Chinese Journal of Optometry Ophthalmology and Visual science

Imaging tests， including ultrasonography， computed tomography， and magnetic resonance imagery are very important and are used widely in the clinic to obtain a qualitative diagnosis and the location of ocular tumors. But these methods cannot determine the severity of malignant tumors and whether they have local or distant metastasis. Positron emission tomography/computed tomography （PET-CT） displays anatomic and metabolic abnormalities by combining the PET and CT imaging and analyzing the standard uptake value （SUV）. PET-CT has been used in the diagnosis of choroidal melanoma， orbital lymphoma， orbital rhabdomyosarcoma and adenoid cystic carcinoma of the lacrimal gland. It provides a new diagnostic tool for confirming ocular tumors and systemic metastatic tumors originating from them.

Objective To investigate corneoscleral dimensions and sagittal heights in the cornea and sclera using ultra-long scan depth spectral domain optical coherence tomography （UL-OCT）. Methods This was a cross-sectional investigation. Forty subjects （80 eyes， 17 men， 23 women； mean age， 25.8±2.8 years） were recruited for the study. UL-OCT image acquisition was taken for each eye. Custom software was used to quantify corneal/scleral sagittal height and dimensions of the corneoscleral junction. The differences in sagittal heights and dimensions of the corneoscleral junction in the four quadrants were analyzed with a paired t test and repeated measures ANOVA. Results There were no significant differences in the X and Y axis coordinates in the corneoscleral junction， the tangential curvature difference between the corneoscleral junction and the mean tangential curvature of the central 3 mm cornea and the corneal/scleral sagittal height （chord distances of 1.5， 3， 5 and 7 mm from the corneal apex） in the same locations between the left and right eyes. Except for the X axis coordinates， other dimensions were larger on the nasal side than the temporal side （P<0.05）. There were no significant differences among all dimensions between the superior and inferior sides at the vertical meridian. The values of the X axis coordinates at the vertical meridian were closer to the corneal apex than the horizontal meridian. The values of the Y axis coordinates and the tangential curvature difference between the corneoscleral junction and the mean tangential curvature of the central 3 mm cornea were largest on the nasal side compared to other locations （P<0.05）. Conclusion There are no significant differences for any dimensions at the same location between the left and right eyes. The corneosclera presents a larger junction angle on the nasal side than at other locations.

Objective To investigate the characteristics of damage to intraocular membranes from ocular trauma using color Doppler flow imaging （CDFI） for diagnosis. Methods We retrospectively studied 1 162 eyes of 1 156 patients who sustained ocular injuries from January 2013 to December 2013. CDFI was used to detect damage to ocular membranes. The surgical diagnosis was also reviewed. Results Among 1 162 eyes of 1 156 patients， vitreous hemorrhage presented in 1 071 eyes， endophthalmitis presented in 78 eyes， and posterior vitreous detachment presented in 624 eyes. There were 521， 221 and 117 eyes with retinal detachment， choroidal detachment and choroidal hemorrhage， respectively. While trauma to intraocular membranes is typically associated with a single injury identified with CDFI， most of the patients suffered from various injuries. Color Doppler flow imaging detected the damaged tissues with 2D images. Moreover， the imaging can analyze the retina and choroid blood flow to help distinguish retinal or choroidal detachment. In this study， 99.1% of the ultrasound diagnoses matched the clinical and surgical diagnoses. Conclusion Color Doppler flow imaging is an economical and simple way to detect intraocular membrane injury from ocular trauma. It is also noninvasive and repeatable. The use of retinal and choroidal blood flow analysis can increase the detection rate of intraocular membrane injury from ocular trauma.

Objective To evaluate the effect of laser in situ keratomileusis （LASIK） for myopia as well as changes in the macula after surgery. Methods This was a prospective clinical study. Thirty patients （60 eyes） were selected randomly to undergo LASIK. Spectral domain optical coherence tomography （SD-OCT） was used to evaluate the total macular volume （TMV） and central retinal thickness （CRT） before surgery， and 10 days and 1 month after surgery. Data were analyzed by a repeated measures design and Pearson correlation analysis. Results Preoperatively， mean BCVA was -0.063±0.041， mean TMV was 7.31±0.31 mm3， and mean CRT was 220.3±21.1 μm. Ten days after surgery， mean BCVA was -0.043±0.081， mean TMV was 7.32±0.26 mm3， and mean CRT was 221.6±20.8 μm. One month after surgery， mean BCVA was -0.074±0.061， mean TMV was 7.35±0.29 mm3， and mean CRT was 219.8±22.9 μm. CRT had changed significantly 10 days postoperatively compared to preoperative measurements and postoperative measurements at 30 days （P＜0.05）， and TMV measurements changed significantly between 10 and 30 days postoperatively （P＜0.05）. The variations in TMV and CRT do not correlate significantly with the change in spherical equivalent. Conclusion Mild macular edema is common shortly after LASIK， but no association with a loss of BCVA has been established.

