Toric IOL An option or a must? ~ 15% cataract surgical patients >1.5 D Options: spectacles, CLs, Incision along steep axis, LRI, AK, toric IOL, Excimer Laser or a combination Walter J. Stark, MD Professor of Ophthalmology Johns Hopkins University Baltimore, Maryland Vision without astigmatism Vision with astigmatism 1.5D cyl @ 90 Vision with astigmatism 3.0D cyl @ 90 Quality of vision is deteriorated considerably by astigmatism No astigmatism 1.0 D astigmatism 2.0 D astigmatism Incision along Steep Axis Arcuate and transverse corneal incisions flatten the corneal meridian in which they are placed. 3.0mm limbal incision at 180 degrees flattens the cornea 0.5D for a temporal incision and 0.8D for a nasal incision. The more centrally an incision is placed, the more it flattens the corneal curvature Working Nomogram Kevin Miller-UCLA Surgical Outcomes 1 clock hour paired incisions per diopter Up to 3 D Incision Length (clock hours) Astigmatic Change (diopters) Incision depths of 550 to 650 µm were investigated. 1 1.1 ±0.12 2 1.9 ±0.14 3 3.4 ± 0.30 1
Advantages of LRIs over Toric Can use any IOL style: Premium Designs No axis rotation Minimum investment with no recurring costs Flexibility in charge passed onto patient Can be used in aborted planned Toric cases Advantages of Toric over LRIs No additional corneal surgery Avoids irregular astigmatism No new instrumentation Essentially no technique learning curve More predictable than LRI? Alcon IQ Aspheric Toric SN6AT Series: Aspheric anterior surface Toric posterior surface +6 to + 30 diopter range A constant ~ 119.0 Capsular placement only Cylinder Powers, continued A wide range of cylinder powers means more candidates can benefit from AcrySof IQ Toric IOL. ALCON LENS MODELS SN6AT3 SN6AT4 SN6AT5 SN6AT6 SN6AT7 SN6AT8 SN6AT9 Cy ylinder Power IOL Plane Corneal Plane* Recommended Corneal Astigmatism Correction Range 1.50 D 2.25 D 3.00 D 3.75 D 4.50 D 5.25 D 6.00 D 1.03 D 1.55 D 2.06 D 2.57 D 3.08 D 3.60D 4.11 D 0.75 D to 1.54 D 1.55 D to 2.05 D 2.06 D to 2.56 D 2.57 D to 3.07 D 3.08 D to 3.59 D 3.60 D to 4.10 D *Based on average pseudophakic human eye. 4.11 D and up Patient selection and evaluation Corneal topography for all cataract patients Avoid irregular astigmatism Especially if a hard contact lens may be needed Keratoconus or post PK eyes Add LRI if necessary Do not guarantee spectacle independence Better vision without glasses than with standard IOL 336 available lenses 2
AcrySof IQ Toric IOL Calculator acrysoftoriccalculator.com Input Patient data Keratometry IOL spherical power Surgically induced astigmatism (3 mm) Incision location Output Recommended IOL model and spherical equivalent power Optimal axis placement Magnitude and axis of anticipated residual astigmatism Holladay II Formula www.hicsoap.com 3
20/20 without glasses TORIC IOL DAY OF SURGERY: Mark patient in sitting position Fixate at distance Reference Marks Axis Marks Axis Marks 4
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Reduction of Residual Refractive Cylinder Off axis IOL rotation has a significant impact on astigmatism correction. 63% of patients achieved 0.50 diopters of residual refractive cylinder 1. 87% of patients achieved 1.00 diopters of residual refractive cylinder 1. 1º IOL rotation = 3% loss of lens cylinder power Complete loss of cylinder power can occur with a rotation of >30º 64 year old woman 4 months s/p CE/Toric IOL OD Distortion, glare, and halos BCVA 20/50 (150 (+1.50 +0.50 050x 100) HCL over refraction 20/30 (+3.00) Toric IOL aligned along 175 o Target 26 o Open posterior capsule Vitreous prolapse into anterior chamber POOR SURGICAL JUDGEMENT Irregular astigmatism Keratoconus Promised 20/10 vision Complicated surgery Complicated surgery Post operative Hyperopia UNHAPPY PATIENT Needs RGP but will have residual astigmatism from Toric IOL 6
71 year old man Poor vision OD Pseudophakic OS BCVA 20/50 ( 0.75 +1.00 x 80) Nuclear sclerotic cataract consistent with vision IOL Master: 1.70D at 77 o Manual keratometry: 1.50D at 87 o Always do cornea computer analysis prior to premium IOL Irregular astigmatism no toric or presbyopic correcting IOL Tll Tell patient t the possible need for a contact t lens after surgery especially if they have Keratoconus, irregular astigmatism, or have had keratoplasty Conclusion Astigmatism management is an integral component of modern IOL surgery Incision Site, LRI, Toric IOLs, andexcimer Laser all have respective roles These techniques are within the ability of all anterior segment surgeons Avoid irregular astigmatism Under promise and over deliver 7