Macular thickness as a predictor of loss of visual sensitivity in ethambutol-induced optic neuropathy

Ethambutol is a common cause of drug-related optic neuropathy.Prediction of the onset of ethambutol-induced optic neuropathy and consequent drug withdrawal may be an effective method to stop visual loss.Previous studies have shown that structural injury to the optic nerve occurred earlier than the damage to visual function.Therefore,we decided to detect structural biomarkers marking visual field loss in early stage ethambutol-induced optic neuropathy.The thickness of peripapillary retinal nerve fiber layer,macular thickness and visual sensitivity loss would be observed in 11 ethambutol-induced optic neuropathy patients（22 eyes） using optical coherence tomography.Twenty-four healthy age-and sex-matched participants（48 eyes） were used as controls.Results demonstrated that the temporal peripapillary retinal nerve fiber layer thickness and average macular thickness were thinner in patients with ethambutol-induced optic neuropathy compared with healthy controls.The average macular thickness was strongly positively correlated with central visual sensitivity loss（r2=0.878,P=0.000）.These findings suggest that optical coherence tomography can be used to efficiently screen patients.Macular thickness loss could be a potential factor for predicting the onset of ethambutol-induced optic neuropathy.

Comparison and interchangeability of macular thickness measured with Cirrus OCT and Stratus OCT in myopic eyes

AIMTo investigate the difference of macular thickness measurements between stratus optical coherence tomography (OCT) and Cirrus OCT (Carl Zeiss Meditec, Dublin, CA, USA) in the same myopic patient and to develop a conversion equation to interchange macular thickness obtained with these two OCT devices.METHODSEighty-nine healthy Chinese adults with spherical equivalent (SE) ranging from -1.13 D to -9.63 D were recruited. The macular thickness was measured by Cirrus OCT and Stratus OCT. The correlation between macular thickness and axial length and the agreement between two OCT measurements were evaluated. A formula was generated to interchange macular thickness obtained with two OCT devices.RESULTSAverage macular thickness measured with Stratus OCT (r=-0.280, P=0.008) and Cirrus OCT (r=-0.224, P=0.034) were found to be negatively correlated with axial length. No statistically significant correlation was found between axial length and central subfield macular thickness (CMT) measured with Stratus OCT (r=0.191, P=0.073) and Cirrus OCT (r=0.169, P=0.113). The mean CMT measured with Cirrus OCT was 53.63±7.94 µm thicker than with Stratus OCT. The formula CMTCirrus OCT=78.328+0.874×CMTStratus OCT was generated to interchange macular thickness obtained with two OCT devices.CONCLUSIONMacular thickness measured with Cirrus OCT were thicker than with Stratus OCT in myopic eyes. A formula can be used to interchange macular thickness measured with two OCT devices in myopic eyes. Studies with different OCT devices and larger samples are warranted to enable the comparison of macular values measured with different OCT devices.

Comparison of retinal nerve fiber layer and macular thickness measurements with Stratus OCT and OPKO/OTI OCT devices in healthy subjects

AIM: To compare retinal nerve fiber layer(RNFL) and macular thickness measurements obtained with the Stratus optical coherence tomography(OCT) and OPKO/OTI OCT devices.METHODS: Included in the study were 59 eyes of 30 participants. All measurements for each eye were done on the same day with both devices. Student’s paired t-tests were used to compare the central macular thickness and RNFL measurements of the Stratus OCT and OPKO/OTI OCT. Pearson correlation was used to assess the relationship between the devices. Coefficient of variation(COV) was calculated to assess intersession repeatability.RESULTS: Using both the Stratus OCT and OPKO/OTI OCT, respectively, the measured mean average RNFL thicknesses were 98.9±11.1 μm and 115.1±9.6 μm(P =0.001),and the measured mean central retinal thicknesses(CRT)were 196.2 ±18.8 μm and 204.5 ±21.1 μm(P 【0.001).Measured by the two devices, the RNFL thickness values were correlated in all quadrants, as were the retinal thickness values except the inferior outer sector. COV for average RNFL and CRT thickness were 2.9% and 4.6%for Stratus OCT, and 2.1% and 4.2% for OPKO/OTI OCT,respectively.CONCLUSION: We found good reproducibility of RNFL and retina thickness measurements for both Stratus OCT and OPKO/OTI OCT devices. However, even though the two OCT systems provided statistically correlated results,the values for both RNFL and macular thickness were statistically different. RNFL and macular thickness measurements with the OPKO/OTI OCT were higher than that of the Stratus OCT; therefore, the two OCT systems cannot be used interchangeably for the measurements of RNFL and macular thickness.

