The demand of MEMS biosensors in biomedical applications is enormous which has driven the review of such devices. Various biosensors that are available in the market and under research are inadequate in providing pickup and amplification of the bio-signals for diagnosis and treatment purposes. In this review, various biosensors implemented and deployed through invasive and non-invasive techniques are reviewed to determine their adequacy in diagnosis and treatment. A MEMS device also has been specifically designed for the pickup of intra-ocular pressure for early diagnosis of glaucoma. Piezoresistive type pressure sensor is designed to provide better accuracy in the pickup of such biomedical signals. The designed device which is analyzed using the COMSOL Multiphysics provided better sensitivity of around 26.6mV/V/MPa and a non-linearity of < 1%, which will promote better diagnosis.