AIM: To study the changes in choroidal thickness in central serous chorioretinopathy(CSCR)over a 3mo follow-up using spectral domain optical coherence tomography(SD-OCT).

METHODS: This prospective study included 60 eyes, both eyes of 20 patients(mean age: 33.65±5.24 years)with classic acute unilateral central serous chorioretinopathy and normal fellow eye and 20 eyes as healthy controls. Fluorescein angiography and OCT were done. The subfoveal choroidal thickness(SFCT), central macular thickness(CMT), 1000 μm temporal and nasal to the centre of the fovea and the subretinal fluid were measured.

RESULTS: There was a statistically significant difference in SFCT among the three groups at the three different locations. SFCT in eyes with CSCR(372.40±34.39 μm)was significantly greater than that in each of the unaffected fellow eyes(302.10±8.9 μm)and control eyes(279.80±14.49 μm)at the base line and after 3mo follow-up. The mean CMT in CSCR was 317±141.86 μm, with a statistically significant positive correlation between SFCT and CMT.

CONCLUSION: The increase in the choroidal thickness at different locations as well as hyper-dilated and hyper-permeable vessels known as “pachychoroid” seems to play an important role in a broad spectrum of diseases that includes central serous chorioretinopathy.

AIM: To compare the non-invasive tear film break-up time(NIBUT), tear break up time(TBUT), basal tear secretion(BTS)and blink rate in four ethnic groups: Malay, Chinese, Indian and Nigerian.

METHODS: Totally 120 healthy(61 males and 59 females)subjects(without dry eye symptoms and ocular surface disorder)with the age 20 to 39 years were recruited; 30 were Malays, 30 were Chinese, 31 were Indians and 29 were Nigerians. Based on McMonnies questionnaire and clinical examination, normal subjects were selected. NIBUT, TBUT, BTS were assessed in only one eye(right)of each subject and blink rate was also assessed.

RESULTS: There was significant difference in the NIBUT, TBUT, BTS and blink rate among 4 different ethnic groups(P=0.018),(P=0.001),(P=0.011), and(P=0.004)respectively. No statistically significant difference of NIBUT, TBUT, BTS and blink rate was found between the genders among different ethnic groups. Indian had higher median for NIBUT(10±6s), TBUT(7±5s)and BTS(20±20 mm)than others races. Chinese had lower median for NIBUT(7.5±4s)and TBUT(4±2s)while Malay had low BTS(9.5±16 mm)among the groups. There was no significant correlation of blink rate with NIBUT, TBUT and BTS(r= -0.119, P=0.195),(r=-0.086, P=0.352),(r= -0.123, P=0.180)respectively.

CONCLUSION: This study showed the variability in tear-film measurements values in four ethnic groups.

AIM: To investigate the feasibility of constructing corneal stromal scaffolds and the optimal preservation conditions of corneal stromal lenses obtained from the small incision lenticule extraction(Smile)surgery.

METHODS: Constructing a bilayer lens by adhering together two corneal stromal lenses with human fibrin sealant(FS). Human corneal fibroblasts were isolated and cultured from Smile derived corneal stromal lenses in vitro, and the toxicity of FS on human corneal fibroblasts was detected by MTT method. The bilayer lenses were then placed in anhydrous glycerin, sodium hyaluronate eye drops, a simulated wet room environment and fetal bovine serum groups respectively, and stored at 4℃ for 14d. The transparency, hardness and stability of the scaffolds were then compared. Afterwards, the bilayer lens scaffolds were stored in anhydrous glycerin at room temperature, 4℃ and -20℃. After 14d of preservation, the diverse effects of temperature on the transparency and hardness of the scaffolds were compared.

RESULTS: MTT results showed that the cells of the experimental group and the control group had similar proliferation trend within 0-72h. The cytotoxicity rating of the experimental group was 0 at 36-48h and 1 at 24h and 60-72h. The relative survival rate of the cells within 0-72h was over 90%. FS-bonded bilayer lens scaffold had a smooth surface, close bonding, good transparency and suitable hardness. After 14d of storage at 4℃, none of the nine bilayer lens scaffolds in the anhydrous glycerol group showed signs of cracking cracking after rehydration, and their transparency was good. In the sodium hyaluronate group, three of the nine scaffolds cracked and the remaining six were still intact. In the simulated wet room environment group, none of the 9 scaffolds cracked, but there were different degrees of shrinkage, their surface was rough and transparency was lower. In the fetal bovine serum group, all the 9 stents were cracked, and the single corneal stromal lens was soft and edema was serious. Out of the 15 bilayer lens scaffolds preserved in anhydrous glycerol at room temperature, 2 remained colourless and transparent, 5 slightly yellowed but still remained transparent, 8 yellowed substantially with a significant reduction in transparency. Out of the 15 bilayer lens scaffolds preserved in anhydrous glycerol at 4℃, 5 remained colourless and transparent, and 10 slightly yellowed while remaining transparent. Of the 15 bilayer lens scaffolds preserved in anhydrous glycerol at -20℃, none of the scaffolds yellowed, therefore, remaining colourless and transparent.

