[The Surgical Effects of Medial Rectus Recession on Divergence Insufficiency Esotropia].

OBJECTIVE: To study the surgical effects of medial rectus recession (MRR) on divergence insufficiency esotropia (DIE). METHODS: Nine DIE patients who were admitted to and had MRR at Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University between December 2017 and June 2020 were included in this retrospective study. All patients were followed up for 1 year at least. The postoperative esodeviation, near-distant disparity (NDD) and visual function were observed and compared. RESULTS: The mean age of the 9 patients was 28.8 years old (10-49 yr.), including 3 adolescent patients (≤18 yr.). The mean preoperative esodeviation was (19.8±13.2) PD for near and (32.6±15.3) PD at distance, while, the mean postoperative esodeviation 1 year after MMR was (-0.2±3.5) PD for near and (6.0±2.2) PD at distance, showing significant improvement over the mean preoperative esodeviation ( P=0.012, P=0.007). NDD dropped from (12.8±2.4) PD before the surgery to (6.0±2.2) PD 1 year after the surgery, showing significant improvement ( P=0.008), and remained stable 1 year after the surgery ( F=0.075, P=0.900). There was no significant improvement of near stereopsis ( P=0.306). Binocular function at distance was significantly improved after surgery (Worth 4 dots test : P=0.017; Bagolini striated glasses: P=0.035). The patients were divided into two groups, the adolescent group (age≤18 yr., n=3) and the adult group (age>18 yr., n=6). Prior to the operation, the mean spherical diopter of the adolescent group (OD -1.75 D, OS -1.92 D) was lower than that of the adult group (OD -6.17 D, OS -6.04 D) ( P=0.012). The average value of preoperative AC/A of the adolescent group was 4.33. It was 2.33 in the adult group, which was lower than the normal value, and significantly lower than that of the adolescent group ( P=0.12). There was no significant difference in esodeviation or NDD between the adolescent group and the adult group before and after operation. CONCLUSIONS: Medial rectus muscle recession can effectively improve the NDD and the binocular function at distance of patients with divergence insufficiency esotropia. Postoperative esodeviations both for near and at distance tend to regress after the surgery. Therefore, it is recommended that the amount of MRR be increased in the treatment of DIE.

Effect of positional isomers on the photochromic behaviors of bipyridyltriazolium chloroantimonate hybrids.

Two chloroantimonate hybrids with isomeric bipyridyltriazoliums and similar packing patterns, {[2-bpt]2[(SbCl5)Cl2]}n (1) and {[4-bpt]2[(SbCl5)Cl2]}n (2) (2-bpt2+ = protonated 3,5-bis(pyridine-2-yl)-1,2,4-triazole, 4-bpt2+ = protonated 3,5-bis(pyridine-4-yl)-1,2,4-triazole), have been designed and synthesized. Distinct intermolecular electronic interactions and photochromic behaviors are attributed to the remarkable modulation of positional isomeric effect on the electron deficiency of the acceptors and donor-acceptor matching relationship. 1 is the first reported photochromic chloroantimonate hybrid.

The efficacy of superior oblique posterior tenectomy in the treatment of A-pattern exotropia without ocular intorsion: A retrospective study.

BACKGROUND: Superior oblique weakening is a common method to treat A-pattern strabismus. This study aims to evaluate the surgical results of the bilateral superior oblique posterior tenectomy procedure to treat A-pattern strabismus patients who had bilateral superior oblique overaction without objective ocular intorsion. METHODS: The records of 18 consecutive patients who underwent surgery of superior oblique posterior tenectomy close to its insertion with superior oblique overaction (SOOA)-associated A-pattern strabismus between September 1, 2015 and August 31, 2018 were retrospectively reviewed. Ocular alignment, objective torsion, A-pattern and ocular motility were assessed. Ocular alignment was measured in the primary position, 25° upgaze, and 25° downgaze using the prism bar cover test, and torsion was measured using fundus photographs. RESULTS: A total of 18 patients (mean age: 15 years; 6 female, 12 male) underwent bilateral superior oblique posterior tenectomy and simultaneous horizontal rectus muscle surgery were included. The mean preoperative A-pattern deviation was 15 PD and the mean postoperative A-pattern deviation was 2.25 PD with a mean reduction of 12.75 PD. The mean preoperative superior oblique overaction was 2.28 and the mean postoperative superior oblique overaction was 0.43 with a mean reduction of 1.85. There was no significant correlation between the ocular torsional, vertical alignment change and the superior oblique posterior tenectomy procedure. CONCLUSIONS: Superior oblique posterior tenectomy surgery selectively improved the A-pattern and superior oblique overaction but not affect the primary position vertical deviation, as well as the ocular torsion. It is an effective procedure to treat the mild to moderate superior oblique overaction associated A pattern strabismus without ocular intorsion.

