Effect of Light Conditions and Accommodation on Implantable Phakic Contact Lens Vault by Anterior Segment Optical Coherence Tomography.

Purpose: To investigate the dynamic pupil and vault changes in eyes with implantable phakic contact lens (IPCL) under photopic and scotopic settings, as well as during accommodation using the anterior segment optical coherence tomography (AS-OCT). Methods: A prospective observational study included consecutive 36 eyes of myopic patients who underwent IPCL V2.0 implantation. Under photopic and scotopic light settings, as well as during accommodation, all patients were scanned using CASIA OCT (CASIA2; TOMEY, Nagoya, Japan). The pupil size, the vault (distance between the back surface of the IPCL and the anterior lens capsule), ACD-lens (distance between the posterior corneal surface and the anterior lens surface), IPCL-lens (distance between the posterior corneal surface and the anterior IPCL surface), and lens thickness (LT) were the study parameters. Results: The vault was significantly lower under photopic conditions (p-value<0.001). The pupil size was significantly smaller in photopic conditions (p-value<0.001). LT (p-value=0.975) and ACD-lens (p-value=0.917) were not significantly different between scotopic and photopic conditions, while the ACD-IPCL was significantly larger during photopic conditions (p-value=0.013). There were significant changes in all parameters between accommodative and non-accommodative conditions. Conclusion: The IPCL vault decreased significantly under photopic light conditions and accommodation.

Macular vessel density before and after panretinal photocoagulation in patients with proliferative diabetic retinopathy.

INTRODUCTION: Diabetic retinopathy (DR) is microangiopathy causing ischemia leading to proliferative diabetic retinopathy and macular edema. Panretinal photocoagulation (PRP) reverses the ischemia leading to regression of neovessels. Most previous studies showed the large vessel effects of PRP, while optical coherence tomography angiography (OCTA) allowed noninvasive quantification of microvascular retinal changes. AIM: To study the effect of PRP on microvascular retinal vessels in a detailed manner at different retinal and choroidal levels using OCTA. PATIENTS AND METHODS: This study was a prospective interventional study. 30 eyes of 18 diabetic patients with PDR were included. All patients were evaluated clinically and with OCTA (Avanti RTVue-XR system, Optovue) to evaluate superficial and deep vessels density (VDs), choroidal flow, and FAZ area before PRP (base line) and 1 month and 6 months after PRP. RESULTS: PRP improved vessels density at superficial (SCP), deep (DCP), and choriocapillaris levels. Foveal vessel density at SCP and DCP were statistically significantly increased. SCP was 28.76 ± 2.56 at base line and was increased to 29.84 ± 2.47 and 30.89 ± 2.20 after 1 month and after 6 months, respectively. DCP was 34.08 ± 5.59 at base line and was increased to 34.93 ± 5.66 and 36.09 ± 5.62 after 1 month and after 6 months, respectively. Foveal choriocapillaris was statistically significantly increased from 63.04 ± 2.66 at base line to 63.48 ± 2.65 and 63.98 ± 2.78 after 1 month and 6 months, respectively. Choroidal flow was increased from 1.74 ± 0.07 at base line to 1.75 ± 0.09 at 1 month which was nonsignificant (P = 0.72), but it was significantly increased to 1.87 ± 0.27 6 months after PRP (P = 0.009). FAZ area was significantly improved after PRP. FAZ area was decreased from 0.56 ± 0.27 at base line to 0.50 ± 0.21 after 1 month and to 0.46 ± 0.21 after 6 months. CONCLUSION: OCTA parameters were significantly improved by PRP in PDR patients, possibly due to redistribution of blood in occluded capillary plexuses. TRIALS REGISTRY: NCT04976361.

Early and delayed suture adjustments after adjustable suture strabismus surgery: a randomized controlled trial.

