Small-incision lenticule extraction versus femtosecond lenticule extraction for myopic:a systematic review and Meta-analysis

AIM： To examine differences in efficacy, accuracy, safety, aberrations and corneal biomechanical between Small incision lenticule extraction （SMILE） and femtosecond lenticule extraction （FLEx） for myopia. METHODS： Comprehensive studies were conducted on the PubMed, MEDLINE, EMBASE, and Cochrane Controlled Trials Register before 31 July, 2015. Meta-analyses were performed on the primary outcomes [loss of ≥2 lines of corrected distance visual acuity （CDVA）, uncorrected distance visual acuity （UDVA） ≥20/20, spherical equivalent （SE） within ±0.50 diopters （D）, final refractive SE], secondary outcomes were high-order aberrations （HOAs） and corneal biomechanical [central corneal thickness （CCT）, corneal hysteresis （CH） and corneal resistance factor （CRF）]. RESULTS： Seven trials describing a total of 320 eyes with myopia were included in this Meta-analysis. No significant differences were found in the efficacy [UDVA weighted mean difference （WMD） -0.01; 95%CI： -0.04 to 0.01; P=0.37, UDVA ≥20/20, OR 1.49; 95%CI： 0.78 to 2.86; P=0.23], accuracy （SE WMD -0.03; 95%CI： -0.12 to 0.07; P=0.58 , SE within ±0.5 D OR 1.25; 95%CI： 0.34 to 4.65; P=0.74）, HOAs （WMD -0.04; 95%CI： -0.09 to 0.01; P=0.14） and CCT WMD 1.83; 95%CI： -7.07 to 10.72; P=0.69, CH WMD -0.01; 95%CI： -0.42 to 0.40; P=0.97, CRF WMD 0.17; 95%CI： -0.33 to 0.67; P=0.50） in the last fellow-up. But for safety, FLEx may achieve fewer CDVA lost two or more two lines （OR 11.11; 95%CI： 1.27 to 96.86; P=0.03） than SMILE, however CDVA （WMD 0.00; 95%CI： -0.03 to 0.02; P=0.77） is similar. CONCLUSION： SMILE and FLEx are comparable in terms of both efficacy, accuracy, aberrations and corneal biomechanical measures in the follow-up,but FLEx seems to be better in safety measures. The results should be interpreted cautiously since relevant evidence is still limited, although it is accumulating. Further large-scale, well-designed randomized controlled trials are urgently needed.

Study of self-made freeze-dried bilayered fibrin-binding amniotic membrane in ocular trabeculectomy in rabbits

AIM: To investigate the antifibrotic effect of freeze-dried bilayered fibrin-binding amniotic membrane on trabeculectomy in a rabbit model. METHODS: Twenty-four Japanese white rabbits were randomized into three groups: the experimental group (ocular trabeculectomy in combination with freeze-dried bilayered fibrin-binding amniotic membrane transplantation), the control group (ocular trabeculectomy in combination with natural bilayered fibrin-binding amniotic membrane) and the blank group (single trabeculectomy). Clinical observation, hematoxylin-eosin staining, Massion staining, real-time PCR and immunohistochemistry for alpha -SMA were performed on days 7, 14, 21 and 30 following surgery. RESULTS: Statistical differences were noted in survival. analysis and intraocular pressure(IOP) among groups on days 7, 14, 21 and 30 following surgery. Histology, immunohistochemistry and real-time PCR further demonstrated that trabeculectomy in combination with freeze-dried bilayered fibrin-binding amniotic membrane resulted in good wound healing and no scar formation. CONCLUSION: Self-made freeze-dried bilayered fibrin-binding amniotic membrane may inhibit the formation of scarring in glaucoma after trabeculectomy.

