Patients with Fuchs endothelial dystrophy or other forms of corneal endothelial disease frequently also have a cataract. Both conditions cause reduced and blurred vision, and both require surgery to correct. In appropriately selected patients, cataract removal and corneal endothelial transplantation can be performed as a single combined procedure, sometimes called a triple procedure. This avoids the need for two separate operations, reduces the overall surgical burden, and can provide better visual outcomes than staging the procedures separately. The decision to combine or stage the procedures depends on several clinical factors, and in some patients an ultrathin DSAEK graft is more appropriate than DMEK. This post explains how these decisions are made.
What is Fuchs endothelial dystrophy?
Fuchs endothelial dystrophy is the most common indication for corneal endothelial transplantation in Australia. It is a genetically inherited condition causing progressive loss of the corneal endothelial cells, the single layer of cells lining the inner surface of the cornea that maintains corneal clarity by actively pumping fluid out of the corneal stroma. As endothelial cells are lost over decades, the cornea becomes progressively oedematous, causing blurred and hazy vision, glare, and eventually painful epithelial bullae in advanced cases.
Fuchs dystrophy typically presents in the fifth to seventh decade of life, which is also the age at which cataracts develop. The coexistence of cataract and Fuchs dystrophy in the same patient is therefore common and creates a surgical planning decision that requires careful thought.
How cataract surgery affects Fuchs dystrophy
Cataract surgery in a patient with Fuchs dystrophy is not straightforward. The phacoemulsification energy used during cataract surgery causes additional endothelial cell loss, which in a cornea already compromised by Fuchs dystrophy can precipitate or accelerate corneal decompensation. A patient with borderline endothelial function who undergoes cataract surgery alone may develop progressive corneal oedema in the months after surgery, ultimately requiring a corneal transplant as a second procedure.
This is the fundamental problem that the triple procedure addresses. By combining cataract surgery with endothelial transplantation in a single operation, the patient avoids the phacoemulsification stress on a Fuchs dystrophy cornea and has the endothelial disease treated at the same time.
Combined versus staged procedures: what the evidence shows
The question of whether to combine cataract and endothelial keratoplasty in a single sitting, or to stage them as separate procedures, has been addressed in multiple clinical studies and two systematic reviews and meta-analyses, both of which support the combined approach in appropriately selected patients.
A 2024 systematic review and meta-analysis published in Acta Ophthalmologica [1] compared combined DMEK and sequential DMEK (staged after prior cataract surgery) in patients with Fuchs dystrophy and cataract. The review found that both approaches achieved significant improvement in corrected distance visual acuity, with no statistically significant difference in the primary visual acuity outcome between combined and sequential DMEK. Endothelial cell density and rebubbling rates were comparable between groups.
A broader systematic review and meta-analysis published in Frontiers in Medicine [2] analysing 36 studies found that combined cataract surgery did not significantly increase the risk of primary graft failure or cystoid macular oedema compared with DMEK alone, supporting the safety of the combined approach.
The clinical conclusion from the evidence is that combined cataract and DMEK is safe and effective, produces comparable visual outcomes to staged procedures, and avoids the need for a second operation and second anaesthetic episode.
DMEK versus ultrathin DSAEK: how I decide
For most patients with Fuchs dystrophy and good corneal anatomy, DMEK is my preferred endothelial transplant technique. DMEK replaces only the Descemet membrane and endothelium, leaving the entire stroma intact and providing the most anatomically precise restoration of the corneal layers. The evidence is consistent that DMEK achieves superior best-corrected visual acuity and faster visual recovery than ultrathin DSAEK.
A 2023 systematic review and meta-analysis published in Eye [3] analysed seven studies comprising 362 eyes and found that DMEK resulted in better best-corrected visual acuity at three months, six months, and one year compared with ultrathin DSAEK. However, ultrathin DSAEK had a significantly lower rebubbling rate (11.0% versus 33.7% for DMEK) and a lower overall complication rate (25.2% versus 57.3%).
