Intraocular Pressure Before and After Corneal Refractive Surgery: A Prospective Comparison of Corvis ST and Ocular Response Analyzer.

PRECIS: The study showed that Corvis ST's bIOP and ORA's IOPcc do not agree well, before or after PRK, and may not be used interchangeably. bIOP remained unchanged after PRK. PURPOSE: To evaluate the agreement between the biomechanically-corrected intraocular pressure (bIOP) measured by the Corvis-ST and the cornea-compensated IOP (IOPcc) measured by the Ocular Response Analyzer (ORA) before and after photorefractive keratectomy (PRK). METHODS: In this prospective interventional study, a total of 53 patients (53 eyes) were included. Measurements were acquired using both the Corvis-ST and ORA devices before and 3 months post- PRK. The agreement between the two devices was evaluated using limits of agreement (LoA) and Bland-Altman plots. RESULTS: The participants had a mean age of 29.6±5.21 years (range: 21 to 40), with 41 (77.4%) of them being female. Following the surgery, the average change in IOP was 0.3±1.7 mmHg for bIOP and -1.6±4.0 mmHg for IOPcc. The corresponding 95% LoA were -3.5 to 4.2 mmHg and -9.5 to 6.3 mmHg, respectively. The 95% LoA between bIOP and IOPcc after PRK was -2.3 to 8.5 mmHg. Notably, the bIOP values were higher for IOPs <20 mmHg and lower for IOPs >20 mmHg compared to IOPcc. CONCLUSIONS: The findings indicate a weak agreement between the Corvis ST-bIOP and the ORA- IOPcc both before and after PRK. These devices may not be used interchangeably for IOP measurement. bIOP exhibited less variation compared to the IOPcc, suggesting that the bIOP is a superior option for IOP reading following PRK.

Intravitreal Injection of Anti-Vascular Endothelial Growth Factors Combined with Corticosteroids for the Treatment of Macular Edema Secondary to Retinal Vein Occlusion: A Systematic Review and Meta-Analysis.

PURPOSE: To evaluate the efficacy and safety of intravitreal anti-vascular endothelial growth factor (anti-VEGF) and corticosteroid combination therapy for the management of treatment-naïve or recurrent/refractory macular edema caused by retinal vein occlusion (RVO) in comparison with anti-VEGF monotherapy. METHODS: In this systematic review and meta-analysis study, the data from publications in the electronic databases including PubMed, Embase, Cochrane Library Central Register of Controlled Trials, ISI and Scopus from January 1, 2007, through November 20, 2020, were compiled. Heterogeneity was statistically quantified by the I2 statistic, and meta-analysis was performed using a random-effects model. RESULTS: Twenty-four related studies were identified, including a total of 1280 eyes, which consisted of 685 and 507 patients with central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO), respectively. This study demonstrated a greater improvement in best-corrected visual acuity (BCVA) in the combination group compared to anti-VEGF monotherapy for both CRVO and BRVO cases at 6 months after initiating therapy. The improvement in vision was more notable in BRVO cases than in CRVO cases. However, the changes in central macular thickness (CMT) did not differ significantly between the different treatment approaches, and the results were inconclusive. Including all cases with RVO, there was no inferiority in terms of BCVA improvement and CMT reduction in the triamcinolone subgroup compared with the slow-release dexamethasone implant subgroup. A greater improvement was noticed in terms of BCVA in the sequentially treated subgroup compared to the simultaneous treatment subgroup, while there was a greater reduction in CMT in the simultaneous subgroup with the highest reduction recorded at 1 month after treatment. CONCLUSIONS: This study suggests that combination therapy with intravitreal anti-VEGF and corticosteroid (such as intravitreal or subtenon triamcinolone or dexamethasone implant) has a slightly better effect on improving BCVA in cases with BRVO or CRVO at 6 months compared to monotherapy.

Characterization of Central and Nasal Orbital Adipose Stem Cells and their Neural Differentiation Footprints.