Background: Adjustable sutures increase the success rate of strabismus surgery. However, the optimal timing of postoperative suture adjustment remains controversial. This trial was aimed at comparing the surgical outcomes and pain scores of early or 2 - 4 h and delayed or 24 h postoperative suture adjustment in adult patients undergoing strabismus surgery. Methods: An open-label, prospective, randomized, comparative interventional study was performed in consecutive adult patients scheduled for eye muscle surgery. Patients were randomized into two groups: the early group, with suture adjustment 2 - 4 h postoperatively, and the delayed group, with suture adjustment 24 h postoperatively. Subjective pain scores during the adjustment were also analyzed. The angles of misalignment at 1 and 3 months and the success rate at 3 months postoperatively were compared. Results: Forty-five (90%) patients completed the follow-up, including 23 (92%) in the early adjustment group and 22 (88%) in the delayed adjustment group, with a mean (standard deviation) age of 25.6 (9.5) years and a male-to-female ratio of 46.7:53.3. Thirty patients (66.7%) had exotropia, and 15 (33.3%) patients had esotropia. Both groups had comparable baseline characteristics (all P > 0.05). The mean pain scores during adjustment did not differ significantly between groups (P > 0.05). The postoperative angles of alignment were comparable between the groups before suture adjustment and at the 1- and 3-month follow-ups (all P > 0.05). The success rate in the early adjustment group was slightly higher (87.0% versus 63.6%), but the difference was not statistically significant (P > 0.05). The success rate was comparable between the groups in patients with esotropia or exotropia (both P > 0.05). Conclusions: Although the early adjustment group had a slightly higher success rate, the difference was not significant. Both groups had comparable subjective pain scores during adjustment, final motor alignment, or success rate. Future clinical trials should be performed different time intervals for postoperative suture adjustment, and subjective and objective outcomes, such as diplopia and stereopsis, should be compared between patients with a first strabismus surgery and those who underwent reoperation. This could better resolve the persistent controversy related to the optimal time for suture adjustment.

Corrected Intraocular Pressure Variability with Central Corneal Thickness Measurement.

PURPOSE: To evaluate variability in measured intraocular pressure (IOP) values when correlated with central corneal thickness measurements obtained by both ultrasonic and optical tools. PATIENTS AND METHODS: We included 46 eyes of 46 healthy subjects (age range 35-76 years). Exclusion criteria for the current study were patients with confirmed diagnosis of glaucoma, glaucoma suspect patients and those having corneal opacities, scars or prior cornea-based laser vision correction. Central corneal thickness (CCT) was measured using two methods: ultrasonically (CCT1) by pachymeter and optically (CCT2) using anterior-segment optical coherence tomography (AS-OCT). The IOP was measured in all subjects using Goldmann applanation tonometry (GAT). RESULTS: No significant difference was detected comparing intraocular pressure values and CCT-corrected intraocular pressure (IOPcc1 and IOPcc2) (P=0.47 and P=0.06, respectively) among the study participants. A significant negative correlation was found between corneal thickness-corrected IOP values and the measured central corneal thickness by both optical and ultrasonic tools (P=0.004 and P=0.001, respectively). CONCLUSION: Intraocular pressure appears to be dependent and positively correlated with CCT changes. However, this does not appear to depend largely on methods used for measuring the CCT in the current study. Corrected intraocular pressure is negatively correlated to both ultrasonically and optically measured central corneal thickness.

Clinical Profile of HLA-B27-Associated Uveitis in an Egyptian Cohort.

PURPOSE: To describe the clinical profile of patients with HLA-B27-associated uveitis at 2 Egyptian tertiary eye centers. METHODS: A retrospective study reviewing the medical records of all patients with HLA-B27-associated uveitis served at 2 uveitis referral clinics in Egypt between January 2010 and June 2018. RESULTS: The study included a total of 554 patients. Anterior uveitis was the most common type. Ankylosing spondylitis was an important systemic comorbidity in the present study, affecting 27.4% of our patients. Cataract was the most frequent ocular complication. By the conclusion of the study, 6.1% of the affected eyes had a BSCVA poorer than 20/200. CONCLUSION: The clinical profile of HLA-B27-associated uveitis in our cohort of Egyptian patients is similar to that reported from other regions of the world. In our study, a relatively high rate of cataract was observed.

Differential time-course tear film quantitative changes following limbal relaxing incisions.

