[Validity and reproducibility of sensor contact lens profiles in comparison to applanation tonometry in healthy eyes]. / Validität und reproduzierbarkeit von sensorkontaktlinsen-profilen im vergleich zur applanationstonometrie bei gesunden augen.

PURPOSE: The aim of this study was to check the validity of the profiles gained by a sensor contact lens in one eye. We compared these values with measurements done by applanation tonometry in the other eye. The measurements were done in different body postures and head positions. All examinations were repeated 2 to 8 weeks afterwards to check the reproducibility. PATIENTS, MATERIAL AND METHODS: Five young healthy individuals with normal eyes had the intraocular pressure (IOP) of their right eye measured by applanation tonometry (Goldmann and Perkins) in different postures (45 minutes upright, 30 minutes supine, 20 minutes head-body down and 30 minutes upright). Simultanously the left eye had a sensor contact lens, which measured the changes of the corneal curvature due to changes of the IOP within intervals of 5 minutes. Within 2-8 weeks all examinations were repeated completely in the same manner. RESULTS: After 45 minutes in upright position the mean IOP remained unchanged (14 mmHg), increased after 30 minutes in supine position (20 mmHg), increased again after 20 minutes in head-body-down position (22.4 mmHg) and came back to 14 mmHg after 30 minutes in upright position. A very similar profile was obtained in the repeat examinations. In contrast, the mean profiles gained by the sensor contact lens were not in a positive slope-like shape, but the mean values showed a flat or surprisingly, an even downward profile (head-body-down position). No statistical differences were found between all mean values of the first and repeat examinations. CONCLUSIONS: Intraocular pressure measurements gained by applanation tonometry showed the expected physiological positive slope profile during changes of the body and head positions (upright, supine, head-body-down). None of the profiles simultaneously gained by the sensor contact lens had a slope-like shape, but were flat or even downward. The reasons for the lacking validity between applanation tonometry and sensor contact lens cannot be explained. This makes the interpretation of Triggerfish profiles uncertain and they should therefore be done with caution. The reproducibility of the applanation tonometry values as well as of the sensor contact lens values was good and showed no significant differences.

[Continuous 24 h monitoring of changes in intraocular pressure with the wireless contact lens sensor Triggerfish™. First results in patients]. / Kontinuierliche 24-h-Aufzeichnung von Augendruckschwankungen mittels drahtlosem Kontaktlinsensensor Triggerfish™. Erste Ergebnisse an Patienten.

BACKGROUND: For many years researchers have been striving for a non-invasive 24 h continuous method of ambulatory intraocular pressure monitoring. A wireless device with a contact lens sensor is now on the market for clinical use, which is not a quantitative measurement of the intraocular pressure but is at least a recording of qualitative changes. These changes of corneal curvature due to changes of the intraocular pressure result in a distinct profile which gives information about fluctuations of the intraocular pressure, the behaviour during supine sleeping time and the 24 h efficacy of glaucoma therapy. We investigated the practicability and tolerability of this device. METHOD: The sensor is embedded in a soft silicone contact lens and consists of 4 strain gauges. Additionally there is an antenna made out of gold and a microchip. A second antenna is fixed around the eye which sends impulses to the microchip and receives data from the microchip. The data are sent to a recorder via a wire. Measurements are made for 90 s every 8.5 min resulting in 144 measurements within 24 h. Of the 4 strain gauges 2 sense changes in the corneal curvature due to changes of the intraocular pressure. This device was used in 11 patients with ocular hypertension or glaucoma. RESULTS: The result of the 24 h continuous measurement is a pressure profile which may be flat, fluctuating and with no, some or many spikes. We describe 2 examples of profiles from patients with glaucoma. The changes in the profiles were mostly during the sleeping hours in a supine position. Due to the lack of validation of the results it is not known if intermittent spikes are true spikes or artefacts. Practicability was simple and tolerability was reported to be good by all patients. CONCLUSIONS: For the first time a practicable, well tolerated, non-invasive device for continuous 24 h monitoring of changes of the corneal curvature due to changes of the intraocular pressure is available. It is not a direct measurement of the intraocular pressure. The resulting profile gives additional information about the behaviour of the intraocular pressure, especially during out-of-office times and night times. Disadvantages are the high cost of the contact lens sensor and the lack of validation of the results and reproducibility in patients.

[Glaucoma and oxidative stress. Determination of malondialdehyde--a product of lipid peroxidation]. / Glaukom und oxidativer Stress. Bestimmung von Malondialdehyd--einem Lipidperoxidationsprodukt.