BACKGROUND: The unique potential of stem cells to restore vision and regenerate damaged ocular cells has led to the increased attraction of researchers and ophthalmologists to ocular regenerative medicine in recent decades. In addition, advantages such as easy access to ocular tissues, non-invasive follow-up, and ocular immunologic privilege have enhanced the desire to develop ocular regenerative medicine. OBJECTIVE: This study aimed to characterize central and nasal orbital adipose stem cells (OASCs) and their neural differentiation potential. METHODS: The central and nasal orbital adipose tissues extracted during an upper blepharoplasty surgery were explant-cultured in Dulbecco's Modified Eagle Medium (DMEM)/F12 supplemented with 10% fetal bovine serum (FBS). Cells from passage 3 were characterized morphologically by osteogenic and adipogenic differentiation potential and by flow cytometry for expression of mesenchymal (CD73, CD90, and CD105) and hematopoietic (CD34 and CD45) markers. The potential of OASCs for the expression of NGF, PI3K, and MAPK and to induce neurogenesis was assessed by real-time PCR. RESULTS: OASCs were spindle-shaped and positive for adipogenic and osteogenic induction. They were also positive for mesenchymal and negative for hematopoietic markers. They were positive for NGF expression in the absence of any significant alteration in the expression of PI3K and MAPK genes. Nasal OASCs had higher expression of CD90, higher potential for adipogenesis, a higher level of NGF expression under serum-free supplementation, and more potential for neuron-like morphology. CONCLUSION: We suggested the explant method of culture as an easy and suitable method for the expansion of OASCs. Our findings denote mesenchymal properties of both central and nasal OASCs, while mesenchymal and neural characteristics were expressed stronger in nasal OASCs when compared to central ones. These findings can be added to the literature when cell transplantation is targeted in the treatment of neuro-retinal degenerative disorders.

Human Wharton's Jelly Mesenchymal Stem Cell Secretome Modifies the Processes of Neuroprotection and Epithelial-Mesenchymal Transition in Retinal Pigment Epithelium at Transcriptional Level.

BACKGROUND: Retinal pigment epithelium (RPE) cells are potential targets for treating retinal detachment (RD) and proliferative vitreoretinopathy (PVR), considering the importance of neuroprotection and epithelial-mesenchymal transition (EMT) of RPE in these conditions. This study investigated the effect of human Wharton's jelly mesenchymal stem cell secretome (WJMSC-S) on the expression of genes involved in both neuroprotection and EMT in RPE cells in vitro (TRKB, MAPK, PI3K, BDNF, and NGF). METHODS: RPE cells from passages 5-7 were treated with WJMSC-S (or the vehicle culture medium as control) for 24 h at 37◦C and subsequently subjected to RNA extraction and cDNA synthesis. Gene expression level was evaluated using real-time PCR in the treated versus control cells. RESULTS: The results of our study showed that WJMSC-S led to a significant downregulation in three out of five studied gene expression (MAPK, TRKB, and NGF), and simultaneously, remarkably upregulated the expression of the BDNF gene. CONCLUSIONS: According to the present data, WJMSC-S can affect the EMT and neuroprotection processes at the mRNA level by suppressing EMT and promoting neuroprotection in RPE cells. This finding may have positive clinical implications in the context of RD and PVR.

Angle κ and its effect on the corneal elevation maps in refractive surgery candidates.

