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<article article-type="research-article" dtd-version="1.3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:lang="ru"><front><journal-meta><journal-id journal-id-type="publisher-id">helmholtzeyeinstitute</journal-id><journal-title-group><journal-title xml:lang="ru">Российский офтальмологический журнал</journal-title><trans-title-group xml:lang="en"><trans-title>Russian Ophthalmological Journal</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">2072-0076</issn><issn pub-type="epub">2587-5760</issn><publisher><publisher-name>Real time Publishers</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.21516/2072-0076-2025-18-4-62-67</article-id><article-id custom-type="elpub" pub-id-type="custom">helmholtzeyeinstitute-1956</article-id><article-categories><subj-group subj-group-type="heading"><subject>Research Article</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="ru"><subject>КЛИНИЧЕСКИЕ ИССЛЕДОВАНИЯ</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="en"><subject>CLINICAL STUDIES</subject></subj-group></article-categories><title-group><article-title>Контрастная чувствительность и время восстановления после фотостресса у больных диабетом с диабетической ретинопатией и без нее</article-title><trans-title-group xml:lang="en"><trans-title>Contrast sensitivity and photostress recovery time in diabetics with and without diabetic retinopathy</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Хуссейн</surname><given-names>Ф.</given-names></name><name name-style="western" xml:lang="en"><surname>Hussain</surname><given-names>F.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Файза Хуссейн — клинический оптометрист</p><p>Равалпинди, 4600</p></bio><bio xml:lang="en"><p>Faiza Hussain — clinical optometrist</p><p>Rawalpindi, 4600</p></bio><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0001-7352-4313</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Фирдоус</surname><given-names>М.</given-names></name><name name-style="western" xml:lang="en"><surname>Firdous</surname><given-names>M.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Марьям Фирдоус — доцент (аспирант)</p><p>Равалпинди, 4600</p></bio><bio xml:lang="en"><p>Maryam Firdous — Assistant Professor (Ph.D scholar)</p><p>Rawalpindi, 4600</p></bio><email xlink:type="simple">instructor_optometry@pio.edu.pk</email><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0003-3254-5585</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Уллах</surname><given-names>С.</given-names></name><name name-style="western" xml:lang="en"><surname>Ullah</surname><given-names>S.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Саиф Уллах — магистр оптометрии, (аспирант)</p><p>Равалпинди, 4600</p></bio><bio xml:lang="en"><p>Saif Ullah — Assistant Professor of Optometry (Ph.D scholar)</p><p>Rawalpindi, 4600</p></bio><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Кайюм</surname><given-names>С.</given-names></name><name name-style="western" xml:lang="en"><surname>Qayyum</surname><given-names>S.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Садаф Кайюм — доцент</p><p>Равалпинди, 4600</p></bio><bio xml:lang="en"><p>Sadaf Qayyum — assistant professor</p><p>Rawalpindi, 4600</p></bio><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Шах</surname><given-names>М.</given-names></name><name name-style="western" xml:lang="en"><surname>Shah</surname><given-names>M.