[Static Retinal Vessel Analysis in Population-based Study SHIP-Trend]. / Statische Gefäßanalyse der retinalen Blutgefäße in einer populationsbasierten Kohorte unter Berücksichtigung des Diabetes mellitus.

BACKGROUND: Interdisciplinary investigations of possible connections between general diseases and ophthalmological changes are difficult to perform in the clinical environment. But they are gaining in importance as a result of the age-related increase in chronic diseases. The collection of health-related parameters in the Study of Health in Pomerania (SHIP) project allows to derive conclusions for the general population. METHODS: The population-based SHIP trend study was conducted between 2008 and 2012 in Greifswald. The baseline cohort included 4420 subjects (response 50.1%) at the age of 20 to 84 years. The pre-existence of arterial hypertension, diabetes mellitus and smoking status were questioned in a standardized questionnaire, the blood pressure and the HbA1c were determined by the laboratory. The vascular diameter of retinal arterioles and venules were determined by means of non-mydriatic fundus images and the retinal arterial (CRAE) and venous equivalent (CRVE) were calculated therefrom. The association of diabetes mellitus, HbA1c, smoking status and blood pressure with the retinal vascular parameters was tested for age and sex with linear regression models. RESULTS: In 3218 subjects with evaluable standardized fundus photographs, significant associations of elevated HbA1c (> 6.5%), smoking status and systolic and diastolic blood pressure were found with the retinal vessel widths CRAE and CRVE. Anamnestic diabetes mellitus, on the other hand, was not associated with any of the vascular parameters. CONCLUSION: This research study reveals a relevant correlation between general diseases and the retinal blood flow in the eye. Therefore, general diseases can induce ophthalmological changes and eye examination can provide information for the assessment of general diseases.

Relationship of systemic blood pressure with ocular perfusion pressure and intraocular pressure of glaucoma patients in telemedical home monitoring.

BACKGROUND: We evaluated the relation of systemic blood pressure with intraday variations in ocular perfusion pressure and intraocular pressure in patients with primary open-angle glaucoma in a telemedical home monitoring scenario. MATERIAL/METHODS: In the project Teletonometry Mecklenburg-Vorpommern (TTMV) patients were equipped with a home monitoring system for 24-hour self-measurements of intraocular pressure and blood pressure for a period of six months. All measurements were transmitted via telephone modem to an electronic patient record. Ocular perfusion pressure (OPP) was automatically calculated from self-measurements of intraocular pressure (IOP), systolic (SBP) and diastolic blood pressure (DBP) using the equation: OPP=[2/3*(2/3*DBP+1/3*SBP)]-IOP. We present the temporal characteristics of 70 patients with primary open-angle glaucoma based on 3282 self-measurements. RESULTS: The diurnal ocular perfusion pressure trend showed four characteristic phases (7am - 12am, 12am - 6pm, 6pm - 10pm, and 10pm - 7am). Between 7am and 12am ocular perfusion pressure and simultaneously systolic and diastolic blood pressure were significantly depressed compared to all other phases (p<0.05) whereas intraocular pressure showed no significant shifting. Instead intraocular pressure was significantly depressed between 6pm and 10pm (p<0.05) where ocular perfusion pressure reached the highest intraday values. CONCLUSIONS: We found that ocular perfusion pressure in patients with primary open-angle glaucoma showed remarkable circadian fluctuations. A significant decrease in the morning was associated with significantly depressed systolic and diastolic blood pressure levels. In addition we observed normal intraocular pressure values in the morning but a significant decrease in the evening which did not affect ocular perfusion pressure. These conclusions strengthen the evidence that systemic blood pressure fundamentally influences ocular circulation and consequently glaucoma progression.

Laser scanning confocal microscopy for conjunctival epithelium imaging.

BACKGROUND: Conjunctival disorders may adversely affect tear film and promote/induce the development of sicca syndrome (also known as Sjögren's syndrome). The basic diagnostics of sicca syndrome are slit lamp examination and functional tests (such as the Schirmer test, break-up time, or fluorescein/rose bengal staining). However, morphological analysis requires time and effort, both in terms of technical equipment and labor, and the results are not available immediately. In contrast, when using laser scanning confocal microscopy (LSCM), the anatomy and morphology of the conjunctival epithelium may be evaluated in vivo during the clinical examination. MATERIAL AND METHODS: We examined the conjunctival epithelium of 23 subjects with healthy eyes using LSCM. We compared intraindividual morphological patterns of normal conjunctival epithelium derived from the Heidelberg Retina Tomograph II - Rostock Cornea Module (HRTII-RCM) with those from impression cytology. All examinations were performed on the conjunctiva bulbi at the 12 o'clock position, 2 mm from the limbus corneae. RESULTS: LSCM and impression cytology examine the conjunctival epithelium from identical perspectives. This facilitates an intraindividual comparison of morphological patterns. In addition, artifact detection and the mapping of light/dark pattern recognition of the LSCM to the microscopy of the impression cytology were reliable. LSCM allows in vivo discrimination of non-secretory from secretory cells in conjunctival epithelium. Non-secretory epithelium shows dark, light and bright cytoplasm of epithelial cells on LSCM, in contrast to impression cytology. Nucleoplasmic ratio ranged from 1:1 to 1:4. Shape, size and interior structure were reliable criteria to distinguish goblet cells from non-secretory cells. The interior structure of the goblet cells showed dark or highly reflective bright homogeneous textures. CONCLUSION: LSCM is a feasible method for examining the morphology of conjunctival epithelium using non-invasive in vivo imaging. Morphological criteria for squamous metaplasia of the conjunctiva in sicca syndrome are already known from cytology, and can be used in almost the same manner in LSCM. The separation of epithelial microcysts from small goblet cells is difficult with LSCM. Finally, the clinical application of LSCM in the staging of sicca syndrome has to be evaluated in future studies.