Comparison of central macular thickness between two spectral-domain optical coherence tomography in elderly non-mydriatic eyes

AIM: To compare central macular thickness (CMT) measurements obtained by two spectral-domain optical coherence tomography (SD-OCT) exams, and to evaluate measurement reproducibility and agreement between these two exams, and to investigate the relationship between CMT and possible influencing factors such as age, sex, eye (OD/OS), and operators in elderly non-mydriatic eyes. METHODS: Seventy-two normal subjects were included. Every subject underwent CMT measurement twice using one of two SD-OCT (OSE-2000, Moptim, Shenzhen, China & 3-D OCT-1000, Topcon, Tokyo, Japan) instruments respectively where we randomly chose one eye in each patient for the test; these exams were performed by two operators over an hour period with a brief rest between sessions. Comparison of the OSE-2000 and 3-D OCT-1000 CMT measurements was based on paired- t test The mean difference between the CMT measurements was calculated. General linear model analyzed the relationships among eye (OD/OS), operator, sex, and CMT values using age as co-variant. All tests were considered statistically significant at P <0.05. The main outcome measures included CMT. RESULTS: When evaluated with general linear model analysis, CMT measurements were found to have high reproducibility across the two instruments between the two operators for the OSE-2000 single line scan and 3-D OCT-1000 macular scans (P=0.731; P=0.443). There was statistically significant difference in CMT values between the two instruments (P<0.001) and the mean difference was -46.83 mu m at 95% confidence limits (-49.15,-44.51). Age was positively correlated with CMT (beta coefficient =0.516, P=0.001; beta coefficient=0.453, P =0.009) and sex was correlated with CMT from the OSE-2000 (P=0.021) but not with the 3-D OCT-1000 (P=0.056). According to the actual thickness measurements, the CMT of the male was thicker than the female's but there was no statistical difference. There was interaction between sex and eye in OSE-2000 and not in 3-D OCT-1000 (P=0.02; P =0.374). No significant correlation was found between CMT and the influencing factor of eye in both of the instruments (P=0.884; P=0.492). CONCLUSION: Reproducibility of CMT measurement using the two SD-OCTs is excellent in normal eyes according to the operator factor analysis. OSE-2000 has a different posterior retinal boundary of CMT measurement, which results in the CMT value differences, compared with the 3-D OCT-1000. Age is positively correlated with CMT measurement while sex is correlated with CMT in the OSE-2000 but not in the 3-D OCT-1000 and eye (OD/OS) had no correlation with CMT values. Mydriatic drops may not be necessary for CMT measurement using high scan rate SD-OCT in normal eyes in dark room.

Changes in macular thickness following glaucoma surgery

Dear Sir,Previous reports have illustrated reversible structural changes in optic disc cupping,the lamina cribrosa,and the retinal nerve fiber layer(RNFL)following glaucoma surgery[1-3].However,few studies have assessed changes in macular thickness following such intervention.Our aim was to investigate the impact of intraocular pressure(IOP)reduction after glaucoma surgery on total macular thickness

Macular Thickness by Optical Coherence Tomography in Normal Togolese Melanoderma Subjects: A Case Study of 338 Eyes

Objective: Maculopathies are more and more frequent. For the follow-up of its evolution and therapy, it seems important for us to determine the baseline in normal subjects by Optical Coherence Tomography (OCT). The goal here is to determine the acceptable range of macular thickness in normal black subjects in Lomé. Methodology: This is a retrospective study over a 6-month period. It did not include all patients with retinopathy of any cause, maculopathy, and glaucoma. The analyzed variables were the average macular thickness, the central macular thickness, and the total macular volume. Results: Out of the 433 macular OCT performed, 191 patients were selected;a total of 338 eyes. These included 96 men and 95 women. A sex ratio was 1.01. The median age was 44.1 years with extremes ranging from 10 to 70 years. The average macular thickness was 263.4 μm for the right eye and 263.7 μm for the left eye. The central macular thickness was 174.1 μm for the right eye and 173.3 μm for the left eye. The total macular volume was 7.4 in both eyes. Discussion: No significant statistical difference existed between the two sexes. The average macular thickness found in this study was within the range of normality observed in the literature, which is between 216 and 288 μm. Conclusion: The average macular thickness of the normal subject in Lomé was 263.4 μm.

