Search

Purpose: To examine changes in the retinal vasculature of rat pups after 14 days of minute-by-minute small variations in oxygen., Methods: Arterial oxygen data from a preterm infant who developed severe retinopathy of prematurity (ROP) was translated to equivalent values for the rat. Newborn rat pups were raised for 14 days in a cage in which a computer controlled the atmosphere to mimic the fluctuating oxygen profile (group V). Positive controls (P) of 12-hour cycles of 80% and 21% were run concurrently, as were room air controls (C). All were killed at day 14., Results: Groups V and P had significantly larger avascular retinal areas than C [median, interquartile range (IQR) 1.7%, 0-7.9%; 10%, 8.1-13%; 0%, 0-0%, respectively; each group n = 30]. Group P had a higher capillary branch count than C (median, IQR: 310/mm(2); 253-311 mm(2); versus 277/mm(2), 272-364/mm(2), respectively), but this was not significant using a multilevel analysis. Group V had significantly reduced capillary counts compared with C (median, 261/mm(2); IQR, 215-290/mm(2); P < 0.05 multilevel analysis). No neovascularization was seen in any group, though abnormal terminal vessels were seen at the avascular/vascular retina interface in 73% of rats in group P and 21% of rats in group V. In situ hybridization on serial sections demonstrated VEGF in the inner nuclear layer of the retina in P and V, whereas C showed trace levels only., Conclusions: The vaso-obliterative stage of ROP can be induced in rats using clinically relevant oxygen levels.

Objectives: The life expectancy for patients with cystic fibrosis has risen constantly within the last 10 years to an average age over 20 years in western countries. However, most of these patients are partially respiratory insufficient. Frequently their physicians must decide whether it is acceptable to expose them to reduced air pressure on board of an aeroplane during long distance flights or how their fitness to fly can be improved prior to their annual vacation. We investigated the effect of intensified daily physiotherapy -carried out during a four weeks stay on Gran Canaria, Spain- on lung-function parameters, oxygen saturation and saliva neopterin as marker for ongoing inflammation in the respiratory tract., Methods: 10 out of 12 patients (age 19 34 years, mean 28.6 years) were investigated two weeks prior and two weeks after their trip to the Canaries, Spain. Lung function on ground level and during flights to and from the island, oxygen saturation and saliva-flow adjusted neopterin in saliva were measured., Results: Over the entire group vital capacity (VC) improved significantly from 2.89 l (range 1.37 3.95) to 3.36 l (range 1.23 5.24). Intrathoracic gas volume as a sign for pulmonary hyperinflation- declined slightly from 3.79 l (range 2.06 6.17) to 3.48 l (range 2. 18 5.85). The oxygen saturation increased from 89.5% (range 79 - 92%) during the flight to the Canaries to 94% (range 82 - 96%) during the return flight. Saliva neopterin dropped from 0.8 pmol/min. (range 0.2 6.8 pmol/min) to 0.6 ( range 0.1 2.6 pmol/min) pointing to diminished inflammation in the respiratory tract., Conclusion: Our results indicate that fitness to fly can be improved by intense physiotherapy as shown by improvement of vital capacity and oxygen saturation during flight. The influence of an additional climate change on the improvement of lung function in CF-patients needs further evaluation.