BACKGROUND: Primary open-angle glaucoma (POAG) is a multifactorial disease, in which aging, race, genetic disposition, vascular status, probably inflammation, and maybe oxidative stress may play a specific role. We wanted to know if by using a common test for a specific oxidative stress product differences would be found in the aqueous humor and serum of patients with POAG, cataract without pseudoexfoliation, cataract with pseudoexfoliation, and volunteers without ocular disease. PATIENTS AND METHODS: We examined the aqueous humor of 33 patients with POAG, 111 patients with cataract without pseudoexfoliation, 39 patients with cataract and pseudoexfoliation syndrome and the serum of all three groups plus of 43 volunteers without ocular disease. Malondialdehyde as an oxidative stress product of peroxidation of lipids was proven by thiobarbituric acid-reacting substances (TBARS). RESULTS: The amount of TBARS is given in micromol/l: (1) in the serum of the group with cataract 1.176, with cataract and pseudoexfoliation 1.019, with POAG 0.992, and with healthy eyes 0.983; (2) in the aqueous humor of the group with cataract 0.279, with cataract and pseudoexfoliation 0.274, and with POAG 0.298. There were no statistically significant differences of TBARS (p<0.05) in either the aqueous humor or in the serum of patients with POAG in comparison to those patients without POAG. However, there was a significantly positive correlation between the values in the serum and the aqueous humor. CONCLUSION: For the first time malondialdehyde as a product of lipid peroxidation was determined in the aqueous humor of glaucomatous eyes. With the TBARS method used in our study, it was not possible to detect statistically significant differences of the lipid peroxidation product malondialdehyde between patients with or without POAG. It has to be taken into account that the cataract of the patients in the control group might be a disease per se caused by at least a certain amount of oxidative stress and that these subjects might therefore not be ideal as a control group.

TNF-alpha promoter polymorphisms and primary open-angle glaucoma.

PURPOSE: Primary open-angle glaucoma (POAG) is a multifactorial optic neuropathy with a strong hereditary component. Recent studies suggested a role for tumour necrosis factor-alpha(TNF-alpha) in the pathogenesis of POAG. The purpose of the present study was to investigate a hypothesized association between the TNF-alpha-308G>A and -238G>A gene polymorphisms and the presence of POAG in a Caucasian population. METHODS: The present case-control study comprised 114 unrelated patients with POAG and 228 healthy control subjects, matched for age and gender. Genotyping of the TNF-alpha-308G>A and -238G>A polymorphisms was performed using polymerase chain reaction. RESULTS: Allelic frequencies and genotype distributions of both the TNF-alpha-308G>A and -238G>A gene polymorphisms did not significantly differ between patients with POAG and control subjects. Presence of the TNF-alpha-308A-allele was associated with an odds ratio (OR) of 0.96 for POAG, whereas an OR of 0.52 was found among carriers of the TNF-alpha-238A-allele. CONCLUSION: Our data suggest that none of the investigated TNF-alphagene polymorphisms is a major risk factor among Caucasian patients with POAG.

[Transpupillary thermotherapy (TTT) for uveal melanomas. Long term results of a single TTT with an adapter for a conventional infrared laser]. / Transpupillare Thermotherapie (TTT) von Aderhautmelanomen. Langzeitergebnisse einer alleinigen TTT mit einem Adapter für einen konventionellen Infrarotlaser.

BACKGROUND: An increasing number of orbital recurrences after TTT have been reported; the aim of our paper was to present our long-term results after a maximum follow-up of 8 years and 2 months. PATIENTS AND METHOD: Among 18 eyes, 10 tumors were classified as small, and 8 as medium sized (with a maximum prominence of 5.6 mm): 5 melanomas had a juxtapapillary location, 6 a macular (or juxtamacular) location, and 7 were located in the midperiphery of the fundus. RESULTS: After a median follow-up of 7 years in seven tumors a complete regression (scar formation) could be achieved, and in six a partial regression (with a maximum residual prominence of 2.9 mm) could be seen. In three patients a recurrence was treated either by another TTT or a Ruthenium-106 plaque; in another two recurrences, enucleation had to be performed. In none of the cases has an orbital recurrence occurred so far. CONCLUSION: To prevent recurrences, adequate technique and appropriate selection of patients are mandatory in our opinion (no tumors higher than 3 mm). The higher the tumor prominence, the greater the chance of recurrences. Amelanotic melanomas and macular melanomas seem to respond poorly to thermotherapy.