Lens Opacities Research Articles

Oxysterol Compounds in Mouse Mutant αA- and αB-Crystallin Lenses Can Improve the Optical Properties of the Lens.

PurposeTo investigate how cataract-linked mutations affect the gradient refractive index (GRIN) and lens opacification in mouse lenses and whether there is any effect on the optics of the lens from treatment with an oxysterol compound.MethodsA total of 35 mice including wild-type and knock-in mutants (Cryaa-R49C and Cryab-R120G) were used in these experiments: 26 mice were treated with topical VP1-001, an oxysterol, in one eye and vehicle in the other, and nine mice were untreated controls. Slit lamp biomicroscopy was used to analyze the lens in live animals and to provide apparent cataract grades. Refractive index in the lenses of 64 unfixed whole mouse eyes was calculated from measurements with X-ray phase tomography based on X-ray Talbot interferometry with a synchrotron radiation source.ResultsHeterozygous Cryaa-R49C lenses had slightly irregularly shaped contours in the center of the GRIN and distinct disturbances of the gradient index at the anterior and posterior poles. Contours near the lens surface were denser in homozygous Cryab-R120G lenses. Treatment with topical VP1-001, an oxysterol, showed an improvement in refractive index profiles in 61% of lenses and this was supported by a reduction in apparent lens opacity grade by 1.0 in 46% of live mice.ConclusionsThese results indicate that α-crystallin mutations alter the refractive index gradient of mouse lenses in distinct ways and suggest that topical treatment with VP1-001 may improve lens transparency and refractive index contours in some lenses with mutations.

Outcomes of 25-gauge pars plana vitrectomy alone with air tamponade for the management of rhegmatogenous retinal detachment with inferior breaks

BackgroundThis study was investigated the surgical outcomes of primary rhegmatogenous retinal detachment (RRD) with inferior retinal breaks (IRBs) that were repaired by 25-gauge pars plana vitrectomy (PPV) with air tamponade.MethodsThis retrospective review included 81 consecutive patients who had RRD with IRBs and underwent PPV with air tamponade in our hospital from January 2017 to January 2020. The main outcomes were single surgery anatomical success (SSAS) rate, postoperative best-corrected visual acuity (BCVA), and complications.ResultsThe patient population consisted of 29 women and 52 men (mean age, 52.12 years); the mean follow-up interval was 8.88 months. The mean number of affected quadrants was 1.65 (range, 1–4 quadrants) and the mean number of breaks was 3.25. A single break was present in 20 cases (24.7%); two to 10 breaks were present in 61 (75.3%) cases. The SSAS rate was 91.36% (74/81) and the final anatomical success rate was 96.30% (78/81). More than half of the patients had BCVA < 0.3 logarithm of the minimum angle of resolution at the last follow-up. Axial length and patient age were candidate risk factors for redetachment (axial length, p = 0.03; age, p = 0.002). Postoperative complications included macular epiretinal membrane formation in one patient, lens opacity in three patients, and clinically significant macular edema in one patient.ConclusionsPPV with air tamponade may be effective for the treatment of primary RRD with IRBs. Extensive preoperative discussion may be necessary for young patients and patients with particularly long axial length.

