Back To Basics   

 I was trying to come up with a topic for our current Newsletter when I realized it might be time to go back to basics. In the series of articles to follow, I will give my recommendations for evaluating and treating patients' presentations that all of us see frequently.

Symptoms of "recent onset of flashes and floaters" is a common complaint. An acute posterior vitreous detachment is the most common diagnosis in this presentation. However, the most frequent differential includes migraine variant. The visual symptoms are similar and may include a scintillating scotoma which starts in the periphery and moves centrally before drifting out again and resolving. Another common presentation is a fortification spectrum such as a flashing lightning-bolt that blocks the visual field. In these cases, our job is to rule out retinal pathology. I no longer send these patients for a neurologic consult but do recommend if they are concerned that they discuss it further with their physician with the understanding that retinal pathology has already been ruled out.

In patients with symptoms of acute posterior vitreous detachment, a retinal tear may occur in 10-15 percent of patients. All patients with acute PVD symptoms deserve a careful dilated retinal exam, however, some patients are at greater risk than others. There are a myriad of risk factors but the important ones include high myopia, male sex, patients who have had cataract surgery and patients with a family history of retinal detachment or retinal pathology in their fellow eye.

A very important symptom in acute PVD is the presence of hundreds of dot-like floaters that represent vitreous hemorrhage. There is up to a 70 percent chance of a retinal tear being present when there is any level of vitreous hemorrhage present associated with PVD. A clinical pearl here is to remember that lightly pigmented fundi represent the greatest diagnostic challenge for identifying retinal tears. In blond fundi, the RPE layer exposed by a retinal tear does not give the brighter brick-red appearance that is seen in more darkly pigmented fundi. This makes retinal holes and tears more difficult to visualize. Additionally, hemorrhage can obscure the quality of fundus visualization. If medically safe to do so, recommend that the patient discontinue any blood thinners, keep the head above the heart and re-examine in a day or two. B-scan ultrasonography may be indicated if there is a significant amount of vitreous hemorrhage not expected to clear rapidly. Scleral depression can be very useful in some cases but is not critical to the diagnosis in every case. Practice the technique and be ready to use it when needed.

With a diagnosis of Acute PVD, I recommend follow-up in 1 to 6 weeks, depending on the level of risk at the initial evaluation. Even low-risk patients deserve a 4-6 week follow-up. I always document the need for further evaluation within 24-48 hours of the onset of new symptoms, highlighting flashes and multiple dot-like floaters as the highest risk symptoms for associated retinal tear.

One final thought, always give a Patient Education sheet that explains PVD and retinal tears and detachment. Include your phone number for emergency contact. From a medical-legal standpoint, you should be protected should the patient have subsequent problems and present elsewhere.

James E. Powers, O.D.

                How To Manage Retinal Tears 

Symptoms of Retinal Tears

Retinal tears can cause a retinal detachment. Retinal detachments can be potentially blinding. The trick is to 'catch' the tear before a rhegmatogenous retinal detachment develops. Jim's article does a good job discussing presentation, so let's look at how a retinal tear usually develops and what you can do to best manage your patient. Flashes can occur from the vitreous 'tugging' on the retina, while floaters can occur from liberated RPE cells from underneath the torn retina, blood or opacities from a PVD.

No one can possibly diagnose a retinal tear by history alone. Someone needs to take a look.

Causes of Retinal Tears

Tears occur when the vitreous pulls hard enough to tear the retina. Due to the strong attachment of the vitreous to the anterior retina, most tears are located anterior to the equator.

A PVD is the most common cause of retinal tears. Recommendations for your patient include dilated examination at the time of new symptoms and then six weeks after the initial symptoms began.

Patients are at highest risk for developing a retinal tear from a PVD during the first six weeks after developing a PVD.

Retinal tears from non-penetrating trauma (e.g. blunt trauma such as a fist) simply do not occur as frequently as those from a PVD. Of all the retinal detachments I've fixed over the past 20-25 years, there is rarely a history of trauma, e.g. boxing.

Examine your patient at the time of new symptoms and then again on the 'other side' of six weeks unless new symptoms develop prior to that follow-up examination.

If the floaters and flashes persist, that's okay. If they disappear-great!-but they still need that follow-up examination looking for asymptomatic tears.

Treatment of Retinal Tears

 In most cases, a retinal tear is easily 'fixed' with laser treatment. Laser photocoagulation creates little or no inflammation, usually does not hurt and is relatively easy to perform.

For those cases where laser won't work-cases where you can't visualize around the entire tear-indirect laser with depression can work. My favorite is cryopexy. Using the indirect ophthalmoscope and a cryo probe allows me to depress and more easily treat those tears located close to the pars plana. There is some discomfort for which a local injection of Lidocaine usually is sufficient.

When to Refer

All acute tears need treatment. A general rule of thumb: if there is no subretinal fluid and no RPE scarring surrounding the tear, assume it is acute.

Retinal tears without subretinal fluid can be referred within 1-2 days. Retinal tears with subretinal fluid are technically a retinal detachment and I'd suggest a faster referral.

When in doubt, just give a call!  A retinal tear is never seen too early!  Feel free to reach out if you have questions.

Randy

Randall V. Wong, M.D.

       An Interesting Pt With A Carotid 

                     Cavernous Fistula  

48YO Female presented to CEC 2/24/2014 with a chronic conjunctivitis OS. History of vomiting and headache Christmas eve, cleared at the ER with a CT Scan. Otherwise healthy.

Then her eye became red 1/1/2014

She self-treated the 1st week with visine, then the 2nd week her Primary Care rx'ed her with antibiotic drops. The 3rd week her optometrist rx'ed her with antibiotic/anti-inflammatory . Then she tried Lotemax x 2 weeks, then a "stronger streroid".

VA 20/20 OD, OS

EOMs:Full

-APD

Slit lamp exam

NL OD

Bleph, 3+ injection OS with corkscew vessels

TBUT 2 seconds OD, OS

Tap 16 OD, 28 OS (Larger heartbeat OS)

DFE:

C/D .4 OU

(-)Venous pulse

 OD wnl    OS Distended Veins noted   

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