Enlargement of the superior rectus and superior oblique muscles causes intorsion in Graves' eye disease.

PURPOSE: To review the prevalence of preoperative and postoperative intorsion in patients with strabismus and Graves' eye disease (GED), and to correlate the intorsion with coexisting superior rectus (SR) and superior oblique (SO) muscle enlargement as a possible mechanism causing intorsion in these patients. METHODS: Charts of consecutive patients with GED who underwent strabismus surgery between 1 January 2010 and 1 April 2013 were retrospectively reviewed. Of these, patients with orbital CT or MRI scan were identified for further analysis. Clinical characteristics documented included age, gender, horizontal and vertical deviation, subjective torsional deviation, specific extraocular muscles (EOMs) operated upon, EOM enlargement on CT/MRI scans and width and thickness of SO, SR group and inferior rectus (IR). RESULTS: Charts of 45 patients (14 males and 31 females) were reviewed. Mean age was 56.8±12.5 years. Of these, seven (15.6%) patients demonstrated intorsion, and 38 (84.4%) patients demonstrated extorsion preoperatively. But after strabismus surgery, 15 (39.5%) of the 38 patients with preoperative extorsion demonstrated postoperative intorsion and 23 (60.5%) patients continued to show postoperative extorsion. On analysis of CT/MRI scans in these patients, only an increase in the thickness of SR group and the thickness/width of SO muscle were significantly associated with preoperative and postoperative intorsion; while age, gender, preoperative horizontal or vertical deviation and IR recession were unrelated to preoperative or postoperative intorsion. Postoperative intorsion was also associated with smaller degrees of preoperative extorsion (<3.5°). CONCLUSIONS: Preoperative SR and/or SO muscle enlargement appear to be a primary contributing factor relating to preoperative and postoperative intorsion in patients with GED-associated strabismus. Patients with only small amounts of preoperative extorsion (<3.5°) in the presence of tight IRs should be carefully evaluated for possible SR and/or SO involvement by CT or MRI scan to predict those at risk for and plan for prevention/treatment of postoperative intorsion.

[An Analysis of Combustion Emission Spectrum and Combustion Products of KClO4/Zr in the Quartz Tubes].

Aiming at understanding the light radiation properties of KClO4/Zr combusting under different conditions, emission spectrum and combustion products for KClO4/Zr combusting in open air and closed quartz tubes were studied respectively. Energy distribution of the light radiation signal and the emission intensity evolution with time were measured with fiber optic spectrometer, and photo-diode and oscilloscope. Spectral efficiency within (590±10), (750±10) and (808±10) nm were analyzed respectively according to the obtained flame emission spectrum. Morphology of the combustion products of KClO4/Zr were observed with scanning electronic microscopy (SEM). Results showed that the flame emission spectrum of KClO4/Zr distributed within the visible and near infrared width wave band, whiel the strongest radiation appeared within 730 nm to 820 nm band. When burning in closed quartz tubes, detected combustion emission spectrum intensity decreased significantly with the decrease in size of the tube. Also, the energy distribution of the emission spectrum showed different variation trends, and to deal with flame emission spectrum distribution, as the change of volume of quartz tubes, (590±10), (750±10) and (808±10) nm bands' spectral efficiency are also present different change rules. Generally, increasing the diameter of the quarts tube favored the increase of the effective light radiation energy detected outside of the tube, and decreasing the diameter of the quartz tubes favored the peak emission intensity of KClO4/Zr. With the increase of tube diameter, KClO4 burning more fully, the product particle size is smaller; the morphology is the rule of the globular. And the change of tube length is not too large effect in the reaction results.

