Management of adult cataract II.ppt

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Management of adult cataract II.ppt

  1. 1. Management of Adult Cataract Prof. Naimatullah Khan Kundi Head, Department of Ophthalmology Khyber Teaching Hospital Peshawar
  2. 2. Cataract Surgery Types: 1. ICCE 1. ECCE  Standard (Manual Nuclear Expression)  Phacoemulsification (Ultrasonic Nuclear Fragmentation) Management of Adult Cataract
  3. 3. Cataract Surgery Intra Capsular Cataract Extraction (ICCE) Definition:  Removal of cataractous lens in its entirety from the eye  Complete removal of the lens and its capsule
  4. 4. Cataract Surgery Extra Capsular Cataract Extraction (ECCE) Definition:  ECCE involves removal of the nucleus and cortex through an opening in the anterior capsule, leaving the posterior capsule in place
  5. 5. Cataract Surgery ICCE  ICCE evolved into a very successful operation  Preferred surgical technique before the refinement of modern ECCE surgery  However there remained 5% rate of potentially blinding complications including:  Infection  Hemorrhage  RD  CME
  6. 6. Cataract Surgery  ECCE has replaced ICCE, almost entirely in most parts of the world: 1. Better operating microscopes 2. More sophisticated surgical aspiration systems 3. More sophisticated IOL implants
  7. 7. Pre-operative evaluation and information  General health  Drug History  Ocular and social histories  Ocular examination  Measurement of visual function  Preoperative measurement
  8. 8. Pre-operative evaluation and information  General health  A complete medical history starting point  Ophthalmic surgeon should work with patient’s primary care physician to achieve optimal management of all medical problems like:  DM  IHD  COPD  Bleeding Disorders  Adrenal Suppression by Corticosteroids
  9. 9. Pre-operative evaluation and information  Awareness of any Drug sensitivities and medications:  Immunosuppressants  Anticoagulants: These may alter the outcome of surgery
  10. 10. Pre-operative evaluation and information  Ocular history  Helps ophthalmologist identify conditions that could affect:  Surgical Approach  Visual Prognosis  Hx of:  Trauma  Inflammation  Amblyopia can affect visual prognosis  Glaucoma  Optic nerve  Retinal disease  Past record may show patient’s visual acuity prior to development of cataract
  11. 11. Pre-operative evaluation and information  Ocular history (cont’d)  Information about the postoperative course in fellow eye  Any problem in the first operation:  ↑ IOP  Vitreous loss  CME  Endophthalmitis  Hemorrhage  The surgical approach & post operative follow-up can be modified for the 2nd operation to ↓ risk of similar complications
  12. 12. Pre-operative evaluation and information  Social History  Important for documenting patient’s subjective visual disability  Surgeons should be aware of patient’s occupation and life style
  13. 13. External examination (pre-op Evaluation)  Body habits:  Bull Neck, Kyphosis, Obesity, Head Tremor  These have effect on surgical approach  Enophthalmos, prominent brow  Entropion, Ectropion & other lid abnormalities noted and treated  Blepharitis: Diagnosed and treated  Abnormal tear dynamics, exposure keratitis ↓ corneal sensation noted
  14. 14. External examination (pre-op Evaluation)  Motility:  Ocular alignment evaluated  EOM tested for their range of movements  Cover testing (muscle balance):  Any abnormality might suggest pre-existing strabismus with amblyopia as cause of visual loss  Tropia: may result in diplopia following surgery
  15. 15. External examination (pre-op Evaluation)  Pupil  Pupillary responses to light and accommodation evaluated  Direct & consensual constriction of pupil  Swinging-flashlight Test:  To detect RAPD (Indicative of serious retinal / optic nerve dysfunction)
  16. 16. External examination (pre-op Evaluation)  Biomicroscopic examination  Conjunctiva  Scarring / lack of mobility over sclera  Symblepharon / shortening of fornices (underlying systemic/ocular surface disease):  Can limit surgical approach  Loss of vascularization (Previous chemical injury / scarring from ocular surgery):  Change in surgical approach
  17. 17. External examination (pre-op Evaluation)  Biomicroscopic examination  Conrnea  Corneal thickness, presence of Guttata and marked abnormalities of endothelium  Specular reflection and SL examination provide estimate of endothelial cell count and morphology
