Central connections of the lacrimal functional unit

Purpose: To study the contribution of each eye to the reflex tear response, after unilateral and bilateral topical anaesthesia. Method: A closed eye, modified Schirmer test was performed bilaterally in 8 normal subjects, in a controlled environment chamber set to 23°C, 45% relative humidity and 0.08m/s airflow. Eye drops were instilled into each eye 10 minutes before the Schirmer test. Experiments were: a) bilateral saline (control) b) unilateral anaesthesia (ipsilateral anaesthetic; contralateral saline) and c) bilateral anaesthesia. Results: There was no difference in between-eye wetting lengths in the saline control eyes (p = 0.394) or the bilaterally anaesthetised eyes (p = 0.171). Wetting length was reduced in both eyes after bilateral anaesthesia compared to saline controls (p = 0.001; p = <0.0005). After unilateral anaesthesia, wetting length was reduced in the anaesthetised eye compared to its saline control by 51.4% (p = <0.0005) and compared to its fellow, unanaesthetised eye (p = 0.005). The fellow eye value was also reduced compared to its saline control (p = 0.06). Conclusions: Wetting length was reduced by topical anaesthesia, when instilled bilaterally and ipsilaterally. The latter response implies an ipsilateral, reflex sensory drive to lacrimal secretion. In the unanaesthetised fellow eye the reduction compared to its saline control was not quite significant. This implies a relative lack of central, sensory, reflex cross-innervation, although the possibility cannot entirely be ruled out. These results are relevant to the possibility of reflex lacrimal compensation from a normal, fellow eye, in cases of unilateral corneal anaesthesia

Changes in collagen orientation and distribution in keratoconus corneas

PURPOSE. To map the collagen orientation and relative distribution of collagen fibrillar mass in keratoconus corneal buttons. METHODS. Structural analysis was performed by obtaining synchrotron x-ray scattering patterns across the samples at 0.25-mm intervals. The patterns were analyzed to produce two-dimensional maps of the orientation of the lamellae and of the distribution of total and preferentially aligned lamellae. RESULTS. Compared with normal corneas, in keratoconus the gross organization of the stromal lamellae was dramatically changed, and the collagen fibrillar mass was unevenly distributed, particularly around the presumed apex of the cone. CONCLUSIONS. The development of keratoconus involves a high degree of inter- and probably intralamellar displacement and slippage that leads to thinning of the central cornea and associated changes in corneal curvature. This slippage may be promoted by a loss of cohesive forces and mechanical failure in regions where lamellae bifurcate

Report of the Inaugural Meeting of the TFOS i2 = initiating innovation Series: Targeting the Unmet Need for Dry Eye Treatment

In March 2015, a meeting was held in London, United Kingdom, to address the progress in targeting the unmet need for dry eye disease (DED) treatment. The meeting, which launched the i2 = initiating innovation series, was sponsored by the Tear Film & Ocular Surface Society (TFOS; www.TearFilm.org) and supported by Dompé. The TFOS i2 meeting was designed to review advances in the understanding of DED since publication of the 2007 TFOS International Dry Eye WorkShop (DEWS) report, and to help launch the highly anticipated sequel, DEWS II. The meeting was structured to discuss the scope of the DED problem, to review the clinical challenges of DED, and to consider the treatment challenges of DED. This article provides a synopsis of the presentations of this TFOS i2 meeting

TFOS DEWS II Report Executive Summary

This article presents an Executive Summary of the conclusions and recommendations of the 10-chapter TFOS DEWS II report. The entire TFOS DEWS II report was published in the July 2017 issue of The Ocular Surface. A downloadable version of the document and additional material, including videos of diagnostic and management techniques, are available on the TFOS website: www.TearFilm.org

Associations with intraocular pressure across Europe: The European Eye Epidemiology (E3) Consortium

