[Current Status of Electronic "Continuous" Eye Pressure Measurements]. / Derzeitiger Stand der elektronischen "kontinuierlichen" Augendruckmessung.

Intraocular pressure (IOP) is generally measured at individual points and usually only once, but rarely more often, during office hours and with various different instruments. This is probably inadequate for diagnosis, assessment of progression, and therapeutic decision making, since the IOP is not a static measurement, but rather one that is subject to greater or lesser fluctuations over shorter or longer periods. This has prompted the desire for more regular or even continuous measurements. This can be achieved with self-tonometers (not discussed in this article) or by using electronic aids with sensors in the eye (invasive; in the intraocular lens, in the ciliary sulcus, on the iris, in the posterior or anterior chamber, suprachoroidal or subconjunctival) or on the eye (non-invasive; sensor contact lens). Despite numerous advances and miniaturisations, there is as yet still no continuous measurement technique (either invasive or non-invasive) that can be used routinely, but development of such a device is at an advanced stage.

[Transient visual deterioration by exposure to cold, phacic anterior chamber lens and forme fruste keratoconus. How can this be explained?]. / Transiente Sehverschlechterung bei Kälteexposition, phaker Vorderkammerlinse und Forme-fruste-Keratokonus. Wie könnte dies erklärt werden?

This article reports on a 41-year-old male patient with forme fruste keratoconus and intolerance to contact lenses. An iris-supported intraocular lens was inserted in this eye with initially satisfactory results. During wintertime the patient coached a team of biathletes even in very low temperatures and/or windy conditions and after 2-3 h experienced a deterioration of vision in this eye. The contralateral eye with a contact lens never gave any such problems in this cold environment. Several factors might be responsible for this deterioration of vision. A very low outside temperature with or without wind induces evaporation of the tear fluid resulting in a more viscous lipid content than in warm conditions. A thin cornea facilitates faster cooling of the aqueous humor and less warming of the aqueous humor due to a deep anterior chamber where the warming iris is more distant from the cornea and partially covered by the optic and haptic of the implanted lens both of which have low heat transmission and slower exchange of the aqueous humor via the small peripheral iridotomy in comparison to the pupil which is covered by the implanted lens. Populations, such as Inuits and Mongolians who permanently live in cold environments, have developed shallow anterior chambers during evolution which protects the cornea from the cold due to the reduced distance from the warming iris to the cornea. In retrospect the implantation of a refractive lens into the posterior chamber would probably have been the better choice in this particular patient constellation.

[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.

[Transient myopia]. / Transiente Myopie.

Although transient myopia is an extremely rare symptom, systemic diseases which can also lead to a life-threatening condition should also be considered in cases of sudden deterioration of vision. Therefore, the initial diagnosis in an ophthalmological clinic or practice plays a decisive role.

[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.

[Corneal melting in both eyes after simultaneous corneal cross-linking in a patient with keratoconus and Down syndrome]. / Beidseitiges Einschmelzen der Hornhaut nach beidseitigem simultanen Kollagen-Crosslinking bei Keratokonus und Down-Syndrom.

Corneal cross-linking is one of the options for treatment of progressive keratoconus. Following the published standards regarding indication and treatment schedules, it seems to be a highly safe and effective operation. Only a very few severe complications, such as stromal scarring and bacterial keratitis, have been reported.We describe a patient with keratoconus and Down syndrome who was treated with corneal cross-linking on both eyes simultaneously. One week after the operation he developed central corneal melting without signs of infection in his right eye, and 1 month after the operation in his left eye. Penetrating keratoplasties had to be performed on both eyes and were successful. A possible reason for the corneal melting might have been a corneal stroma that was thinner than the proposed limit of 400 µm at the centre. The published recommended standards should be met.

[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.

One- and two-step hydrogen peroxide contact lens disinfection solutions against Acanthamoeba: how effective are they?