BACKGROUND: The study aims at evaluating the time-course changes of pre-corneal tear film after simultaneous phacoemulsification and limbal relaxing incisions (LRIs) performed in 2 groups of patients; group-A had vertical and group-B had horizontal LRIs. METHODS: Fourty-two eyes of 28 patients with co-existing cataract and corneal astigmatism were studied before and after simultaneous cataract surgery and LRIs (at weeks 1, 4 and 12), patients were classified into 2 groups according to the orientation of LRIs; vertical (A) and horizontal (B) groups. Pre-corneal tear film stability was assessed by measuring the tear break-up time (TBUT) and the tear volume was determined using Schirmer's I test (Basic Schirmer's test; BST), both preoperatively and postoperatively. RESULTS: TBUT was significantly reduced in both the study groups (P = 0.001) without significant reduction regarding basic Schirmer's test values except for the first postoperative week in the horizontal LRI group-B (P = 0.04). CONCLUSIONS: Precorneal tear film stability is altered in the early postoperative period after simultaneous cataract and LRI incisions shown by TBUT measurement values. These changes do not appear to differ significantly depending on the orientation of LRI incisions.

Evaluation of primary internal limiting membrane peeling in cases with rhegmatogenous retinal detachment.

BACKGROUND: Epiretinal membranes (ERMs) have been reported after pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD). Peeling of the internal limiting membrane (ILM) can prevent post-PPV ERM formation but has a potential negative impact on macular structure and function. PURPOSE: To investigate the anatomical and functional outcomes of ILM peeling during PPV for primary RRD. METHODS: This was a prospective nonrandomized study that included 60 eyes of 60 patients with a primary macula-off RRD and less than grade C proliferative vitreoretinopathy (PVR). Eyes were allocated into 2 groups; Group A underwent PPV without ILM peeling and Group B had ILM peeling. At postoperative month 6, all patients underwent retinal imaging using spectral domain optical coherence tomography (OCT) and OCT angiography and macular function was assessed using multifocal electroretinogram (mfERG). Baseline characteristics and postoperative anatomical and visual outcomes were recorded and statistically analyzed. RESULTS: We enrolled 30 eyes of 30 patients in each group. In Group A, mean age was 44.6 years, while the mean age of Group B patients was 49.9 years. Postoperative LogMAR visual acuity was significantly better in Group A than in Group B (p < 0.001). ERMs were demonstrated on OCT in 13.3% of Group A and none of Group B patients (p = 0.04). Retinal dimples were found in 53.3% of Group B and none of Group A eyes (p < 0.001). OCTA showed a greater vessel density of the superficial capillary plexus (SCP) in Group A compared to Group B eyes (p = 0.046), while no difference was found regarding deep capillary vessel density (p = 0.7). Mean amplitude of mfERG P1 wave was significantly higher in Group A eyes than in Group B (p = 0.002). Both the SCP vessel density and P1 amplitude were positively correlated with visual acuity (p < 0.001). CONCLUSION: This study suggests that ILM peeling prevents ERM development in eyes undergoing PPV for uncomplicated macula-off RRD, but potential damage to macular structure and function were found.Trial registration Retrospectively registered on 09/24/2019 on ClinicalTrials.gov with an ID of NCT04139811.

Comparison Between Silicone Oil and Gas in Tamponading Giant Retinal Breaks.

PURPOSE: The purpose of this study is to compare anatomical and visual outcomes after using silicone oil (SO) or C3F8 gas as tamponades after pars plana vitrectomy (PPV) for retinal detachment (RD) associated with giant retinal tears (GRTs). METHODS: A retrospective chart review was conducted for cases that underwent PPV for GRT-associated RD. We excluded eyes that had prior vitreoretinal surgery, a history of ocular trauma or worse than grade B proliferative vitreoretinopathy (PVR). Baseline demographic and ocular characteristics, surgical details and postoperative anatomical and visual outcomes were recorded and statistically analyzed. RESULTS: We included 88 eyes; 48 eyes had C3F8 gas and 40 eyes had SO as a tamponading agent. Mean age was 39 years. All eyes underwent 23G PPV with no adjuvant scleral buckling and phacovitrectomy was performed for all phakic eyes. Final retinal reattachment was achieved in 86 eyes (97.7%). One eye from each group had recurrent RD. Postoperative vision was significantly better in the gas group (p= 0.008). Prolonged increase of IOP developed in 6 eyes in the SO group and 5 eyes in the gas group. Prolonged uveitis developed in 4 eyes in the gas group and 6 eyes in the oil group (P= 0.04). Epiretinal membranes (ERM) developed in 10 eyes in the gas group and 9 eyes in the oil group. We found no significant difference between both groups regarding postoperative glaucoma or ERM formation. CONCLUSION: Both agents achieved similar favorable anatomical outcomes in a series of eyes with fresh GRT-associated RD and low-grade PVR, with better visual outcome and less frequent uveitis associated with the use of gas tamponade.

