Potential Acuity Research Articles

Indications and Outcomes of Emergency Keratoplasty in a Major New Zealand Eye Tertiary Referral Center, 2000 to 2021.

To report the indications and outcomes of emergency keratoplasty over a 21-year period in Greenlane Clinical Centre, the major tertiary eye referral center in Auckland, New Zealand (Aotearoa). A retrospective review of medical records of all emergency keratoplasties performed in Greenlane Clinical Centre from January 2000 to September 2021 was conducted. Demographic, preoperative, intraoperative, and 1-year postoperative data were collected. Emergency keratoplasty was performed in 102 eyes of 97 patients (54 men), comprising 5.6% of transplants performed (N = 1830) in this period. The mean age was 53 years (range = 4-95 years, SD = 20). Patients of Māori ethnicity were overrepresented (31%). Corneal perforation was present in 90% of eyes, and microbial keratitis was the most common indication. Bacteria were the most commonly isolated organisms (38%). The mean preoperative and 12-month postoperative best potential corrected distance visual acuity was 1.6 and 1.2 (logMAR), respectively. All cases of therapeutic keratoplasty achieved initial therapeutic success, with no eyes lost or requiring repeat emergency keratoplasty. Complications included nonhealing epithelial defects (19%), cataract (19%), glaucoma (15%), allograft rejection (13%), and corneal melting (5%). Fifteen cases (15%) had documented graft failure at 12 months. Multivariate analysis revealed that younger age was the only statistically significant factor associated with failure at 12 months. Emergency keratoplasty was the indication for 5.6% of keratoplasties performed. Our results compare favorably with those in the literature, possibly because of early intervention and lower incidence of fungal keratitis. The reported overrepresentation of Māori has important implications for health access and delivery in New Zealand.

Massive peritoneal inclusion cyst with secondary abscessation

AbstractPeritoneal inclusion cysts are rare intra‐abdominal cystic lesions of controversial pathogenesis and nomenclature. Postulated to be of neoplastic or reactive origin, they are characterised by progressive expansion and variable symptomatology in classically reproductive‐aged females. Local recurrence is frequent while malignant transformation is plausible. Herein, we review a presentation of a massive peritoneal inclusion cyst with secondary abscessation and septic shock in a 58‐year‐old female, reviewing the available literature to highlight the potential acuity of this pathology, the standard of surgical care, and the need for caution by treating surgeons in its evaluation as an entirely benign process.

Rotational stability and capsular bag performance of a hydrophobic acrylic open-loop single-piece intraocular lens.

To evaluate the rotational stability and capsular bag performance of a blue light-absorbing hydrophobic acrylic open-loop single-piece intraocular lens (IOL) with a blast-finished anchor wing haptic design during the first 6 postoperative months. In this prospective clinical study, patients with age-related cataract and potential postoperative corrected distance visual acuity (CDVA) of 0.2 logMAR or better were included. The patients received a non-toric hydrophobic acrylic single-piece IOL with an axis mark (YST0.00; Nidek Co. Ltd, Japan). Surgeries were video-taped. Retroillumination images were acquired 1 h, 1 week and 6 months postoperatively. Rotational stability was assessed by precise image overlay. At 6 months, Purkinje meter measurements were performed to evaluate tilt and decentration. In total, 100 eyes of 77 patients were included in the analysis. Mean absolute rotation was 2.1 ± 1.7° (median 1.7, range: 0-7.9) at 6 months (1 h - 6 months postoperatively). IOL rotation was ≤3° and ≤6° in 74 (74%) and 98 (98%) eyes, respectively. Mean absolute IOL rotation from the end of surgery to 6 months was 2.5 ± 2.2° (median 2.3, range: 0-15.6; n = 78). Mean tilt (pupillary axis) and decentration were 4.1 ± 1.9° (median 4.0, range: 0.5-8.2) and 0.35 ± 0.17 mm (median 0.32, range: 0.06-0.91) respectively (n = 84). Postoperatively, 98 (98%) eyes achieved a CDVA of 0.2 logMAR or better, 95 (95%) of ≤0.1 and 81 (81%) of ≤0.0. This hydrophobic acrylic single-piece IOL showed an excellent rotational stability and capsular bag position with low tilt and decentration values.

