Month: December 2019

Seeing a bluish green spot in the right eye

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By Juan Ding, OD, PhD

Case of the day series

A college student walked in for an urgent visit for seeing a bluish green spot in her right eye constantly for 1 week. She went to Colorado last week and did a lot of hiking, taking many photos everyday, enjoying nature. On the last day of the trip, she started seeing a bluish green spot in the right eye, more obvious in the bright background, but it’s there even after closing eyes. She was very scared and went to the local ER, where they did an ultrasound of the eye and found no retinal detachment, but did not know what’s wrong. After getting back to MA, she could not get an appointment with her regular eye doctor, and being the holiday season it’s busy everywhere. Fortunately her PCP at Umass directed her to our open access clinic.

Her vision is normal, 20/20 in each eye. Everything from the front to the back of both eyes are normal. I found no retinal detachment, not even vitreous floaters.

She asked, “Am I crazy? Am I imagining things?”

What do you do next?

Knowing too well that clinical exam has its limitations, I asked her to take an OCT photo. This is looking at the retina in cross sections, like virtually dissection the retina. There is a very small dot in the right eye, just temporal to the fovea, where the photoreceptor outer segment now shows a small defect (Figure 1). Amsler grid shows a matching scotoma nasal to the fixation.

solar retinopathy

Figure 1. OCT of macula cross section. Red arrow points to the lesion at the photoreceptor outer segment level (ellipsoid zone).

 

So I told her that she’s not crazy, a retinal lesion really exists to perfectly account for her seeing the spot.

But what caused it?

Solar retinopathy is the first thing that comes to mind. She denied looking directly at the sun. also denied exposure to laser including laser pen or in a science project. Then she mentioned that during daily hiking, she did spend a lot of time looking at camera screen which could be very bright due to reflecting sunlight. This seems to be the most plausible explanation for now.

I told her that solar retinopathy may get well on its own in weeks to months. It may also be irreversible. At any rate, there is no treatment for this. So we will monitor again in a few months.

Another treatment for dry eye – azithromycin

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by Juan Ding, OD, PhD

I talked earlier about an off label treatment of dry eye and Meibomian gland dysfunction (MGD), doxycycline; and today I will talk about another off label use of azithromycin (AZM) to treat MGD.

AZM is a macrolide type of antibiotic that has a unique characteristic, to promote lipid accumulation in cells. This works well in MGD, because the Meibomian gland cells work by producing and storing lipid and then releasing it to the tear film. With this additional help, my coworkers and I found that the Meibomian gland cells produce more fat 1. And these effects are unique as doxycycline and other tetracyclines do not have this benefit 2. Other scientists found that AZM significant improves dry eye symptoms and work slightly better than doxycycline 3. Further, the dosage and usage is easier with AZM, which is used for 500 mg on the first day and then 250 mg/day for a further 4 days, whereas doxycycline was used for 100 mg twice a day for 7 days and then 100 mg/day for a further 21 days 3.

AZM also exists in an eye drop format, for example, azasite (1% AZM ophthalmic solution). This also works well for MGD and dry eye, though it’s quite expensive and sometimes not covered by insurance.

Side effects of AZM include diarrhea or loose stools, nausea, abdominal pain, stomach upset, vomiting, constipation, dizziness, etc. it is safe to use during pregnancy and breastfeeding.

I prefer the AZM eye drop, which works more targeted to the ocular surface without systemic side effect. Due to its cost, I typically use it only in patients with MGD and blepharitis (inflammation of the eyelid margin) that have failed other treatments. I have had some very grateful patients who report they can finally open their eyes or that their eyes are no longer constantly red. The usage of this of course requires a prescription and supervision under a qualified physician.

I wish they make this cheaper and make an ointment form of this.

References:

 

  1. Liu Y, Kam WR, Ding J, Sullivan DA. Effect of azithromycin on lipid accumulation in immortalized human meibomian gland epithelial cells. JAMA Ophthalmol. Feb 2014;132(2):226-228.
  2. Liu Y, Kam WR, Ding J, Sullivan DA. Can tetracycline antibiotics duplicate the ability of azithromycin to stimulate human meibomian gland epithelial cell differentiation? Cornea. Mar 2015;34(3):342-346.
  3. De Benedetti G, Vaiano AS. Oral azithromycin and oral doxycycline for the treatment of Meibomian gland dysfunction: A 9-month comparative case series. Indian J. Ophthalmol. Apr 2019;67(4):464-471.

 

Another treatment for dry eye – doxycycline

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The other day a 57 year old woman came in, with a very common complaint, dry eye.

She had dry eye symptoms for a few years previously. Last year, due to Lyme’s disease (infection by Borrelia bacterium which is spread by ticks), her doctor prescribed doxycycline for 14 days. After that, she enjoyed dry-eye free days for almost 8 months, until now when the symptoms are back to haunt her. She tried a few artificial tears which helped only a few minutes. She would really like to have another prescription of doxycycline.

On examination, she has Meibomian gland dysfunction (MGD; here’s my previous article on MGD) and dilated blood vessels on the lid margin suspicious for ocular rosacea. She’s never been diagnosed with rosacea before and denies cheeks turning red.

We know that MGD is a major cause of dry eye, and ocular rosacea (a type of inflammation of the eyelids) will make dry eye worse. In fact, doxycycline has been used off-label to treat MGD and ocular rosacea. In one study, for MGD patients treated with doxycycline for 30 days, about 70% of patients showed some level of improvement after one or multiple (up to three times) treatments 1.

Therefore, for certain patients who failed conventional warm compress and lid hygiene treatment for MGD, it may be worthwhile to try doxycycline

Of course, doxycycline has several side effects, and should be taken with some caution. Many of the side effects are related to the gastrointestinal health, such as loss of appetite, nausea and vomiting, diarrhea. People may also get sensitivity to the sun, so sun protection while using this medication is recommended. Lastly it may also cause discoloring of teeth, while reversible in adults, may be permanent in kids, so it should not be used in children younger than 8 years of age. Fortunately not too many 8 year olds have MGD or dry eye. Doxycycline also should not be used during pregnancy.

Next time I will talk about an even better alternative drug for MGD. If you read the reference below, you will guess what it is.

 

References

  1. De Benedetti G, Vaiano AS. Oral azithromycin and oral doxycycline for the treatment of Meibomian gland dysfunction: A 9-month comparative case series. Indian J. Ophthalmol. 2019;67(4):464-471.