traumatic lens subluxation what to know

Ophthalmology traumatic lense dislocation

1. Traumatic Lens subluxation Mariam magdy adly

2. Lens trauma: Lens subluxation Lens dislocation Anterior posterior

3. Pathophysiology The mechanism in blunt traumatic lens dislocation is due to a compressional anterior-posterior force of the cornea and anterior sclera causing rapid compensatory equatorial expansion of the globe. As a result, the zonular fibers, which anchor the lens to the eye, may become stretched or damaged. Partial zonular dialysis may lead to subluxation while complete zonular rupture leads to complete luxation.

4. Visual acuity: Decreased visual acuity Poor near vision Monocular diplopia refraction: Myopia and astigmatism symptoms

5. Tremulus iris Edges of dislocated lens may be identified in pupillary space Vitreous prolapse gonioscopy Angle recession Ocular examination

6. Retinal breaks Retinal detachment Fundus examination

7. Glaucoma Uveitis Corneal decompensation Amblyopia (young age) Retinal detachment Complication

8. conservative Mininmal Glasses( phakic ) Colored contact lens Miotics Marked Glasses( aphakic ) Optical iridectomy surgical Management:

9. Lens induced uveitis Lens induced glaucoma Lenticular opacity Anisometropia Impending lens dislocation Surgical managment

10. Degree of zonular dehicense Up to 4 clock hours CTR with IOL implantation 3 to 6 clock hours modified CTR with single loop 6-9 clock hours modified CTR with double loop With IOL implantation in the bag or the sulcus More than 9 clock hours Pars plana Lensectomy Vitrectomy probe (clear) Fragmatome ( cataractus ) with scleral fixed IOLS,anterior chamber IOLS Iris fixed IOLS Choice of surgical procedure

11. Perferably away from area of zonular weakness. Use high molecular weight viscoelastic. Capsulorrhexis should be intiated in area remote from the dialysis. Capsulorrhexis is more easily performed with forceps , should be made off center in an eye with significant lens subluxation Cataract incision

12. Good sized rhexis supra capsular technique to decrease stress over the zonules Visco elevation Surgical tips

13. Devices used in surgery Capsular tension ring Indication 1-Missing or damaged zonules 2-Lens subluxation 3-PEX 4-High myopia 5-Marfan syndrome Mechanism Circular expansion of the bag Stable condition during surgery Improve IOL centration Reduced risk of capsular fibrosis Resist capsular shrinkage

14. Cionni ring: designed for scleral fixation with suture. one or two hooks extending from the ring located behind iris just in front anterior capsule. most frequent complication PCO

15. Ahmed capsular tension segment partial ring of PMMA covering approximately one quadrant . hole for temporary or permanent fixation. one or more segments may be used to support the areas of weak capsule.

16. Iris retractors indications contracted pupils. floppy iris. bag fixation in phacodenesis \ subluxated lens.

17. IOL implantation