Cataract surgery in special situations by Dr. Iddi.pptx

Cataract surgery in special situations

1. Cataract surgery in special situations Presenter: dr. iddi ndyabawe Modulator: dr. lusobya Rebecca Makerere university, department of ophthalmology March, 2021

2. outline Glaucoma and cataract Combined cataract extraction and trabeculectomy Potential problems in removing a cataract in a patient with high myopia Potential problems in removing a cataract in a patient with uveitis How to manage a small pupil during cataract surgery Problems operating on a mature ( brunescent /white) cataract. Issues in cataract extraction for diabetic patients Mature cataracts Soft cataracts Posterior polar cataracts Fuchs endothelial dystrophy and cataract surgery

3. Glaucoma and cataract

4. Factors that determine the management of glaucoma and cataract 1. Severity and progression of glaucoma: -IOP level (most important factor) -Optic nerve head changes -Visual field changes 2. Severity and progression of cataract: -VA and visual requirements -Ocular co-morbidities/visual potential

5. 3. Patient factors Age Race (black higher rate of glaucoma progression) Family history of blindness from glaucoma Fellow eye blinded from glaucoma Concomitant risk factors for glaucoma (DM, HTN, myopia, other vascular diseases) Compliance to follow-up and medication use

6. SEVERITY OF GLAUCOMA

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9. SEVERITY OF CATARACT

10. Indications for combined cataract extraction and trabeculectomy General principle: Indications for trabeculectomy – when IOP is raised to a level that there is evidence of progressive VF or ON changes despite maximal medical treatment plus indication for cataract surgery (visual impairment) Medical indications of cataract surgery: - Phacoantigenic uveitis - Phacolytic glaucoma - Phacomorphic glaucoma -Anterior disclocation of crystalline lens -Inability to view the posterior segment

11. What are the common scenarios for trabeculectomy? Uncontrolled POAG with maximal medical treatment - Failure of medial treatment (IOP not controlled with progressive VF or ON damage) - Side effects of medical treatment - Non-compliance with medical treatment - Additional considerations: -Young patient with good quality of vision -One-eyed patient (other eye blind from glaucoma) -Family history of blindness from glaucoma -Glaucoma risk factors (HTN, DM) Uncontrolled PACG after laser PI and medical treatment Secondary OAG or ACG

12. Advantages of combined ce AND trab One operation Faster visual rehabilitation Patient may be able to be taken off all glaucoma medications Prevents post-op IOP spikes HVF monitoring easier with clear media No subsequent cataract operation needed (lower risk of bleb failure)

13. Disadvantages of combined ce and trab Strong evidence that IOP control with trab alone is better than combined surgery More manipulation during the combined operation (higher risk of bleb failure) Vitreous loss during cataract surgery (higher risk of bleb failure) Larger wounds created (higher risk of wound leakage and shallow AC)

14. WAYS TO PERFORM THE COMBINED OP . CORNEAL SECTION ECCE + TRAB ADVANTAGES: -More control -Less conjunctival manipulation -Smaller wound (lower risk of leakage and shallow AC) DISADVANTAGES: -Longer -Higher corneal astigmatism

15. Limbal section ecce + trab ADVANTAGES: -Faster -Less astigmatism DISADVANTAGES: -Larger wound -More conjunctival manipulation -Increased risk of flat AC

16. PHACOEMULSIFICATION + TRAB ADVANTAGES: -More control of AC -Less conjuctival manipulation (main reason) -Smallest wound of the 3 techniques -Less astigmatism -Faster DISADVANTAGES: -More difficult operation for the inexperienced surgeon

17. Ce in specific subsets of glaucoma WHO survey in 2002 highlight cataract and glaucoma as the two greatest sources of visual impairment worldwide, with 17 (47.8%) and 4.4 million (12.3%) persons affected Africa, in particular, has the highest prevalence of glaucoma in the adult population CE lowers IOP by 2-4mmHg CE in specific subsets of patients with glaucoma – primary OAG (POAG), ACG and pseudoexfoliation (PXE). ‘MIGS’+CE better than CE alone

18. CE AND POAG A 2002 Cochrane literature review by Friedman et al. reported a consistent (albeit weak) 2–4 mmHg reduction in IOP by either phacoemulsification or extracapsular cataract extraction. Same results in the mid‑1990s by Matsumura et al and the 1970s by Bigger and Becker The higher the initial IOP, the greater the magnitude of the IOP reduction following surgery.

