KMO and diabetes mellitus: Our study demonstrates that specific kynurenine pathway (KP) disruptions drive distinct ocular pathologies: cataract progression shows a significant decline in KAT activity (KYNA/KYN ratio decreasing with SPONCS grade, p = 0.014), while glaucoma and diabetes exhibit elevated KMO activity (increased 3-HK/KYN ratios, p = 0.032 and p = 0.039, respectively) and neurotoxic 3-HK/KYNA imbalance (p = 0.013), with comorbid cases showing amplified effects.