PURPOSE: To assess the associations of angle κ and Pentacam decentration indices with elevation maps in normal refractive surgery candidates. SETTING: Salouti Cornea Research Center, Salouti Eye Clinic, Shiraz, Iran. DESIGN: Retrospective observational study. METHODS: In this research, the right eyes of 173 refractive surgery candidates were assessed. Data of front and back corneal elevation maps, keratometric data, decentration indices, and corneal astigmatism obtained by Pentacam HR system and angle κ obtained by Orbscan IIz were extracted. Maximum elevation (or depression) for each of the 4 quadrants was recorded. Correlations of elevation values with angle κ, Pentacam decentration indices, keratometry, and astigmatism were examined by Pearson correlation coefficient. 148 age- and sex-matched cases with keratoconus grade 1 were selected as a positive control group, and Pentacam variables were compared between the groups. RESULTS: Overall, data from 173 eyes of 173 normal refractive surgery candidates and 148 eyes of 148 patients with keratoconus were recorded and analyzed. In normal refractive surgery candidates, the mean of angle κ was 5.32 ± 1.36 (SD) degrees. Angle κ had a positive correlation with front and back temporal elevations based on a best-fit sphere (BFS) ( r = 0.339, P = .001; r = 0.300, P < .001, respectively). Front and back keratometric astigmatisms were positively correlated with front and back nasal and temporal elevations ( r ≥ 0.543, P < .001) and negatively correlated with superior and inferior elevations ( r ≤ -0.547, P < .001). These associations no longer existed when using best-fit toric ellipse (BFTE) for calculating elevation data. The thinnest point to vertex decentration was significantly associated with the back temporal elevation (based on the BFTE) in both normal ( r = 0.311, P < .001) and keratoconus ( r = 0.190, P = .021) eyes. CONCLUSIONS: This study showed that elevation maps obtained by the Pentacam system using BFS might be affected by both the large angle κ and corneal astigmatism, confounding the preoperative assessment of refractive surgery candidates. Using BFTE as a reference for calculating elevation data should eliminate most diagnostic issues and thus is encouraged in this context.

Inferior Spear-like Lens Opacity as a Sign of Keratoconus.

PURPOSE: To report 21 cases of typical inferior feather-shape lens opacity associated with keratoconus. METHODS: In this cross-sectional study, we evaluated the association of keratoconus with inferior feather-shape lens opacity in refractive surgery candidates. Visual acuity, demographic, refractive, and topographic characteristics of 26 eyes of 21 patients with inferior feather-shape lens opacity were evaluated in detail. Pedigree analysis was also performed to assess possible inheritance. RESULTS: Overall, 2122 out of 33,368 cases (6.4%) without lens opacity had keratoconus, while 20 out of 21 patients (95.2%) with peculiar lens opacity had definite keratoconus (P < 0.001). Lens opacity was bilateral in 5 cases (24%), and keratoconus was bilateral in all 20 patients with lens opacity. Nine eyes out of thirty-six with a complete data record (25%) had a severe keratoconus and underwent deep lamellar keratoplasty, while 11 (31%) had forme fruste keratoconus. Pedigrees were drawn for eight patients, most families of whom suggested an X-linked recessive inheritance. CONCLUSION: The present study was the first to investigate patients with a peculiar inferior feather-shape lens opacity accompanied by bilateral keratoconus, which was observed in 95% of the patients. This finding should raise awareness as to the possibility of diagnosing keratoconus in the eyes of the patients with these characteristics.

Effects of the secretome of human Wharton's jelly mesenchymal stem cells on the proliferation and apoptosis gene expression of the retinal pigmented epithelium.

Human retinal pigmented epithelium (RPE) can undergo an uncontrolled proliferation in some disorders such as retinal detachment associated with proliferative vitreoretinopathy (PVR). The present study was conducted to evaluate the effect of the conditioned medium secreted by human Wharton's jelly mesenchymal stem cells (WJMSCs-CM) on the proliferation and apoptosis gene expression of the RPE. WJMSCs-CM was collected from WJMSCs after two periods of 24-h and 9-h culture in serum-free medium. RPE cells were cultured in WJMSCs-CM versus serum-deprived media for 24 h. The effect of WJMSCs-CM on RPE cell proliferation was determined using the MTT assay. Relative expression of apoptotic genes (Bcl2, Bax, and IL-1B) was also assessed by real-time PCR. MTT assay demonstrated that RPE cell viability was reduced significantly in WJMSCs-CM treated RPE cells compared to those cultured in serum-deprived medium (64.23 ± 2.44 vs 100.10 ± 5.68; P = 0.006). Moreover, the expression of anti-apoptotic Bcl2 was significantly decreased in WJMSCs-CM compared to serum-deprived medium (0.52 ± 0.06 in WJMSCs-CM vs 1.02 ± 0.2 in serum-free treatment; P = 0.03), while the expression of pro-apoptotic biomarkers of Bax and IL-1B was not significantly different between the two treatments. The represented data showed that WJMSCs-CM can induce apoptosis in RPE cells in vitro through activating apoptosis pathways. This proof-of-the-concept study provides basic evidence for the possible effect of WJMSCs-CM on preventing PVR.

