Fuchs Endothelial Dystrophy Treatment & Management

Updated: May 04, 2018
  • Author: Vikas Mittal, MBBS, MS; Chief Editor: Hampton Roy, Sr, MD  more...
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Treatment

Medical Care

Patients who have Fuchs endothelial dystrophy and clear corneas need no treatment. It is only when the corneal decompensation starts that medical treatment becomes necessary. This treatment is necessary until it is not possible to preserve good vision; at that point, keratoplasty is necessary.

Dehydrating agents

Sodium chloride 5% eye drops are instilled 4-6 times during the day, especially in the early hours of the day and less frequently in the evening. Sodium chloride ointment is used at bedtime.

Glycerine can be used for diagnostic purposes. It causes rapid dehydration of the cornea and clears the vision. Certain patients are able to use it for therapeutic purposes, but it is rather uncomfortable. It is instilled many times a day, as needed.

Use of warm dry air (evaporation)

A hair dryer, kept at arm's distance, can be used to blow warm air over the cornea for 5-10 minutes upon awakening. Drying of the cornea may improve the vision of the patient for some time.

Lowering the intraocular pressure (IOP) 

Lowering the intraocular pressure (IOP) is useful when it is even mildly raised. It occasionally helps even when the pressure is normal, especially in borderline cases of corneal decompensation. Topical carbonic anhydrase inhibitors should be avoided as it hinders the activity of endothelial pump.

Topical nonsteroidal anti-inflammatory drug (NSAID)

Diclofenac 0.1% and ketorolac 0.5% drops may help to alleviate symptoms (eg, itching, burning, gritty sensation) but may increase the risk of poor epithelial healing and subsequent corneal melting.

Supportive treatment for ruptured bullae

Anterior stromal punctures may be indicated.

Multiple ablation pits with Fugo blade can be used.

Soft contact lenses can be useful in cases of bullae formation.

Cycloplegics, local antibiotics, and pad and bandage treat the eye for a couple of days.

Excimer laser phototherapeutic keratectomy, amniotic membrane graft, or a conjunctival flap can also be considered.

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Surgical Care

Failing vision or pain in the presence of epithelial edema and stromal haze, which cannot be treated by the instillation of 5% sodium chloride drops and ointment, necessitates recourse to surgery.

Despite the lack of an accurate estimate of the prevalence of Fuchs endothelial dystrophy, it remains one of the most common indications for corneal transplantation, accounting for up to 29% of cases. [8]

A selection has to be made between the following 2 options: (1) keratoplasty alone, when no cataract is present, or (2) if a cataract is present and adds significantly to visual disability and specular endothelial microscopy results suggest the need for a corneal graft, then a combined corneal transplant, cataract extraction, and lens implant procedure should be performed.

Penetrating keratoplasty (PK) with or without cataract surgery had been the standard treatment for Fuchs endothelial dystrophy since the past 100 years. PK involves replacement of whole cornea, although only endothelial layer is defective. In last few years, major advances in this field have made replacement of endothelial layer possible without disturbing normal anterior structures of cornea using endothelial keratoplasty. Descemet stripping endothelial keratoplasty (DSEK) involves transplant of healthy endothelial layer along with minimal posterior corneal stroma. When automated stripping of Descemet membrane is performed, the procedure is termed Descemet stripping automated endothelial keratoplasty (DSAEK). Descemet membrane endothelial keratoplasty (DMEK) is the transplant of endothelial cells along with the Descemet membrane only. [14]

Patients who undergo DSEK regain early and more superior visual acuity than patients who undergo PK due to lack of surface sutures. [15, 16] These eyes are structurally stronger and more resistant to postoperative traumatic injury, and no suture-related graft infection or graft rejection occurs. There is no risk of expulsive hemorrhage, as this is a closed chamber surgery. Endothelial keratoplasty gives more predictable refractive outcomes than PK. [17]

Ocular coherence tomography (OCT) image of a patie Ocular coherence tomography (OCT) image of a patient with Fuchs endothelial dystrophy showing gross corneal edema of 850 microns and epithelial bullae formation.
Ocular coherence tomography (OCT) image of the sam Ocular coherence tomography (OCT) image of the same patient as above with Fuchs endothelial dystrophy after undergoing Descemet membrane endothelial keratoplasty (DMEK) and showing overall compact cornea with a thickness of 450 microns and thin attached DMEK graft.

