Volume 53 · Issue 05 · 2017

This issue focuses on the research progress of fundus diseases. Professor Wei Wenbin is the responsible editorial committee responsible for the planning, composition and review of the key contents of this issue.

Pars plana vitrectomy (PPV) has become an important means of treating complex vitreoretinopathy, and the introduction of small-gauge PPV instrumentation and techniques has even considerably widened the surgery choice. Though the small-gauge PPV systems have many advantages, ophthalmologists must realize that the small-gauge PPV does not necessarily refer to minimally invasive PPV. Ophthalmologists should not just pursue the small incision, ignore the principle of minimally invasive PPV and the rational choice of indications, and underestimate surgical risks and postoperative complications. Ophthalmologists must be familiar with the advantages and limitations of minimally invasive PPV so as to achieve the best therapeutic effects with minimized trauma. (Chin J Ophthalmol, 2017, 53: 321-324)

Anatomy is the study of the morphology, structure and development of animals, plants and human bodies^[1]。 Human anatomy is the subject of studying the morphological structure of various systems, organs and tissues of healthy human body^[2]。 Dissection is to study the physiological structure of various organs of human or animal or plant bodies, and use special knives and scissors to cut open human or animal or plant bodies. Thus, "anatomy" is a noun and "anatomy" is a verb.

To compare the effects of sterilized air and perfluoropropane (C₃F₈) tamponades on recovery after vitrectomy for the treatment of idiopathic full-thickness macular hole (IFTMH).

Case control study. Seventy-three eyes of 69 consecutive cases underwent vitrectomy with air (53 eyes) or 10% C₃F₈ gas (20 eyes) tamponade. Surgical outcomes were retrospectively analyzed between the two groups, including logarithm of the minimal angle of resolution (logMAR) and optical coherence tomography findings like the size of the macular hole and the photoreceptor layer defect.

Preoperatively, the mean best corrected visual acuity (BCVA) was (0.10±0.49), the mean hole diameter was (777.9±320.7) μm, and the mean diameter of the photoreceptor layer defect was (1 709.3±516.0) μm in the sterilized air group, while in the C ₃F₈ group, the mean BCVA was (0.07±0.50), the mean hole diameter was (853.9±355.0) μm, and the mean defect diameter was (1 480.5±429.9) μm. The primary closure rate was 90.6% in the sterilized air group and 95.0% in the C ₃F₈ group. One month after surgery, the mean BCVA was (0.17±0.41), and the mean diameter of the photoreceptor layer defect was (820.5±598.0) μm in the sterilized air group, while in the C ₃F₈ group, the mean BCVA was 0.12±0.49, and the mean defect diameter was (762.5±658.0) μm. There was no statistically significant difference in the closure rate (χ ²=0.019), BCVA (t=-1.689), hole diameter (t=0.837) and diameter of the photoreceptor layer defect (t=0.338) between the two groups(P>0.05).

Vitrectomy with sterilized air tamponade is safe and effective for the treatment of IFTMH and even cases with relatively large diameters. (Chin J Ophthalmol, 2017, 53: 327-331)

To investigate the visual impact and influence factors of sub-Tenon's anesthesia in retinal detachment patients during pars plana vitrectomy (PPV) or combined phacoemulsification and PPV surgery.

In this prospective case series study, 104 consecutive patients who underwent PPV or combined phacoemulsification and PPV under sub-Tenon's anesthesia between October 2012 and December 2013 were enrolled. Intraoperatively, the patients were asked whether they could see the light of the operating microscope or not at 5 minutes after sub-Tenon's anesthesia, and at the end of phacoemulsification, core vitreous removal, peripheral vitreous removal and the whole surgery, with their contralateral eyes being covered tightly and no photobleaching. The best corrected visual acuity and visual evoked potentials were examined and compared with each other preoperatively and at 1.5 months and 3 months postoperatively. Chi-square test was used to compare the detection rate of amaurosis between different modus operandi and whether covered contra-lateral eye. Student-t test was used to compare the difference of age and preoperative BCVA between the patients with or without experienced amaurois. Lastly, BCVA between different times were tested by one-way ANOVA analysis.