Objectives: Patients with cystic fibrosis (CF) represent a special risk for commercial airlines. Even on ground conditions the oxygen partial pressure (paO subset2) of these patients is partially clearly reduced. The reduced air pressure on board of an airplane can cause a drop of the paO subset2 to a critical point (below 50 mmHg) during a flight. Therefore, medical assistance or at least oxygen-supply over a longer time period could be necessary. Aim of this study was to investigate reaction and clinical outcome of patients with CF during a hypobaric-chamber-flight at altitudes of 2. 000 and 3.000 m to appraise their risk for a flight-trip., Methods: 10 CF-patients (age 19-35 years, mean age 30 y) were investigated in a hypobaric chamber prior to an already booked flight-trip to the Baleares (Spain). Lung-function, oxygen saturation (SO subset2) and paO subset2 by pressure adjusted blood gas analysis were measured on ground level, at 2.000 m and 3.000 m pressure-altitude., Results: Forced expiratory vital capacity (FVC) over the entire group was 2. 9 l (range 1.4 to 4.0 l), forced expiratory 1-second volume (FEV subset1) 2.08 l/sec (range: 1.22 to 3.61 l/sec). Values dropped slightly at 3.000 m chamber altitude (VC=2.7 l, FEV subset1=1.95 l/sec). SO subset2 decreased from 95 % on ground to 89% at 2.000 m and 86 % at 3.000 m chamber altitude. paO2 decreased from 79.5 mmHg at ground level to 60 mmHg at 2000m and 45.5 mmHg at 3.000 m. Only one patient with a paO subset2 of 52 mmHg didn t fall below the critical flight limit of 50 mmHg. No patient felt below a paO subset2 of 40 mmHg. No patient experienced dyspnea during the chamber flight. Two patients without subjective symptoms before the chamber flight developed mild ear blocks during descent presumably due to swollen polyps. Complaints improved quickly by applying decongestant nose-spray. -, Conclusion: The results of the chamber flights indicate that chronically adapted adult lung disease patients without accompanying heart disease and a paO subset2 of > 40 mmHg during flight can anticipate a safe flight trip. These results could be confirmed by the consecutive flight trip to Spain.

Four unusual cases of patients are described with severe thyroid eye disease (TED) who presented with primary hypothyroidism and thyroid-associated dermopathy (TAD). All four patients had moderate or severe TED and elevated circulating thyrotropin (TSH) receptor antibodies.

We have investigated the occurrence of attenuated extracolonic manifestations (AEMs) of familial adenomatous polyposis (FAP) in patients with non-polyposis colorectal cancer. In a prospective case-control study, we observed that significantly more colorectal cancer patients exhibited AEM than did age and sex-matched controls (19.5% vs 7.5%, P < 0.004). However patients with AEMs do not have occult FAP, as we found no heterozygous adenomatous polyposis coli (APC) gene mutations despite extensive analysis of constitutional DNA. Genome-wide DNA replication errors (RERs) occur in a proportion of colorectal cancers, particularly right-sided lesions and in almost all tumours from hereditary non-polyposis colorectal cancer (HNPCC) patients. As AEMs have been reported in familial colon cancer cases, we investigated the relationship of AEMs to tumour RER phenotype. There was indeed an excess of AEMs in patients with right-sided tumours (30.2% of 53 patients vs 14.7% of 116 patients, P < 0.03) and in those with RER tumours (3 out of 12 patients with RER tumours vs none out of 21 patients with non-RER tumours, P < 0.05). Two patients with AEM were from HNPCC families compared with none of those without AEM (P < 0.05). The association of AEMs with colorectal cancer is intriguing, and we speculate that it may be a manifestation of mutational mosaicism of the APC gene, perhaps associated with a constitutional defect in DNA mismatch pair.

Retinopathy of prematurity (ROP) is a potentially blinding disease of preterm infants. 21 days of computer-recorded transcutaneous oxygen (TcPO2) data were compared in 31 infants with stage 3 or greater ROP and 38 infants with no ROP or stage 1 or 2. In a multiple logistic regression adjusted for significant perinatal factors (birthweight, gestation, and intraventricular haemorrhage), babies with stage 3 or higher ROP showed an increased variability of TcPO2 in week 1 (p < 0.01) and 2 (p = 0.012) but not week 3. Variability of TcPO2 in the first 2 weeks of life is a significant predictor of severe ROP.

To test the effectiveness of the 1995 Royal College of Ophthalmologists (RCO) guidelines for screening for retinopathy of prematurity (ROP) in one regional neonatal intensive care unit, an analysis was carried out of screening examination results over a 4 year period, retrospectively applying the rules of the 1995 RCO guidelines. Four hundred and forty-eight examinations would have been performed in 258 infants, significantly fewer than the 764 examinations which had been performed using our existing screening protocol. Threshold ROP developed in 36 infants, and would have been detected promptly in every case. No case of threshold ROP developed in infants of birth weight greater than 1250 g. The 1995 RCO guidelines for ROP screening provide an effective and efficient means of detecting treatable ROP. The need to include infants of birth weight > 1250 g should be reviewed at a future date, following a period of further national data collection.

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.