Ocular biometry of infants and young children with congenital cataract

Objective: To understand the developmental characteristics of early ocular biological parameters in patients with congenital cataract. Methods: Retrospective case series study. The ocular biometry data such as the axial length, corneal curvature, anterior chamber depth and central corneal thickness of 169 patients under 3 years old who were diagnosed with congenital cataract in Eye Hospital of Wenzhou Medical University (Hangzhou Branch) from June 2016 to June 2020 were reviewed, and they were analyzed by 3 age groups. There were 87, 41, and 41 patients in three age groups, 1 to 6 months, 7 to 12 months, and 13 to 36 months, respectively; 108 patients with bilateral affected eyes and 61 patients with unilateral affected eyes were included; 84 patients with partial opacity lens and 85 patients with total opacity lens were included. The right eyes of the patients with bilateral congenital cataract were selected for analysis. Statistical analysis of ocular biological parameters between groups was performed using the independent samples t-test and paired samples t-test. Statistical analysis of the relationship between age in months and biological parameters was performed using the Pearson's correlation test. Results: The axial length at the age of 1 to 6 months in the affected eyes of patients with bilateral cataract was (17.59±1.19) mm, it was shorter than the affected eyes of patients with unilateral cataract [(18.18±1.34) mm], and the axial length in the affected eyes of patients with unilateral cataract were shorter than the healthy eyes [(19.01±0.93) mm]. At the age of 7 to 12 months, the axial length in the affected eyes of patients with unilateral cataract [(19.89±0.74) mm] was shorter than the healthy eyes [(20.48±0.43) mm]. The differences were statistically significant (t=-2.06, -5.62, -3.47, all P<0.05). The axial length in the affected eyes with partial opacity at the age of 1 to 6 months was shorter than those with total opacity [(17.43±1.14) mm vs. (18.06±1.29) mm; t=-2.38, P=0.020]. The difference in axial length (affected eyes vs. healthy eyes) was significantly correlated with the age in months in partial cataract (r=0.53, P=0.001). The corneal curvature in the affected eyes of patients with unilateral cataract was flatter than the healthy eyes at the age of 7 to 12 months [(42.41±1.82) D vs. (43.19±1.96) D; t=-2.29, P=0.038], but was steeper at the age of 13 to 36 months [(43.36±2.32) D vs. (42.55±1.88) D; t=2.17, P=0.043]. The anterior chamber depth in the affected eyes of patients with unilateral cataract was less than the healthy eyes at the age of 1 to 6 months [(2.44±0.37) mm vs. (2.58±0.33) mm; t=-2.08, P=0.048].The central corneal thickness in the affected eyes of patients with unilateral cataract was thicker than the healthy eyes both at the age of 1 to 6 months and 7 to 12 months [(555.26±46.95) μm vs. (541.85±40.78) μm, (542.93±27.63) μm vs. (530.93±30.36) μm; t=3.82, 2.26; P=0.001, 0.040]. Conclusions: Congenital cataracts maybe affect the early development of axial length, corneal curvature, anterior chamber depth and central corneal thickness. The degree of lens opacity maybe affecte the early axial length development. The axial length in eyes with partial opacity can be shorter than those with total opacity before the age of 6 months, and thereafter gradually outnumbered the latter.

Characterization of Dysfunctional Lens Index and Opacity Grade in a Healthy Population.

This study enrolled 61 volunteers (102 eyes) classified into subjects < 50 years (group 1) and subjects ≥ 50 years (group 2). Dysfunctional Lens Index (DLI); opacity grade; pupil diameter; and corneal, internal, and ocular higher order aberrations (HOAs) were measured with the i-Trace system (Tracey Technologies). Mean DLI was 8.89 ± 2.00 and 6.71 ± 2.97 in groups 1 and 2, respectively, being significantly higher in group 1 in all and right eyes (both p < 0.001). DLI correlated significantly with age (Rho = −0.41, p < 0.001) and pupil diameter (Rho = 0.20, p = 0.043) for all eyes, and numerous internal and ocular root-mean square HOAs for right, left, and all eyes (Rho ≤ −0.25, p ≤ 0.001). Mean opacity grade was 1.21 ± 0.63 and 1.48 ± 1.15 in groups 1 and 2, respectively, with no significant differences between groups (p ≥ 0.29). Opacity grade significantly correlated with pupil diameter for right and all eyes (Rho ≤ 0.33, p ≤ 0.013), and with some ocular root-mean square HOAs for right and all eyes (Rho ≥ 0.23, p ≤ 0.020). DLI correlates with age and might be used complementary to other diagnostic measurements for assessing the dysfunctional lens syndrome. Both DLI and opacity grade maintain a relationship with pupil diameter and internal and ocular HOAs, supporting that the algorithms used by the device may be based, in part, on these parameters.

The Effect of Induced Intraocular Stray Light on Recognition Thresholds for Pseudo-High-Pass Filtered Letters.

