Cataract
- What is a Cataract?
- What Causes Cataracts?
- What are Symptoms of Cataract?
- How are Cataracts Diagnosed?
- What is the Treatment for Cataracts?
- What are My Goals After Surgery?
- What Should I Expect After Cataract Surgery?
What is a Cataract?
A cataract is formed when the natural crystalline lens inside of the eye becomes cloudy, foggy and less transparent. The natural lens loses its ability to focus light on the retina. The proteins inside of the natural lens develop structural abnormalities, pigment changes, and becomes more rigid causing scattering of light onto the retina, causing blurred vision.
In addition, the natural lens can focus light onto the retina at different distances by changing its shape known as accommodation. Our ability to focus on varying distances especially near distances deteriorate as we develop cataracts.
What Causes Cataracts?
Most cataracts are due to the natural aging process hence the term "age-related cataracts", but there are secondary causes of cataracts and risk factors that can accelerate the development of cataracts listed below.
- Diabetes
- Hypertension
- Steroids (all forms: IV, oral, inhaler)
- Smoking + Alcohol
- UV light (living closer to the equator)
- Trauma
- Prior ocular surgery
- Systemic disease (Atopic dermatitis, Myotonic dystrophy, Neurofibromatosis)
- Radiation treatment
- Family history or generic predisposition
What Are Symptoms of Cataract?
Symptoms of cataract include the following:
- Blurry vision (distance and/or near)
- Glare & halos (around car headlights or street lights)
- Difficulty driving at night
- Decreased contrast sensitivity
- Decreased color sharpness/brightness (colors are dull appearing)
- Double vision in one eye
- Difficulty with reading at near and intermediate distances
- Difficulty reading street signs
- New glasses prescription does not help
- Increase in near-sightedness "second sight" (ability to read without glasses)
How Are Cataracts Diagnosed?
Cataracts are diagnosed when patients have a dilated eye exam or comprehensive eye exam. Usually, patients are seen by an optometrist first and then are referred to an ophthalmologist for preoperative cataract exam.
A preoperative exam consists of a comprehensive eye exam with some extra steps to prepare for cataract surgery.
History
The following infomation will be gathered during the exam.
- Chief Complaint (CC),
- History of Present Illness (HPI),
- Past Medical History (PMHx),
- Past Ocular History(POHx),
- Past Surgical History (PSHx),
- Medications,
- Allergies.
This history will answer the questions:
- Is the cataract opacity affecting your daily routine and activities?
- Are you interested in surgery
- Based on your medical history, are you a candidate for hospital-based surgery or outpatient surgery?
Co-existing Conditions
- Patients with hypertension and diabetes need to have their blood sugar and blood pressure controlled the day of surgery.
- Patients with recent Myocardia Infraction or heart attack may delay surgery for 6 to 12 months from date of incident.
- Patients with recent Stroke or TIA may delay surgery for 6 to 12 months from date of incident.
- Patient with Heart failure or COPD/Lung disease need to be able to lay flat or head mildly elevated for at least 30 minutes.
- Patients with history of Hepatitis/HIV/infectious blood pathogens have special precautions to avoid needle stick injury.
- Patients with dementia, Parkinson's, tremors, epilepsy may require general anesthesia.
- Patients with history or LASIK or PRK or other refractive procedures require more testing.
Patients Who Wear Contact Lenses
- Patients who wear soft contacts will need to be out of the lenses for 3 to 7 days.
- Patients who wear hard contacts will need to be out of the lenses for 3 weeks.
Additional Testing
Additional testing may include the following:
- Autorefraction: Device that measures refractive error.
- Visual acuity testing: Best Corrected Visual Acuity (BCVA) with Manifest Refraction (Mrx).
- Visual acuity with glasses or corrective lenses.
- Glare Testing: Visual acuity with simulated glare (light source directed towards eyes).
- Ocular vital signs.
- Pupil response testing.
- Intraocular (Eye) Pressure (Contact Tonometry).
- Extraocular (Eye muscle) movements.
- Confrontational Visual field testing .
- Slit Lamp Exam (SLE) and Dilated Fundus Exam (DFE).
- Biometry: Calculation of the intraocular lens and yields the most accurate postoperative refractive result after cataract surgery.
- Keratometry: Measures anterior cornea curvature (steep or flatness) and power
- Optical Biometry: Non-contact method to determine Axial length (eye length).
- A-scan Ultrasonography: Contact method to determine Axial length (eye length from cornea to retina).
