Dr. Cheung’s blog 8/5/2013

Dr. Cheung’s blog 8/5/2013

August 5, 2013

Life’s greatest journey

The twins are here!! We were blessed by the arrival of Elise and Theo on Friday, July 26 at 2:03 pm. Elise sneezed at the world and started crying. Theo came one minute later and met the world with a bang, kicking and screaming despite his small size of 4 pounds and 10 ounces. They were delivered by C-section at 34 weeks and 2 days of gestation because Elise was growing poorly. Her birth weight was 3 pounds and 8 ounces, less than 5 percentile for babies of that age.

Fortunately, they are doing well in  the neonatal intensive care unit, breathing on their own and started feeding already. Elise, in particular, is a voracious eater. Guess she is trying to catch up with her brother. We expect them to be at the NICU for three to four weeks before returning home. My wife is also recovering well from the operation and very happy and eager to be a new mother.

It has been a tough and long journey. At 23 weeks and 2 days of gestation, during a routine ultrasound appointment, my wife was found to have a very weak cervix. She was immediately admitted to the hospital for bed rest and for monitoring of preterm labor. If the twins were delivered at that point, their survival rate was less than 30% and even if they lived, they would face multiple serious medical problems, one of which is blindness. It was a very dark time for me and my wife and as an ophthalmologist, the thought that my own children may be blind was almost impossible to bear.

How do extremely premature infants develop blindness? In the developing eye, the blood vessels in the retina grow from the optic nerve in the back of the eye at 16 weeks of gestation and emanate forward to the front (peripheral) part of the retina. Normally, the vessels reach the nasal peripheral retina by eight months and the temporal (the side close to the ears) peripheral retina by ten months. In premature infants, these developing blood vessels have not reached the peripheral retina to supply it with oxygen. The relative lack of oxygen causes the retina to produce a hormone called VEGF (vascular endothelial growth factor) which in turns stimulate the blood vessels to grow towards it. Unfortunately, high level of VEGF can stimulate both normal and abnormal blood vessels (neovascularization) growth. The neovascularization is leaky and fluid can track under the retina to cause it to detach which mayresult in blindness. VEGF, in addition, can stimulate the cells in the vitreous jelly to grow like scar tissue which in turn can pull on the retina, causing it to detach. This proliferation of abnormal blood vessels and scar tissue in the retina of the premature infants is called Retinopathy of Prematurity (ROP) and is one of the leading causes of blindness in children in this country.

Premature infants younger than 30 weeks of gestation and/or weighing less than 1500 grams (3 pounds and5 ounces) are at risk for developing ROP and require screening by an ophthalmologist who is experienced in this condition. Most ROP exams on infants are done while they are still in the NICU but they can also be done in the office after the babies are discharged. In our office, we instill an eye drop to dilate the pupils of the baby who is tightly swaddle by a blanket. A parent will gently hold the baby’s body while my assistant keeps the head still. I will then put a numbing eye drop in the eyes and a speculum to keep the eye lids open. I then look into the eyes with an indirect ophthalmolscope to evaluate if there in any ROP and if so, the extent, severity and location of the disease. If the disease reaches certain threshold, treatment would be recommended.

In the past, treatment of ROP involved using a freezing probe (CRYO) to burn the peripheral retina that is devoid of blood vessels. The CRYO-ROP trial, published in the late 1980’s, showed a 40% decrease in unfavorable structural outcomes and a 30% decrease in unfavorable visual acuity in treated eyes, compared with observed eyes after 15 years of follow up. However, even with cryotherapy, 44% of children with threshold ROP had vision worse than 20/200 at 10 years of follow up.

Laser has largely replaced cryotherapy as the main treatment modality for ROP. In early 2000’s, the ET-ROP trials demonstrated that Earlier Treatment with laser for high risk ROP prior to reaching threshold disease was beneficial. However, laser treatment can potentially cause cataract, irregular pupils due to scarring of the iris to the lens, and loss of peripheral vision.

Most recently, based on the latest understanding of the science behind ROP, Bevacizumab (Avastin) was used for the treatment of ROP. Bevacizumab is an anti-VEGF molecule, it blocks the effect of VEGF on the developing retina. This medication has been used extensively in other eye diseases such as macular degeneration and diabetic retinopathy to stop abnormal blood vessels growth. In fact, a randomized, controlled, multicenter trial called BEAT-ROP demonstrated that BevacizumabEliminates the AngiogenicThreat of ROP and was superior to laser for the treatment of the most aggressive form of ROP that involves the posterior (central) aspect of the retina. In addition, peripheral retinal vascularization continued as normal in the Bevacizumab group but not in the laser group. While Bevacizumab injection shows great promise as a treatment for ROP, we need to continue to monitor for possible side effects on other body systems of a developing baby. Late recurrences of ROP had been observed in eyes injected with Bevacizumab which underlies the importance of long-term follow up for these babies.

Fortunately, my wife was able to hang in there for 11 weeks to the point that Theo and Elise’s age and weight put them at low risk for developing ROP or other serious medical problems such as bleeding in the brain. As an ER physician and a very active person, it was very tough for her to stay in bed for that period of time. We are most grateful for the medical care and attention that we received at Swedish Medical Center. The perinatologists and nurses at the Antepartum unit and the neonatologists and nurses at the NICU were truly superb. Since my wife and I are very healthy people, we are rarely on the receiving end of the medical system. We realized how fortunate we are to live in a time with tremendous technological progress in medicine. Without the ultrasound monitoring, this pregnancy would probably be lost forty years ago. Yet, as human beings, what we crave most in time of sickness, is not technology but human touch. I was reminded of this important fact while in the NICU where the nurses encouraged us to have “kangaroo care” with the twins. We laid skin-to-skin with the babies and it was amazing to see how their heart rates and respiratory rates improved without any medication. In the weeks that we were in the  hospital, my wife and I poured through the medical literature on incompetent cervix and intrauterine growth restriction, hoping to allay our fears. It didn’t. It only created more questions and worries. What reassured us the most were the caring touches of the nurses and the honest and open discussions with the doctors. And when I saw two teams of highly skilled NICU personnel standing by in the operating room to receive our twins just before the surgeons cut into my wife’s abdomen; despite the huge pang of fear in me, I strangely knew that Elise and Theo will be okay.

That 80-90% of overall UV damage to our eyes is accumulated before the age of 18! Like skin damage from UV exposure, we now know occurred for the most part from exposure before the age of 18. Kids in UV protected sun glasses is highly recommended. Protect their eyes just like you do their delicate skin!

Water & contacts don’t mix. To help prevent eye infections, contact lenses should be removed before going swimming or in a hot tub. Alternatively, wear goggles.

The lenses in children’s eyes do not block as much UV radiation as they do in adults’ eyes, putting them at increased risk for sun damage to the eyes.

Left untreated, glaucoma can lead to vision loss. Glaucoma can strike without pain or other symptoms and is a leading cause of blindness in the United States. According to the American Optometric Association (AOA), early detection and treatment is critical to maintain healthy vision and protect the eyes from the effects of potentially blinding diseases, such as glaucoma.

Age-related macular degeneration is a leading cause of blindness. Learn the risk factors for this disease? Having a close family relative with age-related macular degeneration (AMD) puts you at higher risk for developing the disease yourself.