advances in cataract surgery
Post on 07-May-2015
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Con Moshegov
FRANZCO, FRACSCon MoshegovFRANZCO, FRACS
Ophthalmologist
Advances in Cataract Surgery
Cataract is an opacification of the lens
Acanthamoeba infection
The cataract comes out in one whole piece
Limitations of ECCE
• Prolonged surgery time • Trauma leads to inflammation• Suture distortion of cornea • Prolonged convalescence• Restrictions to activity• Necessitates a regional ‘block’ anaesthetic
The cataract is emulsified then sucked out
Phacoemulsification
Phacoemulsification
Phacoemulsification
Phacoemulsification
• Small incision (2.75 to 3.25mm)
• Can be performed without needles
• Takes only minutes
• Less inflammation
• Faster recovery
• Little restriction to activity
Aqualase
Lens liquifaction device• Alcon Infiniti• Also has ultrasonic
phacoemulsification
Aqualase
• 4 microlitre bursts of water• No heat• Soft plastic tip• Advantages:
– No heat at wound, no wound burns– Less endothelial cell disruption– Less risk of posterior capsular rupture
• Disadvantages:– Expensive – Too slow for hard cataracts
6mm
Intraocular lenses (IOLs)
Small incision surgery
• How do you get the IOL in?
Folding and Insertion of a lens
Advances in IOL technology
Acrysof Natural
Contrast Sensitivity is a better test of functional vision than Visual Acuity!
Sinewave contrast sensitivity is the most widely accepted test of contrast sensitivity
Contrast Sensitivity Decreases with Age
Simulated Image Contrast Enhancement by Aspheric Correction
“Aspheric IOLs emulate the young crystalline lens, whose negative spherical aberration tends to compensate positive spherical aberration of the cornea.”
Aspheric IOLs
Night driving problems related to aberrations
• Long straight street • Simulated speed 35 miles/h• High degree of ambient light
• Long straight road • Simulated speed 55 miles/h• Minimum ambient light (low
beam auto headlights)
City Driving Scene Rural Driving Scene
Night Driving Simulator
Target detection and identification
Night Driving Simulation
With Tecnis™ and at 55 mph, patients identify a pedestrian (rural setting/glare) at 486 feet versus 441 feet for the standard IOL (p=0.0011)
Increased reaction time Safer stopping
Perfect Vision
‘Killing two birds at the same time’
Perfect Vision
Short-sightedness
Long-Sightedness
Astigmatism
Refractive errors
• All of these prevent clear vision without the use of glasses.
• Cataract surgery is increasingly used to reduce peoples dependence on glasses
• If not combined with refractive surgery it would be unwise to promise patients the ability to see perfectly well without glasses
Pre op Biometry
Ultrasound
IOL Master: coherence interferometry
Cornea too steep
Secondary LASIK
Reading without glasses
• Aim for myopia in both eyes• Aim for myopia in one eye (monovision)• Multifocal IOL
Accomodating IOLs
Principle of a Refractive Multifocal IOL
Principle of a Diffractive Multifocal IOL
•Addition of refractive lenscauses light to converge totwo points
ReSTOR pseudoaccomodating IOL
Alcon ReSTOR IOL
Alcon ReSTOR IOL
New Intraocular lenses
However: • Still requires careful patient selection• Optimal distance for reading is short• Best for hypermetropes with presbyopia
– Unaided distance acuity < 6/18• Must control astigmatism
Presbyopia
The procedure in practice
• Almost all done on a ‘day only’ basis
• Hospital or day surgery
• (FBC, EUC, ECG, CXR, INR)
• IVI (or oral) sedation
• Topical anaesthesia
The procedure in practice
• Post op visits on day 1, possibly one week and a month
• Topical corticosteroid, antibiotic and possibly a NSAID
• Eye shield at night
• Abstain from swimming and makeup
• Timing of surgery for second eye is variable
Myth
• My cataract was removed with a laser
Myth
• They had to take my eye out to remove the cataract and then they put it back again
Myth
• My aunt’s cataract had to be removed a second time
Conclusion
• Cataract surgery is one of the most commonly performed operations in Australia
• It has a very high success rate• Developments have taken place to make it
even safer, faster, more accurate and, in some cases, able to free people from a dependence on glasses.
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