A 75-year-old white male presented to our clinic for a second opinion regarding his visual status. Several weeks prior, he was evaluated by a local optometrist and received a new spectacle prescription. However, he was unhappy with the results. At the time, the patient was told that his vision could not be improved further because of cataracts and “some type of cornea problem.”
In our office, his best-corrected visual acuity measured 20/50 O.D. and 20/70 O.S., with a refraction that was nearly identical to the spectacle Rx prescribed by the local optometrist. An ocular health evaluation revealed early nuclear sclerosis and cortical spoking O.U.; however, these changes were mild and inconsistent with his reduced vision. Closer inspection of the corneas revealed a posterior stromal haze and dense, dot-like irregularities at the level of the endothelium. We determined that this was a classic case of Fuchs’ corneal dystrophy.
An Overview of Fuchs’
Fuchs’ dystrophy—named for Austrian physician Ernst Fuchs, who first described the condition in the early 1900s—is a relatively common disorder in adults that tends to present bilaterally yet asymmetrically. Rarely symptomatic before 50 years of age, patients typically report symptoms of diminished vision, foreign body sensation, and pain or discomfort (particularly upon awakening).1
The key clinical finding is central corneal guttae, which represent focal thickenings at the level of Descemet’s membrane. When viewed in direct illumination, guttae appear as gold-colored, hyper-reflective bodies on the posterior corneal surface; under retroillumination they resemble small bubbles or holes in the endothelium. Fine endothelial pigment dusting also commonly is seen in association with guttae.
|Corneal guttae, as seen in this patient with Fuchs’ dystrophy, can be subtle and easily overlooked without careful slit lamp inspection.
In later disease stages, the clinician may observe stromal edema with folds in Descemet’s membrane. And in the most severe presentations, patients may exhibit corneal pannus or bullous keratopathy.
Fuchs’ dystrophy is caused by a primary malfunction of the endothelium, likely inherited via an autosomal-dominant mechanism with incomplete penetrance.1 This leads to widespread loss of endothelial cells and subsequent disruption of the endothelial pump mechanisms that are responsible for maintaining normal stromal hydration.2
The consequence is an excessive influx of aqueous, which results in corneal stromal edema as well as physiologically and optically compromised tissue.
Back In the Day...
Fuchs’ dystrophy was once perceived as a troublesome condition with no genuinely effective treatment—save radical corneal transplantation. It was a troubling diagnosis to make, especially knowing that little could be done to help the patient cope with his or her symptoms. Most individuals sought relief by frequently instilling hypertonic saline drops or ointments throughout the day, and even regularly blasting a hair dryer toward the ocular surface in an attempt to deturgesce the cornea.3
Fortunately, the last 20 years have witnessed not only galactic leaps forward in pharmacologic advancements, but also the refinement of surgical interventions. Today, corneal surgeons are employing remarkable procedures to restore functional vision to patients with Fuchs’ dystrophy.
Current Treatment Strategies
Conservative therapy for early Fuchs’ dystrophy still involves the use of 5% sodium chloride solution throughout the day (e.g., Muro 128 [Bausch + Lomb] every two to six hours) and 5% sodium chloride ointment at bedtime. For more symptomatic cases, NSAIDs such as ketorolac, bromfenac or nepafenac may be helpful in managing patients with painful bullae. It is important to note, however, that NSAIDs merely provide analgesia. Additionally, corneal melts have been associated with excessive and prolonged use of certain NSAIDs, so they should be dosed judiciously.4
Bandage soft contact lenses also may serve to alleviate patient discomfort in cases of advanced Fuchs’ dystrophy. A flatly fit, high water content lens helps to mask the irregular astigmatism and diminish pain associated with epithelial bullae.2,5 SiHi lenses also have been used in this capacity with some success.6
Prior to 2000, penetrating keratoplasty remained the last recourse for most patients with advanced Fuchs’ dystrophy. However, with the advent of deep lamellar keratoplasty, patients now have a surgical option that is less invasive and painful, necessitates a shorter recovery time, and results in fewer instances of rejection.7
In deep lamellar keratoplasty, only the posterior aspect of the cornea is removed, which is replaced with donor tissue in an effort to restore a functional endothelial layer. The preoperative corneal surface is preserved, and transplantation of donor tissue is achieved via a scleral tunnel. The donor “button” is then inserted into the anterior chamber and positioned with the aid of an air bubble.