Homemade lyophilized cross linking amniotic sustained-release drug membrane with anti-scarring role after filtering surgery in rabbit eyes

AIM: To investigate the antifibrotic effect of the freeze-dried bilayered fibrin-binding amniotic membrane as a drug delivery system on glaucoma surgery in rabbit model. The aim of this study was to prepare a novel local delivery system for the sustained and controllable release of 5-Fu. METHODS: Twenty-four Japanese white rabbits were randomized into three groups: the experimental group (ocular trabeculectomy in combination with 5-Fu loaded freeze-dried bilayered fibrin-binding amniotic membrane transplantation), the control group (ocular trabeculectomy in combination with 5-Fu) and the blank group (single trabeculectomy). HE staining, massion staining and immunohistochemistry for alpha -SMA were performed on days 7, 14, 21 and 30 following surgery. The concentration of 5-Fu in rabbit aqueous humor was examined by high performance liquid chromatography (HPLC) 3 days after the surgery. RESULTS: Statistical differences were noted in intraocular pressure among groups on day 7, 14, 21 and 30 following surgery. Histology further demonstrated that trabeculectomy in combination with freeze-dried bilayered fibrin-binding amniotic membrane yielded well wound healing and no scar formation and was beneficial for long term effect. CONCLUSION: HPLC showed a good slow-release effect with freeze-dried bilayered fibrin-binding amniotic membrane.

Two-step strategy—conjunctival flap covering surgery combined with secondary deep anterior lamellar keratoplasty for the treatment of high-risk fungal keratitis

AIM:To investigate whether the two-step strategy[conjunctival flap covering surgery(CFCS)combined with secondary deep anterior lamellar keratoplasty(DALK)]is effective for patients with high-risk fungal keratitis(FK).METHODS:In this noncomparative,retrospective case series,10 subjects(6 males,4 females)with a mean age of 56.5±7.1(range 47-72)y with high-risk FK undergone the two-step strategy were included.Reported outcome measures were healing of the corneal ulcer,recurrence of FK,reject reaction,improvement in best corrected visual acuity(BCVA)and relevant complications.RESULTS:The average diameter of corneal infiltrates was 7.50±0.39 mm,ranging from 6.94 to 8.13 mm.The mean depth of corneal infiltrates was 422.4±77.1μm,ranging from 350 to 535μm.The mean corneal thickness was 597.4±117.3μm,ranging from 458 to 851μm.Hypopyon and endothelial plaques were presented in all patients.The period between the two steps was 3.65±0.9(ranging from 3 to 5)mo.The graft diameter was 7.75±0.39 mm.At the last follow-up(average 9.25±3.39,ranging from 5.5 to 17mo),no fungal recurrence or graft rejection appeared,and all patients showed improvement of BCVA.One patient suffered from liver function impairment due to oral voriconazole for 4wk and recovered spontaneously after 1wk of drug withdrawal.CONCLUSION:The two-step strategy is safe and effective in the treatment of high-risk FK by transforming intentional therapeutic penetrating keratoplasty during acute infection to later optical DALK.It is a practical strategy,especially in areas lacking fresh donor corneas and eye bank services.

Retinal nerve fiber layer thickness changes in obstructive sleep apnea syndrome:a systematic review and Metaanalysis

AIM： To evaluate the retinal nerve fiber layer（RNFL）thickness changes in patients with obstructive sleep apnoea syndrome（OSAS）, and detect possible prevalence of glaucoma in this population.METHODS： Comprehensive studies were conducted on the Cochrane Library, Pub Med and Embase through March, 2015. Only studies that fit the selection criteria about RNFL and OSAS would be included. For the measures, we calculated the 95% confidence interval（CI）and weighted mean differences（WMD）. The systematic review and Meta-analysis was performed by Rev Man 5.2software.RESULTS： Nine case-control studies were analyzed containing a total of 1086 cases and 580 controls.Average RNFL thickness in OSAS was reduced significantly compared with healthy controls in random effects model（WMD =-2.56, 95% CI：-4.82 to-0.31, P =0.003, I2=57%）. A significant RNFL thickness reduction were found between the two groups in inferior quadrant（WMD =-3.11, 95% CI：-5.53 to-0.69, P =0.01）, superior quadrant（WMD =-2.37, 95% CI：-4.7 to 0.04, P =0.05）. In nasal quadrant（WMD =-2.54, 95% CI：-6.53 to 1.45, P =0.21） and temporal quadrant（WMD=-1.26, 95% CI：-2.19 to 0.47, P =0.15） there was no difference of RNFL thickness between the two groups.CONCLUSION： The results show that RNFL thickness is lower in patients with moderate or severe OSAS than in normal subjects or patients with mild OSAS according to the nine homogeneity studies.