  18. 18. External examination (pre-op Evaluation)  Biomicroscopic examination  Conrnea (cont’d)  Thickness> 600 µm suggest poor prognosis for corneal clarity following cataract surgery. Surgery tailored to minimize trauma to corneal endothelium  Cornea inspected for corneal arcus / stromal opacities (may limit view during surgery)
  19. 19. External examination (pre-op Evaluation)  Biomicroscopic examination  Anterior Chamber  Shallow AC:  Intumescent lens  Forward displacement by posterior pathology (e.g. CB Tumor)  AC depth observation and lens nucleus size:  Help surgeon plan and choose between expression / phacoemulsification  Preoperative gonioscopy (esp. when AC-IOL is anticipated)  PAS  Neovascularization  Prominent major arterial circle
  20. 20. External examination (pre-op Evaluation)  Biomicroscopic examination  Iris  Pupil size after dilation noted (important for planning surgical technique)  Presence of PS noted  Poor pupillary dilation: the following measures may provide adequate exposure 1. Radial iridotomy 2. Sector iridectomy 3. Posterior synechiolysis 4. Sphincterotomy 5. Iris retraction
  21. 21. External examination (pre-op Evaluation)  Biomicroscopic examination  Lens  Lens appearance noted before and after dilation of pupil  Visual significance of “oil droplet” nuclear cataracts and small PSCs best appreciated before dilation of pupil  Exfoliation syndrome best seen following dilation  Nuclear size and brunescence evaluated for phacoemulcification (after dilation)
  22. 22. External examination (pre-op Evaluation)  Biomicroscopic examination  Lens (cont’d)  Medial clarity in visual axis evaluated to assess lenticular contribution to the visual deficit  Posterior capsule focused with thin SL beam, the light then changed to cobalt blue and if PC no longer illuminated, the media is 20/50 or worse (blue light scatter)
  23. 23. External examination (pre-op Evaluation)  Biomicroscopic examination  Lens (cont’d)  PSC (small) may cause severe visual loss:  Conversely dense brunescent nuclear sclerotic cataracts may allow surprisingly good visual acuity
  24. 24. External examination (pre-op Evaluation)  Biomicroscopic examination  Lens (cont’d)  Lens position and zonular fibers integrity also evaluated  Lens decentration  Excessive distance between lens and pupillary margin (may indicate subluxation)  Indentation/flattening of lens periphery might indicate focal loss of zonular support
  25. 25. Fundus Evaluation  Ophthalmoscopy (Direct & Indirect) 1. Anatomical integrity of posterior segment assessed 2. Media clarity (direct opthalmoscope) 3. Macular, ON, Retinal vessels, Retinal periphery evaluated 4. ARM may limit visual rehabilitation after otherwise uneventful cataract ext.
  26. 26. Fundus Evaluation  Ophthalmoscopy (Direct & Indirect) (cont’d) 5. Diabetic patients examined carefully for:  Macular edema  Retinal ischaemia  Neovascularization ± Retinal ischaemia may progress to posterior or anterior neovascularization in case of  ICCE or  ECCE (with PC rupture)
  27. 27. Fundus Evaluation  Ophthalmoscopy (Direct & Indirect) (cont’d) 6. Peripheral retinal examination may reveal:  Vitreo-retinal traction  Lattice degeneration  Preexisting retinal holes ICCE & Primary decision of PC are associated with ↑ incidence of RD and CME Which may warrant preoperative treatment
  28. 28. Optic Nerve  Examined for color, CD ratio or any other abnormality  ON functions further evaluated by:  VA  Confrontation VF testing  Pupillary Examination
  29. 29. Other Methods Mature cataract prevents direct visualization of posterior segment  B-Scan ultrasonography  RD  Posterior segment tumor  Light projection  Maddox Rod projection Helpful in detecting retinal pathology
  30. 30. Measurements of visual function 1. VA Testing 2. Brightness Acuity 3. Contrast Sensitivity 4. Visual Field Testing
  31. 31. Measurements of visual function 1. VA Testing  Test both near and distant visual acuity  Refraction to determine BCVA  PH VA  VA can improve after pupillary dilation (esp. in PSC)
  32. 32. Measurements of visual function 2. Brightness Acuity  Test near and distance visual acuity in well lighted room of patient with complaint of glare  Under these conditions, patient with cataract shows ↓ 3 or more lines compared with VA in the dark  Variety of instruments available to standardize and facilitate this measurement