PurposeThe Moorfields Acuity Chart (MAC)—comprising pseudo-high-pass filtered “vanishing optotype” (VO) letters—is more sensitive to functional visual loss in age-related macular degeneration (AMD) compared to conventional letter charts. It is currently unknown the degree to which MAC acuity is affected by optical factors such as cataract. This is important to know when determining whether an individual's vision loss owes more to neural or optical factors. Here we estimate recognition acuity for VOs and conventional letters with simulated lens aging, achieved using different levels of induced intraocular light scatter.MethodsRecognition thresholds were determined for two experienced and one naive participant with conventional and VO letters. Stimuli were presented either foveally or at 10 degrees in the horizontal temporal retina, under varying degrees of intraocular light scatter induced by white resin opacity-containing filters (WOFs grades 1 to 5).ResultsFoveal acuity only became significantly different from baseline (no filter) for WOF grade 5 with conventional letters and WOF grades 4 and 5 with VOs. In the periphery, no statistical difference was found for any stray-light level for both conventional and VOs.ConclusionsRecognition acuity measured with conventional and VOs is robust to the effects of simulated lens opacification, and thus its higher sensitivity to neural damage should not simultaneously be confounded by such optical factors.Translational RelevanceThe MAC may be better able to differentiate between neural and optical deficits of visual performance, making it more suitable for the assessment of patients with AMD, who may display both types of functional visual loss.

Visual Function in Children With Posterior Lens Opacities Before and After Surgery

To evaluate the visual function before and after cataract surgery in children with congenital posterior lens opacities as well as the factors associated with a good visual outcome. Perspective case-series study. Pediatric patients with posterior lens opacities who underwent cataract surgery were recruited in this study. The cataract type, location, area of opacities, and strabismus were examined perioperatively. Moreover, visual acuity, modulation transfer function (MTF), ocular aberrations, and stereopsis were measured before and after cataract surgery. Sixty-nine eyes of 63 patients were studied. The mean age of patients at surgery was 6.5 ± 2.9 years. Visual function including corrected distance visual acuity (CDVA), MTF cutoff frequency, and ocular aberrations were significantly affected in eyes with posterior lens opacities. Postoperatively, CDVA was significantly improved from 0.81 ± 0.53 logMAR to 0.40 ± 0.40 logarithm of the minimum angle of resolution (logMAR) (P < .001). Thirty-nine patients (56.5%) achieved a final VA of 20/40 or better. Moreover, MTF cutoff values were significantly improved, and total ocular aberrations were decreased after cataract removal (both P < .001). The stereopsis was also improved postoperatively (P < .001). The multivariate analysis of the risk factors for postoperative CDVA showed that worse preoperative CDVA, larger size of lens opacities, and mean keratometry were the risk factors (all P < .05). Visual function can be significantly decreased in children with posterior lens opacities, and surgery was effective in improving visual function. Patients with a CDVA of 0.52 logMAR or better, a size of lens opacity <6.5 mm2 and smaller mean keratometry had a greater CDVA postoperatively.

Pigmented posterior lenticonus in unilateral development cataract

A ten-year-old boy presented with progressive blurred vision in his left eye for 1 year. The best corrected visual acuity was 20/20 and 20/100, respectively, in the right and left eyes. Slit-lamp examination showed a posterior lenticonus in the left eye with pigment inside the lens capsule (Figure 1A). Anterior segment optical coherence tomography (AS-OCT, CASIA2, Tomey Corporation, Japan) revealed posterior lenticonus surrounded with well-defined high reflective substances (Figure 1B). Fundus photograph showed normal optic disc and the macular area was obscured by lens opacity (Figure 1C).

Cataract progression after Nd:YAG laser iridotomy in primary angle-closure suspect eyes

Background/AimsProphylactic laser peripheral iridotomy (LPI) is performed in primary angle-closure suspect (PACS) eyes to prevent acute angle-closure attacks. However, accelerated cataractogenesis is a potential risk of the procedure that may...

Lens Opacities Classification System III-based artificial intelligence program for automatic cataract grading.

To establish and validate an artificial intelligence (AI)-assisted automatic cataract grading program based on the Lens Opacities Classification System III (LOCS III). Eye and Ear, Nose, and Throat Hospital, Fudan University, Shanghai, China. AI training. Advanced deep-learning algorithms, including Faster R-CNN and ResNet, were applied to the localization and analysis of the region of interest. An internal dataset from the EENT Hospital of Fudan University and an external dataset from the Pujiang Eye Study were used for AI training, validation, and testing. The datasets were automatically labeled on the AI platform regarding the capture mode and cataract grading based on the LOCS III. The AI program showed reliable capture mode recognition, grading, and referral capability for nuclear and cortical cataract grading. In the internal and external datasets, 99.4% and 100% of automatic nuclear grading, respectively, had an absolute prediction error of ≤1.0, with a satisfactory referral capability (area under the curve [AUC]: 0.983 for the internal dataset; 0.977 for the external dataset); 75.0% (internal dataset) and 93.5% (external dataset) of the automatic cortical grades had an absolute prediction error of ≤1.0, with AUCs of 0.855 and 0.795 for referral, respectively. Good consistency was observed between automatic and manual grading when both nuclear and cortical cataracts were evaluated. However, automatic grading of posterior subcapsular cataracts was impractical. The AI program proposed in this study showed robust grading and diagnostic performance for both nuclear and cortical cataracts, based on LOCS III.

