PRE-OPERATIVE EVALUATION IN CATARACT SURGERY

REPORT ABOUT CATARACT EVALUATION

1. Chairman
Prof. GolamMostafa
Director cum Professor , NIO&H
Moderator
Dr. S. M. EnamulHaque
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
In the day time
Headlights 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

11. Monocular Diplopia or Polyopia
Nuclear change in the inner layer of lens nucleus
resulting in multiple refractilearea that causes
monocular diplopia or polyopia.

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

13. Pertinent Ocular History:
Ophthalmologists should identify conditions that
could affect surgical approach and visual prognosis:-
Trauma
Inflammation
Amblyopia
Glaucoma
Optic nerve anomaly
Retinal disease

14. 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
Ischemic heart disease
COPD
Asthma
Bleeding disorder
Epilepsy etc.

15. Drug History
Systemic α1 adrenergic antagonist medications
(prazosin,terazosin, doxazosin, alfuzosin,
tamsulosin):
For the treatment of BEP, hypertension, urinary
incontinence
Strongly associated with intra operative floppy iris
syndrome(IFIS)
Anti platelet and anti coagulant:
Low risk of hemorrhage in topical anesthesia and clear
corneal incision

16. History of Allergy:
Inquire about and document any allergies, adverse
reaction and sensitivity to:-
Anesthetics
Sulfonamide and other antibiotics
Povidoneiodine and
Latex

17. Others:
Factors limiting patients ability to cooperate or lie
comfortably on the operating room table:-
Deafness
Language barrier
Dementia
Claustrophobia
Restless leg syndrome
Head tremor
Musculoskeletal disorder

18. 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

19. Past records:
If patient has had cataract surgery in the fellow eye it is
important to obtain information about operative and
post operative courses :
IFIS
Elevated IOP
Vitreous loss
Cystoid macular edema
Endophthalmitis
Hemorrhage
Refractive surprise

20. Clinical examination:

21. External examination:
Body habitus:
Kyphosis
Ankylosingspondylitis
Head tremor
Generalized obesity
Supraclavicular fat may affect surgical approach

22. AnkylosingspodylitisKyphosis
4 section operating table

23. Abnormality in the external eye like
Prominent eye brow,
Enophthalmos:
may affect surgical approach
Entropion
Ectropion
Eyelid closure abnormality :
may have impact on ocular surface and
adversely effect post operative recovery

24. Severe blepharitis
Acne rosacea :
risk of endophthalmitisand should be treated
before cataract surgery
Active nasolacrimal disease :
should be treated particularly if there is history
of inflammation,infectionor obstruction
We simply can do a regurgitation test

25. 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 walderglare testing device
Snellenchart
Contrast sensitivity : Pelli-Robson Test
Confrontation test

26. Score 2.0= normal
Score <1.5= visual impairment
Score< 1= visual disability
PelliRobson contrast sensitivity chart

27. Motility Test:
Ocular alignment should be evaluated by Hirschberg
reflex.
Range of movement of extraocularmuscle should be
examined by
version and ductiontest
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.

28. Pupil:
Check light reflex
Direct 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.

29. Slit Lamp Examination:

30. Conjunctiva:
Vascularization or scarring due to previous
Inflammation
Injury
Ocular surgery may compromise healing
Symblepharonmay be associated with underlying
ocular and systemic disease
Infection process should receive appropriate treatment
before cataract surgery.

31. Cornea:
Ocular surface is the principle refractive interface of
the eye.
Diagnosis and management of keratitis sicca,
blepharitisis 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

32. Anterior Chamber :
Depth of AC aids surgical planning
Shallow anterior chamber may indicate
Narrow angle ,
Nanophthalmos,
Short axial length ,
Intumescent cataract,
Weak lens zonules
Gonioscopyis essential to rule out angle abnormality

33. Iris:
Presence of iridodonesisindicates weakened zonular
attachment
Iris colobomamay associated with lens colobomaand
localized absence of zonularattachment
Posterior synechiaedue to prior uveitis makes surgery
more challenging

34. CrystalineLens:
Careful assessment of lenticular opacity and co-
relation of degree of vision loss is important
Position of the lens and integrity of zonularfiber is
essential
Grading of Nuclear sclerosis should be done:

35. 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

37. Fundus Evaluation

38. Ophthalmoscopy:
Full fundus examination to evaluate
Macula
Optic nerve
Vitreous
Retinal vessel
Retinal periphery
Further adjunctive test may be needed in patient with DM
Assess the optic nerve (optic nerve cupping and pallor,
measurement of IOP, VA, Confrontation test and pupillary
examination)

39. 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

40. Posterior staphyloma Retinal detachment

41. Special test:
Potential acuity estimation: Potential Acuity Meter
Visual field testing:
Patient with glaucoma
Optic nerve disease
Retinal disease
Objective test on macular function:
OCT: Edema, hole, traction, neovascularization
FFA: Vascular abnormality

42. Preoperative Measurements:

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

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

45. 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

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

47. Corneal topography:
Topography provides map of the corneal contour
Types :
Placidodisc based topography
Scheimpflugimaging
Useful for
Irregular astigmatism
Patient previously undergone refractive surgery
Posterior corneal astigmatism
Patient desires a toriclens

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

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

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

51. 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)

52. 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 vitrectomymay cause intraoperative
chamber fluctuation which increase risk of posterior
capsule disruption

53. 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
HaigisL formula:Incorporatedin IOL master
Masketformula

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

55. THANK YOU