Without covering the contralateral eyes, the incidence of no light perception in various surgical steps was 0%, while it was 72.1%(75/104), 93.8%(75/80), 96.2%(100/104), 96.2%(100/104) and 86.5%(90/104) at the five timepoints, respectively, when the contralateral eyes were covered tightly. The incidence was 51.9%(54/104), 85.0%(68/80), 85. 6%(89/104), 84.6%(69/104) and 66.3%(88/104), respectively, after photobleaching was excluded. Approximately 95.2%(99/104) of patients reported no light perception at least once, 54.5%(54/99) reported no light perception 5 minutes after sub-Tenon's anesthesia, and 30.3%(30/99) recovered light perception when the surgery was finished. All eyes recovered to at least light perception on the first postoperative day. The best corrected visual acuity and visual evoked potentials at 1.5 months and 3 months postoperatively were significantly better than those before surgery. The BCVA was 1.75±0.78 preoperative, 0.96±0.63 1.5 months after operation, and 0.92±0.57 3 months after operation. There was a significant statistical difference between preoperative BCVA and postoperative BCVA (F=50.61, P<0.01) . In patients without waveform detection preoperatively, PVEP waveform could be found in 43.6% and 61.4% of the pactients at 1.5 months and 3 months after operation respectively. In those had certain waveform preoperatively, PVEP amplitudes rise significantly after surgery (t_1.5=-2.69, t₃=-2.97, P<0.05) .

No light perception was detected in various surgical steps of vitrectomy under sub-Tenon's anesthesia in most patients. The blocking of optic nerve conduction may be caused by sub-Tenon' s anesthesia. Photobleaching can also have some effect. The incidence of no light perception during the surgery was not correlated with preoperative visual acuity, age and gender. Moreover, the effect was transient and harmless to visual function.(Chin J Ophthalmol, 2017, 53: 332-337)

To compare the outcome of pars plana vitrectomy (PPV) with a single-layered inverted internal limiting membrane (ILM) flap versus PPV with ILM peeling for the treatment of macular hole associated retinal detachment (MHRD) in high myopia.

In a retrospective cohort study, PPV with 2 kinds of adjuvant surgical procedures were used in 35 moderately high myopia eyes with MHRD. These eyes were divided into 2 groups: group 1 (17 eyes) receiving PPV and ILM peeling and group 2 (18 eyes) receiving PPV with a single-layered inverted ILM flap. Anatomical reattachment of the retina, macular hole closure, and best-corrected visual acuity (BCVA) were measured at 6 months after surgery.

The retina was successfully reattached in all cases. The difference of the retinal reattachment rate between the two groups was not statistically significant (Fisher's exact test,P=1.000). The rate of macular hole closure was 47.1% in group 1 (8 eyes) and 88.9% in group 2 (16 eyes). The difference of the macular hole closure rate between the two groups was statistically significant (Fisher's exact test,P= 0.012). Significant improvement in logarithm of minimal angle of resolution (logMAR) BCVA was achieved in both groups. There was no difference in the initial, final, or improved logMAR BCVA in the 2 groups.

Single-layered inverted ILM flap technique effectively helps close the macular hole in moderately high myopia with MHRD. This may prevent the possible redetachment from the macular hole. (Chin J Ophthalmol, 2017, 53: 338-343)

To evaluate intraoperative risk factors related to the postoperative visual acuity in idiopathic epiretinal membrane (IERM) .

According to the well-established study criterion, a retrospective observational study was carried out on 37 eyes of 37 patients with epiretinal membrane peeling surgery for IERM between January 2014 and January 2015. Intraoperative situations during membrane peeling were documented, including complexity of operation, superficial hemorrhage and the state of indocyanine green (ICG) staining. Best-corrected visual acuity (BCVA) measurement and optical coherence tomography were performed before and 1, 3, 6 and 12 months after surgery. Multifocal electroretinography and fundus fluorescein angiography were conducted at 6 months postoperatively. The patients were divided into two groups based on the BCVA (≥0.5 and<0.5) at 6 months after surgery. The BCVA was converted to logarithm of the minimum angle of resolution (logMAR) equivalents for statistical analysis. The relationship between intraoperative factors and postoperative visual acuity was analyzed by multiple logistic regression analysis.