The currently favored surgical technique is known as DSEK, which stands for Descemet’s stripping endothelial keratoplasty. DSEK was first reported in 2005.8 Unlike prior techniques that dissected the recipient cornea at mid-stroma, this procedure peels away approximately 150µm—or about 25%—of the posterior stroma, including Descemet’s membrane and the endothelium (much in the same fashion that a capsulorhexis is performed on the anterior lens capsule during cataract surgery). The donor button of posterior stroma, Descemet’s membrane and endothelium are then implanted.
||This individual with Fuchs’ dystrophy exhibited marked endothelial pigment deposition.
DSEK has the advantage of a smaller, potentially self-sealing incision, as well as a smoother recipient interface for the donor tissue. Additionally, DSEK offers a more rapid rate of visual recovery than penetrating keratoplasty; most individuals achieve a functional level (e.g., 20/40 or better) within one to six months postoperatively.9
Although still relatively new and outside the “comfort zone” of many practicing corneal surgeons, DSEK is gaining acceptance both in the U.S. and abroad. A recent publication from the U.K. showed a 36% increase in DSEK procedures performed between 2007 and 2010.10
Also, improvements in microsurgical technique and instrumentation have yielded even more dramatic results with regard to patient outcomes. A three-year retrospective study indicated that a best spectacle-corrected visual acuity (BSCVA) of 20/25 was achieved in more than 70% of individuals who underwent DSEK.11 More impressively, a BSCVA of 20/20 was attained in nearly 50% of DSEK patients.11
Going forward, it is expected that lamellar keratoplasty will become even more precise, as DSEK gives way to the newest procedure––DMEK, or Descemet’s membrane endothelial keratoplasty. Like DSEK, DMEK involves an in vivo stripping of Descemet’s membrane through a scleral incision. However, DMEK peels away only about 80µm—or approximately 15%—of the posterior stroma. DMEK combines the anatomical benefits of DSEK with enhanced visual rehabilitation––typically to 20/40 or better in 90% of cases and 20/25 or better in 60% of cases within the first three months following surgery.9
While there is still no magic bullet for Fuchs’ dystrophy, the prognosis for surgical intervention and visual recovery is now much brighter than ever before. Patients no longer must fear the arduous and uncertain postoperative period that inevitably follows penetrating keratoplasty. Likewise, optometrists can comfortably and confidently refer patients with Fuchs’ dystrophy to corneal surgeons who are actively performing DSEK and DMEK, knowing that they will experience minimal downtime and will be able to resume normal activities in a short period of time.
As for our patient, he underwent uncomplicated DSEK. His visual acuity now measures 20/25 O.U., and he is highly satisfied with the postoperative outcome.
1. Bergmanson JP, Sheldon TM, Goosey JD. Fuchs’ endothelial dystrophy: a fresh look at an aging disease. Ophthalmic Physiol Opt. 1999;19(3):210-22.
2. Seitzman GD. Cataract surgery in Fuchs’ dystrophy. Curr Opin Ophthalmol. 2005;16(4):241-5.
3. Adamis AP, Filatov V, Tripathi BJ, Tripathi RC. Fuchs’ endothelial dystrophy of the cornea. Surv Ophthalmol. 1993;38(2):149-68.
4. Asai T, Nakagami T, Mochizuki M, et al. Three cases of corneal melting after instillation of a new nonsteroidal anti-inflammatory drug. Cornea. 2006;25(2):224-7.
5. Borboli S, Colby K. Mechanisms of disease: Fuchs’ endothelial dystrophy. Ophthalmol Clin North Am. 2002;15(1):17-25.
6. Kanpolat A, Ucakhan OO. Therapeutic use of Focus Night & Day contact lenses. Cornea. 2003;22(8):726-34.
7. Price MO, Price FW. Descemet’s stripping endothelial keratoplasty. Curr Opin Ophthalmol. 2007;18(4):290-4.
8. Price FW, Jr, Price MO. Descemet’s stripping with endothelial keratoplasty in 50 eyes: A refractive neutral corneal transplant. J Refract Surg. 2005 Jul-Aug;21(4):339-45.
9. Price MO, Giebel AW, Fairchild KM, Price FW Jr. Descemet’s membrane endothelial keratoplasty: prospective multicenter study of visual and refractive outcomes and endothelial survival. Ophthalmology. 2009 Dec;116(12):2361-8.
10. Ting DS, Sau CY, Srinivasan S, et al. Changing trends in keratoplasty in the West of Scotland: a 10-year review. Br J Ophthalmol. 2012 Mar;96(3):405-8.
11. Li JY, Terry MA, Goshe J, et al. Three-Year Visual Acuity Outcomes after Descemet’s Stripping Automated Endothelial Keratoplasty. Ophthalmology. 2012 Jun;119(6):1126-9.