# Retinal Vessel Segmentation Using Math-Inspired Metaheuristic Algorithms
## 1 Introduction
The AOA has also been applied to several engineering problems in the existing literature, including the implementation of the AOA for optimization in mechanical engineering design problems [4; 25; 26], designing skeletal structures (e.g., 72 bar space truss, 384 bar double-layer barrel vault, and a 3 bay, 15 story steel frame) [27], the implementation of a dynamic AOA for truss optimization under natural frequency constraints [28], optimizing the shapes of vehicle components using metaheuristic algorithms to minimize fuel emissions [29], applying enhanced hybrid AOAs to real-world engineering problems (e.g., welded beam, gear train, 3 bar truss, speed reducer, multiple disk clutch brake, step-cone pulley, 25 bar truss, and 4-stage gearbox design problems) [30], the enhancement of a hybrid AOA for DC motor regulation and fluid-level sequential tank system design [31], the implementation of an AOA-based efficient text document clustering approach [32], the implementation of a deep convolutional spiking neural network optimized using the AOA for lung disease detection from chest X-ray images [33], and the design of an electric vehicle fast-charging station connected with a renewable energy source and battery energy storage system [34]. The TSA only has a restricted number of real-world applications in the existing literature, including the adjustment of the optimal forecasting interval and enhancement of the interval forecasting performance in ensemble carbon emissions forecasting systems [35], the implementation of a hybrid method (named the Aquila optimizer-tangent search algorithm; AO-TSA) for global optimization problems [36], and the implementation of a basic TSA which integrates the fitness-weighted search strategy (FWSS) and opposition-based learning (OBL) concepts for the solution of complex optimization problems [37]. The GNDO algorithm has several real-world applications in the existing literature, including parameter extraction for photovoltaic models for energy conversion [5], estimating the parameters of the triple-diode model of a photovoltaic system [38], the design of truss structures with optimal weight [39], and enabling voltage and current control in an energy storage system and adjusting the optimum gain settings of the PI controller [40]. The GOBC-PA algorithm has been applied to engineering problems such as the optimization of the parameters of an osmotic dehydration process for enhanced performance in the drying of mushroom products [41], as well as the implementation of a novel search method consisting of deterministic and stochastic approaches and testing its performance over benchmark functions in addition to one- and two-dimensional optimization problems [42]. Finally, the CSA has also been applied to several engineering problems, including tracking global maxima power under partial shading conditions in solar photovoltaic systems [43] and the implementation of a maximum-power point-tracking control system to increase the efficiency of grid-connected photovoltaic systems [44]. In the recent literature, there are also studies that have detailed the application of approaches other than metaheuristic algorithms for retinal vessel segmentation. In [45], [PERSON] et al. propose a preprocessing module including four stages to assess the impact of retinal vessel coherence on retinal vessel segmentation and then applied the proposed method to retinal images from the DRIVE and STARE databases. In [46], [PERSON] et al. propose a novel hybrid algorithm to segment dual-wavelength retinal images with high accuracy and enlarge the measurement range of hemoglobin oxygen saturation in retinal vessels. [PERSON] and [PERSON] propose a novel approach based on gray relational analysis for the segmentation of retinal images under the constraint of a limited sample size and the resulting associated uncertainties [47]. [PERSON] et al.