Agreement in central corneal thickness measurement between Corvis ST and ocular response analyzer.

PURPOSE: To evaluate the agreement and interchangeability of noncontact devices of ocular response analyzer (ORA) and the Corvis ST in central corneal thickness measurement. METHODS: In this prospective comparative study, central corneal thickness (CCT) readings of 284 healthy, nonglaucoma subjects, without previous ocular surgery, were measured with ORA and Corvis ST. Only data from right eyes were analyzed. The mean values of CCT measurements by the ORA versus Corvis ST were compared with the paired sample t test. Bland-Altman plots and 95% limits of agreement (95% LOA) were used to assess the agreement between the measurements of the two devices. RESULTS: The mean (± standard deviation) age of the participants was 28.0 ± 4.9 years, and 36.6% were male. The mean CCT measurements were 555 ± 32 µm by the ORA and 536 ± 32 µm with the Corvis ST (P < 0.001). The Pearson correlation coefficient was 0.964 (P < 0.001). The 95% LOA between the ORA and the Corvis ST was 2.2 to 35.9 µm. CONCLUSIONS: The ORA measured the CCT up to 35.9 µm greater than Corvis ST. Therefore, the two devices may not be used interchangeably for measuring CCT.

Effect of photorefractive keratectomy on agreement of anterior segment variables obtained by a swept-source biometer vs a Scheimpflug-based tomographer.

PURPOSE: To evaluate agreement of anterior segment variables between Pentacam-AXL and IOLMaster 700 before vs after photorefractive keratectomy (PRK). SETTING: Salouti Eye Clinic, Shiraz, Iran. DESIGN: Prospective cohort with interdevice agreement analysis. METHODS: This study included healthy PRK candidates who were assessed with both devices preoperatively and 6 months after PRK. Only data from the right eye of each patient was analyzed. Pentacam-AXL average keratometry (AvgK) and zonal keratometry in the central 2.5 mm zone (zonal-K2.5) were each compared with mean keratometry (Km) from the IOLMaster 700. Other main outcome measures included vector analysis of corneal astigmatism (J0 and J45), central corneal thickness (CCT), anterior chamber depth (ACD), and white-to-white (WTW) distance. Axial length (AL) measurements by the same devices on a new cohort of 40 patients who had undergone PRK were also assessed. A paired t test was used to assess the interdevice measurement differences, and Bland-Altman analysis was used to calculate the 95% limits of agreement (LoA). RESULTS: This study included 97 patients. Preoperative vs post-PRK 95% LoAs between Pentacam-AXL and IOLMaster 700 were as follows: AvgK/Km (-0.42, 0.08 diopter [D]) vs (-0.49, 0.18 D); zonal-K2.5/Km (-0.40, 0.32 D) vs (-0.57, 0.74 D); J0 (-0.33, 0.18 D) vs (-0.28, 0.35 D); J45 (-0.28, 0.23 D) vs (-0.24, 0.27 D); pupil pachymetry/CCT (-18, 12 µm) vs (-2.6, 19.6 µm); apical pachymetry/CCT (-17.4, 12.8 µm) vs (-1.7, 20.9 µm); ACD (-0.03, 0.13 mm) vs (-0.03, 0.13 mm); WTW (-0.68, 0.23 mm) vs (-0.63, 0.14 mm); and AL (-0.07, 0.01 mm) vs (-0.07, 0.03 mm), respectively. CONCLUSIONS: PRK showed a negative impact on interdevice agreement for CCT and corneal power measurements, whereas it did not have a significant effect on the agreement of devices for ACD, WTW, AL, and the J45 astigmatism vectoral component. For IOL power measurement in post-PRK eyes, the 2 devices could be regarded as interchangeable for measuring AL and ACD but not for keratometry readings.

