In this study, investigators at a single center in Germany compared contrast sensitivity in patients with both nuclear cataract and corneal guttae with that seen in patients with nuclear cataract alone. They compared the results of a triple procedure on patients with both conditions vs. cataract surgery alone on patients without corneal guttae as the control group.
Study design
This was a retrospective case series comparing 25 eyes with nuclear cataract and early Fuchs endothelial corneal dystrophy (corneal guttae with no edema) to 25 eyes with nuclear cataract and healthy corneas. The Fuchs group underwent Descemet membrane endothelial keratoplasty (DMEK) combined with cataract surgery (i.e., a triple procedure) and the control group underwent cataract surgery alone. Outcome measures included contrast sensitivity, as measured with the MARS letter contrast sensitivity test and the OPTEC 6500P device, central corneal thickness, corneal volume, and anterior and posterior corneal densitometry.
Outcomes
Preoperatively, MARS letter contrast sensitivity and posterior densitometry were significantly worse in the Fuchs group; however, cataract severity, corneal volume, central corneal thickness, and anterior corneal densitometry were comparable between the groups. Postoperatively, all outcomes were similar between groups. The OPTEC 6500P contrast sensitivity results were mixed, but generally showed preoperative values in the Fuchs group that were worse than controls and postoperative values that were similar to controls.
Limitations
This a retrospective study of a convenience sample, and as a result does not directly show superiority of a triple procedure over cataract surgery alone in eyes with Fuchs endothelia corneal dystrophy and nuclear cataract. It compared available triple procedures among Fuchs patients to available cataract procedures among patients with healthy corneas, which are not true “controls.”
Clinical significance
Corneal guttae alone cause a further decrement in contrast sensitivity beyond what is caused by nuclear cataracts. Treatment of the corneal guttae with DMEK in addition to cataract surgery can return contrast sensitivity and posterior corneal densitometry values to what is observed in patients with healthy corneas after cataract surgery.