Best options for Multifocal & Premium IOL's in cataract surgery

Multifocal IOL's and Premium Lens Implants offer distinct advantages for patients and here is a guide how I am currently approaching them.

Reading Speed: my personal bias is the ReStor reads quite quickly, especially with better light. If dim light is common environment for the patient, then the ReZoom near reading speed is perhaps better but distance night glare might be a concern, in my opinion.

Night Drivers: I offer the Crystallens first, the ReStor Second, and the ReZoom Last. I think night glare with Crystallens is negligible, but in the FDA trial, the ReStor had 4% of patients with severe night glare, and 16% with moderate night glare. This is acceptable to me for most patients with good patient education and modest night driving demands. The ReZooms biggest concern for me is night glare.

Long Armed People: I offer the ReZoom or Crystallens first, and I avoid the ReStor in very tall people, they simply have to hold things too close. Average height, 6 feet and below, are less an issue for reading distance for any of the lenses.

Computer Users: I think the Crystallens and ReZoom do well here, and the ReStor requires some extra time to explain that intermediate vision improves monthly and intermediate can be quite good at 6 months post IOL implantation.

Patients with High Astigmatism: for now, I do laser vision correction to get astigmatism for anything over 1.5 diopers of astigmatism or cylinder. I think the Toric ReStor by Alcon when approved by the FDA will be my IOL of choice for astigmatic patients, given that the Toric IOL by Alcon is already such a phenomenal and predictible IOL in my experience.

Golfers: Some of our most observant patients with high expectations. Here the main outcome is excellent distance vision, which means getting the focus right and rid of any remaining astigmatism. Probably any of the 3 IOL's work well in this setting if the refractive outcome is nailed.

Patient satisfaction: all different for different people. I prefer the ReStor in patients with round corneas as it has excellent near and distance vision when astigmatism is controlled. I like the ReStor and ReZoom's predictibility in refractive target, and I think controlling for the Crystallens slightly more variable refractive outcome by doing the non-dominant eye first for nearer vision is a good idea.


Another Way to Approach this:
ReStor: great for patients who want excellent near and distance vision, and my best outcomes are those with very spherical corneal keratometry readings. These come out 20/20 and are the happiest in my opinion, even patients with very high expectations ~ if their corneas are already close to very spherical.

ReZoom: great IOL for those who do not night drive and want a range of distance, intermediate, and near vision.

Crystallens: great for patients who do not want any aberrations causing reduced contrast sensitivity, such as diabetics, glaucoma patients, and those with subtle macular disease. Also if intermediate is their concern and the patient accepts that near vision is not the true goal of this IOL, then more realistic and they will be happier.

It is fun to see patients appreciate and enjoy their refractive outcome, and this may mean a different IOL depending on the patients lifestyle. I have learned it is very hard to predict what is the right IOL for a patient, but when the different aspects of the IOL's are discussed, they tend to migrate to the best lens option for them. If I don't think the patient will be happy with that IOL then I tell them it not a great option for them, and discourage that choice, based on what they tell me about their expectations.

I tell all patients that even though there is a good chance they may not need glasses, almost all the IOL's do better with night driving with glasses as this reduces defocus and astigmatism, and secondarily reduces glare. Additionally, using glasses is still common for activities that require long periods of concentration, such as heavy reading, golfing, anything where residual defocus bothers them. Reducing dependence on glasses is usually achievable, but completely eliminating glasses might not be.

Treatment for Corneal Ulcer

Recent treatment for a large central suppurative, acute onset corneal ulcer in a 21 yo farm worker:
--gram stain revealed gram-negative bacilli
--treatment was begun with antibiotics Tobramycin (14 mg/ml fortified preparation) hourly to eye and Cefazolin (25 mg/ml) hourly
--24 hour culture results confirmed Pseudomonas aeruginosa
--Treatment was narrowed to be Tobra and Ceftazadime (50 mg/ml) hourly drops on the eye
--a 6 mm suppurative Pseudomonas ulcer stabilized and improved at the 7 mm size
--cutting back on epithelial toxic Tobra to 6x/day and adding Bacitracin ointment improved reepithelization on day 4 and on day 6 was down to 4.5 mm with no suppuration, and an original corneal hypopyon on presentation resolved as the ulcer became sterile.