Pattern of Intermediate Uveitis in an Egyptian Cohort.

Purpose: To describe the clinical experience with intermediate uveitis at six Egyptian tertiary eye centers.Methods: A multicenter retrospective chart review of all patients with intermediate uveitis seen at six ocular inflammation referral clinics in Egypt between January 2010 and January 2017.Results: The study included a total of 781 patients with intermediate uveitis. The study cohort comprised of 282 male and 499 female patients. In over half of our cohort (58.77%), no specific cause could be confirmed. The remaining patients had sarcoidosis (16.26%), tuberculosis (14.85%), multiple sclerosis (9.09%), and TINU (1.02%). By the end of our study, 62% of the affected eyes had a BCVA better than 20/40Conclusion: More than 40% of our patients with intermediate uveitis had sarcoidosis, tuberculosis, multiple sclerosis, or TINU as the underlying etiology. Owing to their potential morbidity, these diseases need to be considered in Egyptian patients presenting with intermediate uveitis.

Evaluation of Optic Nerve Head Parameters and Retinal Nerve Fiber Layer Thickness in Axial Myopia Using SD OCT.

INTRODUCTION: The purpose of this research was to study the effect of increased axial myopia, in non-glaucomatous eyes, and its correlation with ONH parameters, and RNFL thickness, using Cirrus HD 4000 SD-OCT. METHODS: The myopia group included 86 eyes of 86 patients, while the control group involved 92 eyes of 92 patients, attending the Ophthalmology Outpatient Clinic in Minia University Hospital, between November 2013 and March 2015. ONH parameters and peripapillary RNFL thickness measurement were evaluated by using SD-OCT, selecting the standard optic disc cube 200 × 200. RESULTS: The mean age of the myopia group was (36.55 ± 9.44), the mean spherical equivalent was (-12.70 ± 3.87 D), and the mean axial length was (27.88 ± 1.92 mm). The control group had mean age of (34.82 ± 8.87), mean spherical equivalent of -0.65 ± 0.41 D, and mean AL of (22.16 ± 0.82). A significant difference was reported between the two groups, regarding disc area (p = 0.01), rim area (p = 0.001), vertical C/D (p = 0.01), average C/D ratio (p = 0.001), average and temporal RNFL thickness (p = 0.0001, p = 0.001, respectively). CONCLUSION: A significant difference was found between highly myopic non-glaucomatous eyes and the control group, regarding ONH parameters and RNFL thickness as measured by SD-OCT. As OCT magnification adjusted ONH parameters were larger, global and the temporal RNEL were thicker in the myopia group, those magnification adjusted parameters helped in an accurate evaluation of ONH and RNFL in highly myopic eyes, in order to avoid misdiagnosis of glaucoma in such eyes.

Assessment of Posterior Segment Using Spectral Domain OCT in Highly Myopic Eyes.

PURPOSE: Spectral Domain Optical Coherence Tomography (SD-OCT) was used to evaluate retinal and vitreo-retinal changes that occur in highly myopic patients. METHODS: This prospective study included 472 eyes of 472 patients suffering from high myopia (> -6.00 D), between May 2012 and December 2015. All patients were examined, using Cirrus HD OCT (Zeiss Cirrus TM HD-OCT model 4000), to detect any retinal or vitreo-retinal interface abnormalities.All obtained data was analyzed using Statistical Package for the Social Sciences software version 17 (SPSS Inc, Chicago, IL, USA) and the paired two-sided t-test. Bivariate correlations were performed between different parameters using the Spearman correlation coefficient (r). RESULTS: Mean spherical equivalent (MSE) was -13.11± 4.35D. Mean axial length (AL) was 28.5±1.62 mm. Posterior vitreous detachment (PVD) was the most frequent OCT finding; representing 33.4% of the cases, 13.7% of them were associated with macular traction. A statistically significant positive correlation was found between AL and MTM, full thickness macular hole, PVD with traction, and dome shaped macula (r = 0.49 and P = 0.001, r = 0.422 and P = 0.0001, r = 0.25 and P = 0.03, r=0.475, P=0.001 respectively). CONCLUSION: OCT is a valuable tool in detecting retinal and vitreo-retinal interface abnormalities in highly myopic eyes, and it can be used for follow up of those patients to avoid advanced retinal damage.