Salzmann nodular degeneration: prevalence, impact, and management strategies

Abstract

Purpose

This review will summarize the clinical and histological presentation of Salzmann nodular degeneration (SND), its prevalence and risk factors, potential underlying mechanisms, diagnostic tools, management options, and impact on cataract surgery and co-morbid ocular surface diseases.

Method

PubMed review of 44 articles published between 1976 and 2018.

Results

SND is a corneal disease characterized by whitish gray or bluish nodules on the peripheral or central cornea. The clinical presentation of SND is variable and the nodules can be asymptomatic or cause foreign body sensation and/or blurred vision. Histologically, SND appears as subepithelial nodules with thin overlying epithelium, disrupted or absent Bowman’s layer, and activated fibroblasts within the nodule. SND pathogenesis is not fully understood but is thought to involve poor epithelial protection and disruption of the epithelial–stromal interface, allowing for penetration of epithelially derived growth factors into the stroma and subsequent activation of stromal fibroblasts, eventually leading to sub-epithelial deposition of disorganized extracellular membrane components. SND most commonly occurs in Caucasian females in a bimodal distribution, occurring in the fifth or eighth and ninth decades of life. Risk factors for SND include ocular surface diseases and surgery. Surgical intervention is recommended in individuals with symptomatic nodules – primarily superficial keratectomy performed with or without intraoperative mitomycin C, photokeratectomy, and/or amniotic membrane transplantation. These procedures have been successful in removing the lesion and reducing corneal irregularity, but have variable recurrence rates (0–31%).

Conclusion

The pathogenesis of SND is complex and multifactorial. Advances in diagnostic and treatment modalities have allowed for earlier and more accurate diagnosis and effective treatment of SND.

Keywords:

• Salzmann nodular degeneration
• cornea
• diagnosis
• imaging
• treatment

Role of sponsors

The sponsors below provided financial support to cover the researchers time but were not involved in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; or decision to submit the manuscript for publication. We would like to note that the contents of this study do not represent the views of the Department of Veterans Affairs or the United States Government.

Acknowlegments

This study was supported by the Department of Veterans Affairs, Veterans Health Administration, Office of Research and Development, Clinical Sciences Research EPID-006-15S (Dr. Galor), R01EY026174 (Dr. Galor), NIH Center Core Grant P30EY014801 and Research to Prevent Blindness Unrestricted Grant. This study was also supported by the Dr. Ronald and Alicia Lepke Grant, the Lee and Claire Hager Grant, the H. Scott Huizenga Grant, the Grant and Diana Stanton-Thornbrough, the Robert Baer Family Grant, the Emilyn Page and Mark Feldberg Grant, the Jose Ferreira de Melo Grant, the Richard and Kathy Lesser Grant, the Ted and Michele Kaplan Grant and the Richard Azar Family Grant (institutional grants).

Disclosure

The authors report no conflicts of interest in this work.