Non-linear relationship between age and subfoveal choroidal thickness in Chinese patients with proliferative diabetic retinopathy

BACKGROUND No study has investigated the change regularity between age and subfoveal choroidal thickness(SFCT)in proliferative diabetic retinopathy(PDR).AIM To investigate the relationship between the SFCT and age in Chinese patients with PDR.METHODS This was a cross-sectional retrospective study.The participants were hospitalized individuals with type 2 diabetes who underwent vitrectomy for PDR.Contralateral eyes that met the criteria were included in the study.All necessary laboratory tests were performed at the time of admission.Central macular thickness(CMT)and SFCT were two quantitative assessments made using enhanced depth imaging optical coherence tomography.CMT was measured automatically and SFCT was measured manually with digital calipers provided by the Heidelberg Eye Explorer software.RESULTS The final analysis included a total of 234 individuals with PDR.The average age was 55.60 years old±10.03 years old,and 57.69%of the population was male.Univariate analysis revealed a significant negative connection between age and SFCT in patients with PDR[β=-2.44,95%confidence interval(95%CI):-3.46 to-1.42;P<0.0001].In the fully adjusted model,the correlation between SFCT and age remained steady(β=-1.68,95%CI:-2.97 to-0.39;P=0.0117).Spline smoothing showed that the relationship between SFCT and age in patients with PDR was non-linear,with an inflection point at 54 years of age.CONCLUSION Our findings suggest that age is a key determinant of choroidal thickness.The non-linear link between SFCT and age in PDR patients should be taken into account.

Effects of vitrectomy combined with internal limiting membrane peeling in patients with diabetic macular edema

BACKGROUND Diabetic macular edema(DME),a chronic microvascular complication of diabetes,is a leading cause of visual impairment and blindness.Pars plana vitrectomy(PPV)can restore the normal macular structure and reduce macular edema,whereas internal limiting membrane(ILM)peeling is used to treat tractional macular diseases.Despite the advantages,there is limited research on the combined effects of PPV with ILM peeling.AIM To observe the effects of PPV combined with ILM peeling on postoperative central macular thickness(CMT),best-corrected visual acuity(BCVA),cystoid macular edema(CME)volume,and complications in patients with DME.METHODS Eighty-one patients(92 eyes)diagnosed with DME at the Beijing Shanqu Liangxiang Hospital between January and December 2022 were randomly divided to undergo PPV alone(control group:41 patients,47 eyes)or PPV+ILM peeling(stripping group:40 patients,45 eyes);a single surgeon performed all surgeries.The two groups were compared preoperatively and 1 and 3 months postoperatively.RESULTS Preoperatively,both groups had comparable values of CMT,BCVA,and CME volume(P>0.05).After surgery(both 1 and 3 months),both groups showed significant reductions in CMT,BCVA,and CME volume compared to preoperative levels,with the stripping group showing more significant reductions compared to the control group(P<0.05).Further repeated-measures ANOVA analysis for within-group differences revealed significant effects of group and time,and interaction effects for CMT,BCVA,and CME volume(P<0.05).There were no significant differences in the incidence of complications between the groups(retinal detachment:control=2,stripping=1;endophthalmitis:Control=4,stripping=1;no cases of secondary glaucoma or macular holes;χ^(2)=0.296,P=0.587).CONCLUSION PPV with ILM peeling can significantly improve the visual acuity of patients with DME,reduce CMT,and improve CME with fewer complications.

