Imagine experiencing hazy or blurry vision upon waking that persists for hours or doesn’t return to normal at all, along with foreign body sensation, ocular pain and photophobia. This describes Fuchs’ dystrophy, a non-inflammatory, progressive dystrophy of the corneal endothelial cells, that can initially masquerade as cataracts and negatively impact activities of daily living, such as driving.
“When patients come in, they can note decreased vision, blurry vision, glare and halos, all things we hear all the time from cataract patients,” points out Kristen Peterson, MD, of Parker Cornea, in Birmingham, Ala. “As a result, I look for Fuchs’ dystrophy in all patients coming in for a cataract evaluation.”
James Huffman, MD, of Huffman & Huffman, in Lexington, Ky, says Fuchs’ dystrophy patients can have decreased vision because of guttae on the back of the cornea.
“The guttae can cause light scatter, contributing to the visual symptoms of the condition,” explains Natalie Afshari, MD, of the Shiley Eye Institute at the University of California, San Diego.
Dr. Peterson adds that if Fuchs’ dystrophy is left untreated for too long, a patient can develop epithelial edema and painful bullae.
“You just don’t want to wait that long,” she says. “If the patient has fluctuating vision, then that is symptomatic, visually significant Fuchs’ dystrophy.”
Here, these ophthalmologists discuss how to definitively identify, and manage the condition, which rarely occurs in patients younger than age 40, is more common in people of European descent, and has a genetic (autosomal dominant variance) and environmental (smoking) component.
“When you look through the slit lamp, you can see the guttae,” explains Dr. Peterson. “If it’s subtle, it can be made very obvious with retro-illumination. Sometimes, there is pigment on the surface of the remaining endothelial cells.”
Dr. Huffman agrees it’s evident on a slit lamp exam.
“As corneal specialists, we first look at the anterior portion of the cornea, and then move in toward the inside of the eye,” he says. “If the patient has swelling of the cornea, we start looking to see why. Initially, we can see the guttae, and that’s the classic finding seen with Fuchs’ dystrophy.”
Dr. Afshari adds that corneal specialists can also use corneal pachymetry and specular microscopy to assess corneal thickness and the endothelial cell number and size, respectively, as increased thickness or a low number of endothelial cells can help in thediagnosis of Fuchs dystrophy.’
“You just don’t want to wait that long. “If the patient has fluctuating vision, then that is symptomatic, visually significant Fuchs’ dystrophy.” - Kristen Peterson, MD.
Managing Fuchs’ dystrophy consists of:
• Monitoring for progression. Once the condition is diagnosed, Dr. Huffman says he checks the corneal thickness to establish a baseline to see whether it changes over time. If it’s not significant, he’ll tell the patient they may need glasses, or their vision may be a little decreased, but that specific interventions are not yet needed.
Dr. Peterson says as long as the patient is happy with their vision, they can be followed at the slit lamp, until she notes the development of confluent guttae.
“The presence of confluent guttae doesn’t necessarily mean corneal decompensation, which is interesting, but at that point a lot of patients do notice glare and halos, so the slit lamp is one way to monitor for disease progression.”
• Prescribing 5% hypertonic sodium chloride drops. This may decrease corneal edema when it is present, say Drs. Huffman and Afshari. The dosage is 4 times a day, and there is no limit on how long to use, says Dr. Afshari. 5% Hypertonic sodium chloride is also available in an ointment form. It can be used at bedtime and may be more comfortable for the patient.
• Corneal transplant. When the swelling and symptoms get worse, those interviewed say a transplant via Descemet’s membrane endothelial keratoplasty (DMEK) should be considered.
“In DMEK, you’re removing the back 15 μm of the cornea, and then you’re putting a graft on that’s only 15 μm, so you’re literally just taking away the sick part,” notes Dr. Huffman. “DMEK also preserves the integrity of the cornea, has very low rejection rates, and ends in positive visual outcomes, with 70% to 80% of my patients having returned to 20/20 vision.”
“… DMEK also preserves the integrity of the cornea, has very low rejection rates, and ends in positive visual outcomes, with 70% to 80% of my patients having returned to 20/20 vision.” – James Huffman, MD.
Dr. Huffman says he recognizes the crucial role of the Eye Bank Association of America (EBAA)in this area.
“The reason we’ve gotten so much better at corneal transplants,” he says, “is because of how good the eye banks are. The EBAA is a not-for-profit organization, and they’re really doing a lot of research and driving things forward.”
Dr. Peterson points out that Descemet’s stripping endothelial keratoplasty (DSEK) may be preferable, if the patient has large iris defects, is aphakic, or in some cases in which the patient has undergone prior glaucoma surgery.
“I also use DSEK if a patient has had a PK in the past, because it can be difficult to get a DMEK to stay attached in such patients,” she says.
If a patient has both cataracts and Fuchs,’ dystrophy, Dr. Peterson says she commonly performs a DMEK triple procedure, which is phacoemulsification, IOL implantation, and DMEK at the same time.
Rho kinase (ROCK) inhibitors are being studied for the treatment of Fuchs’ dystrophy, says Dr. Peterson.
“In monkeys, researchers were able to show there was regeneration of endothelial cells, cell proliferation, and suppression of apoptosis, so that seems really exciting,” she points out.
Dr. Peterson adds that using a ROCK inhibitor in combination with surgery also looks promising.
Dr. Afshari says her lab is looking at stem cell treatment to potentially take a patient’s cells, convert them to stem cells, correct the trinucleotide repeats in their transcription factor 4 gene, and inject them back into the patient’s eye.
Finally, all three doctors say they are interested in the possibilities of a newer procedure, Descemet’s stripping without endothelial keratoplasty (DWEK), which is just stripping Descemet’s membrane and, consequently, the guttae (mainly in the center of the cornea), without replacing anything, and allowing the patient’s own peripheral endothelial cells to migrate in, possibly enhanced by a ROCK inhibitor. CP
Special thanks to Mitchell P. Weikert, MD, for reviewing this article.