Post LASIK IOL Calculation Worksheet Download

Free Download to help do IOL calculations after Myopic LASIK
Post LASIK IOL clalculation worksheet/shortform
 
disclaimer:  please validate with your clinical experience and criteria
 
Worksheet uses 5 formulas post LASIK and may require previous K's, diopters of LASIK treated, topographic K's after LASIK and may require entering adjusted K values into the IOL Master to determine estimate IOL power at this point.
 
Look for further improvements to the worksheet with newer formulas and techniques.
 
Download free form at :   shop.myeyeconsultant.com

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Spherical Aberration and the Eye as an Ocular System

Sperhical Aberration   (SA):

 

A 4th order aberration of any optical system

Placed in the middle of the Zernicke pyramid.

Occurs from unequal bending of central and peripheral parts of any spherical lens causing blurring of the image.

Either positive or negative spherical aberration occurs.

 

Positive SA resembles a Mexican hat.

  Central rays are bent more than peripheral.

 

Negative  SA produces a doughnut shaped blur

  Peripheral rays are bent more than central rays through cornea.

 

A Normal cornea is aspheric to a Q value of zero.

A Prolate cornea has a negative Q value,  and is flatter toward the periphery. 

An Oblate cornea has a positive Q value and is steeper toward the periphery.

 

A Q value of -0.50 means zero spherical aberration.

Normal cornea is -0.26 which gives positive spherical aberration.

Relaxed young crystalline lens à  negative spherical aberration.

Parabola q value of -0.52 is perfect surface with no SA.

 

 

How do measure Spherical aberration?

Aberrometers, instruments to measure all refractive error  (sph, cyl, HOA)

            Hartmann schack, Tscherning, ray tracing,  Slit skiascopy/double pass

 

 

Factors affecting Spherical aberration:

Age, Accomodation, pupil size, corneal shape, lens curvature

 

More Spherical Aberration an with enlarging pupil

Cornea shape more prolate with more negative spherical aberration

More flatter is more positive spherical aberration (oblate)

 

Spherical Aberration of the eye is close to zero at age 19

Positive SA increases with age  (cornea pos, while lens neg SA changes to pos)

Lens becomes positive over age and through the 20's, 30's years of age.

 

Therefore, contrast sensitivity declines with age as SA of eye increases (even with no cataract!!).

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Treatment for LASIK or PRK Infection

LASIK infections Treatments

Early 1 week:  likely MRSA, staph aureus or Strep

Treat per culture and sensitivity data

Empirically begin with Vancomycin 1% and/or Ceftazadime hourly

 

Later  after 2 weeks:  fungal, yeast, or atypical mycobacteria

Fungal:  use Natamycin 5%  (50 mg/ml) hourly

Yeast infection:  Amphotericin B (1.5mg/ml) hourly

Atypical Mycobacteria:   Amikacin (8 mg/ml) and Clarithromycin (10 mg/ml) hourly

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Blepharitis (eyelid margin inflammation)

Blepharitis is a common cause of eyelid and ocular surface discomfort in patients who are unresponsive to dry eye treatments.  Dry eye is often worse later in the day while blepharitis causes more morning discomfort, irritation, and eye redness.  The most common cause is a dysfucttion of the meibomian glands, or posterior eyelid margin.  When the meibomian glands are dysfunctional, the tear film stability is decreased and tear evaporation is increased, causing ocular discomfort. 

 

Treatment for Blepharitis

 

Lid Hygiene

Warm compresses twice daily for 5 minutes can have a beneficial effect in opening the plugged oily glands of fthe eyelid margin, stabilizing the tear film.  Eye lid massage after the hot compresses is also beneficial and can be done with a sudsy washcloth with baby shampoo.

 

Topical antibiotic ointment

Bacitracin or erythromycin courses of topical antibiotic ointment can benefit at bedtime if there is an anterior blepharitis component associated with the condition.  Bacitracin has better staph coverage than erythromycin. 

 

Additional Treatment

 

Oral doxycycline

As an adjunct to control but not cure the disease, blepharitis can be treated with oral doxycycline of 100-200 mg daily for a one to two month course.  Often 3-4 weeks of treatment is required before a significant improvement is appreciated by the patient.  Oral doxycycline is contraindicated in children under 8 years old, pregnancy, and needs physician clearance in the presence of liver disease, coumadin, birth control pills, and methotrexate. 