- Optical Coherence Tomography (OCT): Noninvasive imaging device uses light to create cross section images of the retina and optic nerve. The machine detects optic nerve or retinal abnormalities that may affect vision. Used to rule out other eye diseases that affect vision other than cataracts.
What Is the Treatment for Cataracts?
The treatment for cataracts is surgery which means removal of cataracts and placement of an intraocular lens.
At this present time there is no medical treatment for cataracts. This means there are not drops, oral, injections or other medications that can eliminate your cataracts.
In the United States there are two main forms of cataract surgery - phacoemulsification cataract surgery and femtosecond laser cataract surgery. The third form of surgery is called manual small incision cataract surgery (MSICS) typically used when cataracts are dense or difficult to remove with the traditional routes below.
Phacoemulsification Cataract Surgery
Traditional cataract surgery involves the use of a blade to make one to two incisions into the cornea. This gives surgeon access to your cataract. Then the surgeon manually removes the anterior capsule (outer layer or wrapping paper of the cataract). Lastly the surgeon uses the phaco-ultrasonic hand device to fragment the lens in tiny pieces for easy removal.
Femtosecond Laser Cataract Surgery
The surgeon uses femtosecond laser technology to make anterior cornea incisions, remove the anterior capsule (outer layer of cataract), soften the cataract lens, fragment the cataract lens, correct astigmatism with corneal incisions. The ultrasonic device is still used for final removal of cataract. The use of femto-laser can decrease the amount of ultrasound energy used to fragment and emulsify the cataract lens which can potential improve postoperative visual recovery.
What Are My Goals After Surgery?
The typical goal for cataract surgery is emmetropia, basically an eye with no refractive error. Usually, doctors aim for emmetropia or slightly myopic (-0.25 D to -0.50D) since it is well tolerated. Patients will usually need reading glasses after surgery.
Sometimes there are patients that want to be nearsighted, typically (-1.50D to -2.00D) depending on daily activities, after cataract surgery and prefer to wear glasses for distance.
Monovision: Patients who had previous refractive surgery or contact lenses where their dominant eye was corrected for distance and their non-dominant eye was corrected for near. Usually patients do not require glasses.
Some patients do not want glasses after surgery which may require a special intraocular lens known as a multifocal lens. Intraocular surgery involves placement of an artificial lens inside the eye.
Types of Artificial Lenses
- Monofocal Lens: A lens with one focus point usually far distance. Patients will need glasses after surgery either for reading or distance vision depending on chosen focus point.
- Toric Lens: An astigmatism corrective lens used to decrease/reduce post operative astigmatism after surgery.
- Multifocal Lens: A lens with multiple focus points: distance, intermediate and near. Patients do not require glasses after surgery. These lenses are not covered by insurance and are out of pocket.
What Should I Expect After Cataract Surgery?
Eye Protection
After cataract surgery, patients are typically discharged from the facility with an eye shield, sometimes an eye patch, and surgical sunglasses.
Eye Drops
Patients typically have one to three eye drops depending on the surgeon and facility protocols. These drops can include the following:
- Antibiotic
- Anti-inflammatory
- Steroid
- Eye Pressure Lowering
- Combination Eyedrops (Antibiotic + Steroid + Anti-inflammatory all in one)
- No Drops (if the patient had dropless cataract surgery)
Transportation Home
Patients need to have a person or home transportation service that will take them home and make sure they arrive home safely.
Post-Op Instructions
Please refer to your specific surgeon for details. Patients will have a post-operative instructions sheet with the drop frequency schedule and activities that should be limited including:
- Keep the eye shield on until appointment.
- Do not bend below the waist to pick up objects.
- Do not swim or have your head underwater.
- Do not rub or place pressure on the eye.
- Do not lift anything weighing over 5 lbs.
- Do not participate in sports or physical activity for a limited duration.
Seek Attention For Post-Op Issues
Patients will have a number to call if post-operative issues arise that require attention including:
- moderate to severe eye pain
- moderate to severe headache
- decreased vision or loss of vision
- severe bloodshot or red eye
- new flashers or new floaters
Post-Op Visits
Patients will have one to five postoperative visits and will have changing instructions and allowable activities.
- Post Op Day 1 (1st eye)
- Post Op Week 1 (1st eye)
- Post Op Day 1 (2nd eye)
- Post Op Week 1 (2nd eye)
- Post Op Month 1