The eye doctor has told you that you have cataracts and you are unhappy with your vision. What’s next?
The eye doctor is unable to change your glass prescription to improve your vision; therefore, you have decided to have surgery.
What is Involved in Eye Cataract Surgery?
A cataract is the lens inside of your eye behind your pupil that becomes cloudy and/or hazy. This cloudy or hazy lens inside your eye needs to be removed to restore your vision.
Types of Cataract Surgery
There are two basic types of cataract surgery.
Intracapsular Cataract Extraction
The removal of the whole lens in one piece. A large incision is made in the eye and a cryoprobe is placed on the capsule of the lens. The whole lens is removed in one piece. The wound is closed with several sutures. This procedure is not used in the United States any longer.
Extracapsular Cataract Extraction
The removal of the cloudy lens material, leaving the clear capsule inside the eye. This capsule is used to hold the intraocular lens in place inside the eye. An opening is made in the anterior capsule and the lens material is removed. This requires a medium-sized incision in the eye.
If the only thing performed was removing your cloudy lens, your vision will still be very blurred as there is no lens in your eye to focus the light onto the retina. After the cataract or lens has been removed, the natural human lens needs to be replaced with an artificial intraocular lens so your eye can see again.
Before your surgery, the eyes are tested and measured with special instruments that provide the eye surgeon with the correct strength of the intraocular lens implant to correct your vision. The lens strength or power is calculated by computers inside of instruments used to measure your eye. The eye surgeon will choose the strength of the lens that will best correct your vision.
The great news is that no matter if you are farsighted, nearsighted, or have astigmatism, your vision can be corrected with the insertion of an IOL that has been calculated to correct your vision.
What Happens Before Surgery?
Before cataract surgery, the eye doctor needs to make sure that you don’t have any other eye diseases that could affect the outcome of your surgery, such as diabetic retinopathy, macular degeneration, glaucoma, or other eye diseases. There will be a series of tests on your eyes to give guidance on the best surgery for you. The testing may include a visual field test, Lenstar, IOL Master, Pentacam, iTrace, specular endothelial microscopy, eye dominance, dry eye testing, and corneal topography.
iTRACE Technologies Instrument
The iTrace Technologies instrument is a great instrument that gives a significant amount of information about the vision system of your eyes. It measures the aberrations in your vision.
The number of aberrations in the eye can provide very important information that the eye doctor uses to guide you with your decision. Every animal and human have aberrations in their vision. Some animals see better than others depending on the optical system of their eyes.
Even if you have better than 20/20 vision and no eyeglass prescription, there are still aberrations in your vision. Mankind would have much better than 20/20 vision if our eyes did not have these aberrations.
The iTrace gives the eye surgeon information about aberrations of the eye due to the shape of your cornea (the clear, front portion of the eye) and aberrations inside the eye secondary to your cataract and/or lens inside your eye. The iTrace also provides information about the asphericity of your cornea and the alignment of your visual axis. It compares the visual axis of your vision to the center of your pupil.
All this information is extremely important if you are considering a multi-focal intraocular lens with your surgery. Many people are not good candidates for multifocal IOLs. If there are too many aberrations in the eye and/or the alignment of the visual axis and center of the pupil are not close together, you may be happy with your vision after surgery.
Determining the Power of the IOL
The Lenstar and IOL Master are the two most common instruments used in the United States to measure the eye for determining the strength of the intraocular lens that is going to be used to correct the vision during the surgery. These two instruments take a variety of measurements of the eye.
A computer in the instrument uses an algorithm to determine the strength of the lens that is going to be used. These instruments are very accurate but not perfect. Even though the results are great, there is no guarantee that the instrument will be perfect in every case.
Lenstar LS 900
The Lenstar features a unique dual zone keratometer with a total of 32 marker points on two concentric rings at 1.65 and 2.3 mm in diameter for improved power calculations of IOL powers to be used to correct vision after surgery. The Lenstar provides a variety of measurements of the eye which are used in the calculation of the IOL power. These include:
Lenstar’s unique dual zone keratotomy with 32 marker points provides great data for IOL calculations.
The white-to-white measurement is the measurement across the cornea from the sclera to the sclera. This measurement is used in advanced IOL calculations.
The Lenstar measures the size of the pupil, which can be used in providing information for suitability with multifocal IOLs.
Accurate measurement of the lens thickness is key to precise optimal IOL power calculation when using the latest advanced formulas.
Anterior Chamber Depth
The depth of the anterior chamber is very important in IOL power calculations. The Lenstar uses optical coherence biometry to precisely measure the anterior chamber depth.