PURPOSE: Effective contact lens disinfection solutions are important to keep the storage case free of acanthamoebae and thus prevent an infection of the eye. The aim of our study was to evaluate the effectivity of two new one-step hydrogen peroxide disinfecting solutions against Acanthamoeba spp. and compare it to the effectivity of other commercially available systems. METHODS: Nine one-step 3% hydrogen peroxide systems including the new systems Silver Sept (platinum and silver disk for intensifying disinfection) and Blue Vision (newly composed catalytic tablet) and 2 two-step systems (0.6 and 3.0% H(2)O(2)) were tested for their effectivity against cysts of two Acanthamoeba keratitis isolates at different concentrations. RESULTS: After a soaking time of 8 h (overnight soaking of contact lenses) the 2 two-step systems completely destroyed the cysts of both Acanthamoeba strains, even at the highest concentration of cysts tested. The nine tested one-step systems showed weaker effects. The new Blue Vision system was able to eradicate the cysts of one strain at the low concentration of cysts. CONCLUSIONS: One-step hydrogen peroxide systems do not have sufficient effects on Acanthamoeba cysts and therefore may not protect the contact lens user from a possible infection of the eye. Further development of tablets like the ones used in the Blue Vision system may result in better cysticidal effects for one-step systems.

[A clinico-pathological case report of necrotizing ulcerating keratopathy due to topical anaesthetic abuse]. / Nekrotisierende ulzerierende Keratopathie nach Lokalanästhetikamissbrauch Ein klinisch-pathologischer Fallbericht.

BACKGROUND: Topical anesthetic abuse is rare, but difficult to diagnose since most patients deny its use and the clinical changes are very similar to other corneal diseases. CASE REPORT: A 45-year-old medical doctor with a 30-year history of soft contact lens wear and recurrent corneal erosion was admitted to our clinic with a ring-shaped keratitis and intense ocular pain. A corneal smear was negative for bacterial infections and acanthamoeba but the contact lens box contained a few dead acanthamoeba and many cocci. Due to the clinical findings and the acanthamoeba found in the contact lens box acanthamoeba keratitis was diagnosed and treatment with gentamycin, pentamidine isethionat (Brolene((R))) and hexamidine (Desomedine((R))) was started. The clinical appearance did not change for 6 weeks after onset of treatment and a perforating corneal transplantation was performed for pain relief and visual rehabilitation. An iris ectropion lacking iris motility and dense cataract developed within 5 weeks and the patient admitted on direct questioning to having taken topical anesthetic (oxybuprocain) by self-medication. The histological investigation revealed few inflammatory cells. The epithelium was largely missing and few vital cells could be found in the stroma and the endothelial cell layer. Acanthamoeba could not be detected in the tissue. CONCLUSION: Topical anesthetic abuse can mimic different corneal diseases and be difficult to diagnose if the patient denies its use. In cases of keratitis with no response to treatment and strong ocular pain, topical anesthetic abuse should be considered.

Viability of Acanthamoeba after exposure to a multipurpose disinfecting contact lens solution and two hydrogen peroxide systems.

BACKGROUND/AIM: Contact lens cases contaminated with Acanthamoeba are a major risk factor for an infection of the eye. In this study the anti-Acanthamoeba activity of three different contact lens storage solutions was tested. METHODS: A new multipurpose contact lens storage solution (Meni Care Plus) and a two step (Titmus H(2)O(2)) and one step (Oxysept Comfort) hydrogen peroxide system were tested for their effects on trophozoites and cysts of three different Acanthamoeba species: A castellanii, A hatchetti, and A lenticulata. RESULTS: After a soaking time of 8 hours (overnight soaking of contact lenses) the Titmus H(2)O(2) 0.6% solution showed very good amoebicidal effects, while Oxysept Comfort 3% H(2)O(2) could not effectively destroy the cysts of any of the three tested species. Viable cysts of the species A lenticulata and A hatchetti were still present after exposure to Meni Care Plus (0.0005% PHMB) for 8 hours. CONCLUSION: Not all of the three tested contact lens storage solutions have sufficient amoebicidal effects. The two step peroxide system Titmus H(2)O(2) is a very effective disinfectant contact lens solution in order to avoid a possible Acanthamoeba infection of the eye.

Microwave treatment of contact lens cases contaminated with acanthamoeba.

