Special Senses System

Eye, Cornea - Vacuolation, Cytoplasmic

Narrative
Comment:
Corneal epithelial vacuoles (Figure 1, Figure 2, and Figure 3) are characterized as discrete, variably sized, generally clear, single to multiple, round to oval cytoplasmic spaces. These can occur in the corneal epithelial, endothelial, or stromal cells (keratocytes). Epithelial vacuoles can occur in specific cell layers (e.g., basal, suprabasal). Vacuoles may enlarge and coalesce to form intraepithelial vesicles or stromal lacunae. Vacuoles in corneal cells can result from various causes, including systemic or topically applied toxins; can appear as features of inherited storage diseases, such as mucopolysaccharidoses; or can be secondary to corneal desiccation or inflammation. True vacuoles must be distinguished from the artifactual clear zones (often perinuclear) that often occur in corneal cells. The vacuolation may be accompanied by inflammatory cells in the underlying stroma (Figure 1, Figure 2, and Figure 3) or the anterior chamber (Figure 1), and corneal epithelial hyperplasia and hyperkeratosis (Figure 3).
Recommendations:
If occurring as a primary toxic or heritable effect, corneal cytoplasmic vacuolation should be diagnosed and assigned a severity grade. An appropriate site modifier (e.g., epithelium, endothelium, stroma) should be included in the diagnosis to indicate the location of the affected cells. When occurring as a feature or sequela to another pathologic process (e.g., inflammation), corneal cytoplasmic vacuolation should not be diagnosed separately unless warranted by severity, but should be described in the pathology narrative.
Related Links:
Eye - Cornea - Edema
References:

Geiss V, Yoshitomi K. 1991. Eyes. In: Pathology of the Mouse: Reference and Atlas (Maronpot RR, Boorman GA, Gaul BW, eds). Cache River Press, Vienna, IL, 471-489.

Abstract: http://www.cacheriverpress.com/books/pathmouse.htm

Greaves P. 2007. Nervous system and special sense organs. In: Histopathology of Preclinical Toxicity Studies: Interpretation and Relevance in Drug Safety Evaluation, 3rd ed. Academic Press, San Diego, CA, 861-933.

Abstract: http://www.sciencedirect.com/science/book/9780444527714

Guillet R, Wyatt J, Baggs RB, Kellogg CK. 1988. Anesthetic-induced corneal lesions in developmentally sensitive rats. Invest Ophthalmol Vis Sci 29:949-954.

Abstract: https://pubmed.ncbi.nlm.nih.gov/3372167/

Kast A. 1991. Keratoconjunctivitis sicca and sequelae, mouse and rat. In: International Life Sciences Institute Monographs on the Pathology of Laboratory Animals, Vol 10, Eye and Ear (Jones TC, Mohr U, Hunt RD, eds). Springer, Berlin, 29-37.

Moore QA III, McCormick CC, Norcross EW, Onwubiko C, Sanders ME, Fratkin J, McDaniel LS, O’Calaghan RJ, Marquart ME. 2009. Development of a Streptococcus pneumoniae keratitis model in mice. Ophthalmol Res 42:141-146.

Full Text: http://www.karger.com/Article/Pdf/229028

National Toxicology Program. 1994. NTP TR-435. Toxicology and Carcinogenesis Studies of 4,4’-Thiobis(6-t-butyl-m-cresol) (CAS No. 96-69-5) in F344/N Rats and B6C3F1 Mice (Feed Studies). NTP, Research Triangle Park, NC.

Abstract: https://ntp.niehs.nih.gov/go/6014

National Toxicology Program. 2012. NTP TR-572. Toxicology and Carcinogenesis Studies of Methyl trans-Styryl Ketone (CAS No. 1896-62-4) in F344/N Rats and B6C3F1 Mice (Feed and Dermal Studies). NTP, Research Triangle Park, NC.

Abstract: https://ntp.niehs.nih.gov/go/36154

Smith RS, Sundberg JP, John SWM. 2002. The anterior segment. In: Systematic Evaluation of the Mouse Eye: Anatomy, Pathology, and Biomethods (Smith RS, John SWM, Nishina PM, Sundberg JP, eds). CRC Press, Boca Raton, FL, 111-159.

Yoshida M, Ikadai H, Maekawa, Takahashi M, Nagase S. 1996. Pathological characteristics of mucopolysaccharidosis VI in the rat. J Comp Path 109:141-155.

Abstract: https://www.ncbi.nlm.nih.gov/pubmed/8245230
  • Image of cornea vacuolation, cytoplasmic in the eye from a male F344/N rat in a chronic study

    Eye, Cornea - Vacuolation, Cytoplasmic in a male F344/N rat from a chronic study. There are clear discrete vacuoles (arrow) in the corneal epithelial cells and inflammatory cells in the anterior chamber (A).

Enlarge Image
Enlarge All Images
Eye, Cornea - Vacuolation, Cytoplasmic in a male F344/N rat from a chronic study. There are clear discrete vacuoles (arrow) in the corneal epithelial cells and inflammatory cells in the anterior chamber (A).
Eye, Cornea - Vacuolation, Cytoplasmic in a male F344/N rat from a chronic study. There are clear discrete vacuoles (arrow) in the corneal epithelial cells and inflammatory cells in the anterior chamber (A).
Eye, Cornea - Vacuolation, Cytoplasmic in a male F344/N rat from a chronic study (higher magnification of Figure 1). There are clear discrete vacuoles in the superficial epithelial cells (arrow).
Eye, Cornea - Vacuolation, Cytoplasmic in a male F344/N rat from a chronic study (higher magnification of Figure 1). There are clear discrete vacuoles in the superficial epithelial cells (arrow).
Eye, Cornea - Vacuolation, Cytoplasmic in a male B6C3F1 mouse from a chronic study. There are clear vacuolesis present in the basal epithelial cells (arrow); there is also corneal epithelial hyperplasia (P) and hyperkeratosis (K).
Eye, Cornea - Vacuolation, Cytoplasmic in a male B6C3F1 mouse from a chronic study. There are clear vacuolesis present in the basal epithelial cells (arrow); there is also corneal epithelial hyperplasia (P) and hyperkeratosis (K).

Author

Margarita M. Gruebbel, DVM, PhD, DACVP
Senior Pathologist
Experimental Pathology Laboratories, Inc.
Research Triangle Park, NC

Reviewers

Ruth E. Hurley, DVM, PHD, DACVP
Senior Veterinary Pathologist
Huntingdon Life Sciences
North Brunswick, NJ

Robert R. Maronpot, DVM, MS, MPH, DACVP, DABT, FIATP
Senior Pathologist
Experimental Pathology Laboratories, Inc.
Research Triangle Park, NC