带中心孔植入式透镜（V4c-ICL）矫正高度近视的视觉质量研究

目的　观察高度近视患者植入带中心孔植入式透镜（implantable collamer lens，ICL）后的临床疗效和视觉相关的生活质量。方法　前瞻性病例研究。选取我院诊断为高度近视，并植入V4c-ICL患者25例（50眼）为研究对象。术前及术后1个月、3个月、6个月分别检查患者屈光状态，裸眼远、中、近视力，最佳矫正远视力，远视力矫正下中、近视力，双眼视力，眼压，角膜内皮细胞密度（corneal endothelial cell density，ECD），并进行国家眼科研究所视功能问卷-25（national eye institute-visual function questionnaire，NEI-VFQ-25）调查及评分。结果　高度近视患者植入V4c-ICL后不同时间球镜、柱镜、等效球镜（spherical equivalent，SE）度较术前均明显降低（F=884.35、17.15、810.25，均为P＜0.05）；术后不同时间裸眼远、中、近视力，最佳矫正远视力，远视力矫正下中、近视力和双眼视力较术前均明显改善（F=604.47、878.13、713.92、22.25、5.33、6.90、16.51，均为P＜0.05）。术前及术后随访期间眼压、ECD无明显变化（F=0.07、1.53，均为P＞0.05）；术后NEI-VFQ-25评分较术前明显提高（F=21.76，P＜0.05）。结论　高度近视患者植入V4c-ICL后屈光不正得到矫正、短期内屈光稳定，随访期间远、中、近视力明显提高，视觉相关的生活质量明显改善。V4c-ICL植入术治疗高度近视安全、有效。     

Displasia septoóptica: alteraciones oftalmológicas en una serie de 5 casos

Septo-optic dysplasia (SOD) is a rare congenital condition of unknown cause, with a characteristic triad that includes optic nerve hypoplasia, pituitary function abnormalities and midline brain defects, in addition to a broad spectrum of symptoms and associations.A total of five clinical cases are presented, four of which met the complete classic triad. All of them showed a wide variety of ophthalmological, endocrinological and neurological alterations.Within the ophthalmological spectrum of SOD, papillary hypoplasia and ocular motility alterations (nystagmus, strabismus) stand out. Other less frequent ones may also appear, such as pupillary alterations, microphthalmia and coloboma.Given the suspicion of SOD, brain MRI scan should be performed, as well as consultation with the paediatric department in order to complete the study and indicate, if necessary, systemic treatment.     

The biological basis of the experience and categorization of colour

We used the Land Colour Mondrian experiments in a Bayesian context to test the degree to which subjects vary in categorizing the colour of different patches, when each patch is made to reflect light of the identical wavelength‐energy composition. The brain uses a ratio‐taking mechanism to determine the ratio of light of every waveband reflected from a surface and from its surrounds. Our (Bayesian) hypothesis was that this ratio‐taking mechanism is similar in all humans and therefore leads to a constant categorization of colours that differs little between them. The similarly categorized colours are the initial priors, with initial hues attached to them. Twenty subjects of different ethnic and cultural backgrounds, for all but one of whom English was not the primary language, viewed eight patches of different colour in two Mondrian displays; each patch, when viewed, was made to reflect identical ratios of long‐, middle‐ and short‐wave light. Subjects were asked to match the colour of the viewed patch with that of the Munsell chip coming closest in colour to that of the viewed patch, without using language. In terms of hue, there was less variability in matching warm hues than cool ones. In terms of colour categorization, there was little variability overall. We take the lack of significant variability between subjects in the matches made as a pointer to similar computational mechanisms being employed in different subjects to perceive colours, thus permitting them to assume that their categorization of colours has universal agreement and assent.     

Visual Impairment Due to Lissencephaly

Lissencephaly is a rare disorder due to abnormal neural migration, causing neurological impairment and clinically characterised by mental retardation and epilepsy. Any disturbance of the visual pathway can cause loss of vision. The authors describe a case of a 6-year-old boy referred to the ophthalmologist presenting poor bilateral vision. This child had no other known medical conditions, and neurological examination was completely normal. Only when a magnetic resonance imaging was made that a lissencephaly-pachygyria with band heterotopia mostly occipital was noted. Cortical defects should be considered in order to diagnosis some visual defects in children.     

Impact of the COVID-19 lockdown on digital device-related ocular health

Purpose:Since the declaration of the lockdown due to COVID-19, the usage of digital devices has gone up across the globe, resulting in a challenge for the visual systems of all ages. The purpose of this study is to assess the impact of the lockdown on digital device usage, and consequently, the ocular surface health implications and circadian rhythm abnormalities related to digital eye strain.Methods:An open online survey was sent through various social media platforms and was open for a period of 2 weeks.Results:A total of 407 usable responses were obtained; the average age of respondents was 27.4 years. Typically, 93.6% of respondents reported an increase in their screen time since the lockdown was declared. The average increase in digital device usage was calculated at about 4.8 ± 2.8 h per day. The total usage per day was found to be 8.65 ± 3.74 hours. Sleep disturbances have been reported by 62.4% of people. Typically, 95.8% of respondents had experienced at least one symptom related to digital device usage, and 56.5% said that the frequency and intensity of these symptoms increased since the lockdown was declared.Conclusion:The study highlighted the drastic increase in use of digital devices after the initiation of the COVID-19 lockdown, and along with it, the slow deterioration of ocular health across all age groups. Awareness about prevention of digital eye strain should be stressed, and going forward, measures to bring these adverse effects to a minimum should be explored.