 

Other treatments of

 

Topical Steroids

Topical steroids can be used short-term, with a mid or low-strength concentration (loteprednol 0.2-0.5%), but should be avoided long term with high strength.  Topical Restatis (cyclosporine A 0.1%).

 

Systemic Omega-3 Fatty Acid Supplements

 

Omega-3 supplements, flax seed or fish oil supplements, can also improve dry eye and may benefit eyelid disease of blepharitis.

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Intraocular lens Explantation (lens implant removal)

Freeing the IOL from the capsular bag

 

Injecting Viscoat or provisc into the capsular bag at the optic-haptic junction can free up that hapgic.   If a cannula with viscoelastic is insufficient to create space in the capsule, then a iris sweep or even a rounded tip 30 needle can gently dissect capsule away from the IOL while viscoat is passed through the needle bore into the capsular bag.

 

 

One piece explant technique

 

An Alcon Acrysof model lens will pass through a 2.2 mm or larger peripheral corneal wound if it is passed with a 'push-pull' technique.  By pulling on a haptic out of the main corneal wound and nudging from the anterior chamber with a second instrument the lens will conrorm to the wound and pass through

 

 

IOL bisection or trisection

 

Using long Vannas scissors or specially designed lens cutting scissors the IOL be cut into two or three pieces.  Tugging the haptics first out the wound allows easier retrieval of the pieces through a smaller wound.

 

Lens Folding technique

Once the IOL is into the anterior chamber and out of the capsular bag, the lens folding forceps can be passed into the AC on top of the IOL.  A second instrument is used beneath the IOL and with upward pressure presses and folds the IOL into the folding forceps.  The IOL is then removed through a 3 mm wound.

 

IOL explantation is expected to be more common and familiar to ophthalmologists as new technology multifocal lenses and patients lifestyles do not always match 100% with newer multifoclal lenses.

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Subluxated IOL with scleral fixation ab externo

G. Condon's tips on scleral fixating IOL's
Steinerts discussion of Scleral fixation of dislocated sulcus IOL's
Ethicon's needle inventory page:
consider the CIF-4 10-0 prolene 10mm curved needle
or STC-6 or CTC-6L 10-0 prolene curved 13 mm needle

Cataract Videos

Blumenthal Extra cap Tutorial
Spin Nucleus into AC

IRIS SUTURING ~ IRIS FIXATED IOLS

In the event there is no remaining anterior or posterior capsule for sulcus support, consider . . . .

IRIS Suturing of decentered sulcus IOL

My personal technique utilizes an Ethicon 10-0 prolene suture on a curved long 14mm needle (fairly sturdy for its diameter and easy to retrieve across the limbus). Packer et al. describe placing peripheral corneal incisions 2 clock hours counterclockwise from the haptic one desires to capture, and passing the needle into the AC, retrieving it 1 clock hour clockwise in a similar sideport incision. I have found it advantageous to pass a 25 gauge needle tip into the receiving sideport incision to help facilitate the prolene needle tip re-surface anterior to the iris plane. After this maneuver, it is much easier to guide the prolene suture out of the AC with a ruff of iris and haptic captured by the needle pass. Place your favorite suture to secure the haptic, Siepser, McCannel or Western knots. I have found the Siepser to allow a tighter knot than the McCannel given that one can place more horizontal tension on the throws. ~ DJW

Packer et al. Favorite tricks for Iris suturing
Google Book: Complications in Phaco pp. 209
Changs Write-up of Siepser Slip Knot in Iris Sutured IOL's
R. Horn description of Western Knot in Iris Suturing
D. Azar's description of suturing a plate haptic IOL to Iris

Strabismus Surgery Guide, adjust per your outcomes

BINOCULAR STRABISMUS SURGERY

 

Esotropia

Medial Rectus OU Recession

15 Δ     3.0 mm

20 Δ     3.5 mm

25 Δ     4.0 mm

30 Δ     4.5 mm

35 Δ     5.0 mm

40 Δ     5.5 mm

50 Δ     6.0 mm

60 Δ     6.5 mm

70 Δ     7.0 mm

 

Esotropia

Lateral Rectus OU Resection

15 Δ     3.5 mm

20 Δ     4.5 mm

25 Δ     5.5 mm

30 Δ     6.0 mm

35 Δ     6.5 mm

40 Δ     7.0 mm

50 Δ     8.0 mm

 

