Khodadoust Line Indicating Graft Rejection in Descemet’s Stripping Automated Endothelial Keratoplasty: A Unique Case Report

Abstract

Purpose:

To highlight the rarity of the endothelial rejection line, also known as the Khodadoust line, as a manifestation following Descemet’s stripping automated endothelial keratoplasty (DSAEK). The objective is to present a meticulously detailed case, including imaging and anterior optical coherence tomography (OCT), to enhance understanding and recognition of this phenomenon.

Methods:

A detailed case presentation involving a 50-year-old male, 3 years post-DSAEK transplantation for endothelial damage resulting from intraocular surgeries. The patient urgently sought consultation due to vision loss while under daily fluorometholone use. Clinical examination revealed acute graft rejection characterized by corneal edema, anterior chamber reaction, and the presence of keratic precipitates forming a Khodadoust line. The management approach included the initiation of a tapered dexamethasone regimen.

Results:

The identified acute graft rejection, marked by the presence of a Khodadoust line, demonstrated favorable responsiveness to the initiated tapered dexamethasone regimen. Corneal OCT and imaging played crucial roles in providing detailed insights into the manifestation.

Conclusions:

While the endothelial rejection line (Khodadoust line) is a rare occurrence following DSAEK, this case underscores its potential association with graft rejection. The successful management outlined in this report suggests the importance of prompt recognition and appropriate anti-inflammatory intervention in such cases to achieve positive outcomes.

INTRODUCTION

Over recent years, endothelial keratoplasties have become the preferred modality for managing endothelial disorders, such as Fuchs endothelial dystrophy, primarily due to their reduced rejection rates compared to the traditional penetrating keratoplasties.1 While Descemet’s membrane endothelial keratoplasty (DMEK) demonstrates even lower rejection rates2 with better visual acuity,3 its technical intricacies mean Descemet’s-stripping automated endothelial keratoplasty (DSAEK) remains a favored choice in scenarios where DMEK poses greater complications or technical challenges. Ultrathin-DSAEK has shown a more favorable complication profile.3

Notably, when rejection occurs, it is exclusively at the endothelial level, given that neither the epithelium nor the anterior stroma is transplanted. Clinical signs include an anterior chamber inflammatory response with keratic precipitates and corneal edema.4 Studies indicate a 3-year immunologic rejection incidence ranging from 1.2% to 9%.1,4,5,6 The Khodadoust line, an endothelial rejection line characterized by the accumulation of lymphoid cells on the endothelial surface indicating immunologic corneal allograft rejection, is rare,4 with only three documented cases.7,8,9 This article introduces a distinct case of endothelial graft rejection in a DSAEK, marked by a Khodadoust line, meticulously detailed with imaging and corneal optical coherence tomography (OCT).

CASE REPORT

A 50-year-old myopic male with a history of pars plana vitrectomy for retinal detachment and cataract surgery presented with reduced right eye vision. Examination revealed corneal edema, central bullae, and Descemet’s membrane folds, with a best-corrected visual acuity (BCVA) of 20/50. With the diagnosis of corneal edema secondary to endothelial damage, a DSAEK procedure was planned. His medical history was significant for epilepsy and psoriasis.

The surgery was executed under retrobulbar anesthesia using a mepivacaine–bupivacaine mix, as described elsewhere.10 The Descemet’s membrane and endothelium are removed from the recipient’s cornea, and a donor cornea lamella, consisting only of deep stroma and endothelium, is inserted using a specially designed glide. Once in place, the anterior chamber is filled with air to adhere the donor lamella to the recipient cornea. The implanted 8.5 mm cornea had a thickness <100 μm and an endothelial cell count of 2400 cells/mm². Cefuroxime was injected as prophylaxis. On the 3^rd postoperative day, the lenticule was entirely adhered.

Postoperative management began with a tapered dexamethasone phosphate 0.1% (dexamethasone) regimen starting every 4 h and antibiotic therapy with tobramycin 0.3% for the initial week. Six months later, with an intraocular pressure of 23 mmHg without graft rejection signs, his treatment was adjusted to bimatoprost 0.03% and timolol 0.5%, dexamethasone was transitioned to tapered fluorometholone 0.1%, which eventually settled to a daily regimen. His BCVA remained at 20/50.

However, 3 years postprocedure, the patient sought urgent consultation due to a 4-day history of deteriorating vision in the right eye. With BCVA of 20/63, the slit-lamp evaluation revealed ocular hyperemia with microcystic edema and Descemet’s membrane folds, along with anterior chamber inflammation and keratic precipitates aligned in a Khodadoust line pattern [Figures 1 and 2a and b]. Dexamethasone was promptly initiated at a frequency of three times daily and subsequently tapered on a weekly basis.

Figure 1.

Anterior segment optical coherence tomography where keratic precipitates can be observed forming a Khodadoust line

Figure 2.

(a) Corneal edema with Descemet’s membrane folds and endothelium rejection line (Khodadoust line), (b) detailed image of Khodadoust line and microcystic edema

Currently, the patient has no signs of rejection and the Khodadoust line is no longer visible. His BCVA has returned to 20/50. His chronic therapeutic regimen consists of travoprost 0.004%, timolol 0.5%, dorzolamide 2%, and once-daily dexamethasone eye drops. Informed consent was obtained from the patient.

DISCUSSION

Rejection following DSAEK occurs in fewer than 10% of patients, a rate considerably lower than that observed with penetrating keratoplasty where rejection ranges from 15.0% to 38.0%.1 Notably, when rejection does manifest, it predominantly affects the endothelial layer, since neither the epithelium nor the anterior stroma are components of the graft. The predominant clinical presentations include blurred vision and photophobia.6 However, Basak and Basak reported that nearly one-third of rejections were identified incidentally during routine postoperative assessments.6

The endothelial rejection line, also known as the Khodadoust line, is characterized by an accumulation of lymphoid cells at the endothelial surface, signifying immunologic corneal allograft rejection.8 This feature has been linked with corneal vascularization, and its infrequent presentation in endothelial keratoplasties is potentially due to the absence of stromal vessels extending into the grafted tissue.4,8 In addition, another study highlighted anterior synechiae alongside stromal vascularization as factors potentially elevating the risk of Khodadoust line formation.8

In the case presented, the surgery was carried out according to the described technique without any complications. The patient’s prior medical history of epilepsy and psoriasis did not affect the surgical outcome nor is it expected to impact the prognosis. He exhibited signs of graft rejection 3 years postoperatively, in a stable daily treatment with fluorometholone 0.1%. Wu et al.1 emphasized the discontinuation of corticosteroids as a pivotal risk factor for DSAEK rejection, a pattern consistent across all documented Khodadoust line presentations.7,8,9 However, we did not find any trigger for the rejection in the presented patient.

Prompt initiation of intensive topical corticosteroid therapy is paramount and typically elicits a swift therapeutic response. In our patient’s case, prior visual acuities were restored in less than a week and the rejection signs disappeared after 2 weeks.

Emphasizing the importance of education is crucial; for the patient in terms of recognizing early symptoms of rejection and ensuring ophthalmologists remain vigilant for initial, subtle indicators, suggestive of graft rejection. The incorporation of anterior segment OCT and topographies can facilitate early diagnosis as it can help in the visualization of keratic precipitates or anterior chamber reactions in the context of corneal edema.

Graft rejection in DSAEK rarely manifests as an endothelial rejection line. Nevertheless, clinicians should be aware of this sign as a potential indicator of graft rejection.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.