Anti-vascular endothelial growth factor drugs combined with laser photocoagulation maintain retinal ganglion cell integrity in patients with diabetic macular edema: study protocol for a prospective, non-randomized, controlled clinical trial

The integrity of retinal ganglion cells is tightly associated with diabetic macular degeneration that leads to damage and death of retinal ganglion cells,affecting vision.The major clinical treatments for diabetic macular edema are anti-vascular endothelial growth factor drugs and laser photocoagulation.However,although the macular thickness can be normalized with each of these two therapies used alone,the vision does not improve in many patients.This might result from the incomplete recovery of retinal ganglion cell injury.Therefore,a prospective,non-randomized,controlled clinical trial was designed to investigate the effect of anti-vascular endothelial growth factor drugs combined with laser photocoagulation on the integrity of retinal ganglion cells in patients with diabetic macular edema and its relationship with vision recovery.In this trial,150 patients with diabetic macular edema will be equally divided into three groups according to therapeutic methods,followed by treatment with anti-vascular endothelial growth factor drugs,laser photocoagulation therapy,and their combination.All patients will be followed up for 12 months.The primary outcome measure is retinal ganglion cell-inner plexiform layer thickness at 12 months after treatment.The secondary outcome measures include retinal ganglion cell-inner plexiform layer thickness before and 1,3,6,and 9 months after treatment,retinal nerve fiber layer thickness,best-corrected visual acuity,macular area thickness,and choroidal thickness before and 1,3,6,9,and 12 months after treatment.Safety measure is the incidence of adverse events at 1,3,6,9,and 12 months after treatment.The study protocol hopes to validate the better efficacy and safety of the combined treatment in patients with diabetic macula compared with the other two monotherapies alone during the 12-month follow-up period.The trial is designed to focus on clarifying the time-effect relationship between imaging measures related to the integrity of retinal ganglion cells and best-corrected visual acuity.The trial protocol was approved by the Medical Ethics Committee of the Affiliated Hospital of Beihua University with approval No.(2023)(26)on April 25,2023,and was registered with the Chinese Clinical Trial Registry(registration number:ChiCTR2300072478,June 14,2023,protocol version:2.0).

Macular and peripapillary retinal nerve fiber layer thickness in children with hyperopic anisometropic amblyopia

AIM:To compare the retinal nerve fiber layer (RNFL) thickness and macular thickness in the amblyopic eye with that in the sound eye of children with hyperopic anisometropic amblyopia using optical coherence tomography (OCT). METHODS:A prospective, nonrandom, intraindividual comparative cohort study includes 72 children with hyperopic anisometropic amblyopia in a single center. Macular thickness, macular foveola thickness, and peripapillary RNFL thickness were compared between the amblyopia eyes and the contralateral sound eyes. ·RESULTS:There were 38 male and 34 female patients, with a mean age as 9.7 ±1.9 years (range, 5-16 years). Hyperopic was +3.62±1.16D (range +2.00D to +6.50D) in the amblyopic eyes, which was significantly higher in the control eyes with +0.76±0.90D (range 0D to +2.00D) (P 【 0.01). The mean peripapillary RNFL thickness was 113.9± 7.2μm and 109.2 ±6.9μm in the amblyopic eye and the normal eye, respectively, reaching statistical significance (P = 0.02). The mean macular foveola thickness was significantly thicker in the amblyopic eyes than the contralateral sound eyes (181.4±14.2μm vs 175.2±13.3μm, P 【0.01), but the 1mm, 3mm or 6mm macular thickness central macular thickness was not significantly different. Degree of anisometropia in the contralateral eyes was not significantly correlated with differences of peripapillary RNFL, macular foveola thickness or central macular thickness. CONCLUSION:Eyes with hyperopic anisometropic amblyopia are found thicker macular foveola and peripapillary RNFL than the contralateral eyes in children.

