Once pterygia reach a critical size, they induce visually significant central with-the-rule astigmatic changes that may not be apparent by subjective refraction. This finding helps to identify those patients who may benefit from surgical intervention.

Corneal-topography analysis is an important component of the evaluation of patients with pterygium, revealing significant abnormalities that are improved by successful removal of the pterygium.

Transversal adaptive filters for digital signal processing have traditionally been implemented into DSP processors due to their ability to perform fast floating-point arithmetic. However, with its growing die size as well as incorporating the embedded DSP block, the FPGA devices have become a serious contender in the signal processing market. Although it is not yet feasible to use floating-point arithmetic in modern FPGAs, it is sufficient to use fixed-point arithmetic and still achieve tap-weight convergence for adaptive filters. This paper examines the feasibility of implementing an adaptive algorithm, namely the LMS algorithm, based on fixed-point arithmetic, using the Altera Stratix device.