Insight into small eyes: a practical description from phenotypes presentations to the management

This narrative review aimed to have an algorithmic approach to microphthalmos by a systematic search.The definition can be related to a number of special phenotypes.In the more challenging cases of complex microphthalmos,relative anterior microphthalmos,and nanophthalmos,the surgeon can approach these cases more safely if they have a deep understanding of the anatomical variations and ideal formulae for intraocular lens computation and knows how to avoid intra-and post-operative complications.In this article,we review the criteria by which we recognize and describe pre-,intra-,and post-operative considerations,as well as discuss the ideal intraocular lenses for microphthalmos,given the intricate varieties of small eye phenotypes.

Incidence and risk factors of retinopathy of prematurity and utility of the national screening criteria in a tertiary center in Iran

AIM: To determine the incidence and risk factors of retinopathy of prematurity(ROP) and the sensitivity of current screening criteria in a tertiary eye center in Tehran, Iran. METHODS: In a cross-sectional observational study, neonates weighing ≤2000 grams at birth or born <34 wk gestational age(GA) and all other infants at risk of ROP admitted to the neonatal intensive care unit(NICU) or referred to our ROP clinic were investigated. The incidence of ROP and severe ROP(i.e. patients needing treatment) were determined. The associations between risk factors and the development and severity of ROP were assessed. We also examined the sensitivity of the current national screening guideline in Iran. RESULTS: Among 207 infants, the incidence of ROP and severe ROP was 33.3% and 11.1%, respectively. Mean GA and birth weight(BW) were significantly lower in ROP vs non-ROP infants(29±2 wk vs 33±3 wk, P<0.001;1274±489 g vs 1916±550 g, P<0.001, respectively). Univariate analysis displayed significant association between ROP incidence and GA, BW, NICU admission period, blood transfusion, surfactant usage, sepsis, intraventricular hemorrhage and patent ductus arteriosus(P<0.05 for all). BW [relative risk(RR): 0.857(0.711-0.873), P<0.001], GA [RR: 0.788(0.711-0.873), P<0.001] and blood transfusion [RR: 1.888(0.995-3.583), P=0.052] were independent ROP risk factors. The sensitivity of country-specific screening guidelines was 95.7% and 100% for overall and severe ROP detection, respectively. CONCLUSION: ROP incidence is relatively high in Iran. Identifying ROP risk factors results in more accurate screening and reduces the risk of irreversible vision loss. The ROP screening criteria utilized in Iran are efficient at the present time.

Scientometric analysis and mapping of 20 years of glaucoma research

AIM：To provide a scientometric analysis in the field of glaucoma.METHODS：A bibliometric method was used to obtain a view of the scientific production in field of glaucoma by data extracted from the Institute for Scientific Information（ISI） from 1993 to 2013.Specific parameters were retrieved from the ISI.Articles about glaucoma were analyzed regarding the topics＇ structure,history,and document relationships using HistCite software.Also,the trends in the most influential publications and authors were analyzed.RESULTS：The number of articles was constantly increasing,and most highly cited articles addressed clinical and epidemiologic topics in this field.During the past three years,there has been a trend towards genomic research studies and also more molecular translational research.CONCLUSION：This was the first scientometric report on glaucoma,analyzing the characteristics of papers and the trends in scientific production.A constant increase was observed in the number of papers,while the subject of papers had a shift in the past three years towards genomic research studies.

How long does the recovery of corneal sensitivity in different corneal regions take after LASEK?

AIM:To determine the corneal sensitivity recovery period after laser-assisted sub-epithelial keratectomy(LASEK)refractive surgery and investigate the effects of ablation depth on it.METHODS:In this study examinations were performed on 90 right eyes of 90 people(34 males and 56 females)with an age range of 20-35 and an average of 22.26±3.8 years old.A sensation of 5 corneal regions,including the center and 4 mid-peripheral regions,i.e.,nasal,inferior,temporal,and superior,each at a distance of 2 mm from the center of the cornea were measured with a Cochet-Bonnet esthesiometer device in 3-time points including before LASEK,1 and 3mo after the surgery,respectively.LASEK was performed on individuals with stabilized myopia of -1.00 to -7.00 diopters and astigmatism of less than 2.00 diopters.Furthermore,the individuals were divided into three groups regarding ablation depth.RESULTS:The highest level of corneal sensitivity before surgery was related to the center of the cornea(59.1±7.76),and the highest level of corneal sensitivity loss was also related to this region.The sensation of all measured corneal regions significantly reduced 1mo postoperatively and returned to their preoperative levels 3mo after surgery(mean of 5 corneal regions in levels of preoperation:58.2±6.48,1mo postoperation:57.3±5.84,3mo postoperation:58.2±5.49;P<0.05).A significant relationship was found between ablation depth and corneal sensitivity changes in the center and temporal regions(P<0.05).CONCLUSION:Corneal sensitivity in myopia and low astigmatism decreases after LASEK and reaches the preoperative level within 3mo.The depth of ablation during surgery affected the recovery of corneal sensitivity.