A study by van der Meulen et al found that straylight pre-DSEK can be a useful clinical metric to predict postoperative improvement, especially in cases where the preoperative visual acuity is near 20/20. Straylight also improved more in younger eyes than in older eyes after the procedure. [18]

Frequent visits are no longer required, as is the case in patients who undergo PK. DSEK can be combined with cataract surgery (ie, phacoemulsification or manual small incision cataract surgery) in patients with associated cataracts. In patients with associated corneal stromal scaring, PK is still the treatment of choice.

Some researchers feel that repopulation of the central corneal endothelium with corneal deturgescence can occur after deliberate central Descemet stripping in patients with Fuchs endothelial dystrophy who have undergone cataract removal. This may offer a novel treatment for patients with Fuchs endothelial dystrophy that could reduce the need for endothelial transplantation. [19] However, further studies are needed to validate this.

Descemet stripping endothelial keratoplasty (DSEK)

Preoperative assessment is required mainly to rule out glaucoma and posterior segment abnormality. Careful slit lamp examination is required to check anterior chamber depth and rule out any associated angle anomalies and peripheral anterior synechiae. Anterior segment optical coherence tomography (OCT) and ultrasound biomicroscopy (UBM) can be helpful in patients having very hazy view. Appropriate methods should be used to check IOP. Ultrasound B-scan is helpful in ruling out gross posterior segment abnormality and disc excavation.

Preparation of donor tissue 

The target is to prepare a donor disc of the required diameter with a posterior one third stroma and Descemet membrane with healthy endothelial cells. Preparation can be manual or automated (Microkeratome); the latter is DSAEK. A femtosecond laser can also be used to prepare donor lenticule (FS-DSEK). With the present data, all methods seem comparable in terms of clinical outcome, although this has yet to be clearly established. Manual dissection is most cost effective and is performed using artificial anterior chamber and blunt dissectors.

Steps of manual preparation of donor disc include the following:

  • Donor tissue is mounted on artificial anterior chamber, and the epithelium is removed to improve the view.
  • Manual lamellar dissection is performed at approximately more than two thirds depth with 2 blunt dissectors (straight and curved).
  • Donor tissue is removed from artificial anterior chamber, and the desired diameter is punched.

Preparation of the recipient bed

Surgery is performed under conventional peribulbar anesthesia, although it can be done under topical anesthesia as well.

Preoperatively, pilocarpine 2% is used to constrict the pupil when only DSEK is planned and the pupil is dilated if cataract surgery is also planned.

The superficial epithelium is scraped off. Three 1-mm side-ports are made at 6-o'clock, 10-o'clock, and 2-o'clock positions. The 10-o'clock and 2-o’clock incisions are for Descemet membrane stripping and to manipulate and unfold the donor lenticule. The 6-o’clock incision is used for anterior chamber maintainer (ACM). Avoiding any kind of viscoelastic substance is desirable, and, if required, use only cohesive viscoelastic agent.

Trypan blue (0.06%) solution is used to stain the diseased endothelium. Circular scoring of the Descemet membrane is performed with a reverse Sinskey hook corresponding to epithelial template mark. Scoring (touching the membrane with optimal pressure) can be performed in a complete circle form (Descemetorrhexis) or in a "can opener" form. Scoring makes a cut in the Descemet membrane, which can later be completely stripped off with the help of the hook. Any remnant strands of Descemet membrane can be manually removed, as they will be seen as bluish-stained residual fragments.

A 5-mm to 5.5-mm sclerocorneal tunnel is prepared similar to making a tunnel in manual small incision cataract surgery. Making the tunnel temporal is desirable, so as to induce minimal astigmatism.

