Studies have revealed 400-1000 putative proteins in the mass range of 2-100 kDa from total injections of approximately 300 ng protein in single CIEF-FTICR analyses of cell lysates for both Escherichia coli (E. coli) and Deinococcus radiodurans (D. radiodurans). We also demonstrate the use of isotope labeling of the cell growth media to improve mass measurement accuracy and provide a means for quantitative proteome-wide measurements of protein expression. The ability to make such comprehensive and precise measurements of differences in protein expression in response to cellular perturbations should provide new insights into complex cellular processes.

[Keratin diseases]

The rapid development in human genome research has resulted in a tremendous increase in our understanding of the molecular basis of many genetic skin diseases. One outstanding example of this is diseases caused by mutations in keratin genes, which comprise several disorders of the epidermis, as for example the different types of epidermolysis bullosa simplex. In this respect, the most important questions have been to 1. Define the molecular defect. 2. Unravel the pathophysiological mechanisms that lead to the characteristic phenotype and 3. Design of new therapeutic strategies. Molecular research has contributed significantly to the first two issues whereas a therapeutic break-through has yet to appear.

[Epidermolysis bullosa simplex: genotype-phenotype correlation in Danish patients]

Epidermolysis bullosa simplex (EBS) is a group of autosomal dominant inherited skin disorders caused by mutations in the keratin genes K5 or K14. We examined five Danish families with EBS-Weber-Cockayne (WC) or EBS-Koebner (K) and two sporadic cases of EBS-Dowling-Meara (DM) in order to investigate the mutational spectrum and evaluate the genotype-phenotype correlation in Danish patients. Three new K14 mutations, one new and one previously described K5 mutation were identified by DNA sequence analysis. The positions of the EBS-DM mutations were consistent with previous studies, whereas the EBS-WC and EBS-K mutations were found in regions of the keratin genes not typically associated with this type of EBS mutations. In conclusion, we found a strict genotype-phenotype correlation. Furthermore, we found that the position of the mutation in the keratin gene is not the only determinant for severity of the disease; the nature of the amino acid substitution should also be considered when predicting the severity of the EBS disorder.

Leiomyoma of the ciliary body. Report of 2 cases

PURPOSE AND METHODS

The files of the Eye Pathology Institute contain only two cases of leiomyoma of the ciliary body. The diagnoses were re-evaluated, applying modern immunostainings.

RESULTS

The tumors were composed of interlacing fascicles of spindle-shaped cells with bright eosinophilic cytoplasm and cigar-shaped nuclei. Both tumors were well-vascularized, mostly by thin, branching capillaries. Larger vessels were also seen. In one case the tumor perforated the sclera. The tumor cells reacted with the reticulum stain and the Masson trichrome and were positive for antibodies against: smooth muscle actin (SMA), muscle specific actin (MSA), laminin and vimentin (one case).

CONCLUSION

Leiomyoma of the ciliary body is a rare smooth muscle cell tumor that may arise from either pericytes, ciliary - or intrascleral heterotopic muscle.

Optic nerve oxygen tension in pigs and the effect of carbonic anhydrase inhibitors

PURPOSE

To evaluate how the oxygen tension of the optic nerve (ONP(O)2) is affected by the administration of the carbonic anhydrase inhibitors dorzolamide and acetazolamide and by alterations in oxygen and carbon dioxide in the breathing mixture.

METHODS

Polarographic oxygen electrodes were placed in the vitreous humor immediately over the optic disc in 20 anesthetized pigs. Blood gasses and cardiovascular physiology were monitored. ONP(O)2 was recorded continuously with breathing gasses of 21% O2-79% N2, 100% O2, 20% O2-80% N2, and 5.19% CO2-19.9%, O2-74.9% N2. Acetazolamide (15-1000 mg) and dorzolamide (6-1000 mg) were administered intravenously.

RESULTS

The mean (+/- SD) ONP(O)2 was found to be 24.1+/-11.6 mm Hg when the pigs were breathing room air and 50.7+/-29.3 mm Hg when they were breathing 100% O2 (n = 15; P < 0.001). In response to breathing 5.19% CO2, ONP(O)2 changed from 20.8+/-5.6 mm Hg (with 20.0% O2) to 28.9+/-3.6 mm Hg (n = 4; P < 0.001). Intravenous injections of 500 mg dorzolamide increased ONP(O)2 from 16.4+/-6.1 mm Hg to 26.9+/-12.2 mm Hg, or 52.5%+/-21.2% (n = 5; P = 0.017). A dose-dependent effect on ONP(O)2 was seen with intravenous dorzolamide doses of 1000, 500, 250, 125, 63, 27, 15, and 6 mg. Intravenous injections of 500 mg acetazolamide increased ONP(O)2 from 23.6+/-9.5 mm Hg to 30.9+/-10.0 mm Hg (n = 6; P < 0.001), and a dose-dependent effect was seen with doses of 1000, 500, 250, 125, 31, and 15 mg.