25-gauge transconjunctival diagnostic vitrectomy in suspected cases of intraocular lymphoma: a case series and review of the literature

AIM:To report the cytology results of 25-gauge transconjunctival(25G-TSV)diagnostic vitrectomy in cases suspicious for intraocular lymphoma(IOL),and compare the results to those reported in the literature.METHODS:Clinical and cytopathological records of 18vitreous biopsy specimens obtained via 25G-TSV diagnostic vitrectomy in 12 patients suspicious for IOL were reviewed retrospectively.A review of the literature in regards to the diagnostic yields of vitreous specimens obtained via 25-gauge and 20-gauge diagnostic vitrectomy in suspected cases of IOL was performed.RESULTS:Eighteen eyes from 12 patients with clinical suspicion of IOL underwent diagnostic 25G-TSV.The cytopathological investigations demonstrated IOL in 15eyes(83.3%).Vitreous analysis was non-diagnostic in 3eyes(16.7%).CONCLUSION:Twenty-five-gauge diagnostic vitrectomy yields adequate sample for cytological evaluation of the vitreous in cases suspicious for IOL.The diagnostic results of the 25G-TSV in the current study are superior to those reported for 20-gauge vitrectomy but equivalent to those reported for 25G-TSV in the published literature.

Visual performance of four types of diffractive multifocal intraocular lenses and a review of articles

AIM: To compare the clinical outcomes of a variety of multifocal intraocular lenses(MIOLs) in patients diagnosed with presbyopia or cataracts. METHODS: This clinical trial study included 141 patients(282 eyes) with different MIOLs implantation. The Symfony(60 eyes), the Re STOR(100 eyes), the AT LISAtri(60 eyes), and the Pan Optix(62 eyes) intraocular lenses were evaluated in this prospective interventional study. The near, intermediate, and distant visual acuities, contrast sensitivity, and defocus curve were measured as valid criteria. To statistically analyze the results, we used the Statistical Package for Social Science software, the non-parametric Wilcoxon signed-rank t, the one-way analysis of variance and the Tukey’s post-hoc test in our analysis. Moreover, we conducted a detailed literature search on the Pub Med database in English about MIOLs, in total 59 studies were included in this review article.RESULTS: The four approaches did not show any significant difference in the best-corrected distance visual acuity(P>0.05). The defocus curves at the contrast of 100% showed that trifocal IOLs had better intermediate performance than the bifocal IOL(P<0.05). There were no statistically significant differences between AT LISAtri and Pan Optix lenses for visual acuity at all distances. The eyes with Pan Optix, Symfony, and AT LISAtri IOL showed better contrast sensitivity than those Re STOR at spatial frequencies of 1, 3, and 6 cpd in photopic and mesopic conditions(P<0.001). CONCLUSION: All four groups of the multifocal lenses were satisfying in terms of distance and near vision. Also, the group of trifocal lenses led to satisfactory outcomes in intermediate vision, without degradation in quality of vision.

Comparison among Ocular Response Analyzer,Corvis ST and Goldmann applanation tonometry in healthy children

AIM： To explore the relationship between different parameters of Ocular Response Analyzer（ORA） and Corvis ST（CST） in a sample of healthy Iranian school-aged children and the relationship between parameters of these 2 instruments against intraocular pressure（IOP）, measured by the Goldmann applanation tonometer（GAT-IOP）, age and gender, and find possible correlation between ORA and CST with GAT.METHODS： This cross-sectional study included 90 healthy children. A general interview and complete eye examination were performed. Following successful GATIOP measurement, ORA and CST were conducted. The CST parameters were A 1/2 length（A1 L, A2 L）, A 1/2 velocity（A1 V, A2 V）, highest concavity deformation amplitude（HCDA）, radius of curvature（Ro C）, peak distance（PD）, central corneal thickness（CCT） and IOP. The ORA parameters were corneal hysteresis（CH）, corneal resistance factor（CRF）, Goldmann-correlated IOP（IOP-G） and corneal compensated IOP（IOP-CC）. Extracted data was analyzed using the Statistical Package for Social Science software.RESULTS： Totally 39 males with age of 9.08±1.60（6-12）y and 51 females with age of 8.96±1.55（6-13）y were included. Many CST parameters were significantly correlated with CH, CRF, IOP-G and IOP-CC. Some CST parameters had a significant correlation with GAT-IOP, including IOP-CST in both eyes and HCDA, A2 L, PD, and RoC in the left eye, but none with age, except A2 L in the right eye. The CRF measurement showed a significant correlation with GAT-IOP in both eyes and CH in the right eye, yet, none with age. Among all CST and ORA parameters, CCT-CST in both eyes and A1 L in right eye had a significant correlation with gender, although this was a negligible negative correlation. Comparison of mean IOP values by different devices showed a significantly highest IOP overestimation by CST and lowest by IOP-CC compared with GAT. Also, IOP-G versus IOP-CST significantly had the lowest IOP overestimation among others. Overall, either low positive correlation or negligible correlation was found between IOP measurements by 3 instruments.CONCLUSION： The study finds the highest IOP overestimation by CST and lowest by IOP-CC compared with GAT. Overall, either low positive correlation or negligible correlation is found between IOP measurements by the 3 instruments.

