目的：探讨光学相干断层扫描血管成像(optical coherence tomography angiography，OCTA)在糖尿病性视网膜病变中的应用。方法：选取2021年中山大学附属第七医院眼科63例糖尿病患者为研究对象，分为无糖尿病性视网膜病变(T0，21眼)、轻度非增殖期(T1，21眼)、中重度非增殖期(T2，14眼)及增殖期(T3，7眼)。收集各组生化指标，包括空腹血糖、糖化血红蛋白、谷丙转氨酶、谷草转氨酶、碱性磷酸酶、血清尿素氮、肌酐、尿素氮肌酐比值，及OCTA数据，即中心视网膜厚度、Angiography3×3及Angiography6×6血管线性密度及血管灌注密度等。采用单因素方差分析比较各组间差异。结果：T2组、T3组与T0组相比，T3组与T1组相比，糖尿病病程延长；T3组与其他各组相比，尿素氮升高；T1组、T2组、T3组与T0组相比，T3组与T1组相比，6 mm ×6 mm外层血流线性密度减少；与T0组相比，T1组、T2组及T3组6 mm ×6 mm完整血流线性密度减少；与T0相比，T2组、T3组6 mm ×6 mm外层血流灌注密度减少；与T0组相比，T3组6 mm ×6 mm完整血流灌注密度减少；T2组、T3组与T0组相比，T3与T1相比，3 mm ×3 mm内层血流线性密度明显减少；T3组与T0组及T1组相比，3 mm ×3 mm完整血流线性密度减少。结论：随着糖尿病性视网膜病变的进展，患者的尿素氮及肌酐逐渐升高，OCTA的血流线性密度及血流灌注密度逐渐减少。与血流灌注密度相比，血流线性密度对于早期糖尿病性视网膜病变筛查可能更为敏感。而利用Angiography6×6模式可能可以更早地发现糖尿病性视网膜病变的视网膜血流变化。

Objective: To explore the applications of optical coherence tomography angiography (OCTA) in diabetic retinopathy. Methods: A total of 63 diabetic patients in the Department of Ophthalmology, Seventh Affiliated Hospital of Sun Yat-sen University in 2021 were divided into 4 groups: the patients without diabetic retinopathy (T0, n=21), mild non-proliferative diabetic retinopathy (T1, n=21), moderate-to-severe non-proliferative diabetic retinopathy (T2, n=14) and proliferative diabetic retinopathy (T3, n=7). Biochemical Indicators were collected in all patients, such as fasting plasma glucose (FPG), glycated hemoglobin A1c (HbA1c), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), the blood urea nitrogen (BUN), creatinine (CRE) and the ratio of blood urea nitrogen and creatinine (BUN/CRE). The Macular Cube 521×128, Angiography3×3, and Angiography6×6 models of OCTA were used to obtain central retinal thickness (CRT), vascular density (VD) and perfusion density (PD) of each group. The data of all subjects was applied to do one-way ANOVA. Results: Prolonged duration of diabetes in T2 and T3 compared to T0 and in T3 compared to T1. Elevated BUN in T3 compared to all other groups. When T1, T2 and T3 were compared to T0, and T3 was compared to T1, the VD of the 6 mm ×6 mm outer layer decreased. Reduced VD of intact 6 mm ×6 mm region in T1, T2 and T3 compared to T0. Declining PD of the 6 mm ×6 mm outer layer in T2 and T3 compared to T0. Diminished PD of whole 6 mm ×6 mm area at T3 compared to T0. The VD of 3 mm ×3 mm inner layer was significantly reduced in T3 compared to T0 and T1. The VD of 3 mm ×3 mm intact area gradually dwindled in T3 compared with T0 and T1 (P<0.05). Conclusion: With the progression of diabetic retinopathy, the levels of BUN and CRE gradually increased, and the OCTA-derived vascular density and perfusion density gradually decrease. Vascular density may be more sensitive for early diabetic retinopathy screening than perfusion density.The use of the Angiography6×6 model may result in an earlier detection of changes in retinal blood flow in diabetic retinopathy.

    泪膜是覆盖于眼球表面的一层液体薄膜，从内而外分为黏液层、水液层和脂质层，每层成分的改变都会导致泪膜不稳定，进而导致干眼的发生。在研究泪膜破裂方式及相关泪液成分改变的基础上，学者Yokoi及其团队分别在2012年和2013年提出了有关干眼治疗和诊断的新概念，称为泪膜导向治疗(tear film-oriented therapy，TFOT)和泪膜导向诊断(tear film-oriented diagnosis，TFOD)，就是根据泪膜破裂模式(tear film break-up pattern，TFBUP)的不同，推断出相应的泪膜成分改变，补充不足的泪膜成分，这种诊疗方法目前正逐渐被接受。本文对不同泪膜破裂方式与泪膜成分改变的关系做了汇总分析，旨在为干眼的诊断和治疗提供更为科学实用的指导方案。

    Tear film is a layer of fluid film covering the surface of eye global, which is divided into mucus layer, aqueous layer and lipid layer from inside to outside. The change of each layer composition will lead to tear film instability, resulting in the occurrence of dry eye. On the basis of numerous studies on the correlation between tear composition and tear film break-up patterns, Yokoi and his team proposed new concepts on the diagnosis and treatment of dry eye called tear film-oriented therapy (TFOT) and tear film-oriented diagnosis (TFOD) in 2012 and 2013. That is according to different tear film break-up patterns (TFBUP), so changes in tear film composition can be deduced and supplemented, and this diagnosis and treatment method is gradually being accepted. In this paper, we summarized and analyzed the relationship between different tear film break-up patterns and changes in tear film composition to provide a more scientific and convenient guidance program for the diagnosis and treatment of dry eye.