Cryopreserved limbal lamellar keratoplasty for peripheral corneal and limbal reconstruction

This study aimed to evaluate the outcomes and described the recovery process of cryopreserved limbal lamellar keratoplasty（CLLK） for peripheral corneal and limbal diseases. Thirteen eyes of 12 patients with a mean age of 41±23.9 y were included. The average follow-up was 12.1±5.6 mo. Stable ocular surface was achieved in all eyes at last follow-up. Epithelialization originated from both recipient and graft in 9 eyes. We conclude that CLLK compensates for the shortage of donor corneas and cryopreserved limbal grafts provide epithelialization sources in ocular surface reconstruction.

Amniotic membrane transplantation with topical interferon alfa-2b after excision of ocular surface squamous neoplasia

To evaluate the outcome of amniotic membrane transplantation（AMT） after tumor excision followed by topical interferon alfa-2 b（IFNα2 b） drops for primary ocular surface squamous neoplasia（OSSN）. Twelve eyes of 12 patients with a mean age of 66±10 y were included. The average followup was 23±10 mo. All 12 patients had limbal involvement. Smooth ocular surface and transparent cornea were achieved in all cases. No sign of inflammation, neovascularization, symblepharon or recurrence was noted at the last follow-up. We conclude that AMT with topical IFNα2 b drops restores a healthy ocular surface in OSSN without recurrence.

Safety profile of 0.0015%tafluprost eye drops in China:a post-marketing observational study

AIM:To investigate the treatment pattern and safety of tafluprost for glaucoma and ocular hypertension(OH)in clinical practice in China.METHODS:This post-marketing observational study included patients who received tafluprost to lower intraocular pressure(IOP)within 30d between September 2017 and March 2020 in 20 hospitals in China.Adverse drug reactions(ADRs)during tafluprost treatment and within 30d after the treatment were collected.RESULTS:A total of 2544 patients were included in this study,of them 58.5%(1488/2544)had primary open angle glaucoma(POAG),21.9%(556/2544)had OH and 19.7%(500/2544)used tafluprost for other reasons.Of 359 ADRs occurred in 10.1%(258/2544)patients,and no serious adverse event occurred.The most common ADR was conjunctival hyperemia(128 ADRs in 124 patients,4.9%).Totally 1670 participants(65.6%)combined tafluprost with carbonic anhydrase inhibitors(CAIs;37.1%,620/1670),sympathomimetics(33.5%,559/1670),β-blockers(33.2%,555/1670),other prostaglandin analogs(PGAs;15.6%,260/1670)and other eye drops(15.1%,253/1670).The highest incidence of conjunctival hyperemia was noted in patients who received tafluprost in combination with other PGAs(23 ADRs in 23 patients,8.8%,23/260)and the lowest was in combination with CAIs(16 ADRs in 16 patients,2.6%,16/620).Tafluprost was applied in primary angle-closure glaucoma(41.6%,208/500),after glaucoma surgery(17.8%,89/500)and after non-glaucoma surgery(15.8%,79/500).CONCLUSION:Tafluprost is safe for POAG and OH,and tolerable when combined with other eye drops and under various clinical circumstances.