If required, cataract surgery with intraocular lens implantation (phacoemulsification or manual small incision cataract surgery) is performed at this stage because the view is comparatively better after removing the Descemet membrane and epithelium.

If viscoelastic agent is used, it is thoroughly and carefully washed out with balanced salt solution (BSS) using an irrigation/aspiration cannula, and an AC is then well formed with BSS.

Transplantation of the donor lenticule 

DSAEK insertion devices can be categorized into 3 groups based on their mechanism of action: the folding technique (ie, taco-folding); glides such as Sheet’s, Busin, or Tan endo-glide; and push-in designs (injectors). Folding and grasping the donor tissue with forceps or the pull-through technique using glides to enable graft insertion through a small incision can be traumatic to endothelium in shallower anterior chambers. The standard Busin glide-assisted graft insertion technique is described below.

The graft is delivered to the patient’s eye using the pull-through technique by Busin. [20] The graft is placed on the plate and pulled into the funnel-shaped part of the Busin glide using a microincision forceps. The Busin glide is then inverted and positioned at the nasal clear cornea tunnel. On the temporal side, a microincision forceps is inserted to pull the graft into the anterior chamber, allowing it to unfold spontaneously. Air is injected underneath the graft until the anterior chamber is completely filled with air, which is left in place for 60 minutes.

Intraoperative OCT can be used to demonstrate the attachment of the donor lenticule with proper orientation to the posterior host stroma. Upon completion of the surgery, air is reduced to about 50% of the anterior chamber volume and is replaced with saline. A bandage contact lens is given in all cases. The eye is patched and the patient is instructed to lie supine for at least 12 hours.

Discharge and steroid therapy

Patients can be discharged after 48 hours. Postoperative medications include topical steroids (prednisolone acetate 1%) in tapering doses, starting from 8 times per day to 1 time per day over 6 months before finally administering topical loteprednol 1 time per day indefinitely. Few surgeons consider completely discontinuing topical steroids.

Descemet membrane endothelial keratoplasty (DMEK)

In contrast to DSEK, which includes posterior donor stroma, DMEK consists of donor endothelium and Descemet membrane without creation of a stromal interface (stromal irregularities or macrofolding or microfolding of donor stromal tissue), inducing significantly less posterior surface aberrations, improving refractive predictability, and resulting in better vision and quicker visual recovery. Compared with DSAEK, DMEK yielded a significantly higher rate of 20/20 and 20/25 vision.

Slit lamp photograph of a 62-year-old man with Fuc Slit lamp photograph of a 62-year-old man with Fuchs endothelial dystrophy showing corneal stromal edema and Descemet folds.
Slit lamp photograph of the same patient as above Slit lamp photograph of the same patient as above who underwent DMEK and showed symptomatic amelioration. Her vision improved to 20/40.

In addition, because less tissue is injected into the recipient’s eye, the overall rejection rate associated with DMEK is shown to be 15 times less than that associated with DSEK. [14]

DMEK and DSAEK yielded similar endothelial survival within a follow-up of 6 months. [21]

DMEK restored physiologic pachymetry, but donor preparation, unfolding, and attachment are currently more challenging with DMEK than with DSAEK. [17] DSAEK allows for easier preparation and implantation, provides the opportunity to use precut donor tissue, and has a lower rebubbling rate.

Graft preparation

The basic aim is to separate the Descemet endothelial complex from corneal stroma.

The corneoscleral button is placed “endothelial side up” on a Teflon block, and a few drops of corneal preservation medium (Optisol) are placed over it such that the liquid reaches the edge of corneoscleral rim. Attempt to keep the tissue-Teflon interface free of fluid to minimize tissue movement during donor harvesting.

An 8.5-mm (the diameter can vary according to the corneal diameters) corneal trephine stained with gentian violet at the edge is then used to make an initial central partial-thickness groove in the corneoscleral button by gentle tapping. The aim is to get a starting point to separate the Descemet membrane from posterior stroma.

The tip of a Sinskey hook is then used to delineate the cleft between the Descemet membrane and underlying stroma all around. At least 2-3 mm of Descemet membrane lift is ensured to help in holding for further separation.