Objective To measure the changes in retinal nerve fiber layer （RNFL） thickness using OCT in patients treated with ethambutol， to detect the axonal loss caused by ethambutol， and to assess the value of OCT in the early diagnosis of toxic optic neuropathy. Methods This was a retrospective observation of 185 eyes of 93 patients collected in ophthalmology department， being treated with ethambutol. They were separated into short-time treatment group （2 months） and long-time treatment group （≥6 months）， and 92 eyes of 46 age-matched TB infected patients who haven′t started the treatment were chosen as the control group. The differences in RNFL thickness from the three groups were compared using ANOVA. All patients underwent a neuro-ophthalmologic examination including visual acuity， color vision， visual fields and fundus examination. Results RNFL thickness of short-time treatment group： temporal （90.35±12.58）μm， inferior （145.91±17.18）μm， nasal （93.18±16.9）μm， superior （139.07±18.65）μm， average thickness （117.01±10.14）μm. RNFL thickness of long-time treatment group： temporal （79.75±17.14）μm， inferior （135.47±19.14）μm， nasal （91.17±20.23）μm， superior （130.44±21.50）μm， average thickness （109.24±14.36）μm. The control group： temporal （95.43±15.61）μm， inferior （139.92±15.35）μm， nasal （90.06±15.61）μm， superior （140.71±19.02）μm， average thickness （116.49±11.49）μm. Compared with the control group， no significant changes of RNFL thickness were found in the short-term group （P>0.05）. There were statistically significant decrease in the mean RNFL thickness of the temporal and superior quadrants between the long-term medication group from the control group （P<0.05）. A prominent decrease in RNFL thickness was observed in all quadrants in 6 eyes diagnosed with ethambutol induced optic neuropathy. Conclusion The short-term administration of ethambutol （0.75 g·d-1） in most of the patients did not cause obvious axonal loss and visual damage， but in the long-term group the RNFL thinning could be found apparently in the temporal quadrant， which maybe of great importance for early diagnosis of ethambutol toxic optic neuropathy.

Objective To investigate the visual acuity and refraction of preschoolers and to discuss the referral criteria for vision and refraction screening. Methods It was a cross-sectional study. Preschool children from 24 kindergartens in the Haidian area were selected for vision testing and refraction measurement. Distance visual acuity was tested by the child symbols chart in 3-year-old children and the logarithmic chart in 4- to 6-year-old children. Refractive error was measured with the Welch Allyn SureSight with noncycloplegy. Medians （M）（Q1-Q3） were used to describe visual acuity and refraction. Rank sum tests were used to analyze the differences in vision and refraction for the different ages. Ranges of normal values were calculated by percentiles. Results The M（Q1~Q3） of the sphere was 1.25 D （1.00-1.75 D） in 3- and 4-year-olds， and 1.50 D （1.00-1.75 D） in 5- and 6-year-old children. The difference in spheres for the different ages was statistically significant （χ2=77.60， P<0.01）. The M（Q1~Q3） of the cylinder was -0.50 D （-0.75- -0.25 D） for all ages. The difference in cylinders for different ages was statistically significant （χ2=60.41， P<0.01）. The Wilcoxon test for two independent samples showed that the difference between 3-year-olds and 4-year-olds was statistically significant （Z=-4.75， P<0.008）. The cylinders of the 3-year-olds were smaller than those for other children. The M（Q1~Q3） values for vision were 0.6 （0.6-0.7） in three-year-olds， 0.8 （0.8-1.0） in four-year-olds and 1.0 （1.0-1.0） in five- and six-year-olds. The differences in vision among the different ages were statistically significant （χ2=11 323.87， P<0.01）. The Wilcoxon test for two independent samples showed that the difference between any pair of groups was statistically significant （P＜0.008）. Visual acuity increased with age in preschool children. Among children with normal vision， the P2.5~P97.5 of the spheres was 0.50-2.75 D in three-year-olds， 0.50-2.50 D in four-year-olds， 0.50-2.75 D in five-year-olds and 0.50-3.00 D in six-year-olds. The P5 of the cylinders was -1.50 D in 3-year-olds and -1.25 D in 4- to 6-year-old children. Among children with normal refraction， the P5 of vision was 0.6 in three- and four-year-olds and 0.8 in five- and six-year-olds. Cylinders were more effective in improving vision than spheres. Conclusion The referral criteria for vision are worse than 0.6 for children three and four years old and worse than 0.8 for five and six years old. The referral criteria for the sphere are ≤+0.25 D and ≥+3.00 D for 3- to 6-year-old children. The referral criteria of the cylinder are ≤-1.75 D for children three years old and ≤-1.50 D for four to six years of age. The referral criteria of spheres can be broad， but the referral criteria for astigmatism should be strict.

Objective To investigate the efficacy and safety of posterior chamber phakic refractive lens （PC-PRL） implants for high myopia. Methods A retrospective case study of phakic intraocular lens implantation was carried out on high myopia patients. Thirty-eight patients （68 eyes） with high myopia （-11.25 to -20.00 D） were implanted with PC-PRLs. Preoperative and postoperative visual acuity， intraocular pressure， corneal endothelial cell count， anterior chamber depth and intraocular lens position were observed and analyzed. The differences between postoperative equivalent spherical errors were analyzed in different refractive error groups with repeated measure ANOVA. Results All patients gained uncorrected visual acuity ≥4.7 in 6 months， which was equal to or better than preoperative best corrected visual acuity. Seven patients （10 eyes） had early high postoperative intraocular pressure. The intraocular pressure returned to a normal level after treatment. All patients had decreased anterior chamber depth postoperatively（F=32.952， P＜0.01）. Horizontal/vertical trabecular iris angle， angle opening distance， and arch height did not significantly change （P＞0.05） in all implanted eyes. No iris bombe or angle block was detected in any patient. Postoperative IOL position and distance from the lens remained stable during the follow-up period. Conclusion Posterior chamber phakic refractive lens implantation for high myopia is a precise and safe procedure with good predictability.