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Management of adult cataract II.ppt
1. Management of Adult Cataract
Prof. Naimatullah Khan Kundi
Head, Department of Ophthalmology
Khyber Teaching Hospital
Peshawar
2. Cataract Surgery
Types:
1. ICCE
1. ECCE
Standard (Manual Nuclear Expression)
Phacoemulsification (Ultrasonic Nuclear
Fragmentation)
Management of Adult Cataract
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. 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. 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. 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. Pre-operative evaluation and information
General health
Drug History
Ocular and social histories
Ocular examination
Measurement of visual function
Preoperative measurement
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. Pre-operative evaluation and information
Awareness of any Drug sensitivities and
medications:
Immunosuppressants
Anticoagulants:
These may alter the outcome of surgery
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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. Optic Nerve
Examined for color, CD ratio or any other
abnormality
ON functions further evaluated by:
VA
Confrontation VF testing
Pupillary Examination
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. Measurements of visual function
1. VA Testing
2. Brightness Acuity
3. Contrast Sensitivity
4. Visual Field Testing
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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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