The size or length of the eye is the most important measurement in calculating the IOL power. The Lenstar uses OLCR technology using a superluminescent diode as a laser source to measure the axial length of the eye.
IOP Power Calculations
The Lenstar provides numerous IOL formulas. These include Olsen, Barrett, Hill-RBF, and standard formulas. People with a history of LASIK or other refractive procedures need special formulas or calculations. The Lenstar has the Barrett True-K and Shammas formulas for these patients.
The Lenstar provides very precise calculations and a variety of formulas for the eye surgeon to use in providing the best IOL correction for your eye.
The IOL Master 700 is the next generation in biometry from Zeiss that gives very accurate measurements for IOL calculations. The SWEPT Source Biometry from the IOL Master 700 provides a full-length OCT image showing the anatomical details of the eye on a longitudinal cut through the eye. The SWEPT Source Biometry scans the eye 2,000 times a second.
The IOL Master 700 is the only instrument with a biometer that has telecentric keratometry which is distance-independent. All measurement calipers are shown on full-length OCT images. The unique Fixation Check provides the eye surgeon with more confidence that a proper measurement was taken.
The IOL Master 700 has the three Barrett IOL formulas, which are Barrett Universal II, Barrett Toric, and Barrett True K. Depending on the eye status, the system automatically chooses the appropriate formula.
In some advanced cataracts or ripe cataracts, the previous instruments discussed may not be able to measure the eye. An ultrasound instrument is capable of measuring the eye with advanced stages of cataracts and may be used if one of the other instruments is unable to penetrate the cataract.
Once all the testing has been performed, the eye surgeon will be able to guide you through the decision-making process with the cataract surgery. The type of cataract procedure and the type of IOL will be decided by you with the help of your eye doctor.
A staff member or surgical coordinator will go over all the details involved with cataract surgery. There are many papers and different forms that you will have to read and sign. You will be given an informed consent document to read over for your cataract surgery. Write down any questions that you may have concerning your surgery. The eye surgeon will go over the informed consent and that is the time to ask your questions.
In most cases, you will be prescribed eye drop medications for use before and after the surgery. Some doctors may inject the medications inside the eye during the surgery. The staff will cover all the pre-op and post-op instructions with you. You will be given a copy for your records and a copy of instructions as a guide to follow.
How is the Cataract Removed or Treated?
In simple terms, the cloudy lens or cataract inside your eye is removed. After the cataract is removed, a new artificial intraocular lens is placed back inside the eye to correct the vision. The power or strength of the IOL is determined by the testing and instruments in the office before the surgery.
The natural lens behind the pupil has a certain amount of focusing strength and this needs to be replaced. The eye would not see very well if all that you had was cataract removal and the lens was not replaced.
The good thing about the intraocular lens is that it can correct any prior refractive error that was present before the surgery. No matter if you are nearsighted, farsighted, or have astigmatism, the strength of the new IOL can correct the vision in most cases.
What Steps Are Involved in Cataract Surgery?
In most instances throughout the United States, eye surgery will take place in an outpatient ambulatory surgery center. There are a few places in the United States where the surgery may still be performed in a hospital on an outpatient basis.
On your arrival at the surgery center, you will be admitted and taken to the pre-op holding area. You will sign more papers and meet with the anesthesia department. You will be asked to lie down on a stretcher and an IV will be started.
In most cases, the IV will be only the tubing. There will be no IV bottle. The anesthesia department will give medications in the IV to relax you. You will not be put to sleep or have general anesthesia except in very rare circumstances.
In some cases, you will get a short-acting drug to put you to sleep for a minute or so. This is so the anesthesia personnel can inject numbing medication behind the eye while you are asleep. Most eye surgeons are using topical anesthesia and are not doing any injections. A variety of eye drop medications will be instilled into the eye to numb it and dilate your pupil, as the cataract is behind your pupil.
When everything is ready, you will be taken to the operating room and placed under a microscope used during eye surgery. The eye will be prepped and draped to sterilize the area around it before the surgery. There are very small incisions made in the cornea near the sclera. These micro-incisions are so small that sutures are seldom necessary to close them.
A gel-like or viscoelastic substance is instilled into the anterior chamber or portion of the eye between the iris and the cornea. This viscoelastic material keeps the eye formed during portions of the surgery. There is a thin, cellophane-like capsule that surrounds the lens of the eye that has the consistency of Saran wrap. A 5mm circular opening or capsulorhexis is made in the anterior capsule to gain access to the cataract.