Improved Function of Orbicularis Oculi by Dynamic Transfer of Contralateral Orbicularis Oculi Muscle in Patients with Facial Palsy.

PURPOSE: The purpose of this study is to introduce the results of a new surgical technique in patients with complete facial nerve palsy using the dynamic muscle transfer of orbicularis oculi muscle (OOM) flap from the contralateral side. METHODS: This case series presents a new surgical technique in three patients with complete facial palsy and lagophthalmos who were unresponsive to other modalities. In this technique, a rectangular flap of OOM was dissected from the upper lid of fellow eye and transferred to the affected eye through a subcutaneous tunnel over the nasal bridge. The flap was divided into two halves for upper and lower lids. Each half was incised longitudinally to increase the length of the flap and cover the lateral part of the affected eyelids. RESULTS: Improvement in exposure keratitis, lagophthalmos, and other related symptoms was observed as soon as the 1st week after the surgery. Partial blinking recovered and the operation was uneventful. CONCLUSION: Muscle flap transfer technique using contralateral OOM for complete facial palsy can be considered as a helpful alternative in patients who are still symptomatic despite conventional treatment modalities.

Assessment of the changes in corneal biomechanical properties after collagen cross-linking in patients with keratoconus.

PURPOSE: To assess the changes in biomechanical properties of the cornea after treatment of keratoconus patients with UV-A/riboflavin corneal collagen cross-linking (CXL) using Corvis ST (Oculus, Wetzlar, Germany) and Ocular Response Analyzer (ORA; Reichert Ophthalmic Instruments, Inc., Buffalo, NY, USA) devices. METHODS: In this prospective, observational case series, 48 eyes from 48 consecutive patients with progressive keratoconus were enrolled. Patients with history or signs of ocular disorders other than keratoconus, previous eye surgery, systemic diseases, or inability to cooperate with any measurement device were excluded. Corvis ST and ORA images were obtained at baseline and 4 months after CXL. The primary outcome measures comprised Corvis ST corneal biomechanical factors [time of highest concavity (T), time of applanation 1 (T1), time of applanation 2 (T2), length of applanation 1 (L1), length of applanation 2 (L2), velocity of applanation 1 (V1), velocity of applanation 2 (V2), deformation amplitude (DA), peak distance (PD), and radius (R)] and the ORA parameters [corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-related IOP (IOPg), cornea-compensated IOP (IOPcc), and waveform score (WS)]. RESULTS: The mean [± standard deviation (SD)] age of patients was 20 ± 5 years, and 27 (56%) were male. At baseline, the averages of the refraction, mean keratometry, and keratometric astigmatism were -3.0 ± 1.8 diopter (D), 47.0 ± 1.8 D, and 3.5 ± 1.5 D, respectively. According to Corvis ST, L2 increased from 0.83 ± 0.25 mm at baseline to 1.15 ± 0.57 mm after CXL; and V2 decreased from -0.81 ± 0.08 to -0.94 ± 0.26 m/s (P = 0.001 and P = 0.032, respectively). ORA parameters showed significant decrease in the CRF (from 7.82 ± 1.72 to 7.21 ± 1.05 mmHg; P = 0.036) and increase in the WS (from 4.58 ± 2.55 to 6.12 ± 1.92; P = 0.002). CONCLUSIONS: According to in vivo observation with Corvis ST and ORA, CXL induces significant changes in corneal biomechanical properties in cases with keratoconus. The parameters with significant changes (L2 and V2) may reflect increased stiffness of the treated cornea. The importance of such observations should be elucidated in future studies.

Clinical and Ultrasonographic Evaluation of Infantile Periocular Hemangioma Treated With Oral Propranolol.