PURPOSE: Microbially contaminated contact lens cases are a predisposing risk factor for Acanthamoeba keratitis. Several findings have shown that microwave irradiation kills the six Food and Drug Administration test challenge microorganisms. We aimed to determine what effect microwave irradiation has on Acanthamoeba trophozoites and cysts. METHODS: Different types of contact lens cases were contaminated with trophozoites and cysts of three different Acanthamoeba species (A. comandoni, A. castellanii, A. hatchetti) and were exposed to microwave irradiation for 3, 5, and 8 minutes, respectively. RESULTS: Trophozoites, as well as cysts of the different Acanthamoeba strains, were effectively killed, even by only 3 minutes of microwave irradiation, and there were no negative effects of irradiation on the contact lens cases themselves. CONCLUSION: We demonstrate that microwave treatment is a very effective, easy, and cheap method to keep contact lens cases free of Acanthamoeba, thus considerably reducing the risk of an Acanthamoeba keratitis.

Surface abnormalities on hydrophilic acrylic intraocular lenses implanted by an injector.

PURPOSE: To describe and evaluate abnormalities on the surface of hydrophilic acrylic intraocular lenses (IOLs) that were implanted using an injector. SETTING: Department of Ophthalmology, University of Graz, Graz, Austria. METHODS: This study comprised 70 eyes having phacoemulsification and implantation of an EasAcryl (n = 50) or Inject-A (n = 20) IOL. Both hydrophilic IOLs are biconvex and have a high water content (26%), plate-haptic design, and no angulation. The IOLs were folded in a cartridge under hydroxypropyl methylcellulose and implanted by an injector. RESULTS: Thirteen EasAcryl and 5 Inject-A IOLs had multiple white lines in the direction of the longitudinal axis on the posterior surface immediately after implantation. On 1 EasAcryl IOL, the white lines were separated by a clear central zone and were on the anterior surface. Another EasAcryl IOL had a 1.0 mm crack. CONCLUSIONS: The abnormalities on the posterior surface of high-water-content hydrophilic acrylic IOLs disappeared or were almost gone within 1 month postoperatively and do not appear to be a concern for surgeons. These abnormalities are likely the result of the IOLs' hydrophilicity and high water content and friction in the injector barrel.

Melanoma-associated retinopathy versus abnormal retinal function due to interferon-alpha/Isotretinoin therapy in cutaneous malignant melanoma.

PURPOSE: To analyze whether an abnormal retinal function in patients with a cutaneous malignant melanoma was due to paraneoplastic retinopathy or due to isotretinoin or interferon-alpha. METHODS: We studied 15 patients with malignant melanoma in stage IIa and IIb who are all participants in a randomized, multicentered, double-blind placebo-controlled clinical trial comparing interferon-alpha/isotretinoin versus interferon-alpha/placebo performed by the Department of Dermatology, University of Graz. Our assessment included a full ophthalmic history and examination, electrophysiological testing (ERG, EOG), dark adaption, color vision and visual field testing. RESULTS: The most prevalent ocular symptom patients complained about was ocular dryness (8 patients). Electrophysiological as well as psychophysical testings showed no abnormalities in 12 patients. In 1 patient the therapy was stopped because of electrophysiological and psychophysiological pathology. This patient suffered from severe reduction of night vision and visual disturbances. Another patient had had night blindness since childhood which remained stable. CONCLUSIONS: We postulate that in 1 of 15 patients, visual complaints are caused with a high probability by melanoma-associated retinopathy although, in the literature, isotretinoin is described to show similar effects on retinal function.

[Hospital data management at the Graz University Ophthalmology Clinic]. / Krankenhausdaten-Management der Universitäts-Augenklinik Graz.

In 1991, the eye hospital at the University of Graz initiated the development of a system for the documentation of patient data and services provided. The starting point of the hospital data management system was the surgical documentation system. This made it possible for the patient to be transferred to the ward accompanied by the completed and signed surgical report. In the subsequent steps we developed a complete client server system adapted to the different specific needs of all the various sections of the eye hospital. A further important feature is the fact that all the data are available for access at every part of the hospital. The current version has been in use since 1996, and will be discussed below. The main features of our hospital data management system are automated coding of medical services provided in the diagnostic, surgical and outpatient areas, and guaranteed authenticated data. Automatic generation of findings, reports, etc, allows the physician to concentrate fully on medical concerns. For a modern, service-oriented hospital, complete records of the services provided are indispensable. Complete recording of services is, however, possible only via automation. In our case, this means not only that the available data are always correct (up to date), but also that there is wide acceptance of and reliance on these data by the medical staff. Since the system is an in-house development, it is possible to react rapidly to suggestions for improvement and to eliminate possible errors immediately. The hospital data management system of the eye hospital at the University of Graz is a well-functioning example that makes it worthwhile discussing the greater use of subsystems.