Clinical characteristics and surgical outcomes of pediatric epiretinal membranes without specific etiologies

Objective: To describe clinical characteristics and surgical outcomes of pediatric epiretinal membranes (ERMs) without specific etiologies. Methods: Medical data of a cohort of pediatric patients (≤14 years) who had ERMs without specific etiologies, underwent surgical removal from January 2019 to September 2021, and were followed up for at least 12 months were retrospectively reviewed. Age at presentation, chief complaints, color fundus photographs, optical coherence tomographic images, preoperative and postoperative visual acuities, anatomical changes, and postoperative complications were assessed. Results: There were 14 patients (17 eyes), including 5 females (6 eyes) and 9 males (11 eyes). The mean age at surgery was 6.31±2.91 years, and the follow-up duration was 17.3±9.5 months. Eight patients were found to have low vision in the school physical examination. Fifteen eyes had an appearance of cellophane macular reflex on fundus images. On optical coherence tomographic images, 10 eyes had"taco"folds, and 7 eyes had"ripple"folds. Five eyes had ellipsoid zone disruptions, while 12 eyes had ellipsoid zone integrity. The preoperative and postoperative best-corrected visual acuities in logMAR were 0.532±0.302 and 0.340±0.298. One patient suffered traumatic cataract and secondary retinal detachment postoperatively, and after further vitrectomy, the retina became attached. Conclusion: Pediatric ERMs without specific etiologies were mostly found in school-age children with cellophane macular reflex and"taco"folds. Vitrectomy may result in both potential visual acuity and macular anatomical improvements.

Visual Function After Implantation of Trifocal and Trifocal Toric Intraocular Lenses Using Intraoperative Aberrometry.

To evaluate patient outcomes and visual function following trifocal and trifocal toric intraocular lens (IOL) implantation using intraoperative aberrometry at a single site in the US. This prospective, single arm study included 21 subjects that completed 3 month follow-up. Inclusion criteria were visually significant cataract and potential post-operative visual acuity of 20/25 or better. Endpoints included postoperative prediction error, refractive outcomes, uncorrected visual acuities at distance (UDVA), intermediate (UIVA), and near (UNVA), contrast sensitivity, and subject responses on the modified Visual Function Quality of Life Questionnaire (VF-14 QOL). Binocular UDVA, UIVA, and UNVA were 20/25 or better in 100% (21/21), 100% (21/21), 90% (19/21) of subjects. The absolute prediction error was 0.50 D or less in 79% (33/42) of eyes, and 81% (34/42) and 86% (36/42) of eyes achieved ≤0.5 D of residual astigmatism and manifest refraction spherical equivalent, respectively. On the modified VF-14 QOL, driving at night, reading small print, and reading a newspaper or book were the tasks that had the lowest percentages of subjects reporting no difficulty or a little difficulty. Implantation with trifocal and trifocal toric IOLs using intraoperative aberrometry can provide high refractive precision, leading to excellent visual performance and low visual task difficulty at all ranges (distance, intermediate, and near).

Evaluation of Agreement Between Sweep Visual Evoked Potential Testing and Subjective Visual Acuity.

