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Indications & techniques of lens surgery

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Indications & techniques of lens surgery

  1. 1. Indications & Techniques of lens surgery Bipin Bista Resident Ophthalmology
  2. 2. Introduction • 2 main categories : Medical & Optical • Medical arises from pathological states of the lens of varying usually lens clarity, position , or other ocular inflammation , glaucoma or threat of glaucoma. • Refractive indication for clear lens ammetropic state: Phakic IOL surgery.
  3. 3. Medical indications for lens surgery • Lenticular Opacification • Lenticular malposition – subluxation , dislocation • Lenticular malformation – coloboma,lenticonus,lentiglobus,spherophakia. • Lens induced inflammation – phacotoxic uveitis, phacolytic glaucoma, phacomorphic glaucoma. • Lenticular tumor – epithelioma, epitheliocarcinoma • Facilitatory (surgical access) : Vitreous base, ciliary body, ora serrata
  4. 4. Lenticular Opacification • True pathological states • Major ocular function (Vision) is obscured • Reduces availability of light, scatters light off the axis, reduces contrast sensitivity, diminishes color intensity, reduces resolution, decrease in accommodation amplitude , myopic alterations. • Laser interferometry : measure light obstruction • Progressive change in cataract density : LOCS-III (Chylak & co- workers) by Scheimpflug photography
  5. 5. Lenticular Opacification • The degree of better vision & risk-outcome ratio can be different in factors like amblyopia, corneal opacification, vitreous opacification, maculopathy, retinopathy, glaucoma and optic neuropathy. • Lens surgery only for ambulatory functions. • Collaborative endeavour : Diabetic, Alzheimer’s , mental disorders, stroke, blood disorders. • Holistic evaluation.
  6. 6. Lenticular malposition • Subluxation • Dysfunctional zonules • Connective tissue disorders • Chronic inflammation & exfoliation • Ocular trauma : Obvious cause • Glare, fluctuation vision & monocular diplopia.
  7. 7. Lenticular malformation • Congenital • Genetic, hereditary, or the result of intrauterine infection or trauma. • Rubella & lowe syndrome • Aniridia & iris coloboma • Early detection & surgical intervention.
  8. 8. Lens induced ocular inflammation • Phacoanaphylatic endophthalmitis • Lens induced glaucoma (phacolytic, phacomorphic)
  9. 9. Refractive indications for lens surgery • Accurate and successful correction of refractive errors. • Refinements in measurement and surgical techniques. • Location for refractive surgical modulations : corneal epithelial surface, corneal stroma, corneal endothelial surface, anterior chamber, iris , pupil, posterior chamber, lens and sclera. • Lens has its presumative popular location for refractive surgery. • Multi-focal IOLs, intra-ocular injection of liquid silicone, intracapsular placement of high water content poly-HEMA lenses, a liquid silicon filled intra-capsular balloon, multiple IOLs (Polypseudophakia), flexing haptic accommodative IOLs.
  10. 10. Indications for different lens surgery techniques • Intracapsular extraction : Zonular absence/dialysis, lens subluxation, lens dislocation. • Nuclear delivery : low endothelial cell count, guttate dystrophy, brunescent cataract, cataracta nigra, torn posterior capsule during phacoemulsification, zonuldialysis. • Phacosection : astigmatism & other nuclear delivery conditions. • Phacoemulsification : normal endothelial cell count, no guttate dystrophy, immature nuclear sclerosis, cortical or subcapsular cataract & astigmatism.
  11. 11. History of cataract surgery techniques
  12. 12. Year Technique Place Surgeon 800 Couching India Unknown 1015 Needle aspiration Iraq Unknown 1100 Needle aspiration Syria Unknown 1500 Couching Europe Unknown 1745 ECCE inferior incision France Daviel 1753 ICCE by thumb expression England Sharp 1860 ECCE superior incision Germany Von graefe 1880 ICCE by muscle hook zonulysis and lens tumble India Smith 1900 ICCE by capsular forceps Germany Verhoeff / Kalt 1940 ICCE capsule suction erysiphake Europe Stoewer / Barraquer 1949 ECCE by PCIOL & operating microscope England Ridley 1951 AC IOL Italy / Germany Strampelli / Dannheim 1957 ICCE by enzyme zonulysis Spain j. Barraquer 1961 ICCE by capsule cryadhesion Poland Krewicz/kelman 1967 ECCE by phacoemulsification U.S J.Shock 1975 Iris-pupil supported IOLs Netherlands Binkhorst/ worst 1984 Foldable IOLs U.S / S.A Mazzocco/Epstein
  13. 13. Intracapsular Extraction • Not been a method choice since 1970. • Has higher rate of PS complications : haemorrhage, vitreous loss, RD, and CME. • Indications : isolated congenital anomaly, absence or decreased zonular fibers, pseudoexfoliation, trauma , following pars plana surgery. • Large incision (12-14 mm) • Most case undergo secondary IOLs implanted.
  14. 14. Intracapsular Extraction
  15. 15. Extracapsular Extraction • Popular since 1980s • Intact posterior chamber & posterior chamber implantation • Performed in large numbers in 3rd world nations. • Done in cases of hard nuclei, capsule rupture with vitreous presentation, high risk corneas. • Small Incision are now the procedure of choice.
  16. 16. Extracapsular Extraction
  17. 17. Extracapsular Extraction
  18. 18. Phacoemulsification • Incision ranging from 3.2 mm down to less than 1.0 mm. • Foldable lens implantation • Smaller the incision lesser the astigmatism • Newest : femtosecond laser assisted phaco-cut precise corneal incision and truely circular capsulorrhexis & partial fragmentation of nucleus, permitting less ultrasonic energy
  19. 19. Surgery of lens capsule - capsulorrhexis • The Continuous Curvilinear Capsulorrhexis : Capsulectomy of choice • Size : 4.5-5.5 mm sufficient to cover the IOL optic edge for ‘in the bag’ placement of IOL. • Keeps the IOL in the bag, away from the iris pigments, holds the IOL optic and haptic in position for refractive stability and posterior capsule clarity. • Execution done through good red reflex, visualisation through staining of capsule . • New generation square-edged IOLs
  20. 20. Phaco
  21. 21. Surgery for presbyopia • Many attempts has been made. • Scleral implants to expand the anterior peripheral sclera in attempts to allow further space for ciliary action • Substances for injecting in capsular bag to restore youthful accommodation ( yet not commercialised) • Monovision : state of anisometropia geared towards emmetropia in one eye.
  22. 22. Astigmatism • Holistic approach • Accurate correction of the optical state of the eye (Biometry & formulas, astigmatism induction avoidance, and pre-existing correction). • ‘on axis’ incision for SICS : incision on the steep axis of the astigmatism • Higher level of correction by cause secondary higher order aberration induction – Different toric IOLs
  23. 23. References • Ophthalmology : yanoff and duker : 4th Edition • American academy of ophthalmology : section 11 : 2014-2015
  24. 24. THANK YOU