Are you having back pain with any of the following?

  • Severe pain, weakness or tingling in your leg(s).
  • Difficulty stopping urination or loss of control of bladder or bowels.
  • Unexplained fever, nausea or vomiting.
  • A history of cancer or unexplained weight loss.

We understand that you are experiencing one or more of the health issues that might be impacting your back pain.

We recommend that you discuss these health issues with your doctor before proceeding with this program.

Once you are cleared by your doctor to do this program, we hope it helps you find relief from your back pain.

Provider photo for Eun-Ha Park

Eun-Ha Park, MD


Welcome to My Doctor Online, a website my colleagues and I developed to make it easier for you to take care of your healthcare needs. On this site you will find answers to many of your questions about my clinical practice. Also included are several online features that will allow you to e-mail me, check your laboratory results and refill prescriptions. If you are a patient who sees me regularly, you can reach my office directly at 415-833-5110.

My Offices

Daly City Medical Offices
Appt/Advice: 650-301-5800

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Keratoconus is a common eye condition in which the cornea, or the outer dome of the eye, becomes thinner and weaker. Over time, the weakened cornea starts to bulge outwards in a cone shape, due to the natural pressure exerted on it from inside the eye. This coning leads to scarring on the cornea and blurry vision. 

People with keratoconus often find that: 

  • Their glasses prescriptions change frequently.
  • Glare can worsen. 
  • Sensitivity to light occurs.

Keratoconus typically affects people in their teens or early twenties and progresses until they reach their midthirties, when it may stabilize. The condition typically affects both eyes, but may be worse in one eye.

Causes and Risk Factors

We don’t know the exact cause of keratoconus. You may be more likely to develop the condition if you:

  • Have family members with keratoconus. 
  • Have certain medical conditions. For example, people with sleep apnea have a higher risk of keratoconus.
  • Rub your eyes frequently.

A very small percentage of patients who have had Lasik may develop symptoms that are similar to keratoconus.


Symptoms typically start during the late teen years. However, they can start at any time. They include:

  • Blurred vision
  • Frequent changes in eyeglass prescriptions
  • Increased light sensitivity
  • Difficulty driving at night
  • Halos or ghosting around lights (especially at night)
  • Eye strain
  • Headaches and general eye pain
  • Eye irritation
  • Excessive eye rubbing

For many people, the disease causes only mild astigmatism and does not get worse. In others, the condition may continue to progress over 10 to 20 years and cause irregularity, thinning, and scarring of the cornea.


The early signs of keratoconus are subtle and easily missed during eye exams. As the condition progresses, the signs and symptoms become more obvious. To confirm a diagnosis, we will:

  • Ask you about your medical history and symptoms.
  • Have you see an optometrist to measure your eye glass prescription.
  • Perform a complete eye exam.
  • Measure the thickness of your cornea.
  • Take photographs of both eyes.
  • Perform a Pentacam corneal topography imaging study. This shows the shape and thickness of the cornea and can detect early cone formation.


Treatment will depend on the severity of the condition and whether it’s getting worse.

Medical treatment is typically offered first. In advanced cases, surgical treatment may be needed.

Medical treatment

An astigmatism can be corrected with glasses or soft toric contact lenses. However, as the cornea continues to bulge outward, glasses are no longer effective. Most people will need some kind of contact lens. There are a range of contact lens options that we’ll discuss with you, including:

  • Custom soft lenses. These are an option in the early stages of the disease.
  • Gas permeable lenses. A rigid lens replaces the irregular shape of the cornea with a smooth surface that improves vision.
  • “Piggybacking” lenses. A rigid gas permeable contact lens is placed over the top of a soft contact lens.
  • Hybrid lenses. These lenses provide the clear vision of a gas permeable lens with the comfort of a soft lens.
  • Scleral and semiscleral lenses. These are gas permeable lenses with a large diameter that allows the edge of the lens to rest on the white of the eye.

Avoid rubbing your eyes and use allergy eye drops (like Zaditor or Patanol) as needed. We may also talk to you about lubricating your eyes if they are dry.


In most cases, the cornea stabilizes before severe coning occurs. However, surgical treatment may be needed if the condition progresses and contact lenses can no longer provide clear vision.

Corneal tissue replacement surgery. We will talk to you about a deep anterior lamellar graft (DALK) or a complete corneal transplant. If scarring develops, the only definitive treatment is a corneal transplant. Full transplant is only necessary in about 10 percent of people. The success rate is greater than 90 percent.