The primary objective of this study was to evaluate the agreement of visual acuity (VA) obtained with the sweep visual evoked potential (sVEP) method with the VA obtained with the Snellen chart. The secondary objective was to examine the effect of age and gender on agreement. Best corrected VAs of subjects were recorded with the Snellen chart, and sVEP testing was performed according to the recommendations of the International Society for Clinical Electrophysiology of Vision (ISCEV). Snellen VAs and sVEP measurements were analyzed using logMAR conversion for statistical analysis. Agreement was evaluated with Bland-Altman analysis. The study included 49 subjects with a mean age of 53.5±17.3 years (range: 19-75 years) and mean Snellen VA of 0.31±0.32 logMAR (range: 1.3-0.0 logMAR). In the Bland-Altman analysis, the mean differences between the VA and sVEP measurements (VA-sVEP) were significantly different and outside the limits of agreement (p=0.035). A significant proportional bias (p=0.0007) was found in the regression analysis performed between VA-sVEP and the mean VA. According to the Bland-Altman analysis of sex subgroups, there was a significant difference between VA and sVEP measurements in female subjects (p=0.006). The difference between VA and sVEP measurement increased significantly with older age (R2: 0.306, p<0.001, β: 0.05 [0.03, 0.08]). In conclusion, sVEP measurements and VAs did not show statistical agreement. Cranial anatomy and endocrine differences of the subjects may affect their sVEP measurements. The difference between the methods varies according to VA level. Directly using sVEP results instead of VA would not be appropriate.

Tear film dynamics of a new soft contact lens.

To present the objective metrics from a study that evaluated the clinical performance of a senofilcon A contact lens, both with and without a new manufacturing technique. This was a single-site, five-visit, controlled, randomised, subject-masked, 2 × 2 crossover study (May-August 2021) with a 2-week lens dispensing period (bilateral wear) and weekly follow-up visits. Healthy adult (18-39 years), habitual spherical silicone hydrogel contact lens wearers were included. The High-definition (HD) Analyzer™ was used to objectively measure the lens-on-eye optical system resulting from the study lenses at 1-week follow-up. Measurements assessed were vision break-up time (VBUT), modulation transfer function (MTF) cutoff, Strehl ratio (SR), potential visual acuity (PVA) for 100% contrast and objective scatter index (OSI). Of the 50 enrolled participants, 47 (94.0%) were randomly assigned to one of the two possible lens wear sequences (test/control or control/test) and dispensed at least one study lens. The estimated odds ratio of VBUT > 10 s was 1.582 (95% confidence interval [CI]: 1.009 to 2.482) in test versus control lens. The least squares mean difference estimates of MTF cutoff, SR and PVA for 100% contrast between test versus control lens were 2.243 (95% CI: 0.012 to 4.475), 0.011 (95% CI: -0.002 to 0.023) and 0.073 (95% CI: -0.001 to 0.147), respectively. The estimated ratio of median OSI between test versus control lens was 0.887 (95% CI: 0.727 to 1.081). The test lens demonstrated superiority over the control lens with respect to VBUT and MTF cutoff. No serious adverse events were reported; eight adverse events (three ocular, five non-ocular) were indicated by six participants during the study. The test lens demonstrated an increased probability of having a longer VBUT (>10 s). Future studies may be designed to assess the efficacy and long-term use of the test lens in a larger population.

Flanged Sutureless Intrascleral Fixation of Dislocated Hard 1-Piece Polymethyl Methacrylate Intraocular Lenses.

To describe the vitreoretinal surgical technique and report the outcomes of our method of sutureless flanged intrascleral haptic fixation of dislocated 1-piece polymethyl methacrylate intraocular lenses with rigid haptics. Ciliary sulcus-based scleral tunnels were created by placing valved 27-gauge (g) trocar cannulas limbus parallel with conjunctival displacement. After complete vitrectomy, the rigid haptics were then externalized using 27g forceps. Cautery was then used to form flanges at the haptic tips. The haptics were then pushed back into the mouths of the scleral tunnels. Flanged intrascleral fixation was successfully achieved in eight eyes of seven patients. The average age at the time of surgery was 75 ± 13.7 years, with a mean follow-up of 17.9 ± 16.3 months (range 3-42 months). Intraocular lens dislocation/subluxation was the most common indication for surgery. All patients fully recovered to their potential acuity by their third postoperative visit. The most significant complication was erosion of one haptic in one patient, which was successfully managed without requiring intraocular lens exchange. There were no complications of subsequent dislocation, endophthalmitis, retinal detachment, or uveitis-glaucoma-hyphema syndrome. Flanged sutureless intrascleral fixation of dislocated 1-piece polymethyl methacrylate intraocular lenses with rigid haptics can be safely and successfully performed, avoiding the large wound creation accompanying intraocular lens exchange and the disadvantages of suture-based techniques.