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Мутахир Шах — консультант-оптометрист</p><p>ул. Мухаммада Туфаила Ниази, район G-9 Mauve, G 9/1 G-9, Исламабад, 44000</p></bio><bio xml:lang="en"><p>Mutahir Shah — consultant optometrist</p><p>Muhammad Tufail Niazi Rd, G-9 Mauve Area G 9/1 G-9, Islamabad, 44000</p></bio><xref ref-type="aff" rid="aff-2"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Уллах Хан</surname><given-names>Ф.</given-names></name><name name-style="western" xml:lang="en"><surname>Ullah Khan</surname><given-names>F.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Фахим Уллах Хан — консультант-офтальмолог</p><p>Равалпинди, 4600</p></bio><bio xml:lang="en"><p>Faheem Ullah Khan — consultant ophthalmologist</p><p>Rawalpindi, 4600</p></bio><xref ref-type="aff" rid="aff-1"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="ru"><institution>Пакистанский институт офтальмологии, Глазная больница Al-Shifa Trust</institution><country>Пакистан</country></aff><aff xml:lang="en"><institution>Pakistan Institute of Ophthalmology, Al-Shifa Trust Eye Hospital Rawalpindi</institution><country>Pakistan</country></aff></aff-alternatives><aff-alternatives id="aff-2"><aff xml:lang="ru"><institution>Больница KRL</institution><country>Пакистан</country></aff><aff xml:lang="en"><institution>KRL Hospital</institution><country>Pakistan</country></aff></aff-alternatives><pub-date pub-type="collection"><year>2025</year></pub-date><pub-date pub-type="epub"><day>09</day><month>01</month><year>2026</year></pub-date><volume>18</volume><issue>4</issue><fpage>62</fpage><lpage>67</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Хуссейн Ф., Фирдоус М., Уллах С., Кайюм С., Шах М., Уллах Хан Ф., 2026</copyright-statement><copyright-year>2026</copyright-year><copyright-holder xml:lang="ru">Хуссейн Ф., Фирдоус М., Уллах С., Кайюм С., Шах М., Уллах Хан Ф.</copyright-holder><copyright-holder xml:lang="en">Hussain F., Firdous M., Ullah S., Qayyum S., Shah M., Ullah Khan F.</copyright-holder><license xml:lang="ru" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>Данная работа распространяется под лицензией Creative Commons Attribution 4.0.</license-p></license><license xml:lang="en" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>This work is licensed under a Creative Commons Attribution 4.0 License.</license-p></license></permissions><self-uri xlink:href="https://roj.igb.ru/jour/article/view/1956">https://roj.igb.ru/jour/article/view/1956</self-uri><abstract><p>Сахарный диабет (СД) является серьезной проблемой общественного здравоохранения и одной из основных причин диабетической ретинопатии (ДР) — заболевания, которое может привести к ухудшению зрения и слепоте. Раннее выявление изменений сетчатки имеет решающее значение для предотвращения потери зрения.</p><p>Цель работы — изучение взаимосвязи между временем восстановления после фотостресса (ВВПФ) и контрастной чувствительностью (КЧ) у пациентов с СД и ДР и без нее в сравнении со здоровыми лицами группы контроля.</p><sec><title>Материал и методы</title><p>Материал и методы. Сравнительное поперечное исследование проведено базе глазной больнице Al-Shifa Trust, Равалпинди, Пакистан. Всего включено 60 участников в возрасте от 40 до 75 лет, включая 40 лиц с СД (20 с ДР и 20 без ДР) и 20 лиц группы контроля. Оценивались острота зрения, КЧ с использованием таблицы Пелли — Робсона и ВВПФ с использованием прямого офтальмоскопа. Корреляция между ДР и ВВПФ/КЧ анализировалась с использованием корреляционного теста Спирмена с уровнем значимости p &lt; 0,05.