We wanted to investigate the value of using a lid speculum and scleral indentation in performing binocular indirect ophthalmoscopy (BIO) in neonates at risk of retinopathy of prematurity (ROP). We performed a prospective masked comparison of BIO examinations using either a lid speculum and scleral indentation (SI) or no scleral indentation (NSI), in our neonatal intensive care unit. We did 57 consecutive BIO examinations of infants weighing less than 1500 g and/or having a gestational age of less than 32 weeks. With NSI, zone I ROP was reliably seen in 53 of 57 examinations; the superior, nasal, and temporal aspects of zone II were seen in 45 of 57 examinations; inferior zone II, in 22 of 57 examinations; and zone III in 1 of 57 examinations. SI facilitated complete peripheral fundus examination in all cases but had to be abandoned in two infants due to acute changes in oxygen saturation levels. Five infants developed threshold disease, and in two of them details of the active ROP ridge were missed with NSI. The gentle use of an eyelid speculum and globe rotation allows rapid and relatively atraumatic assessment of the peripheral fundus, even in babies who are being ventilated. Although threshold ROP may be diagnosed by observation of posterior retinal vessel dilation and tortuosity ("plus" disease), accurate grading of ROP is likely to require SI. In the absence of clearly developed "plus" disease, borderline or prethreshold disease may occasionally be missed using BIO with NSI. SI is necessary to examine the inferior midperipheral retinal vasculature (zone II) and the far peripheral temporal retina (zone III) and is associated with few complications.(ABSTRACT TRUNCATED AT 250 WORDS)

A photometric study of the effect of pupil dilatation on Nd:YAG laser iridotomy area was performed in 21 eyes of 21 patients. The iridotomy area was 0.075 (0.055) mm-2 (mean (SD)) before pupil dilatation and 0.073 (0.070) mm-2 after pupil dilatation (t test NS). Iridotomy area after pupil dilatation correlated with iridotomy area before pupil dilatation (r = 0.815, p < 0.01) but did not significantly correlate with measures of iridotomy shape or position, or with changed iris area following pupil dilatation. Two iridotomies became reduced to less than 20% of their initial area following pupil dilatation. Our findings suggest that the only effective method of avoiding development of unacceptably small iridotomy area after pupil dilatation is to create a sufficiently large iridotomy at the time of initial laser surgery.

Ninety-six low birth-weight premature infants at risk of retinopathy of prematurity (ROP) were screened over a 25-month period, yielding 30 eyes of 15 infants with 'treatable' disease. The response and complications of cryotherapy were prospectively evaluated in these infants over a 3-24-month period. Six eyes of three infants progressed to cicatricial disease despite treatment. One infant developed angle closure glaucoma but neither eye showed cicatricial disease. In 24 eyes of 12 infants regression of active ROP was observed after treatment. The local and systemic complications associated with cryotherapy are discussed.

Whole blood viscosity (WBV) and haematocrit (Hct) were measured in 8 very low birth weight premature neonates developing acute severe retinopathy of prematurity (ROP) and 7 control neonates without retinopathy or mild ROP. Single samples were collected at 32-34 weeks conceptual age. There was no statistically significant difference in WBV or Hct between the two groups. The results of this preliminary report suggest that WBV does not appear to play a major role in the development of advanced ROP, though larger studies are required to investigate this further.

Argon laser pretreatment followed by Nd:YAG laser iridotomy 4 to 6 weeks later was performed in the right eye of 10 patients. Primary Nd:YAG laser iridotomy was performed in the left eye. Significantly more Nd:YAG laser energy was needed to produce an iridotomy in pretreated eyes (P less than .001). Pretreated eyes developed a significantly larger pigment epithelium defect around the iridotomy site and a greater degree of pigmentation of the inferior part of the trabecular meshwork 6 months following treatment. Argon laser pretreatment followed by Nd:YAG laser iridotomy 4 to 6 weeks later appears to offer no advantages over primary Nd:YAG laser iridotomy.

A case of retained intraorbital and intracerebral wooden foreign body following an orbitocranial penetrating injury through the lower lid of an adult is described. Initial failure to recognise the true nature of the injury led to intracerebral abscess formation and monocular blindness. Diagnosis and management of such cases are discussed.

