Anterior lamella actinic changes as a factor in involutional eyelid malposition

Purpose: We conducted a noncomparative, retrospective chart review of 45 patients and 51 eyelids with the diagnosis of involutional entropion or ectropion that underwent full-thickness lower eyelid shortening between June 2001 and February 2004, in whom the severity of actinic damage was analyzed in relation to the eyelid position. Patients with any different surgical approach or other primary causes of abnormal eyelid position, such as paralytic, congenital, or mechanical factors, were excluded. Methods: After excision, all eyelid specimens were examined by a single anatomic pathologist, who was masked to the type of eyelid malposition. The extent of dermal actinic change was evaluated under light microscopy, according to a previously validated grading system. Results: Fifty-one eyelids from 26 male and 19 female patients were analyzed. The mean age at the surgery was 76 +/- 10 years (range, 52 to 92 years), affecting one side in 39 cases and both sides in 6 cases. The most frequent eyelid malposition was ectropion, which affected two thirds of the cases (35 eyelids). Half of the patients presented with mild actinic skin changes; however, the severity of the histologic skin actinic changes was significantly worse in patients with ectropion in comparison to those with entropion (p < 0.0001). Conclusions: Actinic damage affecting the anterior lamella of the lower eyelid contributes as an additional factor in final eyelid position in patients with involutional eyelid changes. More severe and extensive actinic changes were present in eyelids with ectropion.

New type of dual-channel PAM chlorophyll fluorometer for highly sensitive water toxicity biotests

A new type of dual-channel PAM chlorophyll fluorometer has been developed, which is specialised in the detection of extremely small differences in photosynthetic activity in algae or thylakoids suspensions. In conjunction with standardised algae cultures or isolated thylakoids, the new device provides an ultrasensitive biotest system for detection of toxic substances in water samples. In this report, major features of the new device are outlined and examples of its performance are presented using suspensions of Phaeodactylum tricornutum (diatoms) and of freeze-dried thylakoids of Lactuca sativa (salad). Investigated and reference samples are exposed to the same actinic intensity of pulse-modulated measuring light. The quantum yields are assessed by the saturation pulse method. Clock-triggered repetitive measurements of quantum yield typically display a standard deviation of 0.1%, corresponding to the inhibition induced by 0.02 mug diuron l(-1). Hence, for diuron or compounds with similar toxicity, the detection limit is well below the 0.1 mug l(-1) defined as the limit for the presence of a single toxic substance in water by the European Commission drinking water regulation. The amounts of water and biotest material required for analysis are very small, as a single assay involves two 1 ml samples, each containing ca. 0.5 mug chlorophyll. Both with Phaeodactylum and thylakoids the relationship between inhibition and diuron concentration is strictly linear up to 10% inhibition, with very similar slopes. Apparent inhibition depends on the actinic effect of the measuring light, showing optima at 6 and 4 mumol quanta m(-2) s(-1) with Phaeodactylum and thylakoids, respectively.