All patients completed follow-ups in an average duration of (14.41±2.33) months. Among the 37 patients, 28 patients (75.7%) were in the BCVA ≥0.5 group. and 9 patients (24.3%) were in the BCVA<0.5 group. Statistical analysis revealed that superficial hemorrhage during membrane peeling was associated with poor visual acuity after surgery (OR: 7.221, 95% CI: 1.775-29.372, P=0.006) . The peeling complexity was positively increased with presence of superficial hemorrhage (γ=0.336,P=0.042) and ICG staining (γ=0.593,P=0.000) . The electroretinography revealed that the average latency of N1 wave at ring 1 in eyes with superficial hemorrhage (16.88±1.27)ms was longer than that in eyes without superficial hemorrhage (12.80±4.21)ms at 6 months postoperatively (t=-2.187, P= 0.042). The fluorescein angiography showed 8 in 10 eyes with superficial hemorrhage had leakage on the macular fovea.

Superficial hemorrhage in IERM peeling is a risk factor for the poor postoperative visual function. Complex peeling contributes to superficial hemorrhage and the positive staining of ICG. (Chin J Ophthalmol, 2017, 53:344-351)

To investigate the clinical manifestations and imaging characteristics of acute syphilitic posterior placoid chorioretinitis (ASPPC).

Retrospective study of 10 patients diagnosed ASPPC in the Department of Ophthalmology, Beijing Tongren Hospital from 2011 to 2016, including 6 males (10 eyes involved) and 4 females (8 eyes involved) with an age of (43.4±11.6) years (range, 26-60 years). Their clinical manifestations and imaging characteristics were summarized.

All 10 ASPPC patients complained about the reduction of visual acuity, and the majority of them had both eyes involved. The initial visual acuity ranged from finger count to 0.8, with an average of 0.4 and a median visual acuity of 0.3. The intraocular pressure was in the normal range. The inflammation of anterior chamber occurred in only one patient (1/10). The lesions were located at the posterior pole as shown on fundus photographs. There are six placoid lesions, four yellowish massive lesions and seven mixed lesions (placoid and yellowish massive lesions). Partial or whole disappearance, abnormality and opacity of the ellipsoid layer, retinal pigment epithelial (RPE) nodules, and cells in the vitreous body were observed by optical coherence tomography. There were partial detachment between the neuronal retina and RPE layer with fine-sand like hypereflective dots. The lesion size and morphology on autofluorescence (AF), fundus fluorescence angiography (FFA) and indocyanine green angiography (ICG) were almost consistent with those on fundus photography. The lesions were hyperautofluorescent in a placoid or massive shape. The lesions on FFA showed slight hyperfluorescence with unclear edges from the venous phase, and the fluorescence increased with the time and leaked in the late phase. Vascular walls showed blood staining in the late phase. The lesions on ICG showed hypofluorescence with hyperfluorescence and hypofluorescence dots like fine needles in the middle and late phases.

ASPPC mainly occurs among the young adults without gender difference. The characteristic is the contradiction between sever clinical symptoms and slight signs on the fundus. The lesion area shown on fundus photography, FFA, ICG and AF is consistent, as well as injuries of the ellipsoid layer, RPE nodules and cells in the vitreous body. The above manifestations and imaging characteristics of ASPPC are significant for the diagnosis and differential diagnosis. (Chin J Ophthalmol, 2017, 53:352-357)

To observe and analyze related factors of neonatal asphyxia complicated with retinal hemorrhage.

It was a retrospective case series. Seven hundred and twenty-one cases with neonatal asphyxia after 72 hours of birth were enrolled in this study. Fundus examination was performed on these newborns using the third generation wide-angle digital retina imaging system (RetCamⅢ), and the bleeding level was divided into level I, level Ⅱ and level Ⅲ. The conditions of the newborn and the mother during pregnancy were correlatively analyzed. The other factors were also analyzed including delivery mode, birth weight, gestational age, gender, grade of neonatal asphyxia, scalp hematoma, intracranial hemorrhage, fetal intrauterine distress, mother's age and antenatal complications. Single factor χ² test and multivariate logistic regression analysis were used to screen and judge risk factors causing retinal hemorrhage related to neonatal asphyxia.

