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    How does high-refractive error affect quantitative pupillometry values?
    (2025) Kocabas, Dilara Ozkoyuncu; Yavrum, Fuat
    PURPOSE: To evaluate the static and dynamic pupil responses in differentiating eyes with high-refractive errors from emmetropic controls. METHODS: The study was conducted using data obtained from 36 participants with high myopia, 26 participants with high hyperopia, and 38 age-gender-matched controls. The cycloplegic spherical equivalent refraction (SER), axial length (AL), and pupil responses were examined. In static pupillometry, pupil diameters were recorded at scotopic, mesopic, and photopic light intensities. The mean pupil dilation speed was calculated according to changes in pupil size over time, as dynamic pupillometry. RESULTS: The mean scotopic and mesopic pupil diameters were smaller in high hyperopic eyes compared with high myopic and control eyes (P < 0.05). The photopic pupil diameter in the high hyperopic group was significantly lower than in the high myopic group (P = 0.003). There was no statistical difference between the high myopia and control groups regarding static pupillometry (P > 0.05). No significant difference was noted between the refractive groups regarding the speed of pupil dilation (P = 0.241). While SER and AL were correlated with scotopic and mesopic pupil diameters (P < 0.05), no correlation was observed with photopic pupil diameter or the speed of pupil dilation (P > 0.05). CONCLUSIONS: The difference in static pupil responses was prominent in high hyperopic eyes compared to high myopic and emmetropic eyes. Unlike static pupil responses, the speed of pupil dilation was not affected by high-refractive errors. © © 2025 Indian Journal of Ophthalmology.
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    Impact of malnutrition on pupillary responses in pediatric population
    (Sage Publications Ltd, 2026) Kocabas, Dilara Ozkoyuncu; Yavrum, Fuat; Sukun, Elmas Yuksel; Yavrum, Begum
    Purpose : To investigate the effect of nutritional status on pupillary responses in children aged 5 to 18 years. Methods : This cross-sectional study comprised 92 eyes of malnourished children and 80 eyes of age- and gender-matched healthy children based on BMI Z-score. Serum ferritin, hemoglobin, serum 25-hydroxyvitamin D, and vitamin B12 levels were recorded. Pupillary responses were taken using Sirius topography (CSO, Italy) with the automated pupillometry function. Static pupillometry consisted of pupil diameters at scotopic, mesopic, and photopic luminances. In dynamic pupillometry, the mean pupil dilation speed at the 10th second was calculated by dividing the distance by time in each 0.2 s period. Results : No significant difference was observed between the groups regarding age, gender, visual acuity, and spherical equivalent (p > 0.05). Mean hemoglobin, serum ferritin, serum 25-hydroxyvitamin D, and vitamin B12 levels were lower in malnourished children than healthy children (p < 0.001). The malnutrition group had lower mean pupil diameters under all luminance and higher speed of pupil dilation compared to the control group (p < 0.05). While malnutrition subgroups were similar in terms of pupil diameters under all luminance (p > 0.05), the speed of pupil dilation was significantly different between the groups (p = 0.024). BMI z-score was positively correlated with mesopic and photopic pupil diameter but also negatively correlated with the speed of pupil dilation (p < 0.05). Conclusion : Malnourished children have smaller pupil diameters and higher speed of pupil dilation than healthy controls, indicating an autonomic impairment.
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    Optical quality of the cornea one year after Cretan protocol plus in eyes with keratoconus
    (Taylor & Francis Ltd, 2025) Kocabas, Dilara Ozkoyuncu; Yavrum, Fuat; Ozulken, Kemal
    Clinical relevance Cretan protocol plus is a novel technique that combines corneal cross-linking with refractive procedures in patients with keratoconus. Visual improvement is not only limited to visual acuity, the optical quality may also be enhanced by the Cretan protocol. Background To evaluate the higher-order aberrations (HOAs) and optical quality of the cornea 1 year after the Cretan protocol plus in keratoconus patients. Methods The uncorrected (UDVA) and corrected (CDVA) distance visual acuity, manifest refraction spherical equivalent (MRSE), and topographical analysis of the cornea were assessed. The corneal optical quality parameters, including total HOA (Z(3-8)), vertical coma (Z(3)(-1)), horizontal coma (Z(3)(1)), vertical trefoil (Z(3)(-3)), oblique trefoil (Z(3)(3)), and spherical aberration (Z(4)(0)), modulation transfer function (MTF) and Strehl ratio of point spread function (PSF) over the 4 mm diameter pupil were recorded via Sirius dual-scanning corneal tomography. All data were analysed preoperatively, 1 month, 6 months, and 1 year postoperatively. Results Twenty eyes of 16 keratoconus patients with 1 year of follow-up were included. After the Cretan protocol plus, the mean UDVA, CDVA, MRSE, corneal astigmatism, simulated keratometry-1, simulated keratometry-2, and maximum keratometry (Kmax) improved significantly throughout the follow-up visits (p < 0.001). Total HOA, vertical coma, and spherical aberration were significantly reduced at 1 year compared with the preoperative values (p < 0.05). Vertical coma was decreased from preoperative to all postoperative time points (p = 0.009). Regarding optical quality, MTF 5 and MTF 10 at both the vertical and horizontal meridians were significantly increased 1 year after the Cretan protocol plus compared to preoperatively (p < 0.05). Significant improvements in the PSF occurred at all postoperative time points (p < 0.001). Conclusions The Cretan protocol plus is more efficient in improving optical quality while reducing corneal aberrations in keratoconus patients. Vertical coma and PSF could be objective indicators of optical performance after this procedure.