Cataract evaluation ppt

Cataract surgery is the most common surgery that we perform on a outpatient basis. Evaluation of the patient is critical and essential for a desirable visual outcome.

1. Pre-operative Evaluation in Cataract Surgery Chairman Prof. Golam Mostafa Director cum Professor , NIO&H Moderator Dr. S. M. Enamul Haque Assistant Professor Department of Cornea, NIO&H Presenter Dr. S.M. Hasanuzzaman FCPS part 2 Student ,NIO&H

2. What is cataract? Cataract comes from Latin cataracta , meaning waterfall. Any opacity in the lens or its capsule is called cataract. Cataract may be- 1. Nuclear 2.Cortical 3.Subcapsular 4.Polar

3. Nuclear cataract Cortical cataract PSC Posterior polar cataract

4. Epidemiology Cataract is the leading cause of vision loss. Most common surgery performed on an outpatient basis . WHO estimated cataract solely causes 48% blindness worldwide 3 million cataract surgery performed annually in USA Direct medical cost related to the treatment of cataract is approximately 6.8 billion USD annually(our total budget is 67 billion USD)

5. Indication of Cataract Surgery: Refractive Medical Therapeutic Cosmetic

6. Assessment Outline: History: ocular Medical Surgical Drug Allergy Socioeconomic Clinical Examination: Ocular Exam General Exam Systemic Exam Investigation: Biometry Others

7. History:

8. Vision: Decreased visual acuity: Patients tell the ophthalmologists Others deny: until demonstrated by ophthalmologist Different types of cataract may have different effect on visual acuity PSC :Greatly impaired near vision Nuclear cataract : myopic shift (patient experience second sight) Cortical cataract: Hyperopic shift

9. Glare and contrast Sensitivity: Glare: patient often report an increase glare I n the day time H eadlights from on coming cars due to 1. PSC 2.Anterior cortical cataract Contrast: The ability to detect subtle variations in shading A significant loss in contrast sensitivity may occur without a similar loss in visual acuity. Poor night vision

10. Monocular Diplopia or Polyopia Nuclear change in the inner layer of lens nucleus resulting in multiple refractile area that causes monocular diplopia or polyopia .

11. Characteristics and Effect of Cataract: Type Growth rate glare Effect on dis tance Effect on near Induced Myopia Cortical Moderate Moderate Mild Mild none Nuclear Slow Mild Moderate None Moderate PSC Rapid Marked Mild Marked None

12. Pertinent Ocular History: Ophthalmologists should identify conditions that could affect surgical approach and visual prognosis:- Trauma Inflammation Amblyopia Glaucoma O ptic nerve anomaly R etinal disease

13. Medical History: Complete medical history is the starting point for pre-operative evaluation Patient should achieve optimum management of all medical illness specially Diabetes Hypertension I schemic heart disease COPD Asthma B leeding disorder E pilepsy etc.

14. Drug History Systemic α 1 adrenergic antagonist medications ( prazosin ,terazosin, doxazosin , alfuzosin , tamsulosin ): F or the treatment of BEP, hypertension, urinary incontinence S trongly associated with intra operative floppy iris syndrome(IFIS) Anti platelet and anti coagulant: Low risk of hemorrhage in topical anesthesia and clear corneal incision

15. History of Allergy: Inquire about and document any allergies, adverse reaction and sensitivity to:- Anesthetics Sulfonamide and other antibiotics P ovidone iodine and L atex

16. Others: Factors limiting patients ability to cooperate or lie comfortably on the operating room table:- Deafness L anguage barrier Dementia Claustrophobia R estless leg syndrome H ead tremor Musculoskeletal disorder

17. Social History: Surgeon should aware of patients:- Occupation Hobby Lifestyle Decision of cataract surgery is not only based on patients visual acuity but also on the ramification of reduced vision on individuals quality of life

18. Past records: If patient has had cataract surgery in the fellow eye it is important to o btain information about operative and post operative courses : IFIS E levated IOP V itreous loss C ystoid macular edema Endophthalmitis H emorrhage R efractive surprise

19. Clinical examination:

20. External examination: Body habitus: Kyphosis Ankylosing spondylitis H ead tremor G eneralized obesity S upraclavicular fat may affect surgical approach

21. Ankylosing spodylitis Kyphosis 4 section operating table

22. Abnormality in the external eye like P rominent eye brow , Enophthalmos : may affect surgical approach Entropion Ectropion E yelid closure abnormality : may have impact on ocular surface and adversely effect post operative recovery

23. Severe blepharitis A cne rosacea : risk of endophthalmitis and should be treated before cataract surgery Active nasolacrimal disease : should be treated particularly if there is history of inflammation,infection or obstruction We simply can do a regurgitation test

24. Measurement of visual function: Visual Acuity: Distance and near visual acuity must be tested and careful refraction should be done so that BCVA can be determined. Glare testing: Brightness acuity tester Miller walder glare testing device Snellen chart Contrast sensitivity : Pelli - R obson Test Confrontation test

25. Score 2.0= normal Score <1.5= visual impairment Score< 1= visual disability Pelli Robson contrast sensitivity chart

26. Motility Test: Ocular alignment should be evaluated by Hirschberg reflex. Range of movement of extraocular muscle should be examined by version and duction test If there is any documented muscle deviation cover and uncover test Abnormal motility may suggest pre-existing strabismus with amblyopia as a cause of vision loss.