Recommendation for Presbyopia-Correcting Intraocular Lenses: A Delphi Consensus Statement by the ESASO Study Group

To establish consensus among experts in lens and refractive surgery to guide general ophthalmologists on issues related to presbyopia-correcting intraocular lenses (IOLs). A modified Delphi method to reach a consensus among experts. A steering committee formulated 105 relevant items grouped into four sections (preoperative considerations, IOL selection, intraoperative considerations, and postoperative considerations). The consensus was defined as ≥ 70% of experts agreeing with the evaluation of a statement. Ten experts participated and completed all rounds of questionnaires (100% response rate). Of 68 items considered in the preoperative considerations, consensus was achieved in 48 (70.6%). There was a lack of consensus over IOL selection, the experts only agreed on the importance of the patient's habits for the optical IOL design selection. Of the 14 considerations related to intraoperative issues, the experts reached a consensus on 10 (71.4%). The postoperative considerations section reached the highest consensus in 10 items of 13 (76.9%). Key recommendations for a diffractive multifocal IOL were a potential postoperative visual acuity > 0.5, a keratometry between 40-45 diopters, a pupil >2.8mm under photopic conditions and <6.0 mm under scotopic conditions, a root mean square of higher order corneal aberrations <0.5 µm for 6-mm pupil size, while monofocal or non-diffractive IOLs should be considered for patients with coexisting eye disorders. A lack of agreement was found in the issues related to the IOL selection.

Use of Endoscopy in Keratoprostheses with Biological Haptics.

In severe ocular surface disease where penetrating keratoplasty cannot be successfully performed, implantation of a keratoprosthesis can achieve visual rehabilitation. Osteo-odonto-keratoprosthesis offers good tissue integration due to its biological haptics, resulting in a better survival rate and lower extrusion rate. Due to corneal opacity, which is often complete, assessing the potential visual acuity is challenging. Also, during implantation of a keratoprosthesis or during later intraocular revision surgery, there is a limited field of view of the peripheral retina or ciliary body region. This is due to the small size and central location of the prosthesis optics and the geometric conditions of the prosthetic haptics. These factors can complicate surgery. Endoscopic video assistance was used in 7 eyes of 6different patients (6 male, 2 female, mean age 66 ± 9 years). In 3 eyes the indication was for preoperative estimation of potential visual acuity during a 23 G vitrectomy. In 2 eyes it was used during implantation surgery itself, and in 2 eyes it was used during revision surgery and vitrectomy. An endoscope with semirigid optics and an image guidance system with 3,000 pixels and 70°field of view from PolyDiagnost was used, with a 23 G trocar system. Endoscopy was successfully applied in all eyes examined. In 1 of 3 eyes where endoscopy was performed to estimate the visual acuity potential, a keratoprosthesis was subsequently planned. In the other two eyes, the visual acuity potential was rated insufficient for future keratoprosthesis surgery. Detailed assessment of the retina and optic disc was limited to gross pathologies because of low image resolution. During implantation, it was possible to visualize correct positioning of the posterior haptic behind the host cornea. Retroprosthetic membranes could successfully be removed by endoscopy-assisted vitrectomy. Endoscopy assistance offers advantages in visualization both for determining the indication for KPro surgery, during implantation, and in the management of complications after implantation of a keratoprosthesis. Low resolution of the imaging system places limits on assessment capabilities. Although technical improvements and miniaturization may enhance its future capabilities, endoscopy in its current form is already a valuable addition in the context of keratoprosthesis surgery.