  33. 33. Measurements of visual function 3. Contrast Sensitivity  Patients with cataracts may experience ↓ contrast sensitivity even when Snellen acuity is preserved  Variety of instruments and charts available to test in clinical setting
  34. 34. Measurements of visual function 4. Visual Field Testing (VFT)  VFT may help to identify visual loss from other disease process:  Glaucoma  ON disease  Retinal abnormalities  Confrontation VFs should be tested  Goldmann or automated VF testing helps to document degree of preoperative visual loss  Light projection helpful to test peripheral VF in patients with dense cataracts
  35. 35. Measurements of visual function 5. Special Tests 1. Potential acuity estimation  Helpful in assessing the lenticular contribution to visual loss  Methods:  Laser interferometry  Potential acuity meter
  36. 36. Measurements of visual function 5. Special Tests 1. Potential acuity estimation (cont’d)  Laser interferometer:  Twin sources of monochromic helium-neon laser light creates a diffraction fringe pattern on the retinal surface  Transmission of this pattern mostly independent of lens opacities  Retinal VA estimated by varying the spacing of the fringe
  37. 37. Measurements of visual function 5. Special Tests 1. Potential acuity estimation  Laser interferometer (cont’d)  The area of pattern subtending the retina is considerably larger than fovea  Thus small foveal lesions that limit VA may not be detected  Potential acuity meter: Projects a numerical or snellen vision chart through a small entrance pupil  Image can be projected into the eye around lenticular opacities
  38. 38. Measurements of visual function 5. Special Tests 1. Potential acuity estimation  Potential acuity meter  Projects a numerical or Snellen vision chart through a small entrance pupil  Image can be projected into the eye around lenticular opacities
  39. 39. Measurements of visual function 5. Special Tests 1. Potential acuity estimation (cont’d)  Laser interfermeter & potential acuity meter determinations useful in estimating VA before surgery  Both much predictive in moderate lens opacities  Misleading In:  ARM  Amblyopia  Glaucoma  Serous Retinal Detachment  Small macular scar  Macular edema  Accurate clinical examination of the eye is as good a predictor of the visual outcome as these tests
  40. 40. Measurements of visual function  Cataracts obstruct fundus view  Direct examination may be difficult 1. Maddox Rod 2. Photo-Stress Recovery Test 3. Blue-light entoptoscopy 4. Purkinje’s entoptic phenomenon 5. Electro-retino-graphy (ERG) These tests measure function rather than appearance
  41. 41. Measurements of visual function 1. Maddox Rod  Red line viewed by the patient (orientation)  Grossly evaluates macular function  Large scotoma appears as loss of red line as viewed by the patient
  42. 42. Measurements of visual function 2. Photo-stress recovery test  Photo stress recovery time used to semiquantitavely judge macular function  Penlight shown into a normal eye (photo stress) and recovery period noted  This period is necessary before the patient can identify the Snellen letters one line larger than that individual’s baseline VA (photo stress recovery time)  Normal average time: 27 sec. With std. Deviation of 11 sec.  In most cases this time is 50 sec. Or less  Prolonged time is an indication of macular disease
  43. 43. Measurements of visual function 3. Blue-light entoptoscopy  Patient is asked to view intense, homogenous blue-light background  White blood cells produce shadows as they course through perifoveal capillaries  If the patient sees these shadows, macular function is probably intact  Many patients find the test difficult to comprehend, which limits its usefulness
  44. 44. Measurements of visual function 4. Purkingje’s Entoptic Phenomenon  Subjective test  Rapidly oscillating point source of light is shown through closed eye lids  Ability of the patient to detect shadow images of his/her retinal vasculature provides a very rough indication that retina is attached
  45. 45. Measurements of visual function 5. Electro-retino-Graphy (ERG) & Visual Evoked Response (VER)  In rare cases these tests can be done to evaluate retinal and or ON function where other testing is inconclusive

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