Efficacy and safety of micropulse laser trabeculoplasty for primary open angle glaucoma

AIM: To evaluate the efficiency and safety of micropulse laser trabeculoplasty(MLT) for primary open angle glaucoma(POAG) patients. METHODS: Retrospective study. POAG patients undergoing MLT in Peking University Third Hospital from June 2016 to November 2017. Seventy-two eyes of 72 POAG patients were enrolled. Only one eye of each patient was treated by MLT. The intraocular pressure(IOP) before MLT and at 1 d, 1, 4, 12 and 24 wk and glaucoma medication before and after treatment were compared.RESULTS: The IOP was 20.6±5.9 mm Hg before MLT and 20.8±6.8 mm Hg at 2 h after MTL. The IOP at 1 d, 1, 4, 12 and 24 wk was 17.9±4.4, 18.0±4.3, 17.5±3.4, 17.0±2.7, and 16.5±2.9 mm Hg, respectively. The IOP before and after MLT demonstrated a statistically significant difference by ANOVA analyses(F=5.797, P<0.001). Least significant difference t-tests showed there was no statistically significant difference between pre-MLT IOP within 2 h after MLT(P=0.207). The statistically significant difference was confirmed between the pre-MLT IOP at 1 d, 1, 4, 12 and 24 wk after MLT(P=0.006, 0.009, 0.001, <0.001, <0.001, respectively). The number of glaucoma medications before MLT was 1.7±1.4 and 1.5±1.4 24 wk after MLT with a significantly statistical difference(t=2.219, P=0.031)CONCLUSION: MLT is effective and safe for POAG patients. No patient experienced IOP spikes after MLT. The IOP 6 mo after treatment decreased significantly with less glaucoma medication.

Effect of periocular injection of celecoxib and propranolol on ocular level of vascular endothelial growth factor in a diabetic mouse model

AIM： To investigate the effects of periocular injection of propranolol and celecoxib on ocular levels of vascular endothelial growth factor （VEGF） in a diabetic mouse model. METHODS： Forty 4-6wk BALB-C male mice weighing 20-25 g were used. The study groups included： nondiabetic control （group 1）, diabetic control （group 2）, diabetic propranolol （group 3）, and diabetic celecoxib （group 4）. After induction of type 1 diabetes by streptozotocin, propranolol （10 μg） and celecoxib （200 μg dissolved in carboxymethylcellulose 0.5%） were injected periocularly. The ocular level of VEGF was measured in all the study groups using enzyme-linked immuno sorbent assay （ELISA） method. RESULTS： Ocular VEGF level was significantly increased （1.25 fold） in the diabetic control group when compared to the non-diabetic group one week after induction with streptozotocin （P=0.002）. Both periocular propranolol and celecoxib significantly reduced ocular VEGF levels （P=0.047 and P〈0.001, respectively）. The effect was more pronounced with celecoxib, CONCLUSION： The periocular administration of propranolol and celecoxib can significantly reduce ocular VEGF levels in a diabetic mouse model.

