Campagnoli C, Ambroggio S, Biglia N, Sismondi P (December 1999). "Conjugated estrogens and breast cancer risk". Gynecol. Endocrinol. 13 Suppl 6: 13–9. PMID 10862264. Bhavnani BR (June 2003). "Estrogens and menopause: pharmacology of conjugated equine estrogens and their potential role in the prevention of neurodegenerative diseases such as Alzheimers". J. Steroid Biochem. Mol. Biol. 85 (2–5): 473–82. doi:10.1016/S0960-0760(03)00220-6. PMID 12943738. S2CID 45552896. Ortmann J, Traupe T, Vetter W, Barton M (May 2004). "[Postmenopausal hormone replacement therapy and cardiovascular risk: role of conjugated equine estrogens and medroxyprogesterone acetate]". Praxis (in German). 93 (21): 904–14. doi:10.1024/0369-8394.93.21.904. PMID 15216975. Kuhl H (2005). "Pharmacology of estrogens and progestogens: influence of different routes of administration" (PDF). Climacteric. 8 Suppl 1: 3–63. doi:10.1080/13697130500148875. PMID 16112947. S2CID 24616324. Kurabayashi T (November 2007). "[New evidence of conjugated estrogen and 17beta-estradiol for treatment and prevention of osteoporosis]". Nippon Rinsho (in Japanese). 65 Suppl 9: 369–73. PMID 18161134. Lamba G, Kaur H, Adapa S, Shah D, Malhotra BK, Rafiyath SM, Thakar K, Fernandez AC (June 2013). "Use of conjugated estrogens in life-threatening gastrointestinal bleeding in hemodialysis patients--a review". Clin. Appl. Thromb. Hemost. 19 (3): 334–7. doi:10.1177/1076029612437575. PMID 22411999. S2CID 30468265. Mirkin S, Komm BS, Pickar JH (January 2014). "Conjugated estrogens for the treatment of menopausal symptoms: a review of safety data". Expert Opin Drug Saf. 13 (1): 45–56. doi:10.1517/14740338.2013.824965. PMID 23919270. S2CID 24379298. Bhavnani BR, Stanczyk FZ (July 2014). "Pharmacology of conjugated equine estrogens: efficacy, safety and mechanism of action". J. Steroid Biochem. Mol. Biol. 142: 16–29. doi:10.1016/j.jsbmb.2013.10.011. PMID 24176763. S2CID 1360563.
An advanced case is usually readily apparent to the examiner, and can provide for an unambiguous diagnosis prior to more specialized testing. Under close examination, a ring of yellow-brown to olive-green pigmentation known as a Fleischer ring can be observed in around half of keratoconic eyes. The Fleischer ring, caused by deposition of the iron oxide hemosiderin within the corneal epithelium, is subtle and may not be readily detectable in all cases, but becomes more evident when viewed under a cobalt blue filter. Similarly, around 50% of subjects exhibit Vogts striae, fine stress lines within the cornea caused by stretching and thinning. The striae temporarily disappear while slight pressure is applied to the eyeball. A highly pronounced cone can create a V-shaped indentation in the lower eyelid when the persons gaze is directed downwards, known as Munsons sign. Other clinical signs of keratoconus will normally have presented themselves long before Munsons sign becomes apparent, and so this finding, though a classic sign of the disease, tends not to be of primary diagnostic importance. A handheld keratoscope, sometimes known as "Placidos disk", can provide a simple noninvasive visualization of the surface of the cornea by projecting a series of concentric rings of light onto the cornea. A more definitive diagnosis can be obtained using corneal topography, in which an automated instrument projects the illuminated pattern onto the cornea and determines its topography from analysis of the digital image.