Which of the following type of macular dystrophy is associated with the typical egg yoke lesion located in the central macula?
High-Yield Explanation
Fundus examination in a patient with Best disease can show abnormalities ranging from mild pigmentary disturbance within the fovea to the typical vitelliform or egg yoke lesion located in the central macula. This egg yoke like lesion is typically round and well demarcated and contains homogeneous opaque yellow material lying at the apparent level of the retinal pigment epithelium. The genetic abnormality in this condition is a mutation in the BEST1 gene which encodes a transmembrane calcium-sensitive chloride channel expressed in retinal pigment epithelium. Ref: Fletcher E.C., Chong N., Augsburger J.J., Correa Z.M. (2011). Chapter 10. Retina. In P. Riordan-Eva, E.T. Cunningham, Jr. (Eds), Vaughan & Asbury's General Ophthalmology, 18e.