Plugs for occlusion of the lacrimal drainage system.

BACKGROUND: Next to medical therapy, blockage of the lacrimal drainage system is the commonest form of treating dry eye. Rather than applying an artificial tear, the latter helps to preserve any remaining natural tear fluid, which by far has the best wetting and nutrient capacity for the ocular surface. A temporary block is usually induced by implants to tamponade on the level of the lacrimal puncta or canaliculi. MATERIALS AND METHODS: A Medline search was performed with the keywords 'lacrimal drainage system, punctum, canaliculus, temporary occlusion, plug, dry eye, keratoconjunctivitis sicca' for the years 1986-2006. Plugs are a suitable treatment in patients with moderate or more severe disease. The characteristics of the devices used and procedures as well as the complications described were analyzed. RESULTS: Criteria such as a lack of Schirmer strip wetting, ocular surface staining and the frequency of artificial tears instillation should be assessed prior to making the decision to occlude the lacrimal drainage. Lacrimal plugs made of silicone or a thermodynamic acrylic polymer, such as hydrogel, appear to be safe and effective, although each patient should be followed on a long-term basis to exclude alterations of the lacrimal system such as chronic inflammatory reactions, extrusion or migration, which may all lead to discomfort. High-frequency ultrasound as a non-invasive, simple diagnostic technique can be used to identify the type or position of plug or inflammatory reaction present. CONCLUSION: Tamponade of the lacrimal drainage system is a simple procedure that is underused. Preserving natural tears by blocking the lacrimal drainage system can successfully maintain the integrity of the ocular surface and corneal transparency and visual acuity. In patients with moderate or severe dry eye, it is capable of improving quality of life and preventing loss of vision.

Surgical occlusion of the lacrimal drainage system.

BACKGROUND: If a lacrimal plug that successfully improves dry eye symptoms is spontaneously lost or causes unwanted effects other than epiphora, surgical occlusion of the lacrimal drainage system should be considered. Here we review current irreversible and reversible techniques to occlude the lacrimal drainage and describe a new surgical technique, termed 'punctum switch', which has the advantage of being permanent and yet potentially is reversible. MATERIAL AND METHODS: A PubMed search was performed to identify the current literature on surgical occlusion of the puncta and canaliculi for dry eyes. The characteristics of the procedures are described, classifying them as temporary or permanent and their localization being either on the level of the lacrimal puncta or canaliculi. A 'punctum switch' graft involves a superficial excision of a piece of lid margin including the punctum. This graft is then rotated and fixated so that the excised punctum comes to rest lateral to the remaining lacrimal ampulla, which in turn is covered by full-thickness lid margin tissue. RESULTS: Established methods include cauterizing or ligating the puncta or canaliculi as well as everting the medial portion of the lid. Both thermal and surgical techniques show a high rate of reopening. If permanent occlusion is achieved, this however often is irreversible and can only be treated by means of lacrimal bypass surgery. The 'punctum switch' procedure can achieve long-term occlusion of the canalicular system while offering potential reversibility. CONCLUSION: A large variety of surgical techniques to occlude the nasolacrimal drainage system exists. These vary significantly in terms of complexity and reversibility. Surgical occlusion should be used more often in patients with moderate or severe dry eye, which previously responded well to temporary occlusion with plugs.

Lubricating agents differ in their protection of cultured human epithelial cells against desiccation.