</p></sec><sec><title>Результаты</title><p>Результаты. У лиц с СД выявлена значительно более низкая КЧ и более продолжительное, чем в контроле, ВВПФ (p &lt; 0,05). У лиц с СД и ДР наблюдалась наиболее значительная задержка ВВПФ. Между КЧ и ДР наблюдалась слабая отрицательная корреляция, а между ВВПФ и ДР – умеренная положительная (p &lt; 0,05).</p></sec><sec><title>Заключение</title><p>Заключение. У пациентов с СД, особенно с ДР, ВВПФ значительно выше, чем в контроле без СД. ВВПФ может служить надежным и простым клиническим инструментом для раннего выявления ДР, потенциально способствующим предотвращению потери зрения. Необходимы дальнейшие исследования с более обширной выборкой для изучения механизмов и разработки терапевтических вмешательств, направленных на повышение ВВПФ и КЧ у пациентов с ДР.</p></sec></abstract><trans-abstract xml:lang="en"><p>Diabetes mellitus (DM) is a major public health concern and a leading cause of diabetic retinopathy (DR), a condition that can lead to vision impairment and blindness. Early detection of retinal changes is essential in preventing vision loss.</p><sec><title>Purpose</title><p>Purpose. This study investigates the relationship between photo-stress recovery time (PSRT) and contrast sensitivity (CS) in diabetic patients with and without DR compared to healthy controls.</p></sec><sec><title>Material and methods</title><p>Material and methods. A hospital-based comparative cross-sectional study was conducted at Al-Shifa Trust Eye Hospital, Rawalpindi, Pakistan. A total of 60 participants (age range: 40–75 years) were included, comprising 40 diabetic individuals (20 with DR and 20 without DR) and 20 healthy controls. Visual acuity, CS (using the Pelli — Robson chart), and PSRT (using a direct ophthalmoscope) were assessed. The correlation between DR and PSRT/CS was analyzed using the Spearman’s correlation test, with a significance level set at p &lt; 0.05.</p></sec><sec><title>Results</title><p>Results. The study found significantly lower CS and prolonged PSRT in diabetic individuals compared to controls (p &lt; 0.05). Diabetic individuals with DR showed the most significant delay in PSRT. A weak negative correlation was observed between CS and DR, and a moderate positive correlation was found between PSRT and DR (p &lt; 0.05).</p></sec><sec><title>Conclusions</title><p>Conclusions. PSRT is significantly prolonged in diabetic patients, particularly those with DR, compared to non-diabetic controls. The results suggest that PSRT could serve as a reliable and simple clinical tool for early detection of DR, potentially aiding in the prevention of vision loss. Further studies with larger sample sizes are needed to explore mechanisms and therapeutic interventions to improve PSRT and CS in diabetic retinopathy patients.</p></sec></trans-abstract><kwd-group xml:lang="ru"><kwd>диабет</kwd><kwd>диабетическая ретинопатия</kwd><kwd>контрастная чувствительность</kwd><kwd>время восстановления после фотостресса</kwd></kwd-group><kwd-group xml:lang="en"><kwd>diabetes</kwd><kwd>diabetic retinopathy</kwd><kwd>contrast sensitivity</kwd><kwd>photostress recovery time</kwd></kwd-group></article-meta></front><back><ref-list><title>References</title><ref id="cit1"><label>1</label><citation-alternatives><mixed-citation xml:lang="ru">Yan Y, Wu T, Zhang M, et al. Prevalence, awareness and control of type 2 diabetes mellitus and risk factors in Chinese elderly population. BMC Public Health. 2022 Jul 19; 22 (1): 1382. doi: 10.1186/s12889-022-13759-9</mixed-citation><mixed-citation xml:lang="en">Yan Y, Wu T, Zhang M, et al. Prevalence, awareness and control of type 2 diabetes mellitus and risk factors in Chinese elderly population. BMC Public Health. 