Analysis of macular microvasculature and thickness after ICL implantation in patients with myopia using optical coherence tomography

AIM:To investigate changes in macular vessels and thickness in myopic eyes after intraocular collamer lens(ICL)implantation using quantitative optical coherence tomography angiography(OCTA).METHODS:This retrospective included 73 myopic eyes of 73 patients(average age,27.53±6.16 y)who underwent ICL implantation(28 eyes were Toric ICL).Axial length(AL),uncorrected visual acuity(UCVA),refractive dioptre(RD),intraocular pressure(IOP)and OCTA were measured and compared with before and 1 wk,1,and 3 mo after surgery.OCTA was used to image vessel density(VD)and skeleton density(SD)in both the superficial(SCP)and deep capillary plexus(DCP).Central retinal thickness(CRT)and ganglion cellinner plexiform layer thickness(GCT)were also measured.Changes between pre-and postoperative measurements were analysed by repeated measures analysis of variance.RESULTS:Compared with preoperative data,postoperative data on UCVA revealed significant improvements in all patients(P<0.05).However,there was no significant difference in IOP.After the operation,CRT and GCT exhibited significant changes(P<0.05).Among these measures,CRT was significantly higher at one and three months postoperative(all P<0.01).GCT was significantly higher at 1 wk,1,and 3 mo postoperative(all P<0.01).Changes in VD and SD were nonsignificant in both the SCP and DCP.There was no difference in postoperative changes between the ICL and Toric ICL groups.CONCLUSION:ICL and Toric ICL implantation both have good efficacy and safety for myopic eyes,but macular area changes that occur after surgery need attention.

Retinal thickness and vascular parameters using optical coherence tomography in Alzheimer's disease:a meta-analysis

Examining the retinal tissue has the potential to provide a unique method and technique to quantify Alzheimer’s disease-related changes in participants at various stages of the disease.In this metaanalysis,we aimed to investigate the association of various optical coherence tomography parameters with Alzheimer’s disease and whether retinal measurements can be used to diffe rentiate between Alzheimer’s disease and control subjects.Scientific databases including Google Schola r,Web of Science,and PubMed were systematically searched for published articles that evaluated retinal nerve fiber layer thickness and retinal microvascular network in Alzheimer’s disease and control subjects.Seventy-three studies(5850 participants,including 2249 Alzheimer’s disease patients and 3601controls) were included in this meta-analysis.Relative to controls,Alzheimer’s disease patients had a significantly lower global retinal nerve fiber layer thickness(standardized mean difference [SMD]=-0.79,95% confidence intervals [CI]:-1.03 to-0.54,P <0.00001) as well as each quadrant being thinner in Alzheimer’s disease versus controls.Regarding macular paramete rs,values measured by optical coherence tomography were significantly lower in Alzheimer’s disease than controls for macular thickness(pooled SMD:-0.44,95% CI:-0.67 to-0.20,P=0.0003),foveal thickness(pooled SMD=-0.39,95% CI:-0.58 to-0.19,P <0.0001),ganglion cell inner plexiform layer(SMD=-1.26,95% CI:-2.24 to-0.27,P=0.01) and macular volume(pooled SMD=-0.41,95% CI-0.76 to-0.07,P=0.02).Analysis using optical coherence tomography angiography parameters revealed mixed results between Alzheimer’s disease and controls.Superficial vessel density(pooled SMD=-0.42,95% CI:-0.68 to-0.17,P=0.0001) and deep vessel density(pooled SMD=-0.46,95% CI:-0.75 to-0.18,P=0.001) were found to be thinner in Alzheimer’s disease patients whereas the foveal avascular zone(SMD=0.84,95% CI:0.17-1.51,P=0.01) was larger in controls.Vascular density and thickness of various retinal laye rs were decreased in Alzheimer’s disease patients compared to controls.Our results provide evidence for optical coherence tomography technology having the potential to detect retinal and microvascular changes in patients diagnosed with Alzheimer’s disease and aid in monito ring and early diagnosis methods.

Three-dimensional diabetic macular edema thickness maps based on fluid segmentation and fovea detection using deep learning