27. Pupil: Check light reflex D irect and consensual If there is any abnormality Swinging Flashlight test to detect a relative afferent pupillary defect which indicate extensive retinal disease or optic nerve dysfuction . Size of pupil under different lighting condition may affect the selection of IOL.

28. Slit Lamp Examination:

29. Conjunctiva: Vascularization or scarring due to previous I nflammation I njury O cular surgery may compromise healing Symblepharon may be associated with underlying ocular and systemic disease Infection process should receive appropriate treatment before cataract surgery.

30. Cornea: Ocular surface is the principle refractive interface of the eye. Diagnosis and management of keratitis sicca , blepharitis is critical. Scarring with history of herpetic eye disease Assessment of corneal thickness is important Specular reflection –endothelial cell count and cell morphology Vascularization , any kind of opacity that may block surgeons view

31. Anterior Chamber : Depth of AC aids surgical planning Shallow anterior chamber may indicate N arrow angle , Nanophthalmos , S hort axial length , Intumescent cataract, W eak lens zonules Gonioscopy is essential to rule out angle abnormality

32. Iris: Presence of iridodonesis indicates weakened zonular attachment Iris coloboma may associated with lens coloboma and localized absence of zonular attachment Posterior synechiae due to prior uveitis makes surgery more challenging

33. Crystaline Lens: Careful assessment of lenticular opacity and co-relation of degree of vision loss is important Position of the lens and integrity of zonular fiber is essential Grading of Nuclear sclerosis should be done:

34. LOCS III: Consists of three sets of standardized photographs Evaluates four features: Nuclear opalescence(NO) Nuclear color(NC) Cortical cataract(C) Posterior Sub-capsular cataract(P) Incorporating LOCS III allows better clinical documentation and decrease subjective influence

35. Fundus Evaluation

36. Ophthalmoscopy: Full fundus examination to evaluate Macula O ptic nerve Vitreous R etinal vessel Retinal periphery Further adjunctive test may be needed in patient with DM A ssess the optic nerve (optic nerve cupping and pallor, measurement of IOP, VA, Confrontation test and pupillary examination)

37. Fundus evaluation in Opaque media: B scan ultrasonography of the posterior segment is useful RD, vitreous opacity, posterior staphyloma Light projection Two point discrimination Maddox rod test Blue light entroscopy

38. Posterior staphyloma Retinal detachment

39. Special test: Potential acuity estimation: Potential Acuity Meter Visual field testing: P atient with glaucoma O ptic nerve disease R etinal disease Objective test on macular function: OCT: Edema, hole, traction, neovascularization FFA: Vascular abnormality

40. Preoperative Measurements:

41. Biometry: To calculate lens power result in desired post operative refractive outcome Two parameters: Keratometry Axial length

42. Keratometry : Determines the curvature of anterior corneal surface A scan ultrasonography: Direct contact Immersion method Optical coherence biometry: U tilize two coaxial partially coherent low energy laser beam

43. IOL Power Calculation Formulas are used for calculating appropriate IOL power Popular 3 rd generation formula includes Hoffer Q, Holladay 1,Haigis L, SRK/T 4 th generation formulas like Holladay2, Berret , Olsen utilize additional measurements to refine refractive results

44. Refractive surprise: A refractive surprise is failure to achieve post operative refractive target Source of error Prior keratorefractive surgery Contact lens related corneal warpage Dry eye Silicon oil in the vitreous Inaccurate biometry Wrong IOL selection

45. Corneal topography: Topography provides map of the corneal contour Types : Placido disc based topography Scheimpflug imaging Useful for I rregular astigmatism Patient previously undergone refractive surgery P osterior corneal astigmatism P atient desires a toric lens

46. Additional information of cornea: Corneal pachymetry : Corneal thickness assessing function of endothelium Specular microscopy : <1500 cells/mm2 may increase the risk of corneal decompensation

47. Lab Investigations: RBS Urine R/E ECG SGPT r t -PCR (COVID era) General anesthesia CBC X-ray chest Serum creatinine

48. Special Situation(Uveitis) Active uveitis should be controlled before surgery Otherwise postoperative complications like Macular edema Posterior synechiae Eye should quite without topical steriod for at least 3 months before surgery

49. Special Situation(Glaucoma): Optimum control of intraocular pressure should be achieved prior to cataract surgery. If this cannot be achieved surgeon may consider a combined operation( cataract surgery along with intervention to lower IOP)

50. Special Situation(Retinal Disease) A family history of retinal detachment or any retinal pathology in either of the patients eye is a risk factor for post operative RD. Previous vitrectomy may cause intraoperative chamber fluctuation which increase risk of posterior capsule disruption

51. Special Situation(Refractive Surgery): Refractive surgery only modify anterior corneal curvature thereby altering normal anterior/ posterior curvature ratio True corneal power can be measured by Orbscan Pentacam OCT IOL power formula for post refractive surgery: Double K formula Hoffer Q fomula Haigis L formula:Incorporated in IOL master Masket formula

52. Take Home Message: Before operation ophthalmologists should assess two things D egree to which lens opacity affects vision W hether surgery will improve patients quality of life Most importantly both physician and patient should be satisfied that surgery is appropriate choice for improving vision

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