Raised intraocular pressure (IOP) is the most important risk factor for developing glaucoma, the second commonest cause of blindness globally. Understanding associations with IOP and variations in IOP between countries may teach us about mechanisms underlying glaucoma. We examined cross-sectional associations with IOP in 43,500 European adults from 12 cohort studies belonging to the European Eye Epidemiology (E3) consortium. Each study conducted multivariable linear regression with IOP as the outcome variable and results were pooled using random effects meta-analysis. The association of standardized study IOP with latitude was tested using meta-regression. Higher IOP was observed in men (0.18 mmHg; 95 % CI 0.06, 0.31; P = 0.004) and with higher body mass index (0.21 mmHg per 5 kg/m2; 95 % CI 0.14, 0.28; P < 0.001), shorter height (−0.17 mmHg per 10 cm; 95 % CI –0.25, −0.08; P < 0.001), higher systolic blood pressure (0.17 mmHg per 10 mmHg; 95 % CI 0.12, 0.22; P < 0.001) and more myopic refraction (0.06 mmHg per Dioptre; 95 % CI 0.03, 0.09; P < 0.001). An inverted U-shaped trend was observed between age and IOP, with IOP increasing up to the age of 60 and decreasing in participants older than 70 years. We found no significant association between standardized IOP and study location latitude (P = 0.76). Novel findings of our study include the association of lower IOP in taller people and an inverted-U shaped association of IOP with age. We found no evidence of significant variation in IOP across Europe. Despite the limited range of latitude amongst included studies, this finding is in favour of collaborative pooling of data from studies examining environmental and genetic determinants of IOP in Europeans

Associations with intraocular pressure across Europe: The European Eye Epidemiology (E3) Consortium.

Raised intraocular pressure (IOP) is the most important risk factor for developing glaucoma, the second commonest cause of blindness globally. Understanding associations with IOP and variations in IOP between countries may teach us about mechanisms underlying glaucoma. We examined cross-sectional associations with IOP in 43,500 European adults from 12 cohort studies belonging to the European Eye Epidemiology (E3) consortium. Each study conducted multivariable linear regression with IOP as the outcome variable and results were pooled using random effects meta-analysis. The association of standardized study IOP with latitude was tested using meta-regression. Higher IOP was observed in men (0.18 mmHg; 95 % CI 0.06, 0.31; P = 0.004) and with higher body mass index (0.21 mmHg per 5 kg/m2; 95 % CI 0.14, 0.28; P < 0.001), shorter height (-0.17 mmHg per 10 cm; 95 % CI -0.25, -0.08; P < 0.001), higher systolic blood pressure (0.17 mmHg per 10 mmHg; 95 % CI 0.12, 0.22; P < 0.001) and more myopic refraction (0.06 mmHg per Dioptre; 95 % CI 0.03, 0.09; P < 0.001). An inverted U-shaped trend was observed between age and IOP, with IOP increasing up to the age of 60 and decreasing in participants older than 70 years. We found no significant association between standardized IOP and study location latitude (P = 0.76). Novel findings of our study include the association of lower IOP in taller people and an inverted-U shaped association of IOP with age. We found no evidence of significant variation in IOP across Europe. Despite the limited range of latitude amongst included studies, this finding is in favour of collaborative pooling of data from studies examining environmental and genetic determinants of IOP in Europeans.Medical Research Council (G1000143), Cancer Research UK (C864/A14136), Research into Ageing (262), Wellcome Trust, Richard Desmond Charitable Trust (via Fight for Sight), National Institute for Health Research, Stichting Lijf en Leven, Krimpen aan de Lek, MD Fonds, Utrecht, Rotterdamse Vereniging Blindenbelangen, Rotterdam, Stichting Oogfonds Nederland, Utrecht, Blindenpenning, Amsterdam, Blindenhulp, The Hague, Algemene Nederlandse Vereniging ter Voorkoming van Blindheid (ANVVB), Doorn, Landelijke Stichting voor Blinden en Slechtzienden, Utrecht, Swart van Essen, Rotterdam, Stichting Winckel-Sweep, Utrecht, Henkes Stichting, Rotterdam, Lameris Ootech BV, Nieuwegein, Medical Workshop, de Meern, NWO (Graduate Programme 2010 BOO (022.002.023)), Laboratoires Thea (Clermont-Ferrand, France), inter regional grant (PHRC) and the regional Council of Burgundy, European Community’s Seventh Framework Programme (FP7/2007-2013), Rheinland-Pfalz AZ 961-386261/733), Johannes Gutenberg-University of Mainz, Boehringer Ingelheim, PHILIPS Medical Systems, Novartis Pharma, Novartis European Union (European Social Fund—ESF), Greek National Strategic Reference Framework (NSRF) (Research Funding Program: THALES), European Social FundThis is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1007/s10654-016-0191-