Subsequently, the edge of the Descemet membrane is held with one or two blunt suture-tying forceps and gently pulled in a direction parallel to endothelium and toward the opposite edge.

In one attempt, 20%-30% of the Descemet membrane can be separated. This is performed in each quadrant until all of the Descemet membrane is separated from stroma. Four to five rotations are required to separate the whole of the Descemet membrane.

Simultaneous and coordinated movements of both hands are used when the edge of the Descemet membrane is held with two forceps. In addition, the Descemet membrane is kept in corneal preservation medium at all times. When two thirds of the Descemet membrane is peeled from one side, a small skin biopsy punch (3 mm) is used to punch a hole in the stroma-epithelium complex. The Descemet membrane is reposited, and the entire corneal tissue is flipped and the underside of the DM marked with dye (the letter P or S or F) to identify the right side up in case the graft roll becomes reversed. The remaining dissection is then completed. A small tear in the Descemet membrane endothelial complex does not necessitate tissue replacement, and a good anatomical and visual outcome can be achieved in such cases. [22] After the Descemet membrane is completely peeled off, it tends to roll over, and it is kept afloat in corneal preservation medium until its injection into the eye.

Recipient preparation

The surgery is performed under peribulbar anesthesia.

Epithelium is removed to improve visibility. The sideports are made and the ACM attached. The Descemet membrane is stripped as performed during routine Descemet stripping endothelial keratoplasty.

However, a few researchers have advocated that this scoring is unnecessary in cases of Fuchs endothelial dystrophy.

A small peripheral iridotomy is performed at the 6-o’clock position using an automated vitrector. Finally, the ACM is removed and the paracentesis wound hydrated.

Donor injection

The harvested Descemet membrane endothelial complex is stained with trypan blue 0.06% to improve its visualization inside the eye.

Staining with trypan blue dye and its subsequent wash is performed by instilling the same drop by drop at the edge of the corneoscleral rim, avoiding direct instillation onto the endothelium.

The Descemet membrane–endothelium complex tends to roll up spontaneously with the endothelium at the outer side. This Descemet membrane roll is aspirated into a customized injector mounted on a 2-mL syringe.

The customized Descemet endothelial complex injector is prepared from a routine Akreos (Bausch and Lomb, USA) intraocular lens (IOL) injector. The injector is cut from the proximal end and attached to a silicon tube used for phacoemulsification. Hence, a “no-touch” technique is used for insertion into the eye.

Before injecting the Descemet endothelial complex into the eye, the anterior chamber is decompressed by tapping the posterior lip of the paracentesis wound.

The Descemet endothelial complex is injected into the anterior chamber with a single push.

Donor unfolding

The graft is oriented with the endothelial side down (donor Descemet membrane facing recipient posterior stroma) onto the recipient posterior stroma by careful indirect manipulation of the tissue with air and fluid.

Fluid waves from the side ports, intermittent decompression of side ports, and repeated tapping on the corneal surface help the Descemet endothelial complex unfold.

While unfolding, the edges of the Descemet membrane folds should face the corneal stroma instead of the iris.

Once the proper direction of unfolding is confirmed, a small air bubble is injected below the Descemet endothelial complex.

Surface strokes (not massage) are used to unfold it further.

Finally, a large air bubble is used to fill the anterior chamber completely with air.

An air-tight globe is achieved and maintained since an inferior peripheral iridotomy has already been performed.

Topical 5% povidone iodine, homatropine 2%, and prednisolone forte 1% eye drops are instilled, and the eye is patched.

Postoperative course

The patch is opened after 2 hours and slit-lamp examination performed to confirm an attached Descemet membrane.

Slit lamp photograph on postoperative day 1 of a p Slit lamp photograph on postoperative day 1 of a patient who underwent Descemet membrane endothelial keratoplasty (DMEK), showing an intact and well-adherent graft, compact cornea inferior peripheral iridectomy, and an air bubble.

The postoperative medications used are the same as used for DSEK.

If graft detachment is recognized, either clinically or on OCT, it can be managed via repeat air injection.