Deep anterior lamellar grafts (DALK). This is a partial corneal transplant that replaces the distorted front of the cornea with healthy donor tissue. The advantages of this procedure are that the:

  • Eye is stronger.
  • Recovery is quicker.
  • Chance of rejection is very small, which occurs more frequently in a full-thickness transplant.

Corneal Cross-Linking (CXL)

Corneal cross-linking (CXL) strengthens the cornea, which can help prevent the disease from getting worse. Currently, it’s the only treatment that may help slow the progression of keratoconus and reduce the risk for a corneal transplant. This procedure was FDA approved in 2016. 

CXL is not effective for everyone. Older people with advanced disease may not be candidates for this treatment. The procedure:

  • Works best when the disease is still in its early stages.
  • Will not restore vision that has already been lost. Most people will still need glasses or contact lenses after the procedure.  
  • Is usually performed on one eye at a time. The second eye is often treated within 3 months after the first.

Risks involved with CXL include:

  • Infection.
  • Blurred vision while the eye is healing during the first several weeks.
  • Continued progression of disease despite treatment.
  • Postoperative haze. This may get better but it can take several months or up to a year.
  • Poor healing. 
  • Damage by ultraviolet (UV) light to other structures of the eye.
  • Loss of vision.

How to Prepare for CXL

We will arrange for you to:

  • Attend a class where you can learn about the cross-linking procedure and ask questions. 
  • Meet with a cross-linking specialist for a preoperative evaluation. This may be by phone or in person. 
  • Have a refraction (eye glass prescription exam) with an optometrist.

Arrange for someone to drive you home and stay with you for the first 24 hours.

On the day of the CXL

Once you have signed a consent form for the CXL procedure, we will:

  • Give you a sedative medication so you are relaxed and comfortable.
  • Examine your eyes.
  • Numb your eyes.

During treatment the:

  • Eyes are treated with ultraviolet light and vitamin B2 drops. This causes the fibers in the cornea to bond, or cross-link, more tightly. 
  • Cross-links make the cornea stiffer and more stable so it holds its shape. It also stops the thinning process and further loss of vision. 

The procedure takes about 1 hour. After the treatment, we will place a bandage contact lens and a shield over the eye. The contact lens will remain on the eye for a week.

Recovering After CXL

Most people have some pain and tearing for a few days after the corneal cross-linking (CXL) procedure. We will give you specific instructions before you go home. These include:

  • Pain management. Most people take ibuprofen for mild pain. We may also prescribe pain medication if pain is more severe.
  • Eye drops. We’ll tell you how to use antibiotic eye drops. You’ll need to use them for a month.
  • Follow-up appointments. We’ll schedule an appointment the day after the procedure and then a week later. We’ll also see you every few months for the first year after the procedure.

Lifestyle Recommendations

Most people with keratoconus can function normally for many years by using glasses and/or contact lenses. You can take care of your eyes by:

  • Attending the regular eye exams we schedule for you.
  • Telling us about any sudden vision changes. 

Do not:

  • Rub your eyes.
  • Consider LASIK or any other corneal refractive surgery.
Additional References:

Your Care with Me

If you are having symptoms that concern you, your first contact will typically be with your personal physician, who will evaluate your health and symptoms.

If specialty care is needed, your personal physician will facilitate the process of scheduling an appointment in my department. If appropriate, she or he might call me or one of my colleagues while you are in the office so we can all discuss your care together. If we decide you need an appointment with me after that discussion, we can often schedule it the same day or soon thereafter.

During your office visit, we will discuss your medical and family history and I will perform a physical exam. I will explain the findings of your exam and answer any questions or concerns you may have. We will discuss treatment options, and together we will create a treatment plan that is right for you.

In many cases, the cornea stabilizes before severe coning occurs and no further treatment is needed. However, if your cornea continues to get worse, you may need a surgical procedure to improve, control, or eradicate your keratoconus.

If you need to talk with me after your visit or procedure, please call my office. You can also e-mail me with nonurgent issues from this website whenever it is convenient for you.

If you have urgent concerns or issues while my office is closed, or need general medical advice, you can call the Appointment and Advice line, available 24 hours a day, 7 days a week. You will be connected with a nurse who can give you immediate advice.

If you are experiencing an emergency, call 911 or go to the nearest Emergency Room.