Exotropia

Lateral Rectus OU Recession

15 Δ     4.0 mm

20 Δ     5.0 mm

25 Δ     6.0 mm

30 Δ     7.0 mm

35 Δ     7.5 mm

40 Δ     8.0 mm

50 Δ     9.0 mm

 

Medial Rectus OU Resection

15 Δ     3.0 mm

20 Δ     4.0 mm

25 Δ     5.0 mm

30 Δ     5.5 mm

35 Δ     6.0 mm

40 Δ     6.5 mm

 

 

MONOCULAR STRABISMUS SURGERY

 

Esotropia

Medial Rectus Recess        Lateral Rectus Resect

15 Δ     3.0 mm                              3.5 mm

20 Δ     3.5 mm                             4.0 mm

25 Δ     4.0 mm                             5.0 mm

30 Δ     4.5 mm                             5.5 mm

35 Δ     5.0 mm                             6.0 mm

40 Δ     5.5 mm                             6.5 mm

50 Δ     6.0 mm                             7.0 mm

60 Δ     6.5 mm                             7.5 mm

70 Δ     7.0 mm                             8.0 mm

 

Exotropia

Lateral Rectus Recess         Medial Rectus Resect

15 Δ     4.0 mm                             3.0 mm

20 Δ     5.0 mm                             4.0 mm

25 Δ     6.0 mm                             4.5 mm

30 Δ     6.5 mm                             5.0 mm

35 Δ     7.0 mm                             5.5 mm

40 Δ     7.5 mm                             6.0 mm

50 Δ     8.0 mm                             6.5 mm

 

 (Marshall Parks with adjustments by Kenneth Wright)

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IOL Calculation Web Links

http://iol.ascrs.org - helpful links for post refractive surgery lens implant calculations
http://www.lricalculator.com - helpful LRI calculator online
http://www.acrysoftoriccalculator.com/ - toric IOL T3,T4,T5 calculator for sn60wf IOL
http://doctor-hill.com/physicians/physician_main.htm Dr. Hills collection of formulas
http://www.ocularmd.com includes 10 IOL formulas and contributions to database an option

societies
http://www.ascrs.com/
http://one.aao.org/CE/MOC/MOCStudyResourcesDetail.aspx?Topic=1 MOC Exam Study
http://www.aao.org/isrs/ AAO refractive society
http://www.ophthalmologytimes.com/
http://www.eyecounselor.com

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IOL lens Calculation after LASIK/refractive surgery

Post-LASIK IOL calculation Formulas

  

Rough Rule:  add 1 D of IOL power for every 3 to 4 D of LASIK Treatment

 

Masket Regression Formula:

--Adjustment to IOL Master determined power by

=  (Diopters of LASIK Tx) *(0.326)+0.101

 

Latkeny Regression Formula

--use flattest K found now for IOL Master

--target emmetropia or Rx chosen

--adjust by Latkany formula:  -(0.47x+0.85)    where  x = preLASIK spherical equivalent

--example:  for -6 myope post tx =  -(-3+0.85) = +1.97,  or add 2D to IOL power for plano based on flattest K now with IOL Master

 

Corneal Bypass Method  (Keith Walter, JCRS Mar 2006)

--IOL Master with original K values, current axial length

--set target on IOL Master to preLASIK RX to obtain Plano post CEIOL today

 

Topographic Central Corneal Power Adjustment (Koch & Wang)

--Take central power of apical point on Atlas Topographer

--adjust this K power by (0.19)*(Diopters of LASIK treatment)

--use this adjusted K to in Holladay II formula to target IOL power today

 

Feiz Mannis Nomogram  (Ophthalmology vol. 112, N.8, Aug 2005)

--Post Myopic LASIK IOL Power adjustment

-- probably least likely for hyperopic surprise, may overcorrect

D Tx:    Increase IOL Power by

1           0.36

1.5        0.66

2           0.96

2.5        1.25

3           1.55

3.5        1.85

4           2.15

4.5        2.45

5           2.74

5.5        3.03

6           3.34

6.5        3.64

7           3.93

7.5        4.23

8           4.53

8.5        4.83

9           5.12

9.5        5.42

10         5.72

10.5      6.02

11         6.31

11.5      6.61     

12         6.91

 

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