Dilek ORUM, Yasar KAPICI, Hasan Gorkem MARKIRT
Dynamic Medical Theories - 2025;1(3):117-118
It is usually assumed that alcohol use causes pupil dilatation (1), yet other limited number of studies report that alcohol use has no effect on iris recognition (2). On the other hand, literature demonstrates that the pupil dilates until a certain amount of alcohol use, after which it begins to constrict (3). The changes in pupil diameter under various lighting conditions in individuals diagnosed with alcohol use disorder (AUD) but not under the influence of alcohol have not yet been investigated. This study aims to compare the photopic, mesopic, and scotopic vision of individuals diagnosed with AUD with healthy controls (HCs). In this retrospective study, individuals who had pupil measurements performed for any reason and who did not have any ocular pathology were evaluated for eligibility for the study, taking into account their e-nabiz (comprehensive patient registration system)records. The AUD group was composed of individualswho were diagnosed with AUD according to DSM-5-TR in the alcohol/substance treatment unit and whohad a negative ethyl alcohol result on the day thepupil measurement was performed. Individuals withorganic disease or those with the potential to affect themeasured parameters (e.g., medication use, diabetesmellitus, hypertension, rheumatologic diseases, andcoronary artery disease) were excluded. Individualswith normal eye findings were included. HC groupdid not have any active disease and medication use.The measurements (mm) had been performed inlight, soft light, and dark environments using Sirius3D Rotating Scheimpflug Camera & TopographySystem. Pupil diameter measured in light is calledas photopic (50 lux), called as mesopic in soft light(4 lux), and called as scotopic in dark (0.04 lux). We considered one alcohol unit equal to 10 ml or 8 g of pure alcohol. The entire AUD group had answered 'yes' to all four items of the CAGE (an acronym for cut down, annoy, guilty, and eye opener) alcohol questionnaire. The Brief Psychiatric Rating Scale (BPRS) had been administered to all individuals. Statistical analyses were performed using SPSS 26.0 package program (IBM Corp., Armonk, NY , USA). Local ethics committee approval was obtained (Adıyaman University, Date: April 16, 2024; Number: 2024/4-32). While there was no difference in age (p=0.742) and cigarette package/year (p=0.157) between the AUD (n=33 males) and HC (n=33 males) groups, there were differences in BPRS (p<0.001), gamma-glutamyl transferase (GGT) (p<0.001), mean corpuscular volume (MCV) (p<0.001), aspartate aminotransferase to platelet ratio index (APRI) (p<0.001). The proportion of divorced and single individuals (p=0.003), those without a regular job (p=0.003), those with a history of psychiatric admission (p<0.001), and those with a family history of AUD (p<0.001) was higher in the AUD group compared to the HC group. Right scotopic (p=0.005), right mesopic (p=0.033), right photopic (p<0.001), left scotopic (p<0.001), left mesopic (p<0.001), and left photopic (p=0.001) visions were higher in the AUD group than in the HC group. In the correlation analysis performed by controlling the effect of age in the AUD group, a significant positive relationship was found between alcohol unit/year and MCV , GGT, APRI (p<0.05); a negative relationship between alcohol unit/year and BPRS; a negative relationship between BPRS and MCV , GGT, APRI (p<0.05). No significant correlation was found between alcohol unit/year and pupil diameters (p>0.05). The area under the ROC curve of right photopic was 0.804 (p<0.001; 95%CI [0.693-0.916]). This study is noteworthy in that it shows that individuals who were not under the influence of alcohol but had an existing diagnosis of AUD had higher pupil diameters, including photopic, mesopic, and scotopic vision, than HCs. Literature shows that pupil diameter decreases more during miosis and increases more during mydriasis in individuals under the influence of alcohol compared to those not under the influence of alcohol. In other words, alcohol has effects that result in an increase in the lower/upper limits of the pupil diameter. Due to alcohol consumption, the pupil dilates/constricts more than normal which may causes deformation in iris pattern, possibly affecting iris recognition performance (3). Additionally, the sympathetic-parasympathetic hierarchy may be disrupted due to alcohol use (4,5). This retrospective, single-center study enrolled only male participants and relied on electronic records plus a same-day negative ethanol test to verify non-intoxication, introducing potential selection and misclassification biases. Despite excluding major ocular/systemic conditions and medication use, residual confounding (e.g., autonomic changes related to liver status or psychiatric burden) may persist. Pupil size was captured as static diameters under three illumination levels with a single device, without dynamic pupillary reflex metrics, repeated-day measurements, or time-of-day control, which may affect precision. The modest sample size also limits statistical power and generalizability, and the cross-sectional design precludes causal inference. Retrospective nature and inability to verify e-nabiz records are important limitations. Further studies are needed to reduce these limitations.