State of the art management of diabetic macular edema

Macular edema following diabetic retinopathy is one of the ocular complications associated with diabetes, and it is the leading cause of visual loss in the active young and middle aged population in developed countries. While all patients with diabetes particularly those with diabetic retinopathy are at increased risk of developing eye complications, early detection and timely intervention may prevent or delay loss of visual acuity. Systemic management of diabetes through combined control of blood sugar, hypertension, and hyperlipidemia has remained the most effective method to prevent diabetic retinopathy and its progression. Development of diabetic retinopathy and related complications require, surgical and medical interventions including photocoagulation, vitrectomy, and intravitral drug injection to preserve vision. Considering recently most popular treatment of diabetic macular edema(DME) including intravitreal anti-vascular endothelial growth factor(VEGF) agents, several issues such as ideal regimen, duration of treatment, combination therapy and long-term safety have remained unanswered yet and deserve further investigations. In this review, all the articles that had investigated such treatment modalities for DME as well as pharmacokinetic, efficacy, safety, dose and frequency of intravitreal pharmacologic agents and also the effect of macular ischemia, initial macular thickness and optical coherence tomographic patterns of DME on the final outcomes of treatment with Intravitreal drugs are reviewed. In summary, literature searches reveal that almost all studies that have been published up to now provide some evidence that support the use of intravitreal anti-VEGF agents for treatment of either nve or persistent DME in short and long term up to two years.

Safety threshold of intravitreal clonidine in rabbit's eyes

AIM： To determine the safe dose of intravitreal clonidine（IVC）, a potential drug for neuroprotection and angiogenesis inhibition in rabbits. METHODS： A total of 28 rabbits were divided into four groups. Three groups received IVC with concentrations of 15（Group A）, 25（Group B）, and 50（Group C） g/0.1 m L and the control group（Group D） received 0.1 m L balanced salt solution（BSS）. To investigate IVC safety, electroretinography（ERG） was performed at baseline, then at 1, 4 and 8 wk after injection. After last ERG, all rabbits were euthanized, their eyes were enucleated and subjected to routine histopathological evaluation, immunohistochemistry for glial fibrillary acidic protein（GFAP） and terminal deoxynucleotidyl transferase d UTP nick end labeling（TUNEL） test.RESULTS： Based on ERG, histopathology, GFAP and TUNEL assay findings, 15 g IVC was determined as the safe dose in rabbit eyes. While, the results of routine histopathology and TUNEL assay were unremarkable in all groups, toxic effects attributed to 25 and 50 g IVC were demonstrated by ERG and GFAP tests. CONCLUSION： Totally 15 g clonidine is determined as the safe dose for intravitreal injection in rabbits. Contribution of IVC in neuroprotection and inhibition of angiogenesis deserve more studies.

Choroidal neovascularization as the initial manifestation of multiple evanescent white dot syndrome

To report the case of a patient who presented with idiopathic choroidal neovascularization(CNV)as the first sign of multiple evanescent white dot syndrome(MEWDS).A 25-year-old woman presented with recent onset of decreased vision and metamorphopsia in the right eye.The results of fundoscopic examination,fluorescein angiography,and optical coherence tomography(OCT) were compatible with a diagnosis of idiopathic CNV,which was treated with one intravitreal injection of bevacizumab.Five years later,the patient returned complaining of photopsia and decreased vision in the same eye.The fundoscopic examination showed typical signs of MEWDS.After 3 months,recurrence of CNV was observed in the same eye.In conclusion,idiopathic CNV might be the only manifestation of a subclinical occurrence of MEWDS.In this case,it was followed by a recurrence of MEWDS and subsequent reactivation of CNV.

The relationship between abduction deficit and reoperation among patients with infantile esotropia

AIM： To determine the relationship between abduction deficit and reoperation among patients with infantile esotropia （IET）. METHODS： The records of 216 patients （432 eyes） with lET who underwent surgery, from 2010 to 2015 were studied. Patients with lET whose deviation appeared before 6mo of age and had stable preoperative deviation in two examinations with at least 2wk apart and a minimum 3too postoperative follow up were included. Cases with early onset accommodative esotropia, congenital cataract, retinopathy of prematurity （ROP）, manifest nystagmus, fundus lesions, neurologic and ophthalmic anomalies, 6th nerve palsy and Duane＇s syndrome were excluded. Preoperative abduction deficit was considered from -1 to -3 grading scale. Three months after surgery, children were classified into no-need reoperation [deviation〈15 prism diopters （PD）], and need-reoperation groups （deviaUon〉15 PD）. RESULTS： In this retrospective study, 117 female and 99 male patients with the mean surgical age of 4.7±6.4y were included. Reoperation rate was 33.3% and 16.0% in lET patients with and without abduction deficit, respectively in patients who had a history of late surgery. Abduction deficit increased the odds of reoperation by 82% [OR=1.82, 95% confidence interval （CI） =1.05 to 3.19, P=0.003] in patients who had a history of late surgery （〉2 years old, P=0.021）. Abduction deficit was improved significantly after operation （P〈0.001）. CONCLUSION： Based on our results, abduction deficit can be considered as a risk factor of reoperation in lET patients who are operated at the age of more than 2y.