2022 Jul 19; 22 (1): 1382. doi: 10.1186/s12889-022-13759-9</mixed-citation></citation-alternatives></ref><ref id="cit2"><label>2</label><citation-alternatives><mixed-citation xml:lang="ru">Vallianou NG, Geladari EV, Kounatidis D, et al. Diabetes mellitus in the era of climate change. Diabetes Metab. 2021 Jul; 47 (4): 101205. doi: 10.1016/j.diabet.2020.10.003</mixed-citation><mixed-citation xml:lang="en">Vallianou NG, Geladari EV, Kounatidis D, et al. Diabetes mellitus in the era of climate change. Diabetes Metab. 2021 Jul; 47 (4): 101205. doi: 10.1016/j.diabet.2020.10.003</mixed-citation></citation-alternatives></ref><ref id="cit3"><label>3</label><citation-alternatives><mixed-citation xml:lang="ru">Aamir AH, Ul-Haq Z, Mahar SA, et al. Diabetes prevalence survey of Pakistan (DPS-PAK): prevalence of type 2 diabetes mellitus and prediabetes using HbA1c: a population-based survey from Pakistan. BMJ open. 2019 Feb 1; 9 (2): e025300.</mixed-citation><mixed-citation xml:lang="en">Aamir AH, Ul-Haq Z, Mahar SA, et al. Diabetes prevalence survey of Pakistan (DPS-PAK): prevalence of type 2 diabetes mellitus and prediabetes using HbA1c: a population-based survey from Pakistan. BMJ open. 2019 Feb 1; 9 (2): e025300.</mixed-citation></citation-alternatives></ref><ref id="cit4"><label>4</label><citation-alternatives><mixed-citation xml:lang="ru">Haw JS, Shah M, Turbow S, et al. Diabetes complications in racial and ethnic minority populations in the USA. Curr Diab Rep. 2021 Jan 9; 21 (1): 2. doi: 10.1007/s11892-020-01369-x</mixed-citation><mixed-citation xml:lang="en">Haw JS, Shah M, Turbow S, et al. Diabetes complications in racial and ethnic minority populations in the USA. Curr Diab Rep. 2021 Jan 9; 21 (1): 2. doi: 10.1007/s11892-020-01369-x</mixed-citation></citation-alternatives></ref><ref id="cit5"><label>5</label><citation-alternatives><mixed-citation xml:lang="ru">Kropp M, Golubnitschaja O, Mazurakova A, et al. Diabetic retinopathy as the leading cause of blindness and early predictor of cascading complications — risks and mitigation. Epma Journal. 2023 Feb 13; 14 (1): 21–42. doi: 10.1007/s13167-023-00314-8</mixed-citation><mixed-citation xml:lang="en">Kropp M, Golubnitschaja O, Mazurakova A, et al. Diabetic retinopathy as the leading cause of blindness and early predictor of cascading complications — risks and mitigation. Epma Journal. 2023 Feb 13; 14 (1): 21–42. doi: 10.1007/s13167-023-00314-8</mixed-citation></citation-alternatives></ref><ref id="cit6"><label>6</label><citation-alternatives><mixed-citation xml:lang="ru">Shrestha A, Dahal M. Comparing and evaluating photo stress recovery time in diabetic and normal population. Acta Scientific Ophthalmology. 2021; 4 (6): 16–20. https://actascientific.com/ASOP/pdf/ASOP-04-0321.pdf</mixed-citation><mixed-citation xml:lang="en">Shrestha A, Dahal M. Comparing and evaluating photo stress recovery time in diabetic and normal population. Acta Scientific Ophthalmology. 2021; 4 (6): 16–20. https://actascientific.com/ASOP/pdf/ASOP-04-0321.pdf</mixed-citation></citation-alternatives></ref><ref id="cit7"><label>7</label><citation-alternatives><mixed-citation xml:lang="ru">Malik SR, Singh G, Sood GC, et al. Macular function tests with special reference to photostress test. Indian Journal of Ophthalmology. 1971 Sep; 19 (3): 93–101. PMID: 15744978.</mixed-citation><mixed-citation xml:lang="en">Malik SR, Singh G, Sood GC, et al. Macular function tests with special reference to photostress test. Indian Journal of Ophthalmology. 