19. Ce and ocular hypertension

20. Ce and pxf

21. Cataract surgery in pxf Difficulty due to: -weakened zonules -small pupil -raised IOP (risk of suprachoroidal hemorrhage)

22. Ce and narrow angle glaucoma

23. Phaco vs trab !!!

24. Mechanisms of iop change in ce Still debatable!!! A positive relationship between IOP reduction and preoperative lens vault measured by AS‑optical coherence tomography (OCT) Reduction of glycosaminoglycan deposition in the trabecular meshwork due to higher fluid flow rates Inflammation induced morphologic changes in the trabecular meshwork akin to the effects of laser trabeculoplasty; Remodeling of the trabecular endothelium secondary to ultrasonic vibrations Alterations in the blood‑aqueous barrier Changes in anterior chamber architecture Increased posterior zonular traction due to cataract surgery (whether due to lens removal alone or other technical aspects like small capsulorhexis ) has been postulated to improve patency of the trabecular meshwork and result in lower IOP

25. CATARACT SURGERY AND THE DIAGNOSTIC MANAGEMENT OF GLAUCOMA CE greatly enhances the practitioner’s ability to diagnose and follow glaucomatous progression by improving visibility and has the added benefit of improved visual acuity for the patient Fundoscopic examination of the optic nerve, OCT, and stereoscopic disc photos are more accurate after cataract removal Kim et al. found that the presence of a cataract significantly affects measurements of both spectral domain‑OCT (SD‑OCT) and time domain‑OCT (TD‑OCT). - Specifically, patients evaluated by SD‑OCT were measured to have increased retinal nerve fiber layer thickness after cataract surgery as well as changes in signal strength values. In addition, clinical perimetry is improved by more reliable patient performance and the elimination of lens‑induced artifacts.

26. Ce and the surgical management of glaucoma Roles of CE in glaucoma patients: -decreases the IOP -enhanced diagnostic monitoring of glaucoma - distinct surgical advantages when performed first in patients who will later require standard glaucoma‑filtering surgery -Early cataract extraction avoids development of cataract ‑ a common adverse effect of many glaucoma procedures. Within 5 years of trabeculectomy or tube shunt surgery, half of phakic patients develop a visually significant cataract.

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29. WHAT OF CE AFTER TUBES

30. COMBINED CE AND GLAUCOMA SURGERY

31. Potential problems in ce in a patient with high myopia PREOPERATIVE STAGE -Need to access visual potential (amblyopia, myopic macular degeneration) Choose IOL power carefully (counselling for anisometropia) Harder to do biometry (need special formulas to adjust for longer axial lengths) IOL Master biometry in view of high prevalence of staphyloma

32. Intraoperative stage Risk of perforation with retrobulbar anaesthesia ) Lower IOP (harder to express nucleus during ECCE) Deeper AC (harder to aspirate soft lens material) Increased risk of PCR: -Due to weak zonules – avoid stressing zonules/angle instruments downwards -Due to large capsular bag/floppy PC – beware of surge Increased risk of LIDRS: -Lower bottle height -Use second instrument to lift iris at pupillary margin Postop stage: RD risk

33. Ce in a patient with uveitis PREOPERATIVE STAGE: Need to control inflammation -consider waiting for 2-3 months until inflammation settles after an acute episode -consider course of preoperative steroids Assess visual potential (CME, optic disc edema) Dilate pupil in advance (atropine, subconjunctival mydriacaine ) Perform gonioscopy (if synechiae is severe superiorly, consider corneal section) Need to assess for potential intraoperative problems – weak zonules, small pupil Check for phacodonesis , subluxation Check how well pupil dilates/posterior synechiae Density of cataract

34. Intraoperative stage Problem of small pupil Increased risk of PCR (weak zonules, dense cataracts, poor view – hazy cornea) Increased inflammation (consider heparin coated IOL or leave aphakic) Increased risk of bleeding

35. Post operative stage Higher risk of complications: -corneal edema -flare up or inflammation -glaucoma or hypotony -choroidal effusion -CME Consider prophylaxis for infectious etiologies (e.g. herpetic lesions)

36. LENS SUBLUXATION

37. Small pupil during ce PREOPERATIVE STAGE: High risk patients (uveitis, DM, PXF, Marfan’s syndrome, glaucoma on pilocarpine) Prior to operation, prescribe mydriatics (3 days of homatropine 2% three times a day) 2 hours before operation, intensive dilation with: -Tropicamide 1% - Ocufen 0.03% -Phenylephrine q0%

38. Intraoperative stage Infuse AC with BSS mixed with a few drops of 1:1000 adrenaline Use viscoelastics to dilate pupil Remove pupillary membrane (previous inflammation) Stretch pupil gently (with Kuglen hooks) Perform sphincterotomy at 3, 6, 9 and 12 o’clock positions Perform broad iridectomy at 12 o’clock position Perform basal iridectomy and mid-peripheral iridotomy (better apposition than broad iridectomy) Iris hooks Pupil expansion devices (e.g. Morcher pupil expansion ring, Malyugin Ring)

39. PUPIL EXPANSION DEVICES

40. MORCHER PUPIL EXPANSION RING

41. MALYUGIN RING

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45. Problems on operating on a mature ( brunescent /white) cataract 1. Need to assess visual potential: -Pupils (optic nerve function) -Light projection (gross retinal integrity), color perception -Potential acuity meter (macular function) -B-scan ultrasound (gross retinal anatomy) 2. Poor view of capsulotomy/ capsulorrhexis edge: -Consider endocapsular technique -Consider using air instead of viscoelastics -Use of capsular stains (vision blue/trypan blue): possibly toxic to endothelium, capsular fragility, teratogenic