CONCLUSIONS

ONP(O)2 is significantly increased by the carbonic anhydrase inhibition of dorzolamide and acetazolamide, and the effect is dose dependent. These data demonstrate for the first time a direct effect of carbonic anhydrase inhibitors on ONP(O)2.

Resolution of retinal digital colour images

Several digital colour cameras commercially available were fitted on a fundus camera. A test target placed in an artificial eye was used for measurements of the resolution of the resulting digital images and compared to film material. The maximal target resolution of the fundus camera was 6 microm corresponding to 24 microm at the image plane. The best film material matched this closely. To avoid aliasing, the size of the digital image must be 2-3000 pixels to match this resolution. This criterium is fulfilled by present high-end digital cameras. Further development of hardware and software is needed for their introduction into clinical settings.

Long-term outcome of knee and ankle injuries in elite football

To estimate the risk and evaluate the long-term outcome of knee and ankle injuries in former national team elite football, 69 players were randomly selected, followed by clinical and stress radiographic examinations. Thirty-nine players (49 knees) had had knee injuries and 29 ankle injuries (35 ankles). The median time from injury until study examination was 25 years. The knee injuries were tears of the medial collateral ligament (MCL) in 24 cases combined with rupture of the anterior cruciate ligament (ACL) and meniscus lesions in three. Meniscus lesions had occurred in 17 cases including three combined with ACL and MCL and another two with ACL ruptures. Isolated rupture of the ACL had occurred in four cases. The ankle lesions were in 26 of 35 cases ruptures of the lateral ligaments. In all, 12 players had completely stopped football and three had changed occupation. Signs of arthritis were present in 63% of the injured knees and in 33% of the injured ankles. The incidence of arthritis in the group of 17 uninjured players was 26% in the knee and 18% the ankle. In elite football players knee and ankle injuries seem to have a serious long-term outcome, but also uninjured players have a higher risk of developing arthritis than the normal population.

Probing proteomes using capillary isoelectric focusing-electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry

Unlike the genome, the proteome is exquisitely sensitive to cellular conditions and will consist of proteins having abundances dependent upon stage in the cell cycle, cell differentiation, response to environmental conditions (nutrients, temperature, stress etc.), or disease state(s). Therefore, the study of proteomes under well-defined conditions can provide a better understanding of complex biological processes and inference of protein function. Thus, much faster, more sensitive, and precise capabilities for the characterization of cellular constituents are desired. We describe progress in the development and initial application of the powerful combination of capillary isoelectric focusing (CIEF) and Fourier transform ion cyclotron resonance (FTICR) mass spectrometry for measurements of the proteome of the model system Escherichia coli. Isotope depletion of the growth media has been used to improve mass measurement accuracy, and the comparison of CIEF-FTICR results for the analysis of cell lysates harvested from E. coli cultured in normal and isotopically depleted media are presented. The initial studies have revealed 400-1000 putative proteins in the mass range 2-100 kDa from total injections of approximately 300 ng of E. coli proteins in a single CIEF-FTICR analysis.

Evidence that mutations in the X-linked DDP gene cause incompletely penetrant and variable skewed X inactivation

X chromosome inactivation results in the random transcriptional silencing of one of the two X chromosomes early in female development. After random inactivation, certain deleterious X-linked mutations can create a selective disadvantage for cells in which the mutation is on the active X chromosome, leading to X inactivation patterns with the mutation on the inactive X chromosome in nearly 100% of the individual's cells. In contrast to the homogeneous patterns of complete skewed inactivation noted for many X-linked disorders, here we describe a family segregating a mutation in the dystonia-deafness peptide (DDP) gene, in which female carriers show incompletely penetrant and variable X inactivation patterns in peripheral blood leukocytes, ranging between 50:50 and >95:5. To address the genetic basis for the unusual pattern of skewing in this family, we first mapped the locus responsible for the variable skewing to the proximal long arm (Xq12-q22) of the X chromosome (Z=5. 7, P=.002, LOD score 3.57), a region that includes both the DDP and the XIST genes. Examination of multiple cell types from women carrying a DDP mutation and of peripheral blood leukocytes from women from two unrelated families who carry different mutations in the DDP gene suggests that the skewed X inactivation is the result of selection against cells containing the mutant DDP gene on the active X chromosome, although skewing is apparently not as severe as that seen for many other deleterious X-linked mutations. Thus, DDP is an example of an X-linked gene for which mutations cause partial cell selection and thus incompletely skewed X inactivation in peripheral blood leukocytes.