In 721 cases of neonatal asphyxia, retinal hemorrhage was found in 204 newborns (28.29%). The hemorrhage was at level Ⅰ in 77 cases (37.75%) , at level Ⅱ in 38 cases (18.63%) and at level Ⅲ in 89 cases (43.63%) . Four cases also had vitreous hemorrhage. Asphyxia was mild in 673 infants (93.34%) and severe in 48 infants (6.66%). The difference in the degree of retinal hemorrhage between the patients with mild and severe asphyxia was significant (χ²=22.336, P=0.000). When asphyxia was aggravated, the degree of retinal hemorrhage increased. Relative factors analysis showed that delivery mode (χ²=158.643, P<0.05), gestational age (χ²=24.522, P<0.05), birth weight (χ²=11.916, P<0.05) and grade of neonatal asphyxia (χ²=19.809, P<0.05) had correlations with retinal hemorrhage. Logistic regression analysis indicated that grade of neonatal asphyxia and delivery mode were risk factors of retinal hemorrhage in neonatal asphyxia (OR=0.304, 0.085).

The incidence of retinal hemorrhage in neonatal asphyxia was 28.29%. The degree of neonatal asphyxia and delivery mode may play roles in the occurrence of retinal hemorrhage in newborns with asphyxia. With aggravation of asphyxia, the degree of retinal hemorrhage may increase. (Chin J Ophthalmol, 2017, 53: 358-362)

To evaluate the effect of hydrogen-rich saline (HRS) on dry eye rats induced by subcutaneous injection of scopolamine hydrobromide.

Experiment research. Thirty female Wistar rats at about six weeks old were randomly divided into the normal group, dry eye group, HRS eyedrops group, normal saline eyedrops group (NS), HRS intraperitoneal injection group and NS intraperitoneal injection group, with 5 rats in each group. The dry eye was induced by subcutaneous injection of scopolamine hydrobromide in the latter five groups. The clinical signs of dry eye such as tear volume (SⅠt), tear break-up time (BUT) and corneal epithelial fluorescein staining scores were evaluated on day 7, 14, 21 and 28. On the 28th day, ten eyes in each group were enucleated and processed for paraffin sections for HE, PAS and immunohistochemistry stainings. Analysis of variance was used to test the data, and independent samples t-test was used for comparison between the two groups. Two-way repeated measure ANOVA was used to compare the difference among groups at different time points, one-way ANOVA was used to test the comparisons of the clinical signs at one time, and LSD was used to for comparison between two groups.

Before and after the experiment of the day 7, 14, 21, 28, the values of SIt in HRS eyedrops group and HRS intraperitoneal injection group were respectively:(3.625±1.157),(3.313±0.704),(3.250±0.535),(3.313±0.372), (3.375±0.582)mm and (3.500±1.019), (2.893±0.656), (3.321±0.668), (3.179±0.575), (3.214±0.871)mm. The values of BUT were respectively: (2.750±0.707), (2.688±0.594), (2.813±0.753), (3.000±0.756), (2.750±0.707)s and (3.000±0.679), (2.321±0.464), (2.750±0.753), (3.214±0.699), (2.679±0.608)s. The values of fluorescein staining score were respectively: (6.250±0.707), (8.875±0.641), (8.750±0.707), (9.250±0.463), (8.250±1.282) and (6.000±0.679), (9.143±1.027), (8.857±0.770), (9.143±0.949), (8.500±0.760). The difference of SIt, BUT and fluorescein staining score between the groups was statistically significant on the 14th day(F=5.194, 3.894, 16.487, P<0.05), the values of SⅠt, BUT and fluorescein staining score of HRS eyedrops group showed significantly better than NS eyedrops group(P<0.05), HRS intraperitoneal injection group showed significantly better than NS intraperitoneal injection group(P<0.05), and there was no significant difference between HRS eyedrops group and HRS intraperitoneal injection group(P>0.05), which remained stable until the day 28. On the 28^th day, HE, PAS and immunohistochemistry stainings showed the corneal and conjunctival epithelia became smooth and regular, the cell layer number decreased, the tissue hyperplasia and edema were lightened, and the size of goblet cells tended to be normal, and the squamous metaplasia and inflammation were relieved. In HRS eyedrops group and HRS intraperitoneal injection group.