PURPOSE: To evaluate the clinical and ultrasonographic response of periocular infantile capillary hemangioma during treatment with oral propranolol. METHODS: Patients with infantile periocular hemangioma and visual or cosmetic concerns were enrolled in this prospective interventional case series. Propranolol was given at a dose of 2 mg/kg per day for at least 6 months. Evaluation of treatment response was performed at month 3 (time point 1) and month 6 (time point 2). Gray scale ultrasonography and color Doppler imaging were performed at baseline and month 3. RESULTS: Thirty-one patients with mean age of 4.1 ± 2.3 months were eligible for analysis. Complete or near complete clinical resolution was observed in 4 patients (12.9%) at time point 1 and 21 patients (67.7%) at time point 2. Longitudinal diameter, transverse diameter, thickness, arterial peak systolic velocity, and end diastolic velocity reduced significantly from baseline to 3-month follow up. Complete clinical response at time point 2 was significantly higher in patients with peak systolic velocity reduction >50% from baseline to month 3 than patients with peak systolic velocity reduction of 10% to 50% and <10%. CONCLUSIONS: Propranolol is safe and effective for infantile periocular hemangioma. Ultrasonography and color Doppler imaging are useful modalities to monitor and predict the treatment response.

The Argus-II Retinal Prosthesis Implantation; From the Global to Local Successful Experience.

Over the past few years, visual prostheses (namely, Argus II retinal implant) and gene therapy have obtained FDA approval in treating blindness resulting from retinitis pigmentosa. Compared to gene therapy; Argus II is less costly with a demonstrated favorable outcome, though the vision is yet artificial. To obtain better results, expectation counseling and preoperative retinal assessment are critical. The global experience with Argus II has enrolled no more than 300 cases so far. The first Argus II retinal prosthesis in Iran was successfully implanted in Shiraz (October 2017). To date, Argus II artificial retina is implanted in four patients in Iran. Beside successful surgery and post-operative care, rehabilitation efforts with validated outcome measures including visual rehabilitation together with neurovisual, visuo-constructive and cognitive rehabilitation/empowerment approaches are expected to boost the functional outcome. A multidisciplinary approach within a cross-functional team would optimize strategies toward better patient outcomes. As such, establishing a collaborative network will foster organized research efforts to better define outcome assessment and rehabilitation strategies. This technology report paper has been an attempt to provide an overview of Argus-II retinal implant global experience as well as the clinical outcome of the so far cases in Iran. Insights from this report were communicated during the first "Brain Engineering and Computational Neuroscience Conference," 31 January-2 February 2018 in Tehran.

Early Macular Changes after Phacoemulsification in Eyes with High Myopia.

PURPOSE: To evaluate macular changes after cataract surgery in eyes with high myopia. METHODS: This prospective cohort enrolled patients with high myopia (axial length ≥26 mm) who underwent phacoemulsification with intraocular lens implantation. Spectral-domain optical coherence tomography (OCT) scans were obtained at baseline and 2 and 6 months after the operation. Postoperative macular changes on OCT scans were regarded as the main outcome measure. RESULTS: Thirty-four eyes of 31 patients with high myopia were included (age, 60 ± 10 years [mean ± SD]); of these, 14 patients (45.2%) were male. The mean axial length was 27.8 ± 1.5 mm. Epiretinal membrane (one eye, 2.9%), lamellar hole (one eye, 2.9%), myopic foveoschisis (2 eyes, 5.9%), and vitreomacular traction associated with foveoschisis (one eye, 2.9%) were notable findings at baseline examination; no eye showed cystoid macular edema (CME) at this time. At the 2-month examination, three eyes (8.8%) developed CME. At the 6-month follow-up, one eye with CME at 2 months improved, and a new case of CME (5.6%) was detected. The characteristics of epiretinal membrane, lamellar hole, vitreomacular traction, and foveoschisis did not change at the 2- and 6-month examinations and no new cases occurred. CONCLUSION: Uncomplicated phacoemulsification had no significant effect on the prevalence or characteristics of pre-existing macular abnormalities in eyes with high myopia up to 6 months of follow-up. The incidence of CME 2 months after uncomplicated cataract surgery in eyes with high myopia was about 9%.

Outcomes of Light Silicone Oil Tamponade for Failed Idiopathic Macular Hole Surgery.