The peripheral cannabinoid receptor 1 antagonist VD60 efficiently inhibits carbon tetrachloride-intoxicated hepatic fibrosis progression.

This study investigated a peripheral selective CB1 antagonist 3,4,22-3-demethoxycarbonyl-3-hydroxylmethyl-4-deacetyl-vindoline 3,4-thionocarbonate (VD60) that efficiently inhibited hepatic fibrosis with lower psychological side effects. A competitive radiolabeled ligand binding experiment and 3'-5'-cyclic adenosine monophosphate (cAMP) response element-driven luciferase analysis were performed to evaluate the antagonistic activity of VD60. Cell viability and collagen production were examined in the human hepatic stellate cell (HSC) line LX-2 and primary cultured rat HSCs. The antifibrotic effects of VD60 were investigated in a CCl4-induced liver fibrosis mouse model. The concentration of VD60 in the blood and the brain was determined by high-performance liquid chromatography-mass spectrum analysis. Furthermore, the potential underlying mechanisms of VD60 were investigated by Western blot. VD60 selectively competed with the radiolabeled CB1 agonist to bind to CB1. VD60 antagonized CB1 agonist-induced Akt phosphorylation and increased the accumulation of intracellular cAMP. VD60 strongly reduced the expression of α2(I) pro-collagen mRNA and exerted potent antiproliferative effects on primary HSCs and LX-2 cells. The inhibition of reactive oxygen species production and phosphorylation of Akt, extracellular-signal-regulated kinase (ERK), and Smad3 may explain the underlying mechanisms behind the antiproliferative effect of VD60. Moreover, the in vivo antifibrotic activity of VD60 was confirmed in a CCl4-induced liver fibrosis mouse model. Most importantly, the concentration of VD60 in the peripheral blood was much higher than in the brain, suggesting that VD60 could act as a novel peripheral CB1 antagonist to efficiently inhibit hepatic fibrosis and could be used as a lead compound with low brain side effects in peripheral antifibrotic agents.

[Timing of surgery for congenital esotropia].

Congenital esotropia is defined as an esotropia before the age of 6 months, because of its early onset and often constant angle, it cause heavier binocular visual function damage compared with other types of strabismus. Early surgery can improve binocular visual function, but demand reliable, accurate measurements which is difficult to achieve in children, and it may increase the risk of second surgery, amblyopia and anesthesia. Late surgery can gain reliable strabismus angle, but it reduced the likelihood of recovery binocular visual function, and the contracture of medial rectus after a long time esotropia increased mechanical limitation of adduction. Therefore, the choice of timing to do surgery has been controversy over the years. In this paper, we will combine the research status and clinical practice to discuss this issue, and present some point of view for the peer reference.

[Integrated therapy of congenital cataract to prevent blindness and low vision].

Congenital cataract is a major cause of treatable blindness in the pediatric population worldwide. Advances in microsurgical techniques have significantly increased the success rate of surgery. However, visual rehabilitation outcomes are not always satisfactory even after a successful surgery. Due to delayed surgery, irrational aphakic correction, and lack of amblyopic training, a large number of infants in China remain blind or low-visioned after cataract surgery. Appropriate timing of surgical intervention, rational surgical methodology as well as systematic optical correction and amblyopic training are critical for the prevention of blindness and low vision in congenital cataract.

Astaxanthin attenuates the apoptosis of retinal ganglion cells in db/db mice by inhibition of oxidative stress.

