Background/objectives

Anterior segment optical coherence tomography (AS-OCT) can be used to visualise keratic precipitates (KPs) on the corneal endothelium. However, there has been no correlation between characteristic clinical appearances of KPs and AS-OCT morphology. We wished to assess the potential diagnostic role of AS-OCT in patients presenting with inflammatory eye disease and KPs.

Subjects/methods

Six patients with inflammatory KPs were compared to one patient with infective interface keratitis following Descemet Membrane Endothelial Keratoplasty (DMEK) and one patient with endothelial pigment. AS-OCT was performed in each case and morphological features of the KPs were compared. Reflectivity of KPs was also compared numerically by measuring their relative lightness.

Results

AS-OCT images in acute and active inflammation generally demonstrated hyperreflective KP variants in comparison to conditions with moderate or longstanding inflammation. In the patient with infective interface keratitis, KPs were evident on the endothelial surface but no changes could be identified at the graft-host interface. There were no significant differences between infective and inflammatory KPs to help distinguish between the two. Endothelial pigment deposits were clearly differentiated from keratic precipitates with smaller, poorly defined deposits on the endothelium surface which were isoreflective to the cornea.

Conclusion

Hyperreflective KPs could be suggestive of newly deposited KPs and active inflammation; they may also be increased in KPs of herpetic origin. AS-OCT should not be used to differentiate infective infiltrate from inflammatory KPs if a patient were to present with post-operative inflammation and interface infection should still be suspected even if only endothelial deposits are identified on AS-OCT. AS-OCT may be used as a diagnostic and monitoring tool to assess response to treatment in cases where anterior segment inflammation of uncertain aetiology is present.

中文翻译：

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角膜沉淀的前段光学相干断层扫描表征。

背景/目标

前段光学相干断层扫描 (AS-OCT) 可用于观察角膜内皮上的角膜沉淀 (KP)。然而，KP 的特征性临床表现与 AS-OCT 形态之间没有相关性。我们希望评估 AS-OCT 在炎症性眼病和 KP 患者中的潜在诊断作用。

课题/方法

将 6 名患有炎症性 KP 的患者与 1 名接受 Descemet 膜内皮角膜移植术 (DMEK) 后患有感染性界面角膜炎的患者和一名患有内皮色素的患者进行了比较。在每种情况下都进行了 AS-OCT，并比较了 KP 的形态特征。KP 的反射率也通过测量它们的相对亮度进行了数值比较。

结果

与具有中度或长期炎症的病症相比，急性和活动性炎症中的 AS-OCT 图像通常表现出高反射性 KP 变体。在感染性界面角膜炎患者中，内皮表面有明显的 KP，但在移植物 - 宿主界面上没有发现任何变化。感染性和炎症性 KP 之间没有显着差异以帮助区分两者。内皮色素沉积物明显区别于角化沉淀物，在内皮表面上有较小的、边界不清的沉积物，这些沉积物对角膜具有等反射性。

结论

高反射 KP 可能提示新沉积的 KP 和活动性炎症；它们也可能在疱疹起源的 KP 中增加。如果患者出现术后炎症，AS-OCT 不应用于区分感染性浸润和炎症性 KP，即使 AS-OCT 仅发现内皮沉积，仍应怀疑界面感染。AS-OCT 可用作诊断和监测工具，以评估存在病因不明的眼前节炎症时对治疗的反应。