Corneal laser procedure for vision improvement in patients with neovascular age-related macular degeneration and other retinal disorders involving central vision loss: a retrospective cohort study

Background: The purposes of this pilot retrospective observational cohort study are to determine: 1) the safety and efficacy of corneal photovitrification (CPV), a corneal laser procedure, for vision improvement in patients with neovascular age-related macular degeneration (nAMD) and other retinal disorders involving central vision loss, and 2) the correlation between post-treatment (post-treatment (Tx)) best-corrected distance visual acuity (BCDVA) and pre-Tx potential visual acuity (PVA). Methods: BCDVA measurements using ETDRS charts and PVA measurements using Gonzalez-Markowitz PVA charts were analyzed for 72 eyes that received a single CPV treatment. Results: Safety - No clinically significant complications or serious adverse events occurred. Efficacy – Mean BCDVA improved significantly from 20/303 (1.18 log of the minimum angle of resolution (logMAR), 26 letters) at pre-Tx to 20/208 (1.02 logMAR, 34 letters) at 1m post-Tx (p = 0.000001) for a cohort of 57 eyes, improving to 20/198 (1.00 logMAR, 35 letters; 11.6 mean letters gained) at 12m (p = 0.0009) for a cohort of 29 eyes. Mean pre-Tx PVA gains correlated well with mean BCDVA improvements at 1m, 3m, 6m and 12m post-Tx. Conclusions: Subject to a small sample size, the CPV corneal laser procedure is safe and efficacious for vision improvement in patients with nAMD and other retinal disorders involving central vision loss. The pre-Tx PVA correlates well with post-Tx BCDVA; the PVA test may be useful for screening of candidate eyes for CPV treatment and for managing expectations.

The effect of mental load on psychophysical and visual evoked potential visual acuity.

Under real-world conditions, tasks dependent on visual acuity may need to be performed in the presence of a mental load arising from concurrent, non-visual tasks. Therefore, measuring visual acuity concurrently with mentally demanding tasks may reflect a patient's vision more accurately. This study was designed to evaluate the impact of task-induced mental load on high contrast visual acuity, as measured using a letter chart and estimated via sweep visual evoked potentials (sweep VEP). Visual acuity was determined using the Freiburg Vision Test, and also using sweep VEP tested stepwise, from coarse to fine, over 13spatial frequencies, in 31healthy participants (aged 22.4±3.6years). Recordings were repeated while participants concurrently performed an auditory 2-back task. Mental load of the n-back task was confirmed through subjective ratings. Visual acuity determined with the Freiburg Vision Test worsened from -0.02±0.12 to 0.04±0.15logMAR under mental load (p=0.03). Visual acuities estimated by sweep VEPs worsened from 0.38±0.1 to 0.47±0.1logMAR (p<0.001). While the slope of the VEP amplitude versus spatial frequency function steepened significantly with mental load (p=0.01), VEP noise levels were not significantly affected (p=0.07). Visual acuity reduces significantly with a concurrent task that produces mental load. At least part of this reduction appears to be related to alterations in responses within the visual cortex, rather than being purely attributable to higher-level distraction effects.

Does Oblique Effect Affect SSVEP-Based Visual Acuity Assessment?

This study aimed to explore whether there was an effect on steady-state visual evoked potential (SSVEP) visual acuity assessment from the oblique effect or the stimulus orientation. SSVEPs were induced by seven visual stimuli, e.g., the reversal sinusoidal gratings with horizontal, two oblique, and vertical orientations, reversal checkerboards with vertical and oblique orientations, and oscillating expansion-contraction concentric-rings, at six spatial frequency steps. Ten subjects participated in the experiment. Subsequently, a threshold estimation criterion was used to determine the objective SSVEP visual acuity corresponding to each visual stimulus. Taking the SSVEP amplitude and signal-to-noise-ratio (SNR) of the fundamental reversal frequency as signal characteristics, both the SSVEP amplitude and SNR induced by the reversal sinusoidal gratings at 3.0 cpd among four stimulus orientations had no significant difference, and the same finding was also shown in the checkerboards between vertical and oblique orientation. In addition, the SSVEP visual acuity obtained by the threshold estimation criterion for all seven visual stimuli showed no significant difference. This study demonstrated that the SSVEPs induced by all these seven visual stimuli had a similarly good performance in evaluating visual acuity, and the oblique effect or the stimulus orientation had little effect on SSVEP response as well as the SSVEP visual acuity.