1971 Sep; 19 (3): 93–101. PMID: 15744978.</mixed-citation></citation-alternatives></ref><ref id="cit8"><label>8</label><citation-alternatives><mixed-citation xml:lang="ru">Safi S, Rahimi A, Raeesi A, et al. Contrast sensitivity to spatial gratings in moderate and dim light conditions in patients with diabetes in the absence of diabetic retinopathy. BMJ Open Diabetes Res Care. 2017 Aug 8; 5 (1): e000408. doi: 10.1136/bmjdrc-2017-000408</mixed-citation><mixed-citation xml:lang="en">Safi S, Rahimi A, Raeesi A, et al. Contrast sensitivity to spatial gratings in moderate and dim light conditions in patients with diabetes in the absence of diabetic retinopathy. BMJ Open Diabetes Res Care. 2017 Aug 8; 5 (1): e000408. doi: 10.1136/bmjdrc-2017-000408</mixed-citation></citation-alternatives></ref><ref id="cit9"><label>9</label><citation-alternatives><mixed-citation xml:lang="ru">Firdous M, Masud H, Sharif H. Impact of early non-proliferative diabetic retinopathy on contrast sensitivity. Al-Shifa Journal of Ophthalmology. 2019; 15 (1): 21–9. https://alshifaeye.org/assets/downloads/research-centre/AlShifa-Annual-Research-Report-2019.pdf</mixed-citation><mixed-citation xml:lang="en">Firdous M, Masud H, Sharif H. Impact of early non-proliferative diabetic retinopathy on contrast sensitivity. Al-Shifa Journal of Ophthalmology. 2019; 15 (1): 21–9. https://alshifaeye.org/assets/downloads/research-centre/AlShifa-Annual-Research-Report-2019.pdf</mixed-citation></citation-alternatives></ref><ref id="cit10"><label>10</label><citation-alternatives><mixed-citation xml:lang="ru">Chande PK, Raman R, John P, et al. Contrast-sensitivity function and photo stress–recovery time in prediabetes. Clin Optom (Auckl). 2020 Sep 18; 12: 151–5. doi: 10.2147/OPTO.S259397</mixed-citation><mixed-citation xml:lang="en">Chande PK, Raman R, John P, et al. Contrast-sensitivity function and photo stress–recovery time in prediabetes. Clin Optom (Auckl). 2020 Sep 18; 12: 151–5. doi: 10.2147/OPTO.S259397</mixed-citation></citation-alternatives></ref><ref id="cit11"><label>11</label><citation-alternatives><mixed-citation xml:lang="ru">Pramanik S, Chowdhury S, Ganguly U, et al. Visual contrast sensitivity could be an early marker of diabetic retinopathy. Heliyon. 2020 Oct 26; 6 (10): e05336. doi: 10.1016/j.heliyon.2020.e05336</mixed-citation><mixed-citation xml:lang="en">Pramanik S, Chowdhury S, Ganguly U, et al. Visual contrast sensitivity could be an early marker of diabetic retinopathy. Heliyon. 2020 Oct 26; 6 (10): e05336. doi: 10.1016/j.heliyon.2020.e05336</mixed-citation></citation-alternatives></ref><ref id="cit12"><label>12</label><citation-alternatives><mixed-citation xml:lang="ru">Sooryanarayana SP, Hairol MI. Contrast sensitivity, color discrimination and visual acuity as risk factors for visual dysfunction in non-proliferative diabetic retinopathy. Med &amp; Health. Aug 2024; 19 (2): 560–72. https://doi.org/10.17576/MH.2024.1902.16</mixed-citation><mixed-citation xml:lang="en">Sooryanarayana SP, Hairol MI. Contrast sensitivity, color discrimination and visual acuity as risk factors for visual dysfunction in non-proliferative diabetic retinopathy. Med &amp; Health. Aug 2024; 19 (2): 560–72. https://doi.org/10.17576/MH.2024.1902.16</mixed-citation></citation-alternatives></ref><ref id="cit13"><label>13</label><citation-alternatives><mixed-citation xml:lang="ru">Ubani UA, Ihesiulor CG, Okore NE, et al. Photo stress recovery time variations in common posterior segment ocular diseases. Acta Scientific Ophthalmology. 