Reduction of collagen type I in the ciliary muscle of inflamed monkey eyes

Takeshi Sagara, Dan D. Gaton, James D. Lindsey, B'Ann True Gabelt, Paul L. Kaufman, Robert N. Weinreb*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Purpose. To investigate in monkey ciliary muscle the relationship between the extent of anterior segment inflammation and alterations of collagen type I as determined by quantitative imaging densitometry. Methods. Anterior segment inflammation was induced in one eye of five cynomolgus monkey by cannulation of the anterior chamber, by anterior chamber injection of bovine serum albumin, or by disruption of the iris and anterior lens capsule with a needle. Increases in inflammatory cells were scored in hematoxylin and eosin-stained sections. Parallel eye sections were immunostained for collagen type I and developed using diaminobenzidine. Optical density (OD) was measured along two line segments overlying the immunostained ciliary muscle using two-dimensional imaging densitometry. To assess antibody labeling of ciliary muscle structures, additional sections were double-immunostained using antibodies to collagen type I and calponin and examined by confocal microscopy. Results. In each of the inflamed eyes, hematoxylin and eosin-stained sections showed signs of chronic inflammation including lymphocytes and macrophages dispersed among ciliary muscle fibers and in the iris. Double label confocal microscopy showed collagen type I immunoreactivity in the interstitial extracellular matrix between bundles of ciliary smooth muscle fibers. Collagen type I OD scores in each of the inflamed eyes were less by 16% to 55%, compared with the contralateral control eyes. The mean of the OD scores for all inflamed eyes was 39% ± 7% less than the mean of the control eye scores (mean ± SEM, P < 0.001). Regression analysis showed a close correlation between inflammatory cell scores in the treated eyes and the reduction of OD scores (r = 0.94, P = 0.02). Conclusions. These results indicate that the density of collagen type I in the extracellular matrix (ECM) of monkey ciliary muscle is reduced during anterior segment inflammation and support the view that reduction of ciliary muscle ECM may contribute to increased uveoscleral outflow facility during anterior segment inflammation.

Original languageEnglish
Pages (from-to)2568-2576
Number of pages9
JournalInvestigative Ophthalmology and Visual Science
Issue number11
StatePublished - Oct 1999
Externally publishedYes


FundersFunder number
National Eye InstituteR01EY002698


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