CONCLUSION: FS is a safe and non-toxic bio-gel. It can be used to glue Smile-derived corneal stromal lenses to construct corneal stromal scaffolds with good stability, high transparency and suitable hardness. Anhydrous glycerol at -20℃ is the best preservation condition for corneal stromal lens scaffolds.

AIM: To investigate the temperary changes in the refraction, axial length, and choroidal thickness after a Chinese herb(Zhujing formula)feeding or injection of ranibizumab in a guinea pig myopia model.

METHODS: A Guinea pigs model of form-deprived(FD)myopia were randomly divided into 3 groups: Zhujing formula group, ranibizumab group and saline group(n=20 for each group). Zhujing formula group were fed daily with Zhujing formula solution 3.285g/(kg·d)(1.5mL/d)for 1wk. Ranibizumab group were treated with(intravitreal injections of 0.02mg)ranibizumab at the first day. Saline group were fed with 1.5mL 0.9% saline at the first day. The refraction(Diopter), axial length and choroidal thickness were measured before and at day 1, 3 and 7d postoperative.

RESULTS: The spherical equivalent(SE), axial length and choroidal thickness in ranibizumab group showed no significant trend after intravitreal injection(P>0.05). However, SE and axial length showed trendency to greater myopic shift in the Zhujing formula group and the saline group(P<0.05). The effect began to appear on the first day after administration, achieved the maximum effect after 3d, and faded completely until 7d. On the first day after administration, the diopter and the axial length in ranibizumab group showed the lowest among three groups(P<0.05), and choroid thickness showed the thickest among three groups(P<0.05). At 3d after administration, the diopter and the axial length in the saline group showed the lowest among three groups, and choroid thickness showed the thickest among three groups(P<0.05). There was no significant difference in the parameters among the three groups at 1wk after administration(P>0.05).

CONCLUSION: There is a temperary choroidal thickening of the form deprivation myopia recovery period. The ranibizumab inhibited the thickening of the choroid in the whole recovery period of form deprivation myopia, Zhujing formula slight inhibited the thickening at 3d, and the all change persisted only for 1wk.

AIM: To compare the differences of CP-RNFL, optic nerve head(ONH)and macular parameters between ocular hypertension(OHT)patients with different central corneal thickness(CCT)and normal subjects using three dimensional optical coherence tomography(3D-OCT).

METHODS: This is a prospective study including 124 eyes of 77 OHT patients classified as group 1(CCT<555μm)including 38 eyes of 25 patients, group 2(CCT 555-590μm)including 44 eyes of 26 patients and group 3(CCT>590μm)including 42 eyes of 26 patients according to CCT. Totally 124 eyes of 77 normal healthy subjects, matching patients with age and gender, were divided into group four. The CP-RNFL thickness,optic nerve head and macular parameters were measured by 3D-OCT. There were no significant difference in gender, age between four groups and in intraocular pressure among three OHT patients groups.

RESULTS: The optic rim area was significantly smaller in group one than in other three groups, and the thickness of inferior CP-RNFL was significantly thinner than group two and group three, while the thickness of the temporal inner ring of macular was thinner than group three. All the thickness of the central fovea, macular center 1mm, the temporal inner ring of macular in OHT patients were significantly thinner than healthy subjects. The CCT and the rim area in OHT patients were significantly positively correlated.

CONCLUSION: The OHT patients are considered to be different from normal persons in optic nerve head and macular parameters though the parameters are still in normal range. CCT<555μm may be a risk factor of OHT patients converting to POAG, so we should pay more attention to following up these patients and intervention in time.

AIM: To compare the clinical effects and safety of single subthreshold micropulse(STMP)yellow laser and combined ranibizumab intravitreal injection on the treatment of diabetic macular edema(DME).

METHODS: Totally 33 patients(58 eyes)with DME were divided into two groups. Group A(laser group)received STMP yellow laser, and group B(combined treatment group)received ranibizumab intravitreal injection combined with STMP yellow laser. The best corrected visual acuity(BCVA), intraocular pressure(IOP), central macular thickness(CMT), total macular volume(TMV), fluorescein fundus angiography(FFA), multifocal ERG(MERG), autofluorescence(AF)and macular pigment optical density(MPOD)were compared before and after the treatments. And treatment times were counted.