Central Macular Thickness in Uneventful Phacoemulsification Employing Optical Coherence Tomography

Introduction: Cataract is the most common cause of blindness affecting the global population which can be cured by phacoemulsification surgery. The study aimed to evaluate the central macular thickness following uneventful phacoemulsification surgery and analyze its relation to various factors. Methods: This prospective study comprised of 63 subjects diagnosed as age-related cataract on the basis of lens opacities classification system III and undergoing uneventful phacoemulsification surgery with capsular bag intraocular lens implantation. The central macular thickness was evaluated using optical coherence tomography at preoperative period and postoperatively on 1st day, 1st week and 5th week. Effective phacoemulsification time was measured intraoperatively. Results: The mean effective phacoemulsification time was 17.95±14.01 seconds. Best corrected visual acuity improved significantly postoperatively (p=0.03). Mean central macular thickness increased significantly on the 5th postoperative week compared to preoperative assessment (p=0.002). No significant association was detected between patient’s age and preoperative and postoperative central macular thickness. No correlations were observed between effective phacoemulsification time and central macular thickness. Significant association was not noted between central macular thickness and best corrected visual acuity on pre and postoperative examinations. Conclusion: There was a decrease in central macular thickness on the 1st day and 1st week postoperatively followed by a significant increase on the 5th postoperative week compared to the preoperative period, which was independent of effective phacoemulsification time. Increase in central macular thickness in the postoperative period did not affect the quality of vision.

Postoperative Corneal Edema After Phacoemulsification

Aim: To determine the effect of nuclear opalescence (NO) on intraoperative parameters during phacoemulsification using the WhiteStar Signature® PRO and to show the impact of preoperative and intraoperative parameters on postoperative corneal edema.Methods: This prospective study included 267 patients selected to undergo phacoemulsification using the WhiteStar Signature® PRO system at the Department of Ophthalmology of the General Hospital “Dr Josip Benčević”, Slavonski Brod, Croatia. NO was graded using the Lens Opacities Classification System III. Preoperative parameters were age, sex, NO and preoperative central corneal thickness. Intraoperative parameters of phacoemulsification included in the study were ultrasound time (UST), phaco time using Ellips FX technology (EFX) and average phaco power (AVG). Patients were followed up on postoperative days 1 and 7 and after two months. The state of the cornea was noted in each follow-up.Results: There was a statistically significant increase of intraoperative parameters with NO. Postoperative corneal edema depended on all measured intraoperative parameters (UST, EFX and AVG, all p &amp;lt; .001), patient’s age (p &amp;lt; .05) and NO (p &amp;lt; .001) on postoperative day 1, while on postoperative day 7, it depended on UST (p = .011) EFX (p = .012) and NO (p &amp;lt; .05).Conclusion: Older patients, higher grade of NO and amount of energy consumed during phacoemulsification using the WhiteStar Signature® PRO are predictive factors for severity of transient corneal edema. We found this information important for better preoperative planning of phacoemulsification, as well as for better postoperative results.

The protective mechanism of Grx2 in ultraviolet-B (UVB)-induced cataract formation

ObjectiveWe established a mouse cataract model by irradiating Grx2 knockout (KO) and knock-in (KI) genetically modified mice with UVB to explore the protective mechanism of Grx2 against UVB lens damage. MethodsAfter irradiating Grx2 KO and Grx2 KI mice with UVB lamps, we observed and recorded the general physiological conditions and lens opacity of the mice. The crystalline grading system of the University of Oxford was used to classify the opacity of the lens. Lens reactive oxygen species (ROS) contents were detected using a microplate reader, western blot, and enzyme-linked immunosorbent assay (ELISA) to detect antioxidant and antioxidant enzyme contents. Statistical analysis of the recorded data was performed by using SPSS 19.0 software. ResultsAfter UVB irradiation, the weight of Grx2 KO mice was slightly lower than that of wild-type (WT) mice of the same age. Compