Surgical intervention and accommodative responses, I: centripetal ciliary body, capsule, and lens movements in rhesus monkeys of various ages.

Gregg Heatley // Kaufman Lab // Mary Croft // Publications // Dec 01 2008

PubMed ID: 18552393

Author(s): Croft MA, McDonald JP, James RJ, Heatley GA, Lin TL, Lütjen-Drecoll E, Kaufman PL. Surgical intervention and accommodative responses, I: centripetal ciliary body, capsule, and lens movements in rhesus monkeys of various ages. Invest Ophthalmol Vis Sci. 2008 Dec;49(12):5484-94. doi: 10.1167/iovs.08-1916. Epub 2008 Jun 14. PMID 18552393

Journal: Investigative Ophthalmology & Visual Science, Volume 49, Issue 12, Dec 2008

PURPOSE To determine how surgically altering the normal relationship between the lens and the ciliary body in rhesus monkeys affects centripetal ciliary body and lens movement.

METHODS In 18 rhesus monkey eyes (aged 6-27 years), accommodation was induced before and after surgery by electrical stimulation of the Edinger-Westphal nucleus. Accommodative amplitude was measured by coincidence refractometry. Goniovideography was performed before and after intra- and extracapsular lens extraction (ICLE, ECLE) and anterior regional zonulolysis (ARZ). Centripetal lens/capsule movements, centripetal ciliary process (CP) movements, and circumlental space were measured by computerized image analysis of the goniovideography images.

RESULTS Centripetal accommodative CP and capsule movement increased in velocity and amplitude after, compared with before, ECLE regardless of age (n = 5). The presence of the lens substance retarded capsule movement by approximately 21% in the young eyes and by approximately 62% in the older eyes. Post-ICLE compared with pre-ICLE centripetal accommodative CP movement was dampened in all eyes in which the anterior vitreous was disrupted (n = 7), but not in eyes in which the anterior vitreous was left intact (n = 2). After anterior regional zonulolysis (n = 4), lens position shifted toward the lysed quadrant during accommodation.

CONCLUSIONS The presence of the lens substance, capsule zonular attachments, and Wieger’s ligament may play a role in centripetal CP movement. The capsule is still capable of centripetal movement in the older eye (although at a reduced capacity) and may have the ability to produce approximately 6 D of accommodation in the presence of a normal, young crystalline lens or a similar surrogate.