PURPOSE: To study the outcomes of redo macular hole surgery using light silicone oil tamponade. METHODS: In this study, medical charts of consecutive patients who underwent redo pars plana vitrectomy, extended dye-assisted internal limiting membrane peel, and light silicone oil tamponade for failed previous macular hole surgery (from January 2010 to June 2014) were retrospectively reviewed. Best spectacle corrected visual acuity and anatomical closure rates were regarded as outcome measures. RESULTS: Overall, data from 13 patients was recorded and analyzed. The mean (±SD) age of patients was 66 ± 7 years, and four (30.7%) were male. Mean interval between the primary and redo surgeries was 3.7 ± 2.0 months (range, 1 to 8 months). During redo surgeries, 11 (84.6%) subjects underwent additional internal limiting membrane peeling. Mean interval between the redo surgery and silicone oil removal was 5.9 ± 2.1 months (range, 3 to 10 months). After silicone oil removal, patients were followed for 21.8 ± 14.2 months (range, 3 to 51 months). Mean best spectacle corrected visual acuity improved from 20/452 before redo surgery to 20/121 in the last follow-up examination (P < 0.001). Anatomical success was achieved in 11 (84.6%) patients: nine (69.2%) macular holes were closed and two (15.4%) were flat-open. CONCLUSIONS: Redo pars plana vitrectomy with light silicone oil tamponade is an effective method for restoration of macular anatomy and function in patients with persistent macular holes.

The effects of microwave radiation on rabbit's retina.

PURPOSE: Mobile cell phones are used extensively these days, and their microwave (MW) radiation has been shown to affect the eye. The purpose of the present study was to evaluate the effects of MW radiation on rabbit retina. METHODS: This experimental study (concluded in 2015) was conducted on 40 adult white New Zealand rabbits. A Global System for Mobile Communications (GSM) cell phone simulator was used for MW irradiation. The rabbits were randomized into five groups (8 in each) and treated as follows: Group 1: no irradiation (sham); Group 2: irradiation at 10 cm for 1 day; Group 3: irradiation at 30 cm for 1 day; Group 4: irradiation at 10 cm for 3 days; and Group 5: irradiation at 30 cm for 3 days. Scotopic and photopic electroretinography (ERG) responses were obtained at baseline and 7 days after the last exposure. Then all the rabbits were euthanized, and their eyes were enucleated and sent for pathology examination. Kruskal-Wallis and Chi-Square tests were used to evaluate intergroup differences in ERG parameters and histological findings, respectively. RESULTS: ERG responses obtained 7 days after irradiation did not show any statistically significant difference between the groups (P > 0.1, for all tested parameters). There were statistically non-significant trends toward greater changes in the MW irradiated eyes. In pathological examination, retina was normal with no sign of degeneration or infiltration. Ciliary body congestion was observed in greater fraction of those who received higher MW doses. (P = 0.005). CONCLUSIONS: Histopathologically, cell phone simulated MW irradiation had no significant detrimental effect on the retina. However, ciliary body congestion was observed in greater fraction of those who received higher MW doses. Although there was no significant difference between post-treatment mean ERG values, there were statistically non-significant trends toward greater changes in the MW irradiated eyes.

Results for Water-drinking Test, before and after Laser Iridotomy, in Primary Angle-closure Suspects.

