Some eye conditions will prevent you from having refractive surgery, but there are many that do not. Some conditions can even be improved with Custom PRK.
The word “cataract” is used to describe a natural lens that has turned cloudy. Cataracts are not a disease but rather a condition affecting the eye. As the natural lens of the eye becomes cloudy, it does not allow light to pass through it as well as it did when it was transparent. Cataracts usually start as a slight cloudiness that progressively grows more opaque. They are usually white but may take on color such as yellow or brown.
Most people develop cataracts to some degree by the time they reach 65 years old. Cataracts can develop earlier in life due to factors such as sun exposure, medications, or diabetes.
As the cataract becomes more mature (increasingly opaque and dense), the retina receives less and less light. The light that does reach the retina becomes increasingly blurred and distorted. This causes gradual impairment of vision. If left untreated, cataracts can cause blindness. A cataract can only be removed by surgery. Cataract surgery is one of the most common operations performed, usually with excellent results. Generally, cataracts are removed on an out-patient basis, unless admission to the hospital is medically necessary. Most cataract patients are up and about on the day of their cataract surgery.
Symptoms of cataracts include:
- Blurry vision
- Double vision
- Light sensitivity
- Changes in color perception
- Frequent changes in corrective lens prescriptions
If your cataracts are advanced, Dr. Anderson Penno may recommend cataract surgery. This replaces the crystalline lens of your eye with an artificial intraocular lens (IOL). The IOL can correct the cloudiness and nearsightedness (myopia) or farsightedness (hyperopia) in one surgery. It cannot resolve astigmatism.
Glaucoma causes vision loss when high pressure inside of the eye (IOP) damages the optic nerve. It has no early warning signs. The only way to find out if you have glaucoma is through an eye exam using dilation, which will be a part of your Custom PRK evaluation that Dr. Anderson Penno will personally perform before recommending any procedure.
At first, open-angle glaucoma has no noticeable symptoms. Your vision stays normal, and there is no pain. As glaucoma remains untreated, people often notice that they see things clearly in front of them, yet they can no longer see objects to the side and out of the corner of their eye. Without treatment, people with glaucoma may find that they suddenly have no side vision (peripheral vision). It may seem as though they are looking through a tunnel. Over time, the remaining forward vision may diminish until there is no vision left.
If you have glaucoma, you may still be eligible for refractive surgery. It is best to wait to have any kind of procedure until your IOP is stabilized. Custom PRK is safer for glaucoma patients than LASIK because it does not raise your IOP.
Macular degeneration damages the center of your retina (macula). It blots out the center of your vision, eventually expanding until you have only peripheral vision left. Unfortunately, refractive surgery cannot stop or correct the effects of macular degneration.
Macular degeneration does not always prevent you from having refractive surgery. In some cases of macular degeneration, vision may be limited due to the retinal damage or specialized retinal testing and retinal treatment may be recommended. In these cases laser refractive surgery may not be recommended.
Anyone with diabetes should have dilated eye examinations yearly to screen for the development of diabetic retinal disease. High blood sugar can damage the blood vessels that supply your retina, eventually causing blindness. These blood vessels can balloon and leak, blocking the retina. Fluid can accumulate in the macula, distorting vision. In later stages, new abnormal blood vessels can begin to grow inside your eyes causing scarring inside the eye and retinal detachment. Laser refractive surgery can be performed on diabetic patients if their blood sugar is under good control and their refraction is stable. Custom PRK may not be recommended for diabetics if there is active retinal disease or an unstable refraction.
Blepharitis is also known as “Ocular Rosacea” and “Meibomian Gland Dysfunction”. The meibomian glands are tiny oil glands located near the base of the eye lashes on the upper and lower lids.
Blepharitis is a skin condition which affects these oil glands in the eyelids resulting in plugging of the oil glands with inflammation of the lids along the eyelashes. Blepharitis can contribute to dry eye due to the effects on the oil component of the tear film. Blepharitis may contribute to poor quality tears which may not wet the eye properly. Without treatment blepharitis can cause build-up of oil and debris on the upper and lower lids, itching and inflammation of the lid margins, and dry eye. People with blepharitis may be prone to styes or chalazions (pimple like plugging of the oil glands).
Treatment of blepharitis may include any or all of the following:
- warm compresses for three to five minutes twice per day
- artificial tears two to four times per day
- lid scrubs with dilute baby shampoo or commercially available lid scrubs once per day
- antibiotic ointments once or twice per day
- treatment with BlephEx™
Normal skin bacteria play a role in the development of blepharitis so in some cases an oral antibiotic is used much like the use of antibiotics in the treatment of acne. It is not recommended to try squeezing the plugged oil glands as rupture can cause severe and dangerous infections within the lid tissues.
Patients considering Custom PRK or LASIK should treat pre-existing blepharitis to reduce the risk of infection at the time of surgery and to reduce the risk of dry eye post-operatively.
For patients who are considering PRK it is important to treat any pre-existing conditions such as blepharitis in order to reduce the chance of significant dry eye post-operatively.
Those with moderate dry eye may benefit from punctual plugs (small silicone plugs that are placed in the drainage duct in the upper or lower lid to reduce the drainage of natural tears).
Patients with severe dry eye may not be good candidates for PRK or LASIK. If you suffer from dry eye, ask your eye care provider what steps you can take to treat dry eye.
Keratoconus is a condition in which the cornea becomes progressively irregular due to thinning and bulging of the inferior cornea. In the past keratoconus was usually diagnosed when glasses or contact lenses could not be fit properly and corneal mapping was done to measure the shape of the cornea.
Now that corneal mapping is done routinely for pre-operative assessment of PRK and LASIK candidates, keratoconus is diagnosed more often.
A similar condition called pellucid corneal degeneration is also diagnosed more often due to increased corneal mapping. In some cases the irregular shape does not cause any problems for the patient and may not be progressive; these patients are diagnosed with “forme fruste” keratoconus. In some cases keratoconus may worsen over time or require specialized treatment. It is important to understand that each case is different and if you had been diagnosed with keratoconus you should talk to your eye care provider about your individual case.
People with keratoconus or other corneal irregularities should not have PRK or LASIK as any further thinning of the cornea can cause significant worsening of irregularities with a destabilization of the corneal surface called ectasia.
People with a family history of keratoconus may be at risk for keratoconus and may be at an increased risk for ectasia following PRK or LASIK.