A syringe with a balanced salt solution is attached to a cannula. The fluid is injected under the capsule to loosen the lens material from the surrounding capsule. A phacoemulsification tip that vibrates approximately 45,000 times a second is used to dissolve or emulsify the nuclear or center portion of the lens.
During the phaco surgery, fluid is delivered inside the eye with this tip to keep the eye formed and the center of the tip is hollow. A computerized pump is connected to the phaco tip so that the liquid and emulsified cataract material can be aspirated from the eye. Another type of cannula or tip is used to remove the softer cortical material of the cataract. The viscoelastic material is injected into the eye again to keep the eye formed and open the capsule to receive the IOL.
The IOL to correct your vision is placed inside an injector device that rolls the lens up like a pancake or soft taco.
The lens implant is inserted inside the same capsular bag that held your natural lens. Once the lens is inside the eye, the IOL unfolds back to its original shape. The intraocular lens is held in place inside the eye by the same capsule that held the eye’s natural lens.
In almost all cases, sutures are not needed to close the incisions. The incisions are checked to make sure they are closed. Some eye doctors will have them patched after the surgery. In many cases, there are no eye patches applied after the surgery.
You are transported to the recovery area in the surgery center. Once you are doing well, the IV will be removed. You will be given something to drink. Your vital signs will be checked and you will be discharged about 30 minutes after the surgery. The actual surgery only takes a few minutes to perform with no shots around the eye, stitches, or patches. The whole process takes approximately 2 hours.
Femtosecond Laser Cataract Surgery or Bladeless Laser Cataract Surgery
Some eye surgeons are advertising femtosecond laser cataract surgery as bladeless laser cataract surgery.
If you have decided to have a femtosecond laser used during your cataract surgery, there is another step in the surgery that you have to go through. The femtosecond laser may be located in another room in the surgery center.
What is the Benefit of Having a Laser Perform a Portion of the Cataract Surgery?
The femtosecond laser performs several of the surgical procedures in cataract surgery in an extremely precise manner. The laser cuts the microincisions in the cornea. If you have less than 1.25 to 1.5 diopters of astigmatism, the laser will make limbal relaxing incisions on the cornea to correct astigmatism or the irregular shape of the cornea.
Astigmatism means that your cornea is shaped more like a football slice in half length-wise versus a round basketball. The femtosecond laser will change the corneal shape back to a basketball, providing you with better vision without glasses.
Another critical delicate step of cataract surgery is the capsulorhexis of the lens capsule. The laser creates a 5-mm circular capsulorhexis or opening in the anterior capsule which is precisely placed centrally and in a perfect circle.
The femtosecond laser further helps with the cataract procedure by dividing the nucleus of the lens into pieces. The laser is also able to soften the lens which makes the removal of the nucleus more efficient.
The femtosecond laser completes all these steps in approximately 30 seconds or less. After the femtosecond laser is completed, the cataract surgery and IOL insertion are performed. The femtosecond laser provides a more precise surgical cataract procedure, more consistent results with less dependence on glasses, and fewer complications.
Alcon LenSx Femto Laser
The Alcon LenSx Laser System is one of the most common femtosecond lasers used for cataract surgery. The LenSx laser’s OCT technology provides high-resolution cross-sectional images for every cut at the location where the incisions are being performed. The laser has excellent scanning processes and image management. The combination of scans provides precise placement of all the laser applications by accurate positioning of the line scan following the axis of maximum tilt.
The one-piece design of the LenSx Laser SoftFit Patient Interface is an excellently designed interface for the connection of the laser to the patient’s eye. The interface design produces 66 percent laser energy needed to perform the procedure and a minimal rise in the IOP of just 16 mmHg above the baseline of the patient’s IOP. The interface minimizes corneal distortion compared to solid interfaces and forms a solid fixation on the patient’s eye. The laser takes only about 30 seconds to perform its procedure.
Bausch and LOMB Victus Femtosecond Laser
The Bausch and Lomb Victus Laser Workstation is an innovative laser, with high technology, multi-mode versatility, and comprehensive capabilities in a single laser workstation. The laser uses fast impulses and small spot sizes at 80 kHz for cataract surgery. It has detailed precision and control.
The Victus uses REALEYEZ swept-source OCT which is delivered in real-time, high-resolution visualization, and image-guided cataract surgery planning. Auto-recognition automatically recognizes important landmarks of the cornea, pupil, lens or cataract, and anterior and posterior capsule of the lens for precise centering and incision placements. The laser allows for independent adjustment of incision depth, diameter, and axis.