HRS eyedrops group and HRS intraperitoneal injection group can relieve the signs of dry eye, improve the pathological damage of cornea and conjunctiva, and protect the ocular surface of a rat dry eye model, which is better than NS groups from the 14^th day. (Chin J Ophthalmol, 2017, 53: 363-372)

To evaluate the rate of blindness caused by primary angle closure glaucoma (PACG) in Chinese population of more than 40 years old, and to explore the effectiveness of a prevention and treatment system on PACG.

We searched the databases of Pubmed, ScienceDirect, Springer Link, CNKI and Wanfang Data and collected all the original studies of the prevalence and blindness of angle closure glaucoma in China. The population was limited to over 40 years old. The research site was limited to the community-based, while the published time was not limited. Two researchers completed the literature search, data extraction and methodological quality assessment independently, with same criteria. Meta analysis was performed using R software.

Five papers were included in this study finally. A total of 26 437 cases of natural population over the age of 40 were observed, and 306 cases of angle closure glaucoma were found, of which 113 cases had binocular or monocular blindness caused by PACG. The random effect model meta-analysis results showed that the overall blindness rate was 38.3% [95%CI (28.1%, 49.6%)]. In Beijing, where the prevention and treatment system was well established, the blindness rate was far lower than that in the areas where the system was poorly established. Compared with the past, the blindness rate caused by PACG in Beijing decreased sharply.

The rate of blindness caused by PACG is still high in the mainland of China. The prevention and treatment system is effective and worth promoting. (Chin J Ophthalmol, 2017, 53: 373-377)

The patient was a female, 45 years old. He was admitted to the Department of Ophthalmology of Ningbo Eye Hospital for 1 week due to decreased visual acuity of his left eye accompanied by visual object deformation and visual obstruction. The patient has been highly myopic in both eyes since childhood. Several years ago, he underwent laser correction of corneal myopia in both eyes, and denied the history of other eye diseases and systemic diseases. Deny history of ocular trauma and drug allergy. Ophthalmologist examination: Right eye naked visual acuity 0.15, -5.00 DS2.00 DC ×85° corrected to 0.4, left eye naked visual acuity 0.04, -5.00 DS 1.00DC ×85° was corrected to 0.15, there was no conjunctiva congestion in both eyes, the cornea was transparent, the anterior chamber was deep, the aqueous humor was clear, the pupil was round, about 3 mm in diameter, there was light reflection, the lens was slightly opaque, the vitreous was slightly opaque, the optic disk boundary of the fundus of both eyes was clear, the color was pale red, the blood vessels were slender, the fundus was leopard print, the macular reflection of the right eye was not seen, the macular area of the left eye was dark red, and the foveal reflection disappeared (FIG. 1A）。 Auxiliary examination: FFA examination of the left eye on August 11, 2015 showed that there was a punctate fluorescein leakage at the inferior temporal margin of the macular arch ring in the left eye (FIG. 1B), the results of the frequency domain OCT examination of the left eye (Topcon, Japan) on August 8, 2015 showed that the strong reflection light cluster under the fovea of the left eye was accumulated with the anterior macular surface membrane, part of the retinal interlaminar cleavage and the macular lamellar hole (Figure 1C）。 The initial diagnosis was: choroidal neovascularization in pathological myopia in the left eye, epiretinal macular membrane in the left eye, macular lamellar hole in the left eye, high myopia in both eyes, and laser correction of corneal myopia in both eyes. He was admitted to Ningbo Eye Hospital on August 14, 2015, and received ranibizumab injection into the vitreous cavity of his left eye with the informed consent of the patient, and the process went smoothly. After postoperative outpatient follow-up, reexamination of OCT 1 month after injection showed that the strong reflection light group in macular area disappeared, partial retinoschisis, macular lamellar hole with macular epiretinal membrane (Figure 2）。 Three months later, reexamination of left eye OCT showed: macular hole, aggravation of retinoschisis, local neuroepithelial layer detachment (Figure 3）。 OCT of left eye after 3.5 months reexamination showed: macular hole, macular epiretinal membrane, retinal detachment (Figure 4）。 On December 1, 2015, he underwent 25G vitrectomy + peeling + gas-liquid exchange + silicone oil intraocular filling in his left eye at Ningbo Eye Hospital. The operation was successful. After 1 month after the operation, the OCT of his left eye showed that the epiretinal membrane and retinoschisis disappeared, and the retina was well reset (Figure 5）。