AIM: To explore a more accurate quantifying diagnosis method of diabetic macular edema(DME) by displaying detailed 3D morphometry beyond the gold-standard quantification indicator-central retinal thickness(CRT) and apply it in follow-up of DME patients.METHODS: Optical coherence tomography(OCT) scans of 229 eyes from 160 patients were collected.We manually annotated cystoid macular edema(CME), subretinal fluid(SRF) and fovea as ground truths.Deep convolution neural networks(DCNNs) were constructed including U-Net, sASPP, HRNetV2-W48, and HRNetV2-W48+Object-Contextual Representation(OCR) for fluid(CME+SRF) segmentation and fovea detection respectively, based on which the thickness maps of CME, SRF and retina were generated and divided by Early Treatment Diabetic Retinopathy Study(ETDRS) grid.RESULTS: In fluid segmentation, with the best DCNN constructed and loss function, the dice similarity coefficients(DSC) of segmentation reached 0.78(CME), 0.82(SRF), and 0.95(retina).In fovea detection, the average deviation between the predicted fovea and the ground truth reached 145.7±117.8 μm.The generated macular edema thickness maps are able to discover center-involved DME by intuitive morphometry and fluid volume, which is ignored by the traditional definition of CRT>250 μm.Thickness maps could also help to discover fluid above or below the fovea center ignored or underestimated by a single OCT B-scan.CONCLUSION: Compared to the traditional unidimensional indicator-CRT, 3D macular edema thickness maps are able to display more intuitive morphometry and detailed statistics of DME, supporting more accurate diagnoses and follow-up of DME patients.

Comment on “The diurnal variation pattern of choroidal thickness in macular region of young healthy female individuals using spectral domain optical coherence tomography”

Dear Editor,We have read and reviewed the article entitled＂The diurnal variation pattern of choroidal thickness in macular region of young healthy female individuals using spectral domain optical coherence tomography＂by Zhao et al^（[1]）with great interest.

Impact of topical nonsteroidal anti-inflammatory drugs in prevention of macular edema following cataract surgery in diabetic patients

AIM： To evaluate the efficacy of prophylactic administration of topical non-steroidal anti-inflammatory drugs（NSAIDs） on macular edema following cataract surgery in diabetic patients, and to compare between types of NSAIDs（ketorolac tromethamine 0.4% and nepafenac 0.1%）. METHODS： Group 1（control） received artificial tears substitute as a placebo group, group 2（nepafenac） received topical nepafenac 0.1%, and group 3（ketorolac） received topical ketorolac tromethamine 0.4%. Patients were examined postoperatively after completing one week, one month, two months and three months＇ intervals for evaluating cystoid macular edema（CME） development. The main study outcomes were achieving the best corrected visual acuity（BCVA） and change in the central macular thickness（CMT） measured with optical coherence topography（OCT）.RESULTS： Eighty eyes of 76 patients were included in this study. BCVA showed a statistically significant difference at the third month postoperative follow up between the control group and the NSAIDs groups（P=0.04）. There was an increase in the CMT in all cases starting from postoperative first week until third month. CMT showed a statistically significant difference between control group and NSAIDs groups from postoperative first month until third month（P=0.008, 0.027, 0.004）. There was no statistically significant difference between nepafenac and ketorolac groups in BCVA and OCT CMT. CONCLUSION： Prophylactic preoperative and postoperative NSAIDs may have a role in reducing the frequency and severity of CME in diabetic eyes following cataract surgery.

Intraocular retinal thickness asymmetry in early stage of primary open angle glaucoma and normal tension glaucoma

AIM： To investigate the intraocular retinal thickness asymmetry of peripapillary retinal nerve fiber layer（pR NFL） and macular layers measured by spectral-domain optical coherence tomography（SD-OCT） in patients with early stage of primary open angle glaucoma（POAG） and normal tension glaucoma（NTG）.METHODS： A total of 117 patients with early stage of glaucoma（54 patients with POAG and 63 patients with NTG） and 32 normal subjects were recruited for the study. The pR NFL thickness, total macular layer（TML） thickness, and isolated inner macular layer（IML） thickness were measured by SD-OCT. Hemisphere TML thickness asymmetry measured by the posterior pole asymmetry scan was evaluated. Thickness differences of pR NFL and IML between superior and inferior quadrants were calculated. Asymmetry indices（AIs） of the p RNFL, TML and isolated IML were also computed. Areas under the receiver-operating characteristic curves（AROCs） were generated to determine the diagnostic capabilities of different parameters. RESULTS： Intraocular p RNFL thickness differences and AIs between the superior and inferior quadrants were significantly different between normal and NTG groups（P=0.009 and P〈0.001, respectively）. Intraocular p RNFL thickness differences and AIs between the temporal-superior and temporal-inferior sectors were also significantly different between normal and NTG groups（P=0.035 and P〈0.001, respectively）. The thickness differences and AIs of TML between superior and inferior hemispheres were significantly different between normal and NTG groups（P=0.001 and P=0.001, respectively） and between normal and POAG groups（P=0.032 and P=0.020, respectively）. The thickness differences and AIs of macular ganglion cell layer（mG CL） between superior and inferior quadrants were significantly different between normal and NTG groups（P=0.013 and P=0.004, respectively）, and between NTG and POAG groups（P=0.015 and P=0.012, respectively）. The thickness difference of TML between superior and inferior hemispheres showed the highest diagnostic capability for early NTG eyes（AROC=0.832）.CONCLUSION： Intraocular retinal thickness asymmetry in pR NFL, TML and mG CL are found in early stage of NTG. Hemisphere TML thickness asymmetry is also found in POAG eyes. Asymmetry analysis of retinal thickness can be an adjunctive modality for early detection of glaucoma.

