Dieter Franz Rabensteiner

Influence of single-fraction Gamma-Knife radiosurgery on ocular surface and tear function in choroidal melanoma patients

Aim To evaluate ocular surface and tear function in patients with choroidal melanoma treated with single-fraction radiosurgery. Methods 36 patients (median age 62 years; range 26–84 years) were enrolled between 2001 and 2006 at a single institution. They were treated with the Leksell Gamma Knife in one fraction with a median dose of 30 Gy (range 25–35 Gy). In both eyes of all patients treated subjective symptom score (visual analogue scale) was evaluated, central corneal sensitivity testing, Schirmer test without local anaesthesia, and corneal and conjunctival staining were performed before therapy and 3, 6, 12, 24 and 36 months thereafter. The respective untreated fellow eye served as control. Results Three months after radiosurgery, the subjective dry eye symptom score and lissamine green staining score of the ocular surface were significantly higher in the treated eyes compared with the fellow eyes (p<0.001, p=0.028, respectively). After 12 months, a significant difference between the treated and the fellow eyes in corneal sensitivity (p=0.041) and corneal fluorescein staining (p=0.002) was found when compared with pretreatment values. After 24 months Schirmer test values without local anaesthesia were significantly reduced in the treated eyes vis-à-vis untreated fellow eyes and pretreatment values (p=0.004). The dose applied to the lacrimal gland was significantly correlated to ocular surface staining scores (p=0.001) and Schirmer test values (p=0.026) at 24 months after irradiation. Conclusions Stereotactic single-fraction Gamma-Knife radiotherapy of choroidal melanoma with a median dose of 30 Gy significantly affected ocular surface and tear function and increased dry eye symptoms and signs.

Collared Silicone Punctal Plugs Compared to Intracanalicular Plugs for the Treatment of Dry Eye

Abstract Aim: To compare collared silicone punctal plugs to intracanalicular SmartPlugs for the treatment of moderate to severe dry eye. Materials and methods: In this prospective, randomized, single blind, clinical study, 30 patients (60 eyes) who had been diagnosed with moderate to severe dry eye syndrome were enrolled. Study group I (n = 30 eyes) received collared silicone punctal plugs and group II (n = 30 eyes) received intracanalicular SmartPlugs. Data for the Schirmer I test, tear break-up time, vital staining, subjective symptoms and frequency of artificial tear application were recorded at baseline and 3 months after punctal occlusion. Results: There was no statistical significant difference for these values between group I and II. Conclusions: Although published data show free flow with irrigation and probing after SmartPlug insertion, the clinical effect in the treatment of dry eye appears to be the equally well to collared silicone punctal plugs. It seems likely that difference of design and localization between the treatment groups were of minor importance concerning impeding of natural and supplemental moisture.

Pollen Enzymes Degrade Human Tear Fluid and Conjunctival Cells: An Approach to Understanding Seasonal Non-Allergic Conjunctivitis

BACKGROUND During pollen seasons, allergy-like symptoms can be observed in proven non-allergy sufferers. Pollen enzymes are thought to be responsible for conjunctival irritation. We investigated the influence of the well-known aggressive pollen species hazelnut (Corylus avellana) and birch pollen (Betula pendula) on both human tear fluid and conjunctival cell cultures. This study is an approach to seasonal non-allergic conjunctivitis (SNAC) syndrome. METHODS Zymography was carried out in order to investigate the proteolytic activity of the pollen. Thereafter, human tear fluid was incubated with pollen extract, and the results were studied by polyacrylamide gel electrophoresis. In addition, cultivated conjunctival cells (CHANG cells) were incubated with pollen extracts. Cytomorphological changes were analyzed using the CASY1 Cell Counter. Cell viability was quantified via MTS assay. The viability of the cells which were incubated with pollen extract was compared to the viability of control cells. RESULTS Pollen proteases destroy tear fluid proteins, as observed by polyacrylamide gel electrophoresis. The treatment of CHANG cells with pollen extract induced a statistically significant decrease in cell viability, depending on the pollen extract concentration and the incubation period. CONCLUSION Evidence of the destruction of tear fluid proteins and damage to human conjunctival cells by pollen proteases explains conjunctival irritation in proven non-allergic people during the pollen season. One reason why not all people are affected by SNAC syndrome to the same extent could be differences in the concentrations of antiproteases present on the ocular surface.

Non invasive assessment of the human tear film dynamics.