SIGNIFICANCE: Intraocular pressure and ocular biometric changes were similar before and after laser iridotomy in response to the water-drinking test in a cohort of patients at risk of angle closure. The water-drinking test does not seem to be a good provocative test to determine which eyes would benefit from a laser iridotomy. Our data call into question the preoperative predictive value of this test. PURPOSE: The aim of this study was to evaluate the effect of water-drinking test on intraocular pressure and ocular biometric parameters, before and after laser peripheral iridotomy, in patients with an occludable angle. METHODS: Twenty-seven patients, who met the inclusion criteria and had at least 180 degrees of iridotrabecular apposition, underwent a complete eye examination followed by the measurement of ocular biometric (using LenStar LS-900; Haag-Streit AG, Koeniz, Switzerland) and anterior chamber parameters (using Pentacam HR; Oculus Optikgerate GmbH, Wetzlar, Germany). All the measurements were repeated 30 minutes after the water-drinking test. Two weeks after laser peripheral iridotomy, all the measurements were repeated both before and after the water-drinking test. RESULTS: The mean ± SD of the age of the participants was 57 ± 9 years, and 23 (85.2%) were male. Intraocular pressure increased after the water-drinking test in both pre-laser peripheral iridotomy (17.0 vs. 19.3 mmHg, P < .001) and post-laser peripheral iridotomy (15.6 vs. 18.6 mmHg, P < .001) conditions. The thickness values of central cornea increased slightly after the water-drinking test in pre-laser peripheral iridotomy (535 vs. 538 µm, P = .001) compared with post-laser peripheral iridotomy (532 vs. 536 µm, P = .003). The water-drinking test had no significant effect on other biometric or anterior chamber parameters, before or after laser peripheral iridotomy. CONCLUSIONS: The water-drinking test increased intraocular pressure, both before and after laser peripheral iridotomy. Laser peripheral iridotomy had no significant effect on the amount of intraocular pressure change after the water-drinking test. The water-drinking test has no effect on other biometric or anterior chamber parameters.

The Water-Drinking Test Revisited: An Analysis of Test Results in Subjects with Glaucoma.

PURPOSE: The Water-Drinking Test (WDT) has been shown to predict the diurnal IOP change. This study evaluates the factors that may affect the WDT results. METHODS: This study was conducted on 203 glaucoma patients who had undergone trabeculectomy (53) or tube surgery (31), or had a medically controlled open-angle (82) or closed-angle (37) glaucoma. IOP was measured at baseline and then every 15 minutes over a one-hour period after drinking water. The main outcome measures were IOP change (increase in IOP from baseline) at all measurement time points, IOP peak (highest IOP after drinking water), IOP fluctuation (difference between IOP peak and baseline), and assessing the association of these IOPs with a patient's demographic and management modalities. RESULTS: The mean age of the participants was 54±18 years, and 113 (56%) were male. Female patients showed greater IOP fluctuation than males (7.28 vs. 5.92 mm Hg; P=0.016), and a greater IOP peak (22.7 vs. 20.1 mm Hg; P=0.001). The observed associations between gender and IOP changes were only significant in <50 years. IOP at 60 minutes was greater in tube than trabeculectomy (5.6 vs. 3.1 mm Hg; P=0.007). The number of topical medications showed a direct independent association with IOP changes (P<0.001). Compared to other classes of topical medications, latanoprost showed lower WDT-IOP profile (P=0.0003). CONCLUSIONS: WDT-IOP change was diminished in subjects on latanoprost, and was greater in females <50 years, and those on greater number of medications.

Current and Future Techniques in Wound Healing Modulation after Glaucoma Filtering Surgeries.

Filtering surgeries are frequently used for controlling intraocular pressure in glaucoma patients. The long-term success of operation is intimately influenced by the process of wound healing at the site of surgery. Indeed, if has not been anticipated and managed accordingly, filtering surgery in high-risk patients could end up in bleb failure. Several strategies have been developed so far to overcome excessive scarring after filtering surgery. The principal step involves meticulous tissue handling and modification of surgical technique, which can minimize the severity of wound healing response at the first place. However, this is usually insufficient, especially in those with high-risk criteria. Thus, several adjuvants have been tried to stifle the exuberant scarring after filtration surgery. Conventionally, corticosteroids and anti-fibrotic agents (including 5-fluorouracil and Mitomycin-C) have been used for over three decades with semi-acceptable outcomes. Blebs and bleb associated complications are catastrophic side effects of anti-fibrotic agents, which occasionally are encountered in a subset of patients. Therefore, research continues to find a safer, yet effective adjuvant for filtering surgery. Recent efforts have primarily focused on selective inhibition of growth factors that promote scarring during wound healing process. Currently, only anti-VEGF agents have gained widespread acceptance to be translated into routine clinical practice. Robust evidence for other agents is still lacking and future confirmative studies are warranted. In this review, we explain the importance of wound healing process during filtering surgery, and describe the conventional as well as potential future adjuvants for filtration surgeries.