The higher rebubbling rate with DMEK reflects the greater technical complexity of achieving and maintaining graft adhesion with an ultra-thin membrane that has no stromal carrier. While rebubbling is usually manageable with an air injection in the clinic and does not typically affect the final outcome, it is a more demanding postoperative course for both the patient and surgeon.
I choose ultrathin DSAEK over DMEK in several clinical situations.
In vitrectomised eyes, DMEK graft adhesion is significantly more challenging due to the altered vitreous anatomy and fluid dynamics. Ultrathin DSAEK, with its slightly thicker stromal carrier, achieves more reliable adhesion in these eyes and is my preferred technique when the patient has had prior vitreoretinal surgery.
In eyes with significant iris abnormality, anterior chamber depth issues, or other anatomical factors that make DMEK graft unfolding technically more difficult, ultrathin DSAEK provides a more predictable surgical approach.
In older or medically complex patients where minimising surgical time is a priority, ultrathin DSAEK can be technically faster for the graft insertion and positioning stage, reducing the overall procedure duration.
In patients where corneal donor tissue with very thin Descemet membrane is not available, a pre-prepared ultrathin DSAEK graft may be the more reliably available tissue option.
In every case the choice between DMEK and ultrathin DSAEK is made individually, based on the patient's ocular anatomy, their general health, the planned combined procedure, and the available tissue. I discuss the preferred approach and the reasons for it at the pre-operative consultation. For further detail on DMEK specifically, see the post on DMEK corneal transplant surgery.
How the triple procedure is performed
The combined procedure begins with standard phacoemulsification cataract surgery, performed with the same technique as a routine cataract operation. The intraocular lens implant is inserted and positioned. The anterior chamber is reformed and the cataract incisions are secured.
The corneal transplant component is then performed. For DMEK, a pre-stripped Descemet membrane graft from a donor eye bank cornea is loaded into an injector system and introduced into the anterior chamber through a small incision. The graft is unfolded using a combination of gentle fluid movements, tapping on the corneal surface, and an air bubble introduced beneath the graft to push it into apposition with the host Descemet membrane, which has been stripped at the beginning of this stage of the procedure.
For ultrathin DSAEK, a microkeratome-prepared donor lenticule of less than 100 microns thickness is introduced through a slightly larger incision, positioned, and tamponaded with air in the same manner.
At the conclusion of either procedure, the patient lies flat for approximately one hour to allow the air bubble to maintain graft adhesion. The patient is instructed to remain face-up as much as possible for the first 24 to 48 hours, which is the most important determinant of graft adherence in the immediate post-operative period.
What is recovery like after a triple procedure?
Recovery after a combined cataract and corneal transplant is longer than after cataract surgery alone. Vision in the first weeks is typically reduced and hazy as the donor endothelium establishes function and the corneal oedema resolves. Most patients notice meaningful improvement in vision within four to eight weeks, with continued gradual improvement over three to six months as the graft fully deturgesces and the refraction stabilises.
The first post-operative day visit is important to confirm graft adhesion. If the graft has partially or fully detached, a rebubbling procedure is performed in the clinic, which involves injecting a small air bubble into the anterior chamber to re-tamponade the graft. This is a brief procedure that does not require a return to the operating theatre in most cases.
Steroid eye drops are continued for a longer period than after routine cataract surgery, typically one year or more, to reduce the risk of immune-mediated graft rejection. Patients are counselled to report any sudden reduction in vision, pain, redness, or light sensitivity promptly, as these may indicate a rejection episode requiring urgent treatment.
For a detailed overview of anaesthesia for cataract surgery and what to expect on the day, see the guide to cataract surgery anaesthesia on corneaeyedoctor.com.
Patient selection and pre-operative assessment
Not all patients with coexisting cataract and Fuchs dystrophy require or benefit from a triple procedure. The pre-operative assessment involves several specific evaluations beyond the standard cataract workup.