Six albino rabbits were subjected to pulsed Nd:YAG laser irradiation to the retinal surface to determine whether such treatment would lead to proliferative vitreoretinopathy. Choroidal, retinal, and preretinal hemorrhages, noted at the time of treatment, resolved after 7 to 10 days. Histological examination showed no signs of anterior segment damage or proliferative vitreoretinopathy. These preliminary findings suggest that more extensive experimentation is warranted to determine if pulsed Nd:YAG laser may in fact safely be used to separate vitreoretinal adhesions in the treatment of retinal detachment.

A prospective, randomised comparison of Nd:YAG laser iridotomy and operative peripheral iridectomy in the fellow eye of 52 patients presenting with acute angle closure glaucoma has been undertaken. Nd:YAG laser iridotomy resulted in a significantly higher incidence of iris bleeding at the time of treatment (p less than 0.05), higher intraocular pressure one hour (p less than 0.02) and three hours (p less than 0.02) following treatment, and a higher incidence of focal corneal oedema 24 hours following treatment (p less than 0.001). One laser treated patient developed acute angle closure glaucoma two weeks following treatment despite the presence of a small patent iridotomy. After a mean follow-up period of 11.8 months there was no significant difference between the two groups in visual acuity, or intraocular pressure. It is concluded that Nd:YAG laser iridotomy is a satisfactory alternative to operative peripheral iridectomy in the prophylactic treatment of fellow eyes.

Four cases of acute angle closure glaucoma in eyes with a small but patent Nd-YAG laser iridotomy are presented, and similar cases in the literature are reviewed. Theoretically a 15 microns diameter iridotomy should be large enough to prevent angle closure glaucoma due to pupil block. Mechanisms by which larger iridotomies fail to prevent angle closure glaucoma, and the role of provocation tests following iridotomy, are discussed. An iridotomy should be at least 150-200 microns in diameter if acute angle closure glaucoma is to be reliably prevented.

Ophthalmoscopy and three tests of visual function were undertaken in 39 patients with rheumatoid arthritis receiving treatment with antimalarial drugs and in a control group of 16 patients with rheumatoid arthritis who were not receiving such treatment. Visual contrast sensitivity, macular threshold to red light, and central visual fields to red targets were not significantly different in treated patients and controls. There were no abnormalities in visual acuity, but 11 of 76 eyes of treated patients showed minor macular abnormalities on ophthalmoscopy that were not seen in control patients, suggesting that ophthalmoscopy may be the most sensitive measure of early drug toxicity. Five rheumatologists were able to identify 52 of 65 minor changes detected by an ophthalmologist. These studies, and a critical review of published reports, suggest that in clinical practice antimalarial drugs can be administered safely to patients with rheumatoid arthritis without the need for repetitive routine examination by an ophthalmologist or the use of complicated physiological tests. Recording of visual acuity in each eye and ophthalmoscopy by the prescribing doctor may be all that are required to detect early antimalarial maculopathy.

We present the first ten consecutive cases of rhegmatogenous retinal detachment treated by one surgeon using pneumatic retinopexy with Nd:YAG laser disruption of vitreoretinal adhesions. In nine cases the retina has remained reattached, after a follow-up period of 11 to 18 months. The use of the Nd:YAG laser to disrupt vitreoretinal adhesions at the sites of retinal tears is discussed.

A new non-invasive clinical pharmacological model, developed at the Institut für Klinische Pharmakologie, Bobenheim (FR Germany), is reported. The principle of the model is the photographic determination of the diameter of the pupilla before and after administration of drugs active at the pupillar muscle. The area of the pupilla as a parameter of drug effect can be proceeded mathematically. With the reported model the area under the time curve, the pupillary index and the mean myotic or mydriatic time is determined. The area under the curve gives information about the extent of the drug effect. The pupillary index takes the maximum diameter into account and is even more sensitive than the area under the curve, correcting steep and flat profiles of the time curve. The mean mydriatic or myotic time gives a robust measurement concerning the duration of the drug effect. To prove the relevance of our model we used N,N-diethyl-N-(2-[alpha-(tricyclo(2.2.1.02.6)hept-3-ylidene)-benzyloxy]-ethyl)- amine hydrochloride (treptilamine hydrochloride, Asta S 5521) in four different dosages orally and intravenously. The results show: 1. The model is appropriate to show the effect of drugs on the smooth pupillary muscle concerning rate and extent. 2. The drug treptilamine hydrochloride does change the diameter of the pupils. 3. The drug is active after oral application.