Comparison of sweep visual evoked potential of visual acuity and Snellen visual acuity in healthy and amblyopic children.

To evaluate the visual acuity of healthy and amblyopic children using sweep visual evoked potential and compare the results with those of Snellen visual acuity testing. A total of 160 children aged 6-17 years were included in the study. Of these, 104 (65%) were aged 7-17 years old, able to verbally communicate, and did not have any systemic or ocular pathology (Group 1). Group 2 included 56 (35%) children aged 6-17 years, able to verbally communicate, and had strabismus or anisometropic amblyopia whose best corrected visual acuity was between 0.1 and 0.8. All subjects underwent a detailed ophthalmological examination and sweep visual evoked potential measurement. Demographic characteristics, ocular findings, best corrected visual acuity, and sweep visual evoked potential results were recorded. In Group 1, the mean and maximum visual acuity values for sweep visual evoked potential were lower than the Snellen best corrected visual acuity (p<0.001, for both, respectively). Bland-Altman analysis revealed that in Group 1, the distribution of the differences between the Snellen best corrected visual acuity and mean sweep visual evoked potential visual acuity was ±0.11 logMAR, and the distribution of the differences between the Snellen best corrected visual acuity and maximum sweep visual evoked potential visual acuity was ±0.023 logMAR. In Group 2, the mean and maximum sweep visual evoked potential visual acuity were lower than the Snellen best corrected visual acuity (p<0.001 and p=0.009, respectively). Bland-Altman analysis revealed that the distribution of the differences between the Snellen best corrected visual acuity and mean sweep visual evoked potential visual acuity was ±0.16 logMAR, and the distribution of the differences between the Snellen best corrected visual acuity and maximum sweep visual evoked potential visual acuity was ±0.19 logMAR. Sweep visual evoked potential visual acuity measurements have comparable results with Snellen visual acuity measurements. This technique is an objective and reliable method for evaluating visual acuity in children.

Evaluation of the effect of eye movements on the Sweep VEP

AbstractPurposeTo evaluate the effect of fixation stability on the sweep visual evoked potential (sVEP) visual acuity estimate in normal subjects.MethodsTwenty eyes of 10 subjects with normal ophthalmic exam and best‐corrected Snellen chart visual acuity (BCVA) of 20/20 or better in the tested eye underwent sVEP visual acuity estimation using commercially available equipment and software (Diagnosys Espion E3 System Lowell, MA, USA). sVEP was sequentially recorded under two conditions: (i) steady fixation using a central stationary target; and (ii) simulated unsteady fixation with the subject allowed roving eye movements outside the central stationary target. Fixation was monitored using eye‐tracking technology (Tobii Eye Tracker 4C, Tobii Technology AB, Sweden). Fixation stability was classified based on the proportion of fixation points within 4° retinal diameter circle (stable fixation: &gt;75% fixations within 4° circle; unstable fixation: &lt;75% fixations within 4° circle). Within‐subject differences in the estimated sVEP visual acuities under the two tested conditions were assessed using Wilcoxon non‐parametric signed comparisons with significance level set at p &lt; 0.05. Bland‐Altman plots were used to calculate 95% limits of agreement.ResultsSimulated unsteady fixation yielded significant differences in sVEP visual acuity estimation compared to steady fixation (p &lt; 0.0001). The median difference between the two conditions was 0.19 logMAR (~2 Snellen VA lines), with 95% limits of agreement ranging from 0.05 to 0.49 logMAR. Steady fixation overestimated visual acuity compared to BCVA (p &lt; 0.0001), contrary to simulated unsteady fixation, which yielded estimates not statistically different from the expected BCVA (p = 0.91).ConclusionsSimulated unsteady fixation affects sVEP acuity estimates in normal subjects. However, the estimated visual acuities are not significantly different from the expected normal visual acuity of 20/20. sVEP testing can therefore be used to document normal visual acuity without the requirement of steady and central fixation.

