Presbyopic Refractive Surgery Update 2015 Claes Feinbaum MSc PhD Barzilaii Medical Center, Ashkelon, Israel Vision4You

Ophthalmology Times Survey February 2015  Monofocals 58%  Multofocals 17%  Trifocals 6%  Phakic IOLS 6%  Acc. IOLS 3%  Toric IOLS 7%  Others 3%

Refractive Limitations of Current IOLs 1/3 of patients have a residual spherical refractive error of 0.75 D or more 1/3 of patients have a residual spherical refractive error of 0.75 D or more Another 1/3 have sphere corrected but residual cylinder of 0.75 D or more Another 1/3 have sphere corrected but residual cylinder of 0.75 D or more

. Positioned extremely close to the eye's nodal point 1. Positioned extremely close to the eye's nodal point Little to no movement 2. Little to no movement Do not suffer from protein and other debris accumulation on the lens 3. Do not suffer from protein and other debris accumulation on the lens

1. Image degradation 2. Loss in contrast sensitivity 3. Due to one image being in focus, juxtaposed against an out-of-focus background image 4. Compromised by astigmatism, lens tilt, capsular opacities (PCO), pupil dilation and subclinical cystoid macular edema (CME).

In Addition  Diffractive optics may be associated with more may be associated with more 1. chromatic aberration 2. astigmatism 3. coma compared to monofocal intraocular lenses. compared to monofocal intraocular lenses. And please note for previously corneal ablated patients – do NOT use any sophisticated lens design

REFRACTIVE MULTIFOCAL IMPLANTS They generally depend on the pupil diameter, however they have no dispersion of light..  Enhanced quality of distant vision (DV) with a high quality contrast sensitivity, almost equivalent to that of monofocal Major disadvantage: Pupil area dependence. In fact, with an old patient, the pupil diameter is 2-3mm, which considerably reduces the patient's visual field

Transition areas often cause halos and glare that stronly degrade the patient's visual comfort. This can lead to the implant's explantation Finally, the near vision (NV) is degraded most of the time forcing the patient to wear a pair of glasses to be able to read close-up..  To such an extent that surgeons placed a refractive multifocal on one eye and a diffractive mulltifocal on the other eye to compensate for the absence of near vision in the first eye (mix and match technique)

This combination was not a perfect solution, since the binocular vision did not provide the best expected results It was not conceivable: to accurately correct ametropias such as presbyopia with these implants (because of insufficient NV) to accurately correct ametropias such as presbyopia with these implants (because of insufficient NV) To guarantee a good visual outcome, and in a reproducible manner To guarantee a good visual outcome, and in a reproducible manner

The addition is determined by the space between the steps and this will condition the depth of field and defocusing curb The step height determines the distribution of luminous energy between the distance and near focal spots. Some of these implants have a hybrid optic associating a diffractive part and a peripheral refractive part, which due to apodization, allows for a softer transition between the DV and the NV; hence less halos

Poor IV  6/10 maximum Results not always reproducible  optical quality not ensured, excessive astigmatism in post-surgery resulting from the incision size Lower contrast perception (light symmetrical distribution) Unpleasant nocturnal visual symptoms (halos, scatter of light, glare) Diminished effects observed today with standard diffractive multifocal implants:

Problems with the multifocal IOL lens approach  Greater rates of PCO  Higher explantation rates  A high number of dissatisfied patients

Todays multifocal lenses An optical compromise Because of: Dysphotopsia Reduced contrast sensitivity

Mechanical accommodative lenses 1. Synchrony 2. Akkolens 3. Nulens 4. ASO ?????????? Obsolete already?

Accommodating IOLs: Nishi injectable lens ?????? Nishi O, Nishi K, Nishi Y, Chang S. Capsular bag refilling using a new accommodating IOL. J Cataract Refract Surg 2008; 34: *Nishi O, Nishi K, Nishi Y, Chang S. Capsular bag refilling using a new accommodating IOL. J Cataract Refract Surg 2008; 34:

PCO and multifocals Maybe PCO not a big problem for monofocals BUT Multifocals splitting light onto 2 or more focii Resulting in a loss in light intensity so even with small amounts of PCO, the contrast sensitivity will rapidly decline.

Re laser ablations for presbyopia While excimer laser ablations from various manufacturers (PresbyLASIK, Abbott Medical Optics; PresbyMax, Schwind eye-tech solutions; Supracor, Technolas Perfect Vision) and femtosecond laser intrastromal ablation (Intracor, Technolas Perfect Vision) are effective treatments in the majority of patients, visual side effects and reduced vision can occur and may be intolerable for some patients

Reversability?????!!!! Reversability of these procedures has not been shown to date. Therefore, surgeons must take utmost care in patient selection to make sure that the procedure does not cause permanent harm

Dysphotopsias  The potential for those problems need to be explained preoperatively so that patients can decide if they are preoperatively so that patients can decide if they are willing to accept them as a trade-off for the benefit of willing to accept them as a trade-off for the benefit of reduced spectacle dependence at near reduced spectacle dependence at near

IOL position  Affects additional light scatter and subsequently the development of dysphotopsias. The latter problems are under the surgeon’s control and can be minimized by paying attention to angle kappa when considering candidates for a multifocal IOL and performing the implantation

Some thoughts 1. Light scatter will be increased if the incoming rays are not concentric with the diffractive rings, that is the diffractive rings are not concentric with the pupil 2. If a diffractive multifocal IOL is simply centered in the capsular bag, the optic center is likely to end up on the average 0.3 mm temporal to the pupil center 3. Incoming light will not be concentric with the lens (rings) and an asymmetric diffraction pattern will result with increased light scatter.

Recent studies  Positioning a diffractive multifocal IOL so that its center aligns with the visual axis also ensures that light enters the center of the lens perpendicularly=minimizing forward scatter and image defocus  Splitting the difference by centering the IOL halfway between the visual axis (Purkinje image 1) and the center of the pupil is actually the optimal way to position a diffractive multifocal IOL to minimize forward light scatter and reduce additional loss of contrast (

Angle Kappa  Angle kappa is provided on the readout from both optical biometers that now are being used by about 90% of surgeons (IOLMaster, Carl Zeiss Meditec; Lenstar LS 900, Haag-Streit).

How to achieve desired effect  Slightly nasal positioning of the multifocal IOL Placing the multifocal IOL with the haptics oriented vertically Then using a Sinskey hook or similar instrument to push the superior loop towards the nose. The inferior haptic will not rotate, the lens will shift nasally, and it usually stays there postoperatively

Patient selection pearls 1. Patient psychology – lifestyle and visual expectance. 2. A low concern for perfect contrast vision. 3. Slight tolerance for unwanted visual phenomena such as halos 4. Good personality 5. Those who desire perfect distance vision are less suitable. 6. Pupil size matters! 7. One week between the two surgeries. 8. For patients who previously have had a bifocal spectacle correction – try to avoid.

Extra Pearl It is important to look at angle kappa first to decide if a patient is a good candidate for a multifocal IOL, because in eyes with a large angle kappa (i.e., distance between the pupil center and visual axis > 0.7 mm) there is no optimal place to position the lens in order to reduce forward light scatter.