Phototherapeutic keratectomy of a corneal scar due to presumed infection after photorefractive keratectomy.

This case involves a 25-year-old patient who suffered from corneal ulceration several days after photorefractive keratectomy (PRK). A central scar developed, resulting in discomfort and reduction in visual acuity. Four months later, the scar was treated by phototherapeutic keratectomy (PTK) (25 microns depth, 5 mm ablation zone). Some scar tissue was left, but it cleared slowly and steadily over the next few years. The induced hyperopia decreased from 5.00 to 1.37 diopters spherical equivalent within 28 months postoperatively. Best corrected visual acuity increased from 20/60 preoperatively to 20/20 at 28 months postoperatively. Surgeons can encourage patients with postinfectious scars after PRK to try at least 1 PTK treatment.

[Lattice corneal dystrophy. Detection of a point mutation in the kerato-epithelin gene]. / Gittrige Hornhautdystrophie. Nachweis einer Punktmutation im Keratoepithelin-Gen.

BACKGROUND: Lattice dystrophy is an autosomal-dominantly inherited disease. A mutation of the gene coding for kerato-epithelin has been found in patients with this stromal dystrophy. In codon 124 a Guanine to Adenine mutation of the nucleotide 417 has been described. We looked for this mutation in a family with lattice dystrophy treated in our clinic. PATIENTS AND METHODS: Using primers specific for kerato-epithelin gene, we amplified the cDNA extracted from lymphocytes of two patients suffering from lattice dystrophy. The polymerase chain reaction (PCR) products were subcloned and sequenced. RESULTS: Guanine to Adenine mutations, as published were detected in both of our patients at codon 124. CONCLUSION: We found the published mutation in both of our patients, indicating that this Guanine to Adenine exchange is pathognomonic for lattice dystrophy.

Complete capsulorhexis opening occlusion despite capsular tension ring implantation.

An 89-year-old woman and an 86-year-old woman had continuous curvilinear capsulorhexis, phacoemulsification, and implantation of a silicone plate-haptic intraocular lens. Because of presumed weak zonules (high age, pseudoexfoliation), a poly(methyl methacrylate) capsular tension ring was also implanted. Despite this, both patients reported deterioration in visual acuity that was the result of complete occlusion of the anterior capsule opening by fibrotic tissue 4 and 3 months postoperatively, respectively.

Efficacy and safety of 0.3% carbomer gel compared to placebo in patients with moderate-to-severe dry eye syndrome.

PURPOSE: Carbomer gel is a water-soluble polymeric resin that has been reported to maintain the tear film in contact with the eye for an extended period. The efficacy and safety of this new artificial tear were assessed. METHODS: A multicenter, single-masked, randomized, placebo-controlled study was carried out on 123 patients with moderate-to-severe dry eyes. The placebo was a mannitol solution with benzalkonium chloride 0.008% as preservative. Patients were observed over an 8-week period, and subjective and objective changes analyzed, compared to a baseline of no therapy, after 1 to 7 days washout period from previous medication. RESULTS: All primary subjective symptoms decreased significantly in the carbomer gel-treated group compared to the placebo group (i.e., dryness, discomfort, and foreign body sensation). The carbomer gel also significantly improved the rose bengal staining score relative to placebo. When data for the primary subjective efficacy variables were stratified for disease severity, there was a statistically significant improvement from baseline by day 10 for severely affected patients and from day 42 for patients with moderate disease. Secondary subjective symptoms that improved significantly in the tear gel group compared to placebo were photophobia, erythema, tear breakup time, blurry-filmy, dry-sandy sensation, and physician impression. However, no significant improvements in the secondary subjective symptoms of tearing, itching, scaling, conjuctival discharge, palpebral conjunctival redness, bulbar conjuctival redness, conjunctival luster, relief of discomfort, ease of use, and overall acceptability were found in either group over the baseline score. In addition, neither carbomer gel nor placebo improved the baseline fluorescein staining score or the Schirmer test score. Two patients suffered local allergic reactions to the carbomer gel or its preservative, which settled on withdrawal of the medication. CONCLUSIONS: Carbomer gel was more efficacious than was placebo in improving a number of subjective and objective symptoms of moderate-to-severe dry eye syndrome. The results of this study indicate that carbomer gel was a safe as was the placebo.