Specular microscopy to count the endothelial cell density is performed to determine the severity of the endothelial disease and the likelihood of corneal decompensation after cataract surgery alone. Corneal pachymetry and slit lamp examination assess whether oedema is already present. Corneal topography and tomography evaluate the corneal shape and thickness distribution.
If the endothelial cell count is relatively preserved (typically above 1,000 to 1,500 cells per mm² depending on the distribution and clinical findings), cataract surgery alone may be performed with close post-operative monitoring for corneal decompensation. If the cell count is critically low, the cornea is already oedematous, or there is strong clinical evidence that cataract surgery alone will precipitate decompensation, the triple procedure is recommended.
Lens selection in the combined procedure also requires careful thought. Because the corneal curvature and refractive index change as the transplant deturgesces over months, standard IOL power calculation formulae are less accurate than in routine cataract surgery. The refractive target is often set slightly myopic to account for the post-transplant hyperopic shift, and the use of premium diffractive lenses is generally not recommended in the combined setting due to the refractive uncertainty of the post-transplant cornea. For more on what to expect at a cataract surgery consultation, including how lens selection is discussed, see that companion post. The role of complex cataract surgery experience is also relevant when a corneal transplant is being performed simultaneously.
Who performs combined cataract and corneal transplant surgery?
Combined cataract and endothelial keratoplasty is a subspecialty procedure that requires training and experience in both phacoemulsification cataract surgery and DMEK or DSAEK technique. The technical complexity of managing both the cataract and the corneal graft in a single surgical episode, including lens selection in the context of a transplanted cornea, graft tissue handling, and post-operative management, is substantially greater than either procedure performed alone. The importance of cataract surgery experience and volume is especially relevant in the combined procedure setting.
I trained in corneal transplantation at the Royal Victorian Eye and Ear Hospital, one of the busiest corneal transplant centres in the Asia-Pacific region, and completed subspecialty fellowship training in complex cataract and corneal surgery at the Wilmer Eye Institute, Johns Hopkins University. I perform combined DMEK and ultrathin DSAEK procedures at Northpark Private Hospital, Bundoora.
For patients with Fuchs dystrophy or corneal endothelial disease who also have a cataract, I provide a full assessment to determine whether combined or staged surgery is most appropriate, discuss the choice between DMEK and ultrathin DSAEK for their individual eye, and manage care from pre-operative assessment through to long-term follow-up. A referral from your GP or optometrist is required.
References
- Romano V, et al. Combined or sequential DMEK in cases of cataract and Fuchs endothelial corneal dystrophy: a systematic review and meta-analysis. Acta Ophthalmol. 2024;102(1):e22-e30. https://pubmed.ncbi.nlm.nih.gov/37155336/
- Tey A, et al. Effects of Combined Cataract Surgery on Outcomes of Descemet's Membrane Endothelial Keratoplasty: a systematic review and meta-analysis. Front Med. 2022; PMC9002009. https://pmc.ncbi.nlm.nih.gov/articles/PMC9002009/
- Hurley DJ, Murtagh P, Guerin M. Ultrathin Descemet Stripping Automated Endothelial Keratoplasty versus Descemet Membrane Endothelial Keratoplasty: a systematic review and meta-analysis. Eye. 2023;37(14):3026-3032. https://pubmed.ncbi.nlm.nih.gov/36934158/
- Moura-Coelho N, et al. Ultrathin DSAEK versus DMEK: review of systematic reviews. Eur J Ophthalmol. 2024. https://pubmed.ncbi.nlm.nih.gov/37964555/
- Price DA, et al. Initial results of DMEK combined with cataract surgery and implantation of the light-adjustable lens. J Cataract Refract Surg. 2024;50(3):270-275. https://pubmed.ncbi.nlm.nih.gov/38085175/