Factors affecting long-term myopic regression after corneal refractive surgery for civilian pilots in southwest China.

BACKGROUND: The purpose of this study was to analyze myopic regression after corneal refractive surgery (CRS) in civilian pilots and to explore the factors that may cause long-term myopic regression. METHODS: We included civilian pilots who had undergone CRS to correct their myopia and who had at least 5 years of follow-up. We collected retrospective data and completed eye examinations and a questionnaire to assess their eye habits. RESULTS: A total of 236 eyes were evaluated in this study. 211 eyes had Intrastromal ablations (167 eyes had laser in situ keratomileusis, LASIK, 44 eyes had small incision lenticule extraction, SMILE) and 25 eyes had subepithelial ablations (15 eyes had laser epithelial keratomileusis, LASEK and 10 eyes had photorefractive keratectomy, PRK). The mean preoperative spherical equivalent (SE) was - 2.92 ± 1.11 D (range from - 1.00 to -5.00 D). A total of 56 eyes (23.6%) suffered from myopic regression after CRS. Comparisons of individual and eye characteristics between the regression and non-regression groups revealed statistically significant differences in age, cumulative flight time, postoperative SE (at 6 months and current), uncorrected visual acuity (UCVA), accommodative amplitude (AA), positive relative accommodation (PRA), postoperative period, types of CRS and eye habits. Generalized propensity score weighting (GPSW) was used to balance the distribution of covariates among different age levels, types of CRS, cumulative flying time, postoperative period and continuous near-work time. The results of GPS weighted logistic regression demonstrated that the associations between age and myopic regression, types of CRS and myopic regression, continuous near-work time and myopic regression were significant. Cumulative flying time and myopic regression, postoperative period and myopic regression were no significant. Specifically, the odds ratio (OR) for age was 1.151 (P = 0.022), and the OR for type of CRS was 2.769 (P < 0.001). The OR for continuous near-work time was 0.635 with a P value of 0.038. CONCLUSIONS: This is the first report to analyze myopic regression after CRS in civilian pilots. Our study found that for each year increase in age, the risk of civilian pilots experiencing myopic regression was increased. Intrastromal ablations had a lower risk of long-term myopia regression than subepithelial ablations. There is a higher risk of myopic progression with continuous near-work time > 45 min and poor accommodative function may be related factors in this specific population.

[Primary Diseases of 393 Cases of Pediatric Retinal Detachment and the Distribution of Clinical Characteristics].

OBJECTIVE: To investigate the primary diseases and the distribution of the clinical characteristics of pediatric retinal detachment. METHODS: Clinical records of patients aged 0-14 years old who had retinal detachment and who were hospitalized at the Department of Ophthalmology, West China Hospital, Sichuan University between January 2015 and December 2020, were retrospectively analyzed. The information on the demographic data, history, the scope of retinal detachment, and prognosis was retrieved and documented. RESULTS: A total of 464 eyes of 393 patients were included in this study, including 261 male and 132 female patients at a ratio of 1.98:1. The most common type of primary disease causing pediatric retinal detachments was associated with ocular dysplasia (227 cases, 57.8%), followed by trauma (78 cases, 19.8%) and myopia (56 cases, 14.2%). For infants and preschool children, the primary disease was predominantly ocular dysplasia at a rate of 81.8% (126 cases) and 55.8% (43 cases), respectively. For school-age children, in addition to ocular dysplasia (58 cases, 35.8%), myopia (49 cases, 30.2%) and ocular trauma (43 cases, 26.5%) also accounted for a large proportion of the primary diseases. The most common type of pediatric retinal detachment was rhegmatogenous retinal detachment (184 cases, 46.8%), and ocular trauma and myopia were the most common primary diseases, accounting for 37.5% (69/184) and 30.4% (56/184), respectively. 170 patients were diagnosed with traction retinal detachment, the second most common type of pediatric retinal detachment, and familial exudative vitreoretinopathy (FEVER) was the main primary disease, accounting for 47.6% (81/170). Exudative retinal detachment (39 cases, 9.9%) was the least common type of pediatric retinal detachment. Coats disease was the main primary disease causing exudative retinal detachment, accounting for 71.8% (28/39). After the first repair surgery, patients who had complete traction retinal detachment generally had poorer anatomical outcomes compared with those with complete rhegmatogenous retinal detachments (| Z|=3.026, P=0.002). The retinal break was most commonly seen on the temporal side in pediatric rhegmatogenous retinal detachments. In the retinal detachments caused by trauma, the most common type of retinal break was retinal tear, followed by ora serrata dialysis. Myopic rhegmatogenous retinal detachments were most commonly found in the round holes in lattice degeneration region. CONCLUSION: In the current study, boys were found to be more susceptible to retinal detachment than girls did. Ocular dysplasia, ocular trauma and myopia were major etiologic factors for pediatric retinal detachment. Appropriate information and education measures should be emphasized for different age groups.

[Efficacy of Superior Rectus and Lateral Rectus Muscle Belly Union Surgery for Myopic Strabismus Fixus].

OBJECTIVE: To evaluate the effectiveness of superior rectus (SR) and lateral rectus (LR) union suture without scleral fixation for the treatment of myopic strabismus fixus. METHODS: A retrospective review was performed on 27 eyes of 16 patients who underwent lateral part of SR and superior part of LR muscle belly union between January 2010 and October 2015. We collected the ocular data including: best corrected visual acuity,axial length,CT or MRI images,orthoptic measurements (by prism test),and eye movements pre- and postoperatively. RESULTS: The follow up time varied from 3-12 months. All of the patients got satisfactory results except two severe cases. A statistical change of prism test value and eye movement was noticed ( P<0.01). Orthoptic measurements showed that the mean esotropia was improved from (92.50±18.17)Δ preoperatively to (9.19±4.39)Δ postoperatively ( P<0.01). In regards for the vertical deviation,the mean residual hypotropia was (2.38±3.10)Δ postoperatively compared to (21.88±5.74)Δ preoperatively ( P<0.01). At the last follow-up,mean abduction limitation was improved from -3.19±0.62 to -1.15±0.52 ( P<0.01),mean elevation limitation was improved from -2.85±0.82 to -0.78±0.51 ( P<0.01). No special complications were noted. CONCLUSION: Muscle belly suture of SR and LR was an effective surgery to correct ocluar misalignment and motility in myopic strabismus fixus.