The patient was a 29-year-old male. In the process of repairing the laser cigarette lighter, my eyes suddenly lit up and my vision was blurred, so I went to the Department of Ophthalmology of Cangzhou Central Hospital. Eye examination: visual acuity was 1.2 in the right eye and 1 m index in the left eye; There were no obvious abnormalities in the anterior segment and fundus of the right eye, no abnormalities in the anterior segment of the left eye, and a macular hole in the left fundus (Quintessence Picture 1In a). The results of the OCT examination are presented inQuintessence Picture 1Middle B. Clinical diagnosis: traumatic macular hole in the left eye.

The injury and repair of retinal neurons is a common scientific problem in the occurrence, development and prognosis of neuronal visual impairment. Transplant of retinal ganglion cells (RGCs) differentiated from stem cells opens a new avenue for treatment of glaucoma and optic neuronal degenerative diseases. For the goal to explore the optimal method for RGCs replacement, this review summarizes the current information regarding the classification and application of stem cells, the growth characteristics of RGCs and the precise methods to induce RGCs, and discusses some important issues that need resolving and are related to RGCs transplantation. It is hoped that this article will provide useful theoretical basis for the research of this field. (Chin J Ophthalmol, 2017, 53: 381-385)

Genome editing is a cutting-edge technology that generates DNA double strand breaks at the specific genomic DNA sequence through nuclease recognition and cleavage, and then achieves insertion, replacement, or deletion of the target gene via endogenous DNA repair mechanisms, such as non-homologous end joining, homology directed repair, and homologous recombination. So far, more than 600 human hereditary eye diseases and systemic hereditary diseases with ocular phenotypes have been found. However, most of these diseases are of incompletely elucidated pathogenesis and without effective therapies. Genome editing technology can precisely target and alter the genomes of animals, establish animal models of the hereditary diseases, and elucidate the relationship between the target gene and the disease phenotype, thereby providing a powerful approach to studying the pathogenic mechanisms underlying the hereditary eye diseases. In addition, correction of gene mutations by the genome editing brings a new hope to gene therapy for the hereditary eye diseases. This review introduces the molecular characteristics of 4 major enzymes used in the genome editing, including homing endonucleases, zinc finger nucleases, transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeats (CRISPR)/ CRISPR-associated protein 9 (Cas9), and summarizes the current applications of this technology in investigating the pathogenic mechanisms underlying the hereditary eye diseases. (Chin J Ophthalmol, 2017, 53: 386-371)

Previous studies have observed functional deficits in primary visual cortex. With the development of functional magnetic resonance imaging and electrophysiological technique, the research of the striate, extra-striate cortex and higher-order cortical deficit underlying amblyopia reaches a new stage. The neural mechanisms of amblyopia show that anomalous responses exist throughout the visual processing hierarchy, including the functional and structural abnormalities. This review aims to summarize the current knowledge about structural and functional deficits of brain regions associated with amblyopia. (Chin J Ophthalmol, 2017, 53: 392-395)

optical coherence tomographic angiography (OCTA) is a split-spectrum amplitude decorrelation angiography (SSADA) method based on en face OCT^[1]A new technique for non-invasive display of the morphology and changes of retinal and choroidal blood flow. Currently, OCTA has been applied to central serous choroidopathy^[2]Choroidal neovascularization^[3]Polypoid choroidal vasculopathy^[4]and diabetic retinopathy^[5]It has broad clinical application prospects in the diagnosis and treatment of various retinal and choroidal lesions. Only by fully understanding the operating technical characteristics of OCTA, mastering the picture characteristics and reading points of OCTA can this technology be better applied to clinic and improve the diagnosis and treatment level of retinochoroidal vascular diseases.