Diabetic retinopathy is a common diabetic eye disease caused by changes in retinal ganglion cells (RGCs). It is an ocular manifestation of systemic disease, which affects up to 80% of all patients who have had diabetes for 10 years or more. The genetically diabetic db/db mouse, as a model of type-2 diabetes, shows diabetic retinopathy induced by apoptosis of RGCs. Astaxanthin is a carotenoid with powerful antioxidant properties that exists naturally in various plants, algae and seafood. Here, astaxanthin was shown to reduce the apoptosis of RGCs and improve the levels of oxidative stress markers, including superoxide anion, malondialdehyde (MDA, a marker of lipid peroxidation), 8-hydroxy-2-deoxyguanosine (8-OHdG, indicator of oxidative DNA damage) and MnSOD (manganese superoxide dismutase) activity in the retinal tissue of db/db mouse. In addition, astaxanthin attenuated hydrogen peroxide(H2O2)-induced apoptosis in the transformed rat retinal ganglion cell line RGC-5. Therefore, astaxanthin may be developed as an antioxidant drug to treat diabetic retinopathy.

Cannabinoid receptor 1 blockade protects human retinal pigment epithelial cells from oxidative injury.

BACKGROUND: Because oxidative stress is assumed to be a key mechanism in the pathological process of age-related macular degeneration (AMD), increasing numbers of studies have focused on discovering new pathways and treatments for reducing oxidative damage. Our work investigates the potential role of the cannabinoid receptor 1 (CB1) in oxidative stress of primary human retinal pigment epithelial (RPE) cells, a cellular model of AMD. METHODS: Primary human RPE cells were cultured and exposed to hydrogen peroxide for 24 h to induce oxidative damage. The expression of and changes in the CB1 receptor were determined with western blot assay and confocal imaging. The CB1 receptor in the RPE cells was inhibited with small interfering RNA (siRNA) or rimonabant (SR141716). Cell viability, apoptosis, and reactive oxygen species production were measured by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and sulforhodamine B assay, annexin V and propidium iodide staining, and the dichlorofluorescein fluorescence assay, respectively. Intracellular superoxide dismutase activity was assayed with a commercially available assay kit. Phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) protein expression and activation of signaling molecules were assessed with western blot analysis. RESULTS: We showed that human RPE cells express the CB1 receptor. In addition, oxidative stress upregulates the expression of the CB1 receptor. Deleting the CB1 receptor or treating with the CB1 receptor antagonist rimonabant (SR141716) rescued RPE cells from hydrogen peroxide-induced oxidative damage. Rimonabant pretreatment effectively reduced the apoptosis of RPE cells, inhibited the generation of intracellular reactive oxygen species and elevated the activity of superoxide dismutase. In addition, rimonabant significantly strengthened the oxidative stress-induced activation of the PI3K/Akt signaling pathway. CONCLUSIONS: The results demonstrate the expression and regulation of CB1 receptors in human RPE cells. Inhibiting the CB1 receptor may be an effective therapeutic strategy for AMD by downregulating oxidative stress signaling and facilitating PI3K/Akt activation.

[Investigations on cyclotorsion changes following strabismus surgery in superior oblique palsy patients].