46. . 3. High intra-capsular pressure -CCC runs out/splits easily (Argentinian flag sign) 4. Floppy capsule due to chronic bulky lens: viscoelastic tamponade 5. Increased phacoemulsification power - corneal decompensation, higher risk of PCR from surge 6. More zonular stress - harder to separate nuclear fragments 7. White cataract -possibility of posterior polar cataract: may rupture PC during hydrodissection -mobile nucleus with no SLM tamponade

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49. Issue of ce in dm patients 1. Issues: -Difficult cataract surgery -Progression of DR after operation 2. Preoperative stage: -Assess visual potential: consider FFA -Laser PRP if necessary prior to the surgery -Medical consult (stable DM –good control) -List for first case in morning (avoid hypoglycemia)

50. Intraoperative stage Protect corneal endothelium (risk of abrasion and poor healing) Problems with small pupils Consider stitching wound Selection of IOLS: -Large optics (7mm) -Use acrylis IOL (avoid silicone IOL) -Avoid IOL if PDR (risk of neovascular glaucoma) -Avoid AC IOL -Consider heparin-coated IOL

51. POSTOPERATIVE STAGE Control of inflammation (especially in eyes with PDR) Risk of PDR/CSME Risk of rubeotic glaucoma – especially if PCR with vitreous loss Risk of PCO Poor wound healing Risk of endophthalmitis

52. Why does dr progress? Removal of anti-angiogenic factor in lens Secretion of angiogenic factors from iris Increased intraocular inflammation Decreased anti-angiogenic factor from RPE Migration of angiogenic factors into AC

53. MATURE CATARACTS Consider phaco -chop techniques to disassemble nucleus to small pieces – minimizing phaco power dispersed Phaco away from the PC – be mindful of surge, especially with last fragment Consider using a non-sharp second instrument Manage vitreous pressure — give IV mannitol if no contraindications Manage intracapsular pressure — decompress bag with 27G needle before initiating capsulorrhexis and decompress the periphery as wel

54. Soft cataracts • Achieve a good hydrodissection to allow easy rotation of the nucleus • Divide and Conquer to disassemble the nucleus • Consider using a non-sharp second instrument e.g. mushroom to avoid cheese wiring • Decrease the exposure of the tip of the phaco probe

55. Posterior polar cataracts Hydrodelineate rather than hydrodissect to avoid stressing PC weakness • Peel away the epinuclear material from the periphery and leave the central (polar) part to the last • Fill AC with viscoelastic before removing probe to avoid sudden AC fluctuations and movements of the PC

56. POSTERIOR POLAR CATARACT

57. Fuchs endothelial dystrophy and cataract surgery • Soft shell technique — Dispersive viscoelastic to coat the endothelium followed by cohesive viscoelastic to form the AC • Minimize power dispersed — lowered phaco settings, efficient phaco -chop techniques, phaco in the bag • Minimize trauma to endothelium — frequent topping up of viscoelastic, avoid tumbling of fragments

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59. CE IN FECD: preop Corneal transplant and CE, or triple … discuss Ultrasound pachymetry Endothelial cell density Pachymetry measurements greater than 640 µm and/or endothelial cell density of less than 1000/mm2 place a patient at increased risk for corneal decompensation following cataract surgery Benefits of a triple procedure : -avoiding a second surgery, -speeding up visual recovery, -reducing the costs -risks associated with sequential surgery.

60. Surgical tech of ce in fecd special considerations to minimize intraoperative corneal endothelial cell loss and optimizing visual outcomes. IOL selection: - monofocal recommended. -A hyperopic shift is expected in eyes that undergo EK due to changes in posterior corneal curvature. As a result of this known phenomenon, most surgeons target slight myopia during IOL selection. Typically -0.75 to -1.00 for DMEK and -1.00 to -1.25 for DSAEK OVDs: -soft-shell technique Capsulorrhexis : It is advisable to create a capsulorrhexis that is smaller than the IOL optic, to prevent movement of the IOL after implantation. Trypan blue.

61. Technique of ce in fecd FLACS was found to reduce endothelial cell loss in eyes with FECD, as compared to traditional phacoemulsification. In patients with denser nuclear cataracts, phaco -chop had significantly less endothelial cell loss when compared to divide-and-conquer and stop-and-chop techniques. if corneal thickness is greater than 640 um or endothelial cell density is less than 1000 cells/mm2, a triple procedure may be considered over cataract surgery alone.

62. Post op management Patients should be counseled on prolonged visual recovery Same mgt as other CE patients More significant and prolonged corneal edema that can negatively impact visual acuity: 5% hypertonic saline. If postcataract surgery edema persists past 6 weeks, preparation for EK is appropriate Studies have indicated risk factors for greater endothelial cell loss in patients with decreased endothelial cell counts: - shorter axial length, -diabetes mellitus, -longer phacoemulsification time, -higher phacoemulsification intensity, and -posterior capsular rupture

63. Pterygium and ce

64. references AAO Book 11 Wong Cataract Coach Middle Eastern Journal of Ophthalmology PubMed