The Victus Verafit patient interface provides a stable and comfortable connection to the patient’s eye. Intelligent Pressure Sensors monitor the sheer forces on the eye from the docking interface to prevent any undesired corneal distortion.
LENSAR Laser System
This laser provides the eye surgeon with the most advanced technology for managing astigmatism and optimizing patient outcomes. The LENSAR laser is focused on correcting astigmatism to improve the visual outcomes of patients.
THE Augmented Reality imaging system utilizes a variable superluminescent diode for scanning structured illumination to provide high-contrast, high-definition targets, which guide the laser. A new wireless total astigmatism data transfer is now available. The total corneal astigmatism measurements can be transferred wirelessly from the Cassini Corneal Analyzer to the LENSAR laser system. Postoperative data analysis can help the eye surgeon refine pre-, post-, and intraoperative data which allows the surgeon to improve outcomes.
IntelliAxis accurately determines the steep axis landmarks on the cornea. The laser has iris registration and automatic cyclorotation adjustment, providing accurate corneal incision placement by comparing the pre-op image to the images during surgery. Accurate incision planning allows for better patient outcomes. Intelligent incisions employ localized imaging to monitor the cornea immediately before each incision is made for the precise location.
AMO Catalys Precision Laser System
The Catalys laser combines a <600 femtosecond laser with a gentle LIQUID OPTICS interface and integrated 3D Full Volume OCT image guidance to create a precise laser cataract procedure. The liquid optics interface provides gentle docking or connection of the laser to the eye with minimal IOP rise and clear optics for excellent imaging and laser delivery.
The Integral Guidance System provides 3D Full Volume Optical Coherence Tomography and automated surface mapping algorithms. The laser performs precise capsulotomies with an accuracy of within 30um. The laser performs complete segmentation and softening of the nucleus of the lens with adjustable grid sizing. Multiple corneal incision centration options are based on the anatomical landmarks of the eye. The eye surgeon’s cataract surgery treatment plan is customized based on the patient’s anatomy of their eye.
Post-Op Care After Cataract Surgery
In most cases, you will be placed on an antibiotic eye drop before surgery. Some eye doctors start their patients on an NSAID or anti-inflammatory medication eye drop before the surgery. Most of the time, your eye doctor will start you on a corticosteroid, cortisone, or prednisone eye drop after the surgery.
Typically, the antibiotic and corticosteroid eye drops are used 4 times a day for the first week. The eye medications are tapered off over the next 3 weeks. In most cases, you can resume normal activity very soon after cataract surgery. Your eye doctor will provide you with their specific post-operative instructions.
Since there are nearly 4 million cataract surgeries performed in the United States a year, there is a long list of possible complications related to cataract surgery. Still, cataract surgery is one of the safest, most reliable, and most beneficial surgeries performed today. More than 95% of people have excellent results from their cataract surgery.
The shortlist of the more common complications are hemorrhages, infection, swelling in your cornea, retinal detachment, macular edema, and mechanical difficulties during the surgery. Your eye surgeon will go over the risks, benefits, procedures, alternatives, and complications with you.
Lens Replacement Surgery or Refractive Lens Replacement Surgery
Some people are nearsighted, farsighted, or have presbyopia and do not want to wear glasses. They have no cataracts but want a multifocal lens in their eyes to rid them of their glasses. These people are going to pay cash for their surgery as they have no medical reason for the surgery. The surgery is the same except the lens is not cloudy.
Complicated Cataract Surgery
Certain cataract surgeries are considered complicated when other steps are required to perform the surgery. If the eye surgeon is unable to see the fine clear capsule secondary to the severity of the cataract, Trypan blue dye is instilled into the eye and stains the capsule blue. The capsule is easily visualized with the dye. The pupil will not dilate, and iris retractors are needed to open the pupil. There are iris wire hooks, Malyugin ring retractors, and I-Rings used to keep the pupil open.
Cataract surgery is the most common operation that Medicare or CMS covers. Since the advancement of new technologies, cataract surgery has become very safe and reliable over the years.
Cataract surgery is one of the most cost-effective, beneficial, and successful operations performed in the United States. Some of the important keys to a great result are proper testing before surgery, picking the right surgery for you, strategic planning, finding the right eye doctor, and following the instructions given by your eye doctor. Following these steps can help maximize your surgical outcome.
Dr. James E. Croley III is a respected eye surgeon and an eye care pioneer. He is also the author of two books, Believing is Seeing and The Blinding of America.