Yag capsulotomy

yag laser capsulotomy

1. Nd:YAG Laser Posterior Capsulotomy Presented By Dr Rohit Rao

2. NEODYMIUM:YTTRIUM-ALUMINUM-GARNET ( Nd:YAG ) laser Solid-state laser Wavelength of 1064 mm Results in ionization, or plasma formation acoustic and shock waves that disrupt tissue.

3. Hydrodissection -associated cortical cleanup In-the-bag IOL fixation Capsulorhexis diameter slightly smaller than IOL optic IOL material : Hydrogel IOLs are associated with highest rate of PCO. PMMA is intermediate and Silicone and acrylic optic material is the lowest. IOL optic geometry with a square, truncated edge Factors preventing PCO

4. Active lens epithelial proliferation; Transformation of lens epithelial cells into fibroblasts with contractile elements Collagen deposition. PCO occurs due to

5. Nd:YAG laser capsulotomy is indicated for treatment of opacification of the posterior capsule resulting in decreased visual acuity or visual function, or both, for the patient. Indications

6. Contraindications

7. Technique Preoperative Assessment All patients require a complete ophthalmic history and examination before treatment.

8. The goal is to achieve flaps based in the periphery inferiorly. Free-floating fragments should be avoided Cutting in a circle ("can-opener" style) tends to create large fragments. "vitreous floater" of residual capsule may bother the patient.

9. In aphakic eyes, deliberate focus anterior to the capsule has been advocated as a mechanism for opening the capsule while leaving the anterior hyaloid intact.

10. The capsulotomy should be as large as the pupil in isotopic conditions, such as driving at night, when glare from the exposed capsulotomy edge is most likely. A small opening might be preferred for a patient at high risk of retinal detachment.

11. Postoperative Care

12. Elevated intraocular pressure, CME, Retinal detachment, IOl damage, Endophthalmitis, Iritis , Vitritis , Macular holes, Corneal edema Complications

13. Most common, usually transient, Associated with preexisting glaucoma, large capsulotomy size, lack of a PCIOL, sulcus fixation of PCIOL, higher laser energy, myopia, and preexisting vitreoretinal disease. Apraclonidine , timolol, levobunolol , or other beta-adrenergic antagonists are administered 1 hour before the procedure and again following the procedure. Intraocular Pressure Elevation

14. Cystoid Macular Edema CME develops in 0.55% to 2.5% of eyes following Nd:YAG laser posterior capsulotomy . CME may occur between 3 weeks and 11 months after the capsulotomy . Retinal Detachment Retinal detachment may complicate Nd:YAG laser posterior capsulotomy in 0.08% to 3.6% of eyes. Myopia, a history of retinal detachment in the other eye, younger age,and male sex are risk factors following Nd:YAG laser posterior capsulotomy .

15. Intraocular Lens Damage Pitting of IOLs occurs in 15% to 33% of eyes during Nd:YAG laser posterior capsulotomy . Pitting is usually not visually significant . rarely the damage may cause sufficient glare and image degradation that the damaged IOL must be explanted. The type and extent of lens damage depend on the material used in the IOL. Glass IOLs may be fractured by the Nd:YAG laser. PMMA IOLs sustain cracks and central defects with radiating fractures. Molded PMMA IOLs are more easily damaged than higher-molecular-weight lathe-cut lenses. Damage to silicone lenses: blistered lesions and localized pits surrounded by multiple tiny pits. Damage threshold is lowest for silicone, intermediate for PMMA, and highest for acrylic materials.

16. Capsulorrhexis is 4mm or smaller. Contracture of anterior capsule opening by lens epithelial cells due to myofibroblastic differentiation. Pupillary obstruction, Zonules stress Risk of ZD and IOL decentration . Avoided by keeping capsulorrhexis to 5mm or greater Laser photodisruption of rhexix margin(2–3mJ pulses) Deliberate anterior defocusing of laser prevents IOL damage. Capsular Phimosis Syndrome

17. Retained cortex Slowly resorb Or Dense fibrotic sheet Minimal amount of energy used (2mj). Emulsify the hydrated cortex, creating lens “milk.” Liquefied material will clear within 24hrs. May cause inflammation and increased iop.