No abstract

In assessing the corneal endothelium by noncontact specular microscopy, cell count should be given, and this should be > or =75/ endothelium for an expected variance to be at a level close to that recommended for monitoring age-, stress-, or surgery-related changes.

Measures of spontaneous eyeblink activity, despite often being measured, have not been standardized and the reliability of the measures has received very little attention. Video recordings were made of 22 healthy volunteers aged 20 to 58 years, while silently fixating on a 2 m distant, 35 mm high target under 350 lux illumination. Using an event marker, significant fluctuations (up to ±35%) in spontaneous eyeblink frequency (SEBF) or inter‐blink intervals (IBI) were observed in most subjects, on a minute‐by‐minute basis, over a 5‐minute period. However, the eyeblink activity did not conform to a minute‐by‐minute periodicity and time‐dependent trends were uncommon. For subjects <40 years of age, correlation's between SEBF and IBI indicated that 3‐5 minute assessments were likely to be adequate, but that at least 5 min periods are generally required for older patients. Modal IBI values correlated well with an adjusted modal calculated SEBF and represent a more accurate estimate of the dominant eyelid activity. Methods have thus been standardized to allow meaningful measures of spontaneous eyeblink activity to be made in health and disease.

No abstract