Progressive And Severe Peripheral Anterior Synechiae In Patients With Endothelial Keratoplasty And Glaucoma

Iris abnormalities have been previously described after endothelial keratoplasties (EK). However, progressive peripheral anterior synechiae (PAS) formation does not seem to be a common complication of EK compared to penetrating keratoplasty. We describe six cases with previous glaucoma and EK that developed progressive and severe PAS after the transplant, compromising graft survival. 

: Fundación de Oftalmología Médica de la Comunitat Valenciana (FOM), Valencia (Spain)

Retrospective case series of six patients with previous glaucoma and pseudophakic bullous keratopathy that underwent EK and developed postoperative PAS.Two patients had Descemet membrane endothelial keratoplasty (DMEK) and four had Descemet Stripping Endothelial Keratoplasty (DSAEK).Five eyes had multiple glaucoma surgeries before the transplant including an Ahmed drainage device.One case had a pseudoexfoliation glaucoma with no previous glaucoma surgery but required a trabeculectomy after the transplant.Despite focal and mild PAS preoperatively, severe and progressive PAS were developed during the postoperative course.Retrospective analysis of the synechiae by anterior segment optical coherence tomography (CASIA,Tomey) was performed.

Mean follow-up time after the keratoplasty was 27 ± 15 months. PAS were seen before the 6 month follow-up in three cases, between 6 and 12 months follow-up in two cases and after 24 months in one case. There were no visible signs of intraocular inflammation when the synechiae developed. Despite the PAS, intraocular pressure remained stable with medical treatment. The graft failed in two of the eyes with longer follow-up. In three cases the cornea remains clear with low endothelial cell density. One case was complicated by a neurotrophic ulcer and required further surgeries. 

Clinically, PAS is associated with chronic inflammation in the anterior chamber (elevated cytokine levels), a history of narrow angle, and a breakdown of the blood–aqueous barrier. Patients with glaucoma and drainage devices have all three, thus severe progression of the synechiae in these cases might be explained by this phenomenon. Measuring aqueous humor cytokines at the time of the transplant, a higher steroid regime and close follow up of this subset of patients might be recommended. Other possible mechanisms like peripheral Descemet’s membrane tags from the Descemetorhexis or fibrine membranes would be also discussed.