Clinical Profile of Low Vision in Children

Introduction: Visual impairment in children is more common in developing countries like Nepal. A low vision service has been found to be effective in significantly improving their overall development and quality of life. The main aim of this study was to determine the causes of low vision in pediatric population along with their refractive error distribution and visual functions. Methods: A descriptive cross sectional study was carried out in Tribhuvan University, BP Koirala Lions Center for Ophthalmic Studies. A total of 50 low vision children were under went detail low vision examination. They were selected through purposive sampling. Data was analyzed by using the descriptive and inferential statistics with SPSS version 19.0. Results: The study findings showed, most common cause of visual impairment in low vision children was refractive error (20%), followed by congenital cataract (18%) and macular dystrophy (16%). The most commonly prescribed low vision device for distance was telescope and for near was spectacle magnifier. There was average acuity improvement of five lines in distance visual acuity with low vision devices. Conclusion: The study concluded that refractive error and congenital cataract being the commonest cause of low vision in children, which reflect poor accessibility of care service among Nepalese children. Refractive error, the major cause of visual impairment could have been managed even in primary eye care center in Nepal. Children with impairment have potential visual acuity that can be improved with low vision services.

The Effect of Sodium Hyaluronate on the Corneal Biomechanics of Patients with Cataract and Dry Eye Before Operation.

ObjectiveThe aim of this study is to analyze the effect of the artificial tear drop administration time on the regularity of the corneal surface in patients with dry eye.MethodsPatients with cataract who were admitted to the hospital from January 2018 to December 2018 were divided into four groups (A, B, C, and D) based on their grade of noninvasive tear break-up time (NIBUT) and the concentration of the eye drops used. Groups A and C were classified as NIBUT grade 1 (NIBUTf of 6–9 s and NIBUTav of 8–13 s), and groups B and D were classified as NIBUT grade 2 (NIBUTf of <5 s and NIBUTav of ≤7 s). Groups A and B received 0.1% sodium hyaluronate eye drops, and groups C and D received 0.3% sodium hyaluronate eye drops.ResultsIn group A, there was a significant increase (p < 0.05) in the surface regularity index (SRI) and the surface asymmetry index (SAI) measured 1 s after eye drop administration. In group B, there was a significant decrease (p < 0.05) in the SRI and the SAI measured 1 s and 5 and 10 min after eye drop administration. In group C, there was a significant increase (p < 0.05) in the astigmatism degree, SRI, SAI, and irregular astigmatism index (IAI) measured 1 s after eye drop administration. There was a significant decrease (p < 0.05) in potential visual acuity (PVA). In group D, there was a significant increase in the IAI and Q value (parameters of aspheric characteristics of cornea, corneal Q value) measured 1 s after eye drop administration as well as a significant decrease in PVA (p < 0.05).ConclusionThe use of 0.1% sodium hyaluronate eye drops in patients with dry eye aid the temporary recovery of corneal surface regularity and the stability of tear film. The 0.1% sodium hyaluronate had a significant effect for the first 10 min after treatment.