Efficacy of Alzer^®and Diamel, Nutritional Supplements, in the Prevention of Severe Diabetic Macular Edema

Introduction: Macular edema is the main cause of low vision in diabetic patients. Laser photocoagulation continues to be the treatment of choice in conjunction with the use of steroids and anti-angiogenics, but these treatments include possible ocular complications. The nutritional supplement Alzer (whose primary active ingredient is Ginkgo biloba, a powerful antioxidant that acts on vascular factors and oxidative damage, which are two of the mechanisms implicated in the pathogenesis of diabetic macular edema), which has been used on other non-diabetic macular conditions, along with the Diamel nutritional supplement has been shown to be effective on glycemic control and could represent a treatment alternative for mild to moderate macular edema by reducing the thickness of the macular retina and preventing the progression of other more advanced clinical presentations that are harder to treat. Objective: Identify the effect of Alzer along with Diamel in reduction of the thickness of the macular retina among patients with mild to moderate diabetic macular edema. Materials and Methods: A phase II double-blind clinical trial was conducted in 64 patients with non-severe diabetic macular edema over the course of non-proliferative diabetic retinopathy, who attended the ophthalmology service of the Institute of Endocrinology of Havana from January 2016 to December 2016. The treatment was randomly assigned to two groups: one received Alzer plus Diamel (n = 32) and the other group received Alzer placebo + Diamel placebo (n = 32). All patients were given an initial clinical evaluation, blood testing and ophthalmological evaluation at the start of treatment and after one year of follow-up. Results: There was a clinical improvement in the macular thickness upon the conclusion of the study in the patients treated with Alzer and Diamel. This decrease in thickness was statistically significant in the left eye. There was no decrease in visual acuity one year after treatment. Adverse events were mild and uncommon. Conclusions: Severe macular edema did not evolve in the Alzer and Diamel group. The clinical, but not statistically significant, success obtained in the experimental group proves the protocol hypothesis regarding the efficacy of the product being researched. The positive results in this small sample lead to the suggestion of performing larger-scale studies (Phase III). The clinical trial was registered in Clinical Trials.gov Identifier: NCT03533478.

Macular changes of neuromyelitis optica through spectral-domain optical coherence tomography

AIM： To evaluate the thickness of the retinal layers in the macula using spectral-domain optical coherence tomography（SD-OCT） in patients with neuromyelitis optica（NMO）. METHODS： Spectralis SD-OCT, utilizing automated macular layer segmentation, was performed in 26 NMO patients and 26 healthy controls. Visual function including visual field tests and pattern visual evoked potential were recorded in study subjects.RESULTS： Forty-one eyes from 26 NMO patients and52 eyes from 26 age- and sex-matched healthy controls were included. Besides total macular volume, peri-paipillary retinal nerve fiber layer（RNFL） thickness, the thickness of macular RNFL, ganglion cell layer（GCL） and inner plexiform layer（IPL） were also significantly reduced in NMO patients compared to those inhealthy controls（P 〈0.000）. No differences were found in the thickness of macular inner nuclear layer（INL）, outer plexiform layer（OPL）, and outer nuclear layer（ONL） between the two groups. Reversely, the outer retinal layer（ORL） was shown to be thicker in NMO than controls（P 〈0.05）.Compared with the peri-papillary RNFL thickness, the GCL thickness was demonstrated to correlate with visual function better.CONCLUSION： The study provides in vivo evidence of retinal neural loss in NMO patients and demonstrates abetter structure-function correlation between retinal ganglion cell and visual function than peri-papillary RNFL does. In addition, no evidence of primary neural damage is found. Besides, the photoreceptor cells and retinal pigments epithelial（RPE） cells presumably proliferated in compensation in NMO after retinal neural loss.