Isotope-coded protein label based quantitative proteomic analysis reveals significant up-regulation of apolipoprotein A1 and ovotransferrin in the myopic chick vitreous.

This study used isotope-coded protein label (ICPL) quantitative proteomics and bioinformatics analysis to examine changes in vitreous protein content and associated pathways during lens-induced eye growth. First, the vitreous protein profile of normal 7-day old chicks was characterized by nano-liquid chromatography electrospray ionization tandem mass spectrometry. A total of 341 unique proteins were identified. Next, myopia and hyperopia were induced in the same chick by attaching -10D lenses to the right eye and +10D lenses to the left eye, for 3 and 7 days. Protein expression in lens-induced ametropic eyes was analyzed using the ICPL approach coupled to LCMS. Four proteins (cystatin, apolipoprotein A1, ovotransferrin, and purpurin) were significantly up-regulated in the vitreous after 3 days of wearing -10D lenses relative to +10D lens contralateral eyes. The differences in protein expression were less pronounced after 7 days when the eyes approached full compensation. In a different group of chicks, western blot confirmed the up-regulation of apolipoprotein A1 and ovotransferrin in the myopic vitreous relative to both contralateral lens-free eyes and hyperopic eyes in separate animals wearing +10D lenses. Bioinformatics analysis suggested oxidative stress and lipid metabolism as pathways involved in compensated ocular elongation.

The expression of vasoactive intestinal polypeptide in visual cortex-17 in normal visual development and formation of anisometropic amblyopia.

AIMS: To document the expression of vasoactive intestinal polypeptide (VIP) in the visual cortex-17 of kittens with anisometropic amblyopia, and to investigate the relationship between VIP and the development of the visual system. METHODS: Sixteen normal kittens (4-wk of age) were randomly divided into two groups: control and amblyopic. Amblyopia was produced by atropinization of one eye in eight kittens. Four (2 normal and 2 amblyopia) kittens were sacrificed at weeks 3, 6, 9, or 12 post-treatment respectively. Expression of VIP-mRNA in the visual cortex-17 was detected through in-situ hybridization. Neurons in the visual cortex were visualized by transmission electron microscopy (TEM). The number of neurons was analyzed via light microscopy (LM). RESULTS: VIP-mRNA expression was increased with age in control kittens but remained nearly static in age-matched anisometropic amblyopic kittens (p < 0.05). The number of VIP-positive cells of amblyopic kittens decreased dramatically when compared to normal age-matched kittens (p < 0.05). The total comparison between different positive ranks suggested a significant difference. The degree of expression between these two groups was significantly different. Ultrastructurally, in the control group, the nuclear membrane of most neurons was discernable and chromatin was evenly distributed within the nucleus. Abundant cytoplasm and tubular-shaped mitochondria were observed. These cells were also rich in Golgi bodies, ribosomes, and endoplasmic reticulum. In amblyopic kittens, nuclei of most neurons were aggregated, the number of ribosomes and Golgi bodies was reduced, mitochondria were swollen, and mitochondrial cristae were shortened or even absent. The endoplasmic reticulum was distended and reduced in magnitude. CONCLUSIONS: VIP appears to play an important role in visual development, and its mRNA expression is affected by visual experiences. Visual dysfunction may down-regulate the expression of VIP-mRNA by impairing the structure and function of the neurons in the visual cortex, finally leading to amblyopia.

[MR DTI and DTT study on the development of optic radiation in patients with anisometropia amblyopia].

OBJECTIVE: To evaluate the development of optic radiations (ORs) in patients with anisometropia amblyopia using magnetic resonance diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT), and to explore possible mechanism of pathogenesis of amblyopia. METHODS: Brain scan was performed with 3.0 Tesla scanner on 8 patients with anisometropia amblyopia and 15 control subjects with normal sights. The fractional anisotropy (FA) values, the apparent diffusion coefficient (ADC) values, the numbers of neural fiber bundle of ORs, and the voxel numbers of ORs were compared between the patients with anisometropia amblyopia and those with normal sights and between the ipsilateral ORs and the contralateral ORs in the patients with amblyopia. RESULTS: No differences in the FA values, the ADC values, the numbers of neural fiber bundle of ORs and the voxel numbers of ORs were found between the ipsilateral ORs and the contralateral ORs in the patients with amblyopia (P > 0.05). Significant decreases in the FA values and the voxel numbers of ORs were found in the patients with amblyopia compared with the controls (P < 0.05). No differences in the voxel numbers of both ORs in the anterior parts were found between the patients with amblyopia and the controls (P > 0.05). However, the patients with amblyopia had more voxel numbers of ORs in the posterior parts than the controls (P < 0.05). The differences in the ADC values and the numbers of neural fiber bundle of ORs between the patients with amblyopia and the controls were not significant (P > 0.05). CONCLUSION: The compactability, integrity and directivity of ORs decrease in patients with anisometropia amblyopia. The projection of OR fibers is abnormal. The ORs are underdeveloped, especially in the posterior parts, although no abnormal morphologic changes occur. The DTI and DTT can detect the underdevelopment of optic radiations in patients with anisometropia amblyopia indirectly.