Restitution of potential visual acuity in low vision patients with the use of yoke prisms

PurposeTo determine the efficacy of prisms when used for redirection of incoming images towards the preferred reinal loci (PRLs) for restitution of potential visual acuity (PVA) in low vision cases with age-related macular degeneration (AMD). MethodsRetrospective comparative interventional case series review. Low vision rehabilitation (LVR) protocol used included best corrected visual acuity (BCVA), PVA, topographic PRL identification and use of prisms to produce image redirection to the presumed PRL. The primary outcome measure selected for analysis was BCVA for viewing distance targets after use of yoke prisms. ResultsImage relocation with prisms in patients with AMD resulted in significantly better BCVA levels (t32 = 8.57, p < 0.0001) in the better eye. Distance BCVA levels achieved were almost identical to PVA levels (t32 = 0.415, p < 0.681) (y= -0.136 + 1.195x, r = 0.8333, p < 0.001). ConclusionsUse of yoke prisms for image redirection towards a peripheral identifiable PRL may result in PVA restitution in most cases.

Corneal laser procedure for vision improvement in patients with late stage dry age-related macular degeneration - a retrospective observational cohort study

Purpose: To determine the safety and efficacy of corneal photovitrification (CPV), a new corneal laser procedure, for vision improvement in patients with late stage dry age-related macular degeneration (AMD). Design: Retrospective observational cohort study Participants: 32 eyes of 17 patients with late stage dry AMD; each eye received a single CPV corneal laser procedure and had 12 months (12m) post-treatment (Tx) follow-up. Methods: Pre- and post-Tx examinations included slit-lamp biomicroscopy, subjective manifest refraction, best corrected distance and near visual acuity (BCDVA and BCNVA), and potential visual acuity (PVA). Additional examinations including contrast sensitivity (CS), corneal topography (CT), ray tracing aberrometry (RTA) and microperimetry (MP) were obtained for a subgroup (n=12) of eyes. Main Outcome Measures: BCDVA, BCNVA, PVA, CS, CT, RTA and MP measurements Results: Safety – There were no complications or adverse events. Efficacy – Mean (± SD) BCDVA improved significantly (p &lt; 0.004) from 20/238 (1.08 logMAR) at baseline to 20/144 (0.86 logMAR) at 12m post-Tx corresponding to 11.0 (± 13.1) letters gained. Mean contrast sensitivity improved significantly (p &lt; 0.05) by a factor of 1.86 from baseline at 12m post-Tx. Conclusions: Subject to the limitation of a small sample size, this pilot study indicates that the CPV corneal laser procedure is safe and efficacious for vision improvement in patients with late stage dry AMD. The CPV Tx mechanism of action involves retinal irradiance distribution modifications that may stimulate patient use of functional, rather than atrophied, retinal regions.

Effects of whole globe enucleation versus in situ corneoscleral excision on donor cornea tissue quality: a systematic review protocol.

The objective of this review is to systemically compare the effects of whole globe enucleation versus in situ corneoscleral excision on donor cornea tissue quality. Corneal transplantation serves as a sight-restoring surgery for corneal diseases, but the treatment is limited by the persistent shortage of donor corneas globally. Whole globe enucleation and in situ corneoscleral excision are the two methods for eye retrieval. Although studies have reported a higher acceptance rate for corneal donation among donors' relatives with in situ corneoscleral excision than whole globe enucleation, there are concerns regarding the impact on donor cornea tissue quality with in situ corneoscleral excision. Currently, there is limited high-quality evidence comparing the two methods. We will consider prospective and retrospective comparative studies that examine the effects of whole globe enucleation and in situ corneoscleral excision on donor cornea tissue quality. There will be no restrictions on the recipients' characteristics, including age, sex, ocular comorbidities, or potential visual acuity after corneal transplantation. Electronic databases, including (but not limited to) MEDLINE, Embase, Cochrane CENTRAL, ClinicalTrials,gov, and ISRCTN registry will be searched, with no restriction to the language used or date of publication. Retrieval of full-text studies, assessment of methodological quality, and data extraction will be performed independently by two reviewers. A meta-analysis, using fixed or random effects, will be performed for the included randomized controlled trials when there are sufficient similarities in the reporting of outcome measures. If meta-analysis is not possible, the pre-specified outcomes will be narratively synthesized. PROSPERO (CRD42020210575).