Dry eye disease, or keratoconjunctivitis sicca, is a multifactorial syndrome with altered tear film homeostasis leading to ocular irritations. These alterations cause discomfort and stress for the patient, but only a few objective parameters allow for proper differential diagnosis into different subtypes of this condition. The mostly invasively performed standard assessment procedures for tear film diagnosis are manifold, but often correlate quite poorly with the subjectively reported symptoms. Due to the inherent limitations, e.g. the subjectivity of the commonly performed invasive tests, a number of devices have been developed to assess the human tear film non-invasively. Since the production, delivery, distribution and drainage of the tear film is a dynamic process, we have focused our review on non-invasive methods which are capable of continuous or repetitive observations of the tear film during an inter-blink interval. These dynamic methods include (1) Interferometry, (2) Pattern Projection, (3) Aberrometry, (4) Thermography; and (5) Evaporimetry. These techniques are discussed with respect to their diagnostic value, both for screening and differential diagnostic of Dry Eye Disease. Many of the parameters obtained from these tests have been shown to have the potential to reliably discriminate patients from healthy subjects, especially when the tests are performed automatically and objectively. The differentiation into subtypes based solely on a single, dynamic parameter may not be feasible, but the combination of non-invasively performed procedures may provide good discrimination results.

Prevalence of canaliculitis after smartplug insertion during long-term follow-up

Purpose To evaluate the long-term prevalence of canaliculitis associated with the use of SmartPlugs. Methods This retrospective study included 42 eyes of 25 dry eye patients at our institution who received a SmartPlug insertion between 2004 and 2008. Irrigation of the lacrimal system was performed in all patients prior to SmartPlug insertion to ensure the patency of the system. The median follow-up time was 7.9 (5.6–10.5) years after plug insertion. Results Six patients (seven eyes) of 25 patients (42 eyes) developed canaliculitis. The prevalence of canaliculitis per patient was 24%, and the prevalence of canaliculitis per SmartPlug was 16.6%. The median time from SmartPlug insertion to the onset of canaliculitis was 4.7 (1.4–6.0) years. The median age of the affected patients was 61.5 (36–74) years. Five of these patients were women and one was man. The pathogens were identified as Actinomyces in four eyes and as Staphylococcus aureus in three eyes. In five patients (six eyes), the canaliculitis was resolved by the application of topical antibiotics and repeated lacrimal irrigations with antibiotics and povidone-iodine. In one patient, a canaliculotomy was necessary to cure the condition. Conclusions The late onset of complications after SmartPlug insertion requires long-term observation to identify the majority of complications associated with SmartPlugs. In our patients with a follow-up of up to 10.5 years, the use of SmartPlugs was associated with the highest prevalence of canaliculitis published thus far.

Role of the Vitamin K Epoxide Reductase Complex Subunit 1 (VKORC1) −1639G>A Gene Polymorphism in Patients with Retinal Vein Occlusion

Abstract Purpose of the study: Retinal vein occlusion (RVO) is a major vision-threatening disease. Vitamin K epoxide reductase recycles reduced vitamin K, which is essential for the gamma carboxylation of clotting factors II, VII, IX, X and proteins C and S. Recently, the vitamin K epoxide reductase complex subunit 1 (VKORC1) −1639G>A (rs9923231) polymorphism has been reported as a novel risk factor for RVO in a Turkish population. The present study was set to confirm or to refute this association in a larger cohort of patients with RVO. Materials and methods: The present case–control study comprised 285 patients with central RVO, 401 patients with branch RVO and 333 control subjects. Genotypes of the VKORC1 −1639G>A polymorphism were determined by 5′ exonuclease assay (TaqMan). Results: No significant differences in either genotype distributions or allele frequencies of the vitamin K epoxide reductase complex subunit 1 −1639G>A polymorphism were found between patients and control subjects (p > 0.05). In a logistic regression analysis neither branch nor central RVO was predicted by the vitamin K epoxide reductase complex subunit 1 −1639G>A genotypes, but by arterial hypertension, ever-smoking status and in case of central RVO additionally by diabetes mellitus. Conclusions: Our data suggest that the vitamin K epoxide reductase complex subunit 1 −1639G>A gene polymorphism is unlikely a major risk factor for patients with either central or branch RVO.

Change Of Choroidal Volume In Untreated Central Serous Chorioretinopathy.

