A variety of optical and electro-optical instruments are used for both diagnostic and therapeutic applications to the human eye. These generally expose ocular structures to either coherent or incoherent optical radiation (ultraviolet, visible, or infrared radiation) under unique conditions. We convert both laser and incoherent exposure guidelines derived for normal exposure conditions to the application of ophthalmic sources.

The intended depth of CXL using current light sources is achieved only within the central area of the cornea. To provide CXL to the peripheral cornea, the ultraviolet beam either should have an improved intensity profile or may have to be decentered.

BackgroundBesides intraocular pressure, vascular factors play a role in the pathogenesis of glaucomatous optic neuropathy. One of these potential vascular factors is Flammer syndrome. The purpose of the present study was to determine in a Korean population whether signs and symptoms of Flammer syndrome occur more often in normal tension glaucoma patients than in control subjects.MethodsTwo hundred forty-six normal tension glaucoma patients and 1116 control subjects responded to a multiple-choice questionnaire asking about 15 signs and symptoms of Flammer syndrome.ResultsSeven of the 15 signs and symptoms of Flammer syndrome (increased drug sensitivity, good smell perception, reversible skin blotches, tinnitus, long sleep onset time, tendency to perfectionism, and cold hands/feet) were significantly more often positive in normal tension glaucoma patients than in controls. Six additional signs and symptoms (migraines, low blood pressure, headaches, dizziness, increased pain sensation, and feeling cold) also occurred more often, but did not reach statistical significance. Only two items (low body weight and reduced feeling of thirst) were more frequently (not significant) positive in the controls.ConclusionThere is an association between normal tension glaucoma and Flammer syndrome. If future studies confirm this relationship, treatment of Flammer syndrome may help to prevent normal tension glaucoma or to slow down its progression.

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Some effects of background luminance and test target size upon the perimetric operation range have been analysed. Working at a background luminance of 10.3 cd/m 2 , 2 as customary when working with the Goldmann perimeter, or at 1.27 cd/m , as in Octopus perimetry, does not influence the liminal brightness increment A L differently, when introducing disturbances such as pupillary constriction, decrease of transparency of the dioptric media or fluctuation of radiation form the light source producing stimulus and background luminance. This follows from published data as well as from direct measurements. Constancy of AL/L, i.e. validity of Weber's law may only be expected at background luminances L at least 2-3 times larger than the presently used background luminance of 10.3 cd/m 2 .A lower background adaptation level of 1.27 cd/m z however increases the dynamic range by about 5 dB (i.e. by a factor of about 3 times). Larger target sizes, e.g. 0.43 ~ diameter targets, as used routinely in connection with the presently available Octopus programs, in contrast to the target of the order of 0.17 ~ diameter, as used routinely to-day by many perimetrists, enhance in addition the dynamic range and offer better resistance against the effects of blur upon apparent sensitivity. The increase of the dynamic range by the combined reduction of background luminance to 1.27 cd/m ~ (instead of 10.3 cd/m 2) and adopting target 3 instead of target 1 (Goldmann standard) is considerable and amounts e.g. to about 19 dB (i.e. again of about 50 times) at an eccentricity of 50 ~ Colour perimetry, as performed by Verriest and collaborators is considered a promising examination method both for clinical purposes as well as from the research point of view.

A series of pathological conditions such as pupillary block glaucoma, angle block glaucoma, acoria, pupillary membranes and goniosynechias of various origins have been treated successfully by means of pulses emitted from a Nd:YAG Q-switched laser above optical breakdown threshold. Since linear absorption is not required, non-pigmented or entirely transparent structures are easily dissected by this method. We have also opened the supraciliary and suprachoroidal space in a series of cases of wide angle glaucomas. In all cases however, the clefts closed by secondary wound reactions. This method may be applied to extracapsular cataract surgery for opening the anterior capsule before lens extraction and to the hydrophthalmic eye.

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