Megalopapilla is a non-progressive human eye condition in which the optic nerve head (optic disc) has an enlarged diameter, exceeding 2.1 mm with no other morphological abnormalities.
| Megalopapilla | |
|---|---|
| Specialty | Ophthalmology |
| Types | 2 types |
| Differential diagnosis | Normal tension glaucoma |
Clinical features
editIn megalopapilla the optic disc diameter exceeds 2.1 mm (or surface area more than 2.5 mm2[1]) with an increased cup-to-disc ratio.[2] Although the optic disc is looks abnormal, the disc colour, sharpness of disc margin, rim volume, configuration of blood vessels and intraocular pressure will be normal.[3][1] Visual field is normal except for an enlarged blind spot.[4] Visual acuity may be normal,[4] or occasionally reduced.[5]
Types
editThere are two types of megalopapilla. Type 1, which is the most common, is bilateral with a normal configuration of the optic cup.[5] Type 2 is unilateral with a superiorly displaced cup that eliminates the adjacent neuro-retinal rim.[5]
Diagnosis and differential diagnosis
editLarge disc size can be seen in fundus examination by ophthalmoscopy. Since OCT is not influenced by disc size, it can be used in differentiating normal and glaucomatous eyes with large discs.[6]
Since the clinical appearance of megalopapilla resembles that of glaucomatous optic disc, it should be differentiated from Normal tension glaucoma and other pseudo-glaucomatous diseases.[6] Other conditions that resembles megalopapilla includes coloboma of optic disc and orbital optic disc glioma.[4]
History
editBock and Franceschetti were the first to use the term megalopapilla to describe larger-than-normal optic disks.[6]
References
edit- ^ a b Lee, Hyo Seok; Park, Sang Woo; Heo, Hwan (June 2015). "Megalopapilla in children: a spectral domain optical coherence tomography analysis". Acta Ophthalmologica. 93 (4): e301–e305. doi:10.1111/aos.12545. PMID 25178150. S2CID 207033177.
- ^ Optic nerve disorders : diagnosis and management. Jane W. Chan (Second ed.). New York. 2014. p. 250. ISBN 978-1-4614-0691-4. OCLC 884280097.
{{cite book}}: CS1 maint: location missing publisher (link) CS1 maint: others (link) - ^ Sampaolesi, R.; Sampaolesi, J. R. (2001). "Large optic nerve heads: megalopapilla or megalodiscs". International Ophthalmology. 23 (4–6): 251–257. doi:10.1023/a:1014409404579. ISSN 0165-5701. PMID 11944849. S2CID 41882871.
- ^ a b c "OCT USE IN THE DIFFERENTIAL DIAGNOSIS OF MEGALOPAPILLA VERSUS GLAUCOMA". www.aaopt.org.
- ^ a b c Amador-Patarroyo, Manuel J.; Pérez-Rueda, Mario A.; Tellez, Carlos H. (1 January 2015). "Congenital anomalies of the optic nerve". Saudi Journal of Ophthalmology. 29 (1): 32–38. doi:10.1016/j.sjopt.2014.09.011. ISSN 1319-4534. PMC 4314572. PMID 25859137.
- ^ a b c "MEGALOPAPILLA". www.aaopt.org. American Academy of Optometry.