Background: Laser photocoagulation restricted to ablation of the avascular retina has been the conventional but not a completely effective treatment strategy in the management of threshold retinopathy of prematurity (ROP). The purpose of this study was to compare the structural outcomes of additional posterior to ridge diode laser compared to conventional diode laser to avascular retina alone in threshold stage III ROP.

Methods: This was a prospective, randomized study involving infants diagnosed with threshold stage III ROP in one or both the eyes. The infants were randomized into control and study groups. Infants under the control group underwent conventional laser to avascular retina alone while infants under the study group received additional two rows of laser posterior to the ridge in the vascular retina. The infants were followed up at 2 weeks, 1 month and up to 6 months after the laser procedure.

Results: During the study period of 1 year, 42 eyes of 24 infants were recruited into this study with 21 eyes in each group. The mean birth weight was 1,310.48±400.92 g in the test group and 1,341.9±396.2 g in the control group. The mean post conceptional age at the time of intervention was 36.43±2.79 weeks in test group and 36.29±2.55 weeks in the control group. At 1-month post laser, 19 eyes in the study group showed regression of neovascularization laser compared to 18 eyes in the control group. However at the end of 3 and 6 months post laser, both groups had showed similar rates regression of neovascularization (19 of 21 eyes in both groups). Five eyes in the study group and six in the control group required additional laser treatment. Two eyes in the study group and one eye in the control group developed post laser vitreous hemorrhage.

Conclusions: Posterior to ridge laser treatment for severe stage 3 ROP did not show any additional benefit compared to conventional laser.

Background: Laser photocoagulation restricted to ablation of the avascular retina has been the conventional but not a completely effective treatment strategy in the management of threshold retinopathy of prematurity (ROP). The purpose of this study was to compare the structural outcomes of additional posterior to ridge diode laser compared to conventional diode laser to avascular retina alone in threshold stage III ROP.

Methods: This was a prospective, randomized study involving infants diagnosed with threshold stage III ROP in one or both the eyes. The infants were randomized into control and study groups. Infants under the control group underwent conventional laser to avascular retina alone while infants under the study group received additional two rows of laser posterior to the ridge in the vascular retina. The infants were followed up at 2 weeks, 1 month and up to 6 months after the laser procedure.

Results: During the study period of 1 year, 42 eyes of 24 infants were recruited into this study with 21 eyes in each group. The mean birth weight was 1,310.48±400.92 g in the test group and 1,341.9±396.2 g in the control group. The mean post conceptional age at the time of intervention was 36.43±2.79 weeks in test group and 36.29±2.55 weeks in the control group. At 1-month post laser, 19 eyes in the study group showed regression of neovascularization laser compared to 18 eyes in the control group. However at the end of 3 and 6 months post laser, both groups had showed similar rates regression of neovascularization (19 of 21 eyes in both groups). Five eyes in the study group and six in the control group required additional laser treatment. Two eyes in the study group and one eye in the control group developed post laser vitreous hemorrhage.

Conclusions: Posterior to ridge laser treatment for severe stage 3 ROP did not show any additional benefit compared to conventional laser.

Background: To settle the fundamentals of a numerical procedure that relates retinal ganglion-cell density and threshold sensitivity in the visual field. The sensitivity of a generated retina and visual pathways to virtual stimuli are simulated, and the conditions required to reproduce glaucoma-type defects both in the optic-nerve head (ONH) and visual fields are explored.

Methods: A definition of selected structural elements of the optic pathways is a requisite to a translation of clinical knowledge to computer programs for visual field exploration. The program is able to generate a database of normalized visual fields. The relationship between the number of extant receptive fields and threshold sensitivity is plotted for background sensitivity and corresponding automated perimetry. A solution in two planes to the 3D distribution of axons in the ONH is proposed. Visual fields with induced damage in the optic disc are comparable in pattern and quantity to glaucomatous records.

Results: The two-level simulation of the ONH facilitates the analysis of optic-cup/retinal defects. We can generate the virtual optic pathways tailored to the age and morphology of the patient’s eye, and it is possible to reproduce glaucomatous damage by “reverse engineering” engineering. The virtual cortical model renders a quantitative relationship between visual defect and neural damage.

Conclusions: A two-level computing of the retina/optic nerve facilitates the analysis of neuroretinal defects and can be incorporated to automatic perimeters to facilitate visual field analysis.