OBJECTIVE: To investigate cyclotorsion changes after strabismus surgery in superior oblique palsy patients. METHODS: Forty patients (50 eyes) underwent myotomy of inferior oblique (15 patients, 15 eyes), partial myectomy of inferior oblique (15 patients, 15 eyes) or myotomy of inferior oblique combined with inferior rectus recession on the other eye (10 patients, 20 eyes) for treatment of monocular superior oblique palsy. Objective cyclotorsion were examined pre-operation, as well as 1, 7, 30, and 90 d post-operation with fundus photograph and quantitive measurement. Vertical deviation and ocular movement were also assessed before and after surgery. Fundus photograph were also examined in 30 normal persons (60 eyes) without strabismus. RESULTS: The fovea-to-disc angle of normal people was 6.7°±2.5° in the right eye, 5.9°±2.3° in the left eye, and 12.6°±4.3° when combined. The cyclotorsion angle was not statistically significant between two eyes (t=1.29, P=0.20). For the monocular superior oblique palsy patients, preoperative fovea-to-disc angle was 14.3°±6.6° in the affected eyes, 12.2°±4.8° in the fellow eyes, and 26.5°±10.3° when combined. The objective cyclotorsion was also not statistically significant between two eyes (t=1.64, P=0.11). The comparison of total cyclotorsion angle of both eyes showed significant difference between normal people and patients. The fovea-to-disc angle of 1, 7, 30 and 90 d after operation were 11.7°±4.3°, 11.9°±4.9°, 13.5°±5.2° and 15.9°±3.6° respectively. The comparison of objective ocular cyclotorsion for both eyes showed significant difference pre- and post-operation (F=40.13, P<0.01). There is a gradual increasing trend of postoperative excyclotorsion angle with the prolonged time. There were statistically significant difference between 90 d and 1 d, 7 d after surgery. The two inferior oblique weakening procedures, myotomy of inferior oblique and partial myectomy of inferior oblique produced equitable amount of incyclotorsion shift with no statistical difference. The difference between the cyclotorsion change induced by myotomy of inferior oblique and inferior rectus recession in counter side was also not statistically significant. CONCLUSIONS: Monocular superior oblique palsy patients had fundus excyclotorsion change that was nearly equally distributed between two eyes. Weakening the inferior oblique and inferior rectus could correct ocular excyclotorsion, the regression trend was observed 90 d after surgery. Both myotomy and partial myectomy of inferior oblique were equally effective in the correct of ocular cyclotorsion and vertical deviation.

[The operation time and post-operative target eye alignment of intermittent exotropia].

Different from other types of strabismus, children with intermittent exotropia can maintain normal eye alignment and binocular vision in a long period of time. But the course of intermittent exotropia is mostly progressive, the eye position may drift outward even after surgery, so there is a certain risk of recurrence or under correction. These features often lead confusion to the clinicians in determining the operation time and postoperative target eye position. So how to choose the appropriate intervention time and target eye alignment is a challenge for clinicians. In this paper, we will combine the research status and clinical practice, discuss these issues, and present some point of view for the peer reference.

[Surgical treatment of myopic strabismus fixus by modified Yokoyama's surgery].

OBJECTIVE: To evaluate the surgical results of modified Yokoyama's procedure for treating myopic strabismus fixus. METHODS: Retrospective analysis of records of 5 patients (7 eyes) with high myopic strabismus. Pre- and postoperative orthoptic measurements were recorded and analyzed. Anatomic relationships between the muscle cone and globe were analyzed using MRI or CT scan. The surgical procedure is a modification of Yokoyama's technique and medial rectus muscle was also recessed. RESULTS: The average axis length of 7 eyes was 32.62 mm (SD1.84). The mean preoperative horizontal deviation was 82.86 PD (SD 37.62) esotropia and mean vertical deviation was 20 PD (SD 7.91) hypotropia. All patients had marked limitation of elevation and abduction. Displacement of the lateral rectus inferiorly and superior rectus medially was demonstrated in each patient by CT or MRI scan of the orbits and by observation during surgery. After surgery, the supertemporal dislocation of globe was improved. Both the horizontal and vertical deviations decreased significantly, and the abduction and sursumduction motility were also improved gradually. The average follow-up was 5 months, all patients achieved satisfactory results and remained stable. CONCLUSIONS: In high myopic patients, if the deviant paths of the LR and SR muscles were demonstrated by MRI or CT scan, the surgical procedure to restore the dislocated globe back into the muscle cone by uniting muscle bellies of the superior rectus and lateral rectus muscles is effective and recommended.

[The progress of intermittent exotropia].

Intermittent exotropia is a type of strabismus between exophoria and constant exotropia. The onset age is usually one to four years old. Different from other types of strabismus, intermittent exotropia patient can maintain normal binocular vision in a long period of time. So how to choose the optimal timing and effective treatment is a challenge for clinicians. The objective of this article is to review the recent research progress of intermittent exotropia, including the severity classification, non-surgical treatment, timing of surgery and surgical methods, overcorrection and under correction treatment etc., and give some recommendations for the treatment of intermittent exotropia.