Coordinating Your Care

Having all of our Kaiser Permanente departments located together or nearby, including pharmacy, laboratory, radiology, and health education, makes getting your care easier for you.

Another major benefit is our comprehensive electronic medical record system, which allows all of the doctors and clinicians involved in your care to stay connected on your health status and collaborate with each other as appropriate.

When every member of the health care team is aware of all aspects of your condition, care is safer and more effective.

If you come to an office visit
  • At the beginning of your visit, you will receive information about when you are due for your next test, screening, or immunization. We can discuss and schedule any preventive tests that you need. 
  • At the end of your visit, you may receive a document called the "After Visit Summary" that will summarize the issues we discussed during your visit. You can refer to it if you forget what we discussed. You can also view it online under Past Visits.
  • To help you prepare for your visit, please see additional details under Office Visit. 
If I prescribe medications

We will work together to monitor and assess how your medications are working and make adjustments over time. Prescriptions can be filled at any Kaiser Permanente pharmacy. Just let me know which pharmacy works best for you, and I will send the prescription electronically in advance of your arrival at the pharmacy.

If refills are needed in the future, you can:
  • Order them online or by phone. Order future refills from my home page or by phone using the pharmacy refill number on your prescription label.
  • Have them delivered to you by mail at no extra cost. Or you can pick up your medications at the pharmacy. If no refills remain when you place your order, the pharmacy will contact me regarding your prescription.
If lab testing or imaging is needed

For lab tests, I will use our electronic medical record system to send the requisition to the Kaiser Permanente laboratory of your choice. For imaging procedures, we will schedule an appointment with the Radiology department. When the results are ready, I will contact you with your results by letter, secure e-mail message, or phone. In addition, you can view most of your laboratory results online, along with any comments that I have attached to explain them.

If I refer you to another specialty colleague

If we decide together that your condition would also benefit from the care of other types of specialists, our staff will help arrange the appointment(s) with one or more of my specialty colleagues.

If surgery or a procedure is a treatment option

I will recommend you review educational information and tools to help you prepare for your procedure or surgery. The information will often help you decide whether surgery is right for you. If you decide to have a surgery or procedure, the information will provide details about how to prepare and what to expect.

If we proceed with surgery, I will have my Surgery Scheduler contact you to determine a surgery date and provide you with additional instructions regarding your procedure. Once your surgery is scheduled, a medical colleague of mine will contact you to conduct a preoperative medical evaluation that will assure that you are properly prepared for your surgery.

Convenient Resources for You

As your specialist, I have a goal to provide high-quality care and to offer you choices that make your health care convenient. I recommend that you become familiar with the many resources we offer so that you can choose the services that work best for you.

My Doctor Online is available at any time that is most convenient for you. From my home page you can:

Manage your care securely
  • View and compose secure e-mail messages.
  • Manage your prescriptions.
  • View your past visits and test results.
  • View your preventive services to see whether you are due for a routine screening or updated immunization.
Learn more about your condition
  • Read about causes, symptoms, treatments and procedures.
  • Find interactive health tools, videos, and podcasts to help you manage your condition.
  • View programs to help you decide on or prepare for a surgery or procedure.
Stay healthy
  • Locate health education classes and support groups offered at every medical center.
  • Explore interactive programs, videos, and podcasts that focus on helping you stay healthy.
  • View your Preventive Services to see whether you are due for a routine screening or updated immunization.

Related Health Tools:


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If you have an emergency medical condition, call 911 or go to the nearest hospital. An emergency medical condition is any of the following: (1) a medical condition that manifests itself by acute symptoms of sufficient severity (including severe pain) such that you could reasonably expect the absence of immediate medical attention to result in serious jeopardy to your health or body functions or organs; (2) active labor when there isn't enough time for safe transfer to a Plan hospital (or designated hospital) before delivery, or if transfer poses a threat to your (or your unborn child's) health and safety, or (3) a mental disorder that manifests itself by acute symptoms of sufficient severity such that either you are an immediate danger to yourself or others, or you are not immediately able to provide for, or use, food, shelter, or clothing, due to the mental disorder.

This information is not intended to diagnose health problems or to take the place of specific medical advice or care you receive from your physician or other health care professional. If you have persistent health problems, or if you have additional questions, please consult with your doctor. If you have questions or need more information about your medication, please speak to your pharmacist. Kaiser Permanente does not endorse the medications or products mentioned. Any trade names listed are for easy identification only.

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