RESULTS:Compared with those before treatment, there were significant differences in BCVA and TMV 6, 9, 12mo after treatment in the laser group(P<0.05). And there were significant differences in BCVA and TMV 3, 6, 9, 12mo after treatment in the combined treatment group(P<0.05). For both groups, there were significant differences in CMT before and 3, 6, 9, 12mo after treatment(P<0.01). Compared with the P1 amplitude of MEG, Max OD and Mean OD before treatment, there were significant differences for the two groups 12mo after treatment(P<0.01). And the differences were significant in TMV and P1 amplitudes between the two groups after 12mo of treatment(P<0.01). During the follow-up period, the laser times was 3.32±1.09 in the laser group and 3.30±1.18 in the combined treatment group(P=0.943).

CONCLUSION:Both single STMP laser and combined with intravitreal injection of ranibizumab can effectively reduce macular edema, improve vision and safety in DME patients. And the combined treatment group has faster and better effect.

AIM: To investigate the clinical effects of laser photocoagulation combined with anti-vascular endothelial growth factor(VEGF)drugs at different time in the treatment of diabetic retinopathy(DR).

METHODS: A prospective study was conducted. Totally 120 patients(191 diseased eyes)with DR who were admitted to the hospital between January 2018 and January 2019 were divided into group A(treated with simple laser photocoagulation, 30 cases, 44 diseased eyes), group B(treated with intravitreal injection of ranibizumab, 30 cases, 46 diseased eyes), group C(treated with intravitreal injection of ranibizumab after laser photocoagulation, 30 cases, 49 diseased eyes)and group D(treated with laser photocoagulation after intravitreal injection of ranibizumab, 30 cases, 52 diseased eyes). Patients in each group were followed up for 6mo after the end of treatment. The best corrected visual acuity(BCVA), intraocular pressure and central foveal thickness(CMT)of each group were compared before and after treatment. The situation of laser photocoagulation and anti-VEGF treatment, complications and recurrence of diabetic macular edema were observed.

RESULTS: There was no significant difference in BCVA or CMT among the four groups before treatment(P>0.05). The two indexes were improved at 1wk, 1mo, 3mo and 6mo after treatment(P<0.05). Besides, they were better in group C and group D than in group A and group B at different time after treatment(P<0.05). The BCVA and CMT in group D were better than those in group C at 1wk, 1mo and 3mo after surgery(P<0.05). There was no significant difference in intraocular pressure among the four groups before or after treatment(P>0.05). The laser parameters and frequency of laser treatment were lower or fewer in group C and group D than in group A, and lower in group D than in group C(P<0.05). The frequencies of intravitreal injection in group C and group D were fewer than that in group B(P<0.05). There was no significant difference in the frequency of laser treatment or drug injection between groups C and group D(P>0.05). There was no significant difference in the incidence of complications or the incidence of diabetic macular edema among the four groups during follow up(P>0.05).

CONCLUSION: The effect of laser photocoagulation after intravitreal injection of anti-VEGF drug is better than simple photocoagulation, simple intravitreal injection or intravitreal injection of ranibizumab after laser photocoagulation in the treatment of DR. It can improve the BCVA, relieve macular edema, reduce laser energy, frequency of laser treatment and injection frequency of anti-VEGF drug, with safety.

With a new therapy of keratoconus in recent years-corneal cross-linking, the pediatric keratoconus have characterized by corneal dilatation, central thinning, protrusion and conical shape in the children' eyes. By analyzing the epidemiological characteristics of keratoconus and the current methods of treating pediatric keratcoconus, this paper discusses the role of different CXL protocols in the clinical application of pediatric keratcoconus, thus providing some help for the choice of clinical treatment methods.

Optical coherence tomography angiography(OCTA)is a rapid and non-invasive imaging tool, which can provide real-time flow imaging of retina and choroid. Compared with traditional angiography, OCTA can produce more detailed and high-resolution vascular images without increasing the risk due to contrast medium. Age-related macular degeneration(ARMD)is one of the major senile blinding eye diseases in the world, OCTA can well display the image of choroidal neovascularization and provide the possibility for early diagnosis and intervention. This review summarizes the OCTA image characteristics and clinical diagnostic value in patients with ARMD.

Retinitis pigmentosa(RP)was known as pigmentation retinitis even. RP is a group of hereditary eye diseases that cause irreversible visual impairment due to progressive loss of function of retinal pigment epithelial cells and progressive apoptosis of photoreceptors. Because of its heterogeneity in phenotype and heredity and complex pathogenesis, there is currently no single effective treatment. This article mainly elaborates on the progress in the treatment of retinitis pigmentosa in recent years.