Differential expression of antimicrobial peptides in human fungal keratitis

AIM:To analyze a series of antimicrobial peptides(AMPs)in corneal tissue from individuals with fungal keratitis(FK)during the active phase of the fungus infection and after healing.METHODS:Patients undergone lamellar keratoplasty for the treatment of severe FK or corneal scar had their corneal buttons sampled.Quantitative real-time polymerase chain reaction(PCR)was used to ascertain the gene expression of human beta-defensin(HBD)-1,-2,-3,-9,S100A7,8,9,and LL-37.RESULTS:All AMPs’messenger ribonucleic acid(mRNA)expression was considerably elevated in all samples(n=12).In contrast to controls,where HBD-2,-3,and S100A7 mRNAs were expressed at very low levels,it was discovered that HBD-1,-9,S100A8,S100A9,and LL-37 were constitutively expressed in all healed samples(n=4).HBD-1,-2-3,S100A7,and LL-37 mRNAs were significantly increased in all active FK samples(n=8).The levels of HBD-9,S100A8,and S100A9 mRNAs were moderately upregulated in all active FK samples.Subgroup comparison showed that HBD-2 was significantly increased in Fusarium keratitis samples(n=5),and LL-37 mRNAs were significantly enhanced in Aspergillus keratitis samples(n=3).Whereas there was not significantly increased of HBD-1,-3,-9,S100A7,8,9 mRNA in Aspergillus keratitis samples compared with Fusarium keratitis samples.CONCLUSION:AMPs expression is increased in active FK,but not all AMPs are equally expressed.HBD-2 and LL-37 expression levels are the highest,showing some specificity of AMP expression related to FK.Human AMPs,particularly HBD-2 may play a significant role in Fusarium keratitis and LL-37 might be the key player in Aspergillus keratitis.

The present and the prospect of bioengineering cornea

Corneal blindness represents one of the world’s three major causes of blindness,and the fundamental problem of corneal transplantation is a severe shortage of donor tissues worldwide,resulting in approximately 1.5 million new cases of blindness annually.To address the growing need for corneal transplants two main approaches are being pursued:allogenic and bioengineering cornea.Bioengineering corneas are constructed by naturally generating an extracellular matrix(ECM)component as the scaffold structure with or without corneal cells.It is well established that the scaffold structure directs the fate of cells,therefore,the fabrication of the correct scaffold structure components could produce an ideal corneal substitute,able to mimic the native corneal function.Another key factor in the construction of tissue engineering cornea is seed cells.However,unlike the epithelium and stroma cells,human cornea endothelium cells(HCECs)are notorious for having a limited proliferative capacity in vivo because of the mitotic block at the G1 phase of the cell cycle due to“contact-inhibition”.This review will focus on the main concepts of recent progress towards the scaffold and seed cells,especially endothelial cells for bioengineering cornea,along with future perspectives.

SARS-CoV-2 in the ocular surface of COVID19 patients

The 2019 novel coronavirus disease(COVID-19)caused by severe acute respiratory syndrome coronavirus 2(SARSCoV-2)has spread globally,while the routes of transmission of this virus are still controversial.We enrolled 33 patients,without any ocular manifestation,with their ocular surface swabs collected for virus detection.RNA was detected strong positive in samples of both eyes from two patients.Therefore,SARS-CoV-2 may exist in the normal ocular surface of COVID-19 patients,suggesting that this virus might be spread through conjunctival contact.

SARS-CoV-2 in the ocular surface of COVID-19 patients

The 2019 novel coronavirus disease(COVID-19)caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has spread globally,while the routes of transmission of this virus are still controversial.We enrolled 33 patients,without any ocular manifestation,with their ocular surface swabs collected for virus detection.RNA was detected strong positive in samples of both eyes from two patients.Therefore,SARS-CoV-2 may exist in the normal ocular surface of COVID-19 patients,suggesting that this virus might be spread through conjunctival contact.