Donor cornea quality used for penetrating keratoplasty vs deep anterior lamellar keratoplasty

Deep anterior lamellar keratoplasty(DALK) has recently been introduced as an alternative procedure to penetrating keratoplasty(PK) for corneal pathologies not affecting the corneal endothelium. DALK does not rely on donor endothelium and requires less rigid criteria for donor corneal tissue quality. Therefore, DALK makes it possible to use donor corneas deemed unsuitable for PK. Furthermore, lamellar keratoplasty allows acellular corneal tissue to be transplanted. As a result, long-term preservation techniques are being revisited to increase the availability of donor corneas and subsequently alleviate constraints of availability, cost, storage, and transportation in many countries. The recent alterations in corneal transplantation techniques and hence the type of donor cornea tissues used for each technique, may require corneal surgeons and eye banks to reevaluate their selection criteria. The purpose of this systematic review is to present an updated analysis on the type and quality of donor corneas used for PK and DALK, assess the influence of donor and eye bank factors on the quality of donor corneas, and determine whether any of these donor factors affect clinical outcomes, complications, and graft survivals.

Topography versus non-topography-guided photorefractive keratectomy with corneal cross-linking variations in keratoconus

AIM:To compare the visual results of non-topographyguided and topography-guided photorefractive keratectomy(PRK)applying sequential and simultaneous corneal crosslinking(CXL)treatment for keratoconus.METHODS:Interventional and comparative prospective study.Sixty-nine eyes(36 patients)suffering from keratoconus(stages 1 Amsler-Krumeich classification)were divided into four groups:sequential topography-guided photorefractive keratectomy with CXL,simultaneous topography-guided photorefractive keratectomy with CXL,simultaneous nontopography guided photorefractive keratectomy with CXL,and sequential non-topography guided photorefractive keratectomy with CXL.The main outcome measures were pre-and postoperative uncorrected distance visual acuity(UDVA),best corrected distance visual acuity(CDVA),manifest refraction,contrast sensitivity,and keratometry.RESULTS:All analyzed visual,contrast sensitivity,and refractive parameters showed a significant improvement in the four groups(all P<0.05).A noticeable improvement was seen in keratometry in all the groups,and a remarkable difference was observed between topography-guided groups in comparison to non-topography-guided groups(P<0.05).Interestingly,the improvement in all parameters showed a degree of stability to the end of the follow-up.CONCLUSION:The treatment priorities in all four groups are safety,efficacy,and predictability in the correction of the sphero-cylindrical errors in mild and moderate keratoconus.No significant differences among groups in the recorded objective outcomes were found.

Novel treatments and genetics of age-related macular degeneration-a narrative review

Age-related macular degeneration(AMD)remains a leading cause of severe visual impairment in developing countries.Although dry-type AMD and geographic atrophy(GA)are progressive conditions with the associated decrease of visual functions,no well-established treatment regimen was proposed for the disease.Wet-type AMD is effectively treated with intravitreal anti-angiogenic agents,but frequent injections are a major issue for the affected patients.Recent advances in AMD genetics have provided new insights into the pathogenesis and novel therapeutic targets of AMD,but the benefits of using genetic testing and genotype-based risk models for AMD development and progression still lacks evidence.Novel AMD treatments aim to increase the interval among intravitreal injections through new therapeutic agents and modern delivery devices.Simultaneously,gene therapy for dry and wet AMD is widely studied.Although gene therapy possesses a major superiority over other novel treatments regarding a persistent cure of disease,many challenges exist in the way of its broad impact on the ocular health of AMD patients.

Therapeutic approaches for corneal neovascularization

Angiogenesis refers to new blood vessels that originate from pre-existing vascular structures.Corneal neovascularization which can lead to compromised visual acuity occurs in a wide variety of corneal pathologies.A large subset of measures has been advocated to prevent and/or treat corneal neovascularization with varying degrees of success.These approaches include topical corticosteroid administration,laser treatment,cautery,and fine needle diathermy.Since the imbalance between proangiogenic agents and antiangiogenic agents primarily mediate the process of corneal neovascularization,recent therapies are intended to disrupt the different steps in the synthesis and actions of proangiogenic factors.These approaches,however,are only partially effective and may lead to several side effects.The aim of this article is to review the most relevant treatments for corneal neovascularization available so far.

COVID-19 and angiotensin-converting enzyme inhibitors from plant origin

We read with great interest the recently published review paper concerning angiotensin-converting enzyme(ACE)inhibitors from plants entitled“Angiotensin-Converting Enzyme Inhibitors from Plants:A Review of Their Diversity,Modes of Action,Prospects,and Concerns in the Management of Diabetes-Centric Complications”[1].