2022 Jul; 5 (7): 26–33. https://actascientific.com/ASOP/pdf/ASOP-05-0535.pdf</mixed-citation><mixed-citation xml:lang="en">Ubani UA, Ihesiulor CG, Okore NE, et al. Photo stress recovery time variations in common posterior segment ocular diseases. Acta Scientific Ophthalmology. 2022 Jul; 5 (7): 26–33. https://actascientific.com/ASOP/pdf/ASOP-05-0535.pdf</mixed-citation></citation-alternatives></ref><ref id="cit14"><label>14</label><citation-alternatives><mixed-citation xml:lang="ru">Maqsood S. Comparison of photostress recovery time in diabetic patients and emmetrope. Journal of Health and Rehabilitation Research. 2024 Jun 4; 4. https://doi.org/10.61919/jhrr.v4iICIC1.1063</mixed-citation><mixed-citation xml:lang="en">Maqsood S. Comparison of photostress recovery time in diabetic patients and emmetrope. Journal of Health and Rehabilitation Research. 2024 Jun 4; 4. https://doi.org/10.61919/jhrr.v4iICIC1.1063</mixed-citation></citation-alternatives></ref><ref id="cit15"><label>15</label><citation-alternatives><mixed-citation xml:lang="ru">Baptista AMG, Sousa RARC, Rocha FASQ, et al. The macular photostress test in diabetes, glaucoma, and cataract. Proc. of the SPIE. 2013; 8785, id. 8785FW. doi: 10.1117/12.2026235</mixed-citation><mixed-citation xml:lang="en">Baptista AMG, Sousa RARC, Rocha FASQ, et al. The macular photostress test in diabetes, glaucoma, and cataract. Proc. of the SPIE. 2013; 8785, id. 8785FW. doi: 10.1117/12.2026235</mixed-citation></citation-alternatives></ref><ref id="cit16"><label>16</label><citation-alternatives><mixed-citation xml:lang="ru">Loughman J, Ratzlaff M, Foerg B, Connell P. Suitability and repeatability of a photostress recovery test device, the macular degeneration detector (MDD-2), for diabetes and diabetic retinopathy assessment. Retina. May; 34 (5): 1006–13. doi: 10.1097/IAE.0000000000000021</mixed-citation><mixed-citation xml:lang="en">Loughman J, Ratzlaff M, Foerg B, Connell P. Suitability and repeatability of a photostress recovery test device, the macular degeneration detector (MDD-2), for diabetes and diabetic retinopathy assessment. Retina. May; 34 (5): 1006–13. doi: 10.1097/IAE.0000000000000021</mixed-citation></citation-alternatives></ref><ref id="cit17"><label>17</label><citation-alternatives><mixed-citation xml:lang="ru">Glaser JS, Savino PJ, Sumers KD, McDonald SA, Knighton RW. The photostress recovery test in the clinical assessment of visual function. American Journal of Ophthalmology. 1977 Feb 1; 83 (2): 255–60. doi: 10.1016/0002-9394(77)90624-9</mixed-citation><mixed-citation xml:lang="en">Glaser JS, Savino PJ, Sumers KD, McDonald SA, Knighton RW. The photostress recovery test in the clinical assessment of visual function. American Journal of Ophthalmology. 1977 Feb 1; 83 (2): 255–60. doi: 10.1016/0002-9394(77)90624-9</mixed-citation></citation-alternatives></ref><ref id="cit18"><label>18</label><citation-alternatives><mixed-citation xml:lang="ru">Grott R, Chung S. Photostress recovery time as assessed using high-and lowcontrast letters. Poster 117. Optometry and Vision Science. 2001 Dec 1; 78 (12): 98. doi: 10.1097/00006324-200112001-00145</mixed-citation><mixed-citation xml:lang="en">Grott R, Chung S. Photostress recovery time as assessed using high-and lowcontrast letters. Poster 117. Optometry and Vision Science. 2001 Dec 1; 78 (12): 98. doi: 10.1097/00006324-200112001-00145</mixed-citation></citation-alternatives></ref></ref-list><fn-group><fn fn-type="conflict"><p>The authors declare that there are no conflicts of interest present.</p></fn></fn-group></back></article>