Cataract surgery in Fuchs endothelial dystrophy

Cataract surgery alone should be considered in patients with Fuchs endothelial dystrophy who have good endothelial cell density and corneal pachymetry less than 600-640 µm. If precautions are taken to protect the endothelium during surgery with endothelium coating viscoelastics and controlled phacoemulsification parameters, most cases of confluent guttata, without corneal symptoms, do well with cataract and lens implant surgery alone.

Inpatient & Outpatient Medications

Administer oral acetazolamide as needed to control intraocular pressure (IOP). Topical cycloplegics are necessary to avoid any papillary block due to the air bubble in the anterior chamber.

Prednisolone acetate 1% drops are instilled 8 times per day, tapering gradually to bid for 4-8 weeks and qd for several months. Afterward, loteprednol drops 0.25% are given daily for 1-2 years.

If an epithelial defect is present, topical antibiotic drops or ointment is used 4-6 times per day.

For patients with deficient tear secretion, use artificial tears 6-8 times per day.

Further Inpatient Care

If additional surgery is needed to treat various complications of Fuchs endothelial dystrophy that can arise, further inpatient care may be required.

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Diet

No dietary restrictions are noted.

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Activity

Advise the patient to avoid any kind of trauma to the eye. The eye may be cleaned with boiled and cooled wet cotton swabs. After a period of 2 weeks, the patient can take a brisk walk, watch television, and resume any visual task that the eye is capable of with or without refractive correction.

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Complications

The following are potential complications:

  • Graft detachment
  • Graft rejection and failure
  • Tunnel wound gape and aqueous leakage and postoperative infection
  • Secondary glaucoma
  • Endophthalmitis
  • Cataract formation
  • Infective keratitis and, in some cases reactivation of HSV keratitis
  • Epithelial healing problems and ulceration
  • Vitreoretinal problems - Cystoid macular edema, choroidal detachment, and retinal detachment
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Prevention

Eye protection measures include the following:

  • Patients should avoid rubbing and bumping the eye.
  • Patients should use a protective shield at night and protective glasses during the day for at least 3 months, and ideally longer, after surgery.
  • Patients should avoid splashing the eye with tap water when taking a bath.

Patients should observe the following cleanliness guidelines:

  • Avoid cleaning the eye with nonsterile products.
  • Avoid applying cosmetics on the lid margin.
  • Avoid smoke and dusty environment.
  • Avoid putting any drops, other than prescribed drops, in the eye.
  • Do not touch the nozzle of the eye drop bottle during use. Store the medicine bottle in a cool place, preferably inside a refrigerator.

Patients should beware of warning signs; seek urgent consultation if any of the following warning signs occur:

  • Feeling of heaviness and pain
  • Redness of the eye, especially around the cornea
  • Diminution of eyesight
  • Light sensitivity
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Long-Term Monitoring

Perform routine checkups to assess vision, fundus, and intraocular tension.

Examine the condition of the graft on the first, seventh, and twenty-first postoperative day and then every 30 days afterward to evaluate for any signs of graft rejection.

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Transfer

Because the surgery is performed on elderly patients who are sometimes frail and who may have multiple health problems (eg, cardiovascular, respiratory, renal, cerebral systems), be prepared at all times to transfer the patient to an appropriate institution, as and when the need arises.

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Future Advances

Recent work demonstrating the ability to culture human corneal endothelial cells ex vivo on several substrates, including denuded Descemet membrane and amniotic membrane, indicates promising areas of future research. [23] Gene therapy–based approaches may invite therapy for Fuchs endothelial dystrophy as mutations in the COL8A2 gene have already been shown to play a role in etiology, and additional causal mutations in different genes will probably be identified. Genetic modification of corneal endothelial cells has already been accomplished, and Fuchs endothelial dystrophy mutations could theoretically be corrected in corneal endothelial cells as a potential treatment for this disease. [24] Future research and improvements in endothelial keratoplasty, endothelial cell engineering, and gene therapy represent promising new approaches for the management of this common corneal disorder.

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