Combined or sequential?

Sequential surgery is the best option for most Fuchs’ endothelial cell dystrophy and cataract

Roibeard O’hEineachain

Posted: Tuesday, May 1, 2018

Slit-lamp images of eye with Fuchs’ endothelial dystrophy submitted to sequential cataract and DSAEK surgery: pre-DSAEK (left) and one month post-DSAEK (right)

Iva Dekaris MD

The corneas of most Fuchs’ endothelial dystrophy patients appear to endure cataract surgery quite well. Combining phacoemulsification with endothelial grafting in the same operation should be reserved for eyes where either or both conditions are at a more advanced stage, said Iva Dekaris MD, PhD, Svjetlost University Eye Hospital, Zagreb, Croatia.

“In our hands, the majority of our Fuchs’ endothelial dystrophy patients have good visual results for months and years after undergoing phacoemulsification alone,” Dr Dekaris told the 22nd ESCRS Winter Meeting in Belgrade, Serbia.

Dr Dekaris noted that when she and her associates retrospectively analysed their database of all Fuchs’ endothelial dystrophy patients at their centre who underwent phacoemulsification, they found that 66.0% of patients did not require Descemet’s stripping automated endothelial keratoplasty (DSAEK) in the first two years after their cataract procedure. At three-to-four months, 21.65% required DSAEK, as did a further 1.5% after eight-to-12 months and a further 10.82% after one year.

There were also significant differences between patients who later required DSAEK and those who did not, in terms of mean endothelial cell density (ECD) (1,225 cells/mm2 vs 1,742 cells/mm2), mean pachymetry (670µm vs 587µm) and anterior chamber depth (2.38mm vs 3.14mm).

Among the eyes that required DSAEK after phacoemulsification, the interval between the two procedures was three-to-four months in eyes with a corneal thickness greater than 700µm, compared to eight-to-14 months in those with central corneal thickness less than 600µm.

However, there appeared to be an uneven threshold of tolerance for phacoemulsification in terms of the preoperative Fuchs’ parameters, not only throughout the population but sometimes in the same patient. She cited the case of a man who required DSAEK in only one eye despite having very similar central corneal thickness, ECD and anterior chamber depth in both eyes.

Dr Dekaris noted that the advantages of performing endothelial keratoplasty and cataract procedures separately include the greater stability it affords the IOL, reduced vitreous pressure during the DSAEK procedure and better chamber stability and a lower risk of iatrogenic primary graft failure.

The advantages of a combined procedure are that it reduces costs and inconvenience and leads to faster visual rehabilitation. However, as the current study shows, many patients do not need DSAEK after phacoemulsification surgery, she said.

The literature suggests that sequential surgery should be done in eyes where the cornea has guttae and minimal oedema, only mild endothelial cell loss and the cataract is immature. Combined surgery should be performed in eyes with corneal oedema with significant guttae, epithelial oedema, history of morning blurry vision plus visually significant cataract.

In eyes with very dense cataract and/or advanced endothelial dystrophy it is possible to determine the amount of visual loss attributed to each condition. However, in most eyes the distinction tends to be less clear. Moreover, most patients will have an improvement in their vision following cataract surgery only, Dr Dekaris said.

She noted that although phacoemulsification can have a worsening effect on Fuchs’ endothelial dystrophy, treating a cataract when still immature can reduce that effect by reducing the need for phaco power. In addition, she noted that facility in performing the DSAEK afforded by the increased anterior depth following cataract extraction somewhat compensates for the injury to the endothelium phacoemulsification may induce.

She also cautioned that their study was limited by the small number of Fuchs’ endothelial dystrophy patients requiring grafts at their centre. Such patients only accounted for 2.3% of their corneal transplantations during the years 2010 to 2017. “Hopefully centres with higher surgical volume will perform retrospective randomised studies determine which option is better for a particular Fuchs’ endothelial cell dystrophy case,” Dr Dekaris said.

Iva Dekaris: