title: Valid parameters for investigation of the pupillary light reflex in normal and diabetic subjects shown by factor analysis and partial correlation.
abstract: Pupillary test data of 103 normal and 119 diabetic subjects (47 IDDM, 72 NIDDM) were evaluated by factor analysis. From a total of nine pupillary parameters three factors were extracted in the analysis. Factor 1 represents maximal pupillary area, contraction velocity at 1 s, dilation velocity at 6 s and minimal pupillary area--static and simple dynamic parameters; factor 2 amplitude of pupillary unrest, area under the detrended curve of pupillary unrest and period of pupillary unrest--parameters of pupillary unrest; factor 3 fusion frequency of pupillary response following flicker stimuli and latency time of pupillary light reflex--second order dynamic parameters. Factor analysis was then applied to investigate diabetic patients with a high percentage of autonomic neuropathic participants (about 39% had pupillary and about 35% had cardiorespiratory function disorders), which revealed the same three factors as those identified in normal subjects. Furthermore, an age-related database of parameters of pupillary unrest is given. It demonstrates that normal subjects and diabetic patients did not differ in the period of pupillary unrest (normal vs diabetic (mean +/- SEM): 1550 +/- 29 vs 1536 +/- 27 ms; 2p > 0.5). The difference in amplitude (47.8 +/- 2.8 vs 41.0 +/- 2.6% percentile; 2p = 0.071) and area under the detrended curve of pupillary unrest (47.9 +/- 2.8 vs 40.8 +/- 2.6% percentile, 2p = 0.062) seems to show a trend but was not significant. In conclusion, factor analysis revealed three different pupillary test factors.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Internal Medicine I, University Hospital, Regensburg, Germany.
authors.forename: R H
authors.initials: RH
authors.lastname: Straub
authors.forename: U
authors.initials: U
authors.lastname: Thies
authors.forename: A
authors.initials: A
authors.lastname: Jeron
authors.forename: K D
authors.initials: KD
authors.lastname: Palitzsch
authors.forename: J
authors.initials: J
authors.lastname: Schölmerich
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001342:Autonomic Nervous System Diseases / Q000503:physiopathology; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D008875:Middle Aged; D011680:Pupil / Q000502:physiology; D012025:Reflex, Pupillary / Q000502:physiology*