BACKGROUND: In dry eye, as a disease of the ocular surface, the instillation of artificial tears should compensate for the deficit in wetting and protect the mucosa against drying. MATERIAL/METHODS: The desiccation protection of different pharmacological substances was tested using the conjunctival epithelial cell line Chang 1-5c-4 (series 1) and the corneal cell line 2.040 pRSV-T (series 2). On confluent cell growth the cultures were wetted for 20 min with various preservative-free preparations of artificial tears The cell cultures were exposed to a constant air flow for 0, 15, 30 and 45 minutes. Cells were incubated with the vital dye Alamar Blue and subsequently absorption of the oxidised form of the dye was measured using an ELISA-Reader. RESULTS: Cell survival rates in series 1 after 0, 15, 30, 45 min were (1.02;0.81;0.35;0.32) for Artelac EDO, (0.82;0.69; 0.63;0.54) for Vidisic EDO, (0.77;0.80;0.67;0.70) for Vidisic Fluid EDO, (0.76;0.70;0.36; 0.34) for Acuolens, (0.97;0.46;0.35;0.33) for Viscofresh, (0.88;0.85;0.37; 0.33) for Hyal Drops SDU, (0.71;0.44;0.34;0.33) for PBS and in series 2 (1.03;0.84;-0.21;-0.20) for Artelac EDO, (0.89;0.92;0.93;0.86) for Vidisic EDO, (0.96;0.88;0.85;0.85) for Vidisic Fluid EDO, (1.01;0.75;-0.02;-0.03) for Acuolens, (0.98;0.17;-0.22;-0.20) for Viscofresh, (0.97;0.83;0.03;-0.21) for Hyal Drops SDU and (0.96;0.26;-0.24;-0.21) for PBS. Vidisic Fluid EDO and Vidisic EDO showed a significantly better protective effect after a drying period of 30 and 45 min. CONCLUSIONS: The protection capability of pharmacological substances against desiccation can be studied in a standardised cell culture system of human epithelial cell lines. Whether these in vitro results are conferrable to the efficacy of artificial tear drops in vivo has to be evaluated in clinical trials.

[Evidence of lacrimal plugs via high resolution ultrasound]. / Zum Nachweis von Tränenwegokklusiven mittels Hochfrequenzsonographie.

BACKGROUND: The practical value of high-frequency ultrasound (transducer frequency of 20 MHz) for studying lacrimal plugs positioned into canaliculi was proved. MATERIALS AND METHODS: Twelve patients with twenty intracanalicular plugs and two punctum plugs were examined via high-frequency B-scan ultrasonography using 20 MHz transducer (model I3 Sacramento, USA). Detection and localisation of the intracanalicular plugs was made by a 20 MHz sector scanner. The ultrasound examinations were performed 1 - 24 month after the placement of lacrimal plugs. After patient's head positioning, the high-frequency ultrasound investigation was done via immersion fluid (2 % methylcellulose). RESULTS: All patients with dry eye treated by lacrimal plug implant showed echographic structure in the lacrimal canaliculus. In transversal echograms it was possible to image both canaliculi together when the lids were half-closed. Contrary to the normal state, it was not necessary to inject viscous fluid into the canaliculus. High-resolution ultrasound was able to differentiate the normal canaliculus from the findings after plug placement. The echograms can vary from one plug type to another. Highly reflective structures were found after the placement of silicone intracanalicular plugs, e. g. HERRICK-Plug. In contrast, the ultrasonic image taken through acrylic polymer intracanalicular plugs showed homogeneous small reflective inner structure, e. g. SMART-Plug. However, smooth and flat acoustic interface between acrylic polymer plug and the lacrimal canaliculus produced strong echoes. CONCLUSIONS: 20 MHz ultrasound seems to be well suited for the detection and localisation of intracanalicular plugs. By use of 20 MHz ultrasound scans it is possible to get high-quality images of the intracanalicular plug and around lacrimal canaliculus. Compared with UBM, the depth of penetration is much higher with negligible resolution. On the whole, we believe that 20 MHz ultrasound can become a useful tool for evaluating the placement of intracanalicular plugs after insertion.

20-MHz ultrasound and its value in imaging of lacrimal plugs.

BACKGROUND: High-frequency B scan ultrasonography is a proven method for the assessment of anterior segment diseases. Only few studies have used sonography to examine the lacrimal drainage system. We examined the proximal lacrimal drainage system by high-resolution 20-MHz ultrasound to verify the possibility to identify intracanalicular lacrimal plugs. METHODS: Eight patients who had received 12 lacrimal plug implants were examined by high-resolution ultrasound. A 20-MHz sector scanner was used for detection and localization of 2 types of intracanalicular plugs (Herrick) lacrimal silicone plug, Smart trade mark acrylic polymer plug) and 1 punctum plug. Ultrasound examinations were performed 1-24 months after plug placement. Cross-sections of the lacrimal canaliculi were obtained. RESULTS: The various intracanalicular implants were successfully viewed using the 20-MHz ultrasound sector scanner. Intracanalicular plugs were located at the appropriate position as intended. The silicone plugs could be seen as areas of higher reflectivity. In contrast, acrylic polymer plugs were seen as low-reflective inner structures. In a longitudinal echogram, the interface between the acrylic polymer plug and the lacrimal canaliculus produced a strong acoustic impedance. In patients with an intracanalicular acrylic polymer plug, the caliber of the plug could be ascertained and the diameter measured. CONCLUSION: High-resolution ultrasound with a 20-MHz sector scanner is helpful in detecting intracanalicular plugs and is a valuable tool to assess the migration of lacrimal plugs through lacrimal canaliculi. A 20-MHz sector scanner can be used to identify and locate lacrimal plugs in the proximal drainage system even if biomicroscopic signs or clinical data are absent.