Purpose: Choroidal hyperpermeability plays a central role in the pathophysiology of central serous chorioretinopathy (CSC). In active CSC undergoing treatment, choroidal thickness decreases if subretinal fluid (SRF) resolves. This study aimed to investigate the change in choroidal thickness and volume in eyes with untreated CSC. Methods: The authors retrospectively analyzed 27 eyes with treatment-naïve CSC (25 patients), who had a follow-up of 4 to 6 weeks. Retinal and choroidal volume and SRF were segmented manually and calculated using the Spectralis OCT built-in software (Spectralis; Heidelberg Engineering). Results: In treatment-naïve eyes with CSC, an increase in SRF was significantly associated with an increase in choroidal thickness and volume (rho = 0.93, P < 0.01). Eyes with greater baseline choroidal volume showed a significantly greater decrease in SRF during follow-up (rho = −0.47, P = 0.03). Conclusion: In this study, an increase in SRF was associated with an increase in both choroidal thickness and volume in eyes with treatment-naïve CSC. Eyes with thicker baseline choroidal volume showed a greater reduction in SRF.

Assessment of vision-related quality of life in patients with central retinal artery occlusion.

Background: Central retinal artery occlusion (CRAO) is a major cause for severe visual impairment. Its effect on vision-related quality of life has not yet been determined. The purpose of the present study was thus to assess vision-related quality of life in patients with CRAO using the 39-item National Eye Institute Visual Function Questionnaire. Methods: The case–control study comprised 26 patients with unilateral CRAO and a control group consisting of 26 control subjects, matched for age and sex. Vision-related quality of life was measured using the 39-item National Eye Institute Visual Function Questionnaire. Results: After Bonferroni correction, the median 39-item National Eye Institute Visual Function Questionnaire composite score was significantly lower in patients with CRAO than in those in the control group (Pcorr < 0.001). Patients with CRAO showed significantly lower median scores in 9 of 12 subscales: general vision (Pcorr < 0.001), peripheral vision (Pcorr < 0.001), difficulties with near-vision activities (Pcorr < 0.001), difficulties with distance-vision activities (Pcorr < 0.001), role difficulties as a result of vision problems (Pcorr < 0.001), dependency on others because of vision problems (Pcorr < 0.001), limitations in social functioning because of vision problems (Pcorr < 0.001), mental health symptoms because of vision problems (Pcorr < 0.001), and general health (Pcorr = 0.008). Conclusion: Our data suggest that vision-related quality of life is reduced in patients with CRAO.

Positive Influence of Hyaluronate on Cell Vitality of Human Conjunctival Cells after Alkali Injuries

Background:To analyse the influence of hyaluronate (HA) on the cell vitality of human conjunctival cells after chemical injuries from NaOH or alkali-containing household cleaners. Methods:Human conjunctival cells (Chang cells) were incubated either with NaOH solutions or dilutions of household cleaners. HA (0.025%) was added to the cell culture medium of part of the cells subsequent to chemical injuring. After 24 h the cell vitality of the HA-incubated cells, determined by MTS assay (Cell Titer 96® Aqueous One Solution Cell Proliferation Assay), was compared to the control cells without HA addition. Results: The addition of HA to the cell culture medium subsequent to chemical injuring resulted in a significantly lower decrease in cell vitality (mean difference: 11.79; p = 0.00; CI = 98%). Conclusion: Because HA attenuates the decrease in cell vitality of alkali-damaged human conjunctival cells, formulations containing HA may be recommended for the treatment of chemical injuries to the anterior part of the eye.

Extracts of different pollen species and their effect on human tear fluid and an epithelial cell line

Abstract Purpose: Hazelnut and birch pollen are known to destroy tear film components and attack ocular surface cells. We investigated further pollen species from different plant families, whether they show similar effects on human tear fluid and an epithelial cell line in vitro, to provide a broad basis for further research on pollen reactions affecting the tear film and ocular surface. Materials and methods: Regional pollen species from different plant families (Adoxaceae, Betulaceae, Fagaceae, Juglandaceae, Malvaceae, Oleaceae, Pinaceae, Plantaginaceae, Poaceae, Salicaceae, Sapindaceae) were collected. Their proteolytic activity was evaluated by Zymography. Human tear fluid and cells of an epithelial cell line were incubated with pollen extracts. Tear fluid was analyzed by Polyacrylamide gel electrophoresis (PAGE). Cytomorphology was assessed microscopically and cell viability by proliferation (MTS), water-soluble tetrazolium (WST-1) assay and the impedance-based xCELLigence real-time analysis (RTCA). Results: Zymography revealed significant protease activity and PAGE showed the degradation of tear proteins by different pollen species. Cells incubated with pollen extracts presented dose- and time-dependent cytomorphological changes. MTS, WST-1, and RTCA revealed cytostatic as well as cytotoxic effects of pollen extracts. Conclusions: Pollen species from different plant families exert proteolytic activity and degrade human tear fluid as well as epithelial cells, which may play a crucial role in the pathogenesis of allergic and non-allergic reactions affecting the ocular surface.