Background: To settle the fundamentals of a numerical procedure that relates retinal ganglion-cell density and threshold sensitivity in the visual field. The sensitivity of a generated retina and visual pathways to virtual stimuli are simulated, and the conditions required to reproduce glaucoma-type defects both in the optic-nerve head (ONH) and visual fields are explored.

Methods: A definition of selected structural elements of the optic pathways is a requisite to a translation of clinical knowledge to computer programs for visual field exploration. The program is able to generate a database of normalized visual fields. The relationship between the number of extant receptive fields and threshold sensitivity is plotted for background sensitivity and corresponding automated perimetry. A solution in two planes to the 3D distribution of axons in the ONH is proposed. Visual fields with induced damage in the optic disc are comparable in pattern and quantity to glaucomatous records.

Results: The two-level simulation of the ONH facilitates the analysis of optic-cup/retinal defects. We can generate the virtual optic pathways tailored to the age and morphology of the patient’s eye, and it is possible to reproduce glaucomatous damage by “reverse engineering” engineering. The virtual cortical model renders a quantitative relationship between visual defect and neural damage.

Conclusions: A two-level computing of the retina/optic nerve facilitates the analysis of neuroretinal defects and can be incorporated to automatic perimeters to facilitate visual field analysis.

Abstract: This article reviews the history of the femtosecond laser in ophthalmology and its subsequent introduction into the field of cataract surgery. It discusses the innovations that this technology has brought to the field. The article also describes the current system of teaching cataract surgery to ophthalmology residents in the United States and then examines how femtosecond laser-assisted cataract surgery (FLACS) can be a beneficial part of residency education.

Abstract: This article reviews the history of the femtosecond laser in ophthalmology and its subsequent introduction into the field of cataract surgery. It discusses the innovations that this technology has brought to the field. The article also describes the current system of teaching cataract surgery to ophthalmology residents in the United States and then examines how femtosecond laser-assisted cataract surgery (FLACS) can be a beneficial part of residency education.

Background: To compare objective electrophysiological contrast sensitivity function (CSF) in patients implanted with either multifocal intraocular lenses (MIOLs) or monofocal intraocular lenses (IOLs) by pattern reversal visual evoked potentials (prVEP) measurements.

Methods: Fourty-five cataract patients were randomly allocated to receive bilaterally: apodized diffractive-refractive Alcon Acrysof MIOL (A), full diffractive AMO Tecnis MIOL (B) or monofocal Alcon Acrysof IOL (C). Primary outcomes: 1-year differences in objective binocular CSF measured by prVEP with sinusoid grating stimuli of 6 decreasing contrast levels at 6 spatial frequencies. Secondary outcomes: psychophysical CSF measured with VCTS-6500, photopic uncorrected distance (UDVA), and mesopic and photopic uncorrected near and intermediate visual acuities (UNVA and UIVA respectively).

Results: Electrophysiological CSF curve had an inverted U-shaped morphology in all groups, with a biphasic pattern in Group B. Group A showed a lower CSF than group B at 4 and 8 cpd, and a lower value than group C at 8 cpd. Psychophysical CSF in group A exhibited a lower value at 12 cpd than group B. Mean photopic and mesopic UNVA and UIVA were worse in monofocal group compared to the multifocal groups. Mesopic UNVA and UIVA were better in group B.

Conclusions: Electrophysiological CSF behaves differently depending on the types of multifocal or monofocal IOLs. This may be related to the visual acuity under certain conditions or to IOL characteristics. This objective method might be a potential new tool to investigate on MIOL differences and on subjective device-related quality of vision.

Background: To compare objective electrophysiological contrast sensitivity function (CSF) in patients implanted with either multifocal intraocular lenses (MIOLs) or monofocal intraocular lenses (IOLs) by pattern reversal visual evoked potentials (prVEP) measurements.

Methods: Fourty-five cataract patients were randomly allocated to receive bilaterally: apodized diffractive-refractive Alcon Acrysof MIOL (A), full diffractive AMO Tecnis MIOL (B) or monofocal Alcon Acrysof IOL (C). Primary outcomes: 1-year differences in objective binocular CSF measured by prVEP with sinusoid grating stimuli of 6 decreasing contrast levels at 6 spatial frequencies. Secondary outcomes: psychophysical CSF measured with VCTS-6500, photopic uncorrected distance (UDVA), and mesopic and photopic uncorrected near and intermediate visual acuities (UNVA and UIVA respectively).

Results: Electrophysiological CSF curve had an inverted U-shaped morphology in all groups, with a biphasic pattern in Group B. Group A showed a lower CSF than group B at 4 and 8 cpd, and a lower value than group C at 8 cpd. Psychophysical CSF in group A exhibited a lower value at 12 cpd than group B. Mean photopic and mesopic UNVA and UIVA were worse in monofocal group compared to the multifocal groups. Mesopic UNVA and UIVA were better in group B.

Conclusions: Electrophysiological CSF behaves differently depending on the types of multifocal or monofocal IOLs. This may be related to the visual acuity under certain conditions or to IOL characteristics. This objective method might be a potential new tool to investigate on MIOL differences and on subjective device-related quality of vision.