Parameters of ocular fundus on spectral-domain optical coherence tomography for glaucoma diagnosis

In this review, we summarize the progression of several parameters assessed by spectral-domain optical coherence tomography （SD-OCT） in recent years for the detection of glaucoma. Monitoring the progression of defects in the retinal nerve fiber layer （RNFL） thickness is essential. Imaging and analysis of retinal ganglion cells （RGCs） and inner plexiform layer （IPL）, respectively, have been of great importance. Optic nerve head （ONH） topography obtained from 3D SD-OCT images is another crucial step. Other important assessments involve locating the Bruch＇s membrane opening （BMO）, estimating the optic disc size and rim area, and measuring the lamina cribrosa displacement. Still other parameters found in the past three years for glaucoma diagnosis comprise central retinal artery resistive index, optic disc perfusion in optical coherence tomography angiography （OCTA） study, peripapillary choroidal thickness, and choroidal area in SD-OCT. Recently, several more ocular fundus parameters have been found, and compared with the earlier parameters to judge the accuracy of diagnosis. While a few of these parameters have been widely used in clinical practice, a fair number are still in the experimental stage.

Long-term clinical effects of intravitreal injections of conbercept for the treatment of choroidal neovascularization in patients with pathological myopia

AIM:To observe the long-term clinical efficacy of intravitreal injections of conbercept,a novel vascular growth factor inhibitor,for the treatment of pathological myopia choroidal neovascularization(PM-CNV).METHODS:A total of 67 eyes(from 67 patients;mean age,54.90±12.7y)with PM-CNV were retrospectively researched.Based on the different schemes used for the administration of the drug,the patients were divided into two groups:group A(n=35;average age,53.31±13.6y;average diopter,9.25±1.72 D),which received only one injection of pro re nata(PRN;1+PRN regimen),and group B(n=32;average age,56.49±11.8y;average diopter,9.63±2.24 D),which received one injection per month for 3mo(3+PRN regimen).Best-corrected visual acuity(BCVA)analysis,intraocular pressure(IOP)examination,slit-lamp microscopy,fundus examination and optical coherence tomography were per formed at each follow-up.The recurrence and treatment times of CNV were recorded.The patients were followed up for at least 12mo.RESULTS:The BCVA was increased in 29 eyes(82.9%)in group A and 30 eyes(93.75%)in group B;no increase or decrease was observed in 6(17.1%)and 2(6.25%)eyes in groups A and B,respectively.The BCVA(log MAR)values before treatment(0.67±0.48 and 0.71±0.56)were significantly higher than those 12mo after treatment(0.31±0.26 and 0.33±0.17)in groups A and B,respectively(P<0.05).The mean central macular thickness(CMT)values had significantly decreased from 346.49±65.99 and 360.10±82.31μm at baseline to 257.29±40.47 and 251.97±48.26μm in groups A and B,respectively,after 12mo of treatment.A total of 21 eyes in group A needed reinjection(60%;average number of injections,2.51±0.98);the corresponding values in group B were 6 eyes(18.75%;average number of injections,3.74±1.22).There were no adverse ocular and systemic complications during the treatment and follow-up.CONCLUSION:Intravitreal injection of conbercept with 1+PRN or 3+PRN improve the visual acuity,reduce macular edema and reduce the level of CMT in patients with PM-CNV.The 3+PRN regimen demonstrates a lower recurrence rate of CNV than the 1+PRN regimen,but requires more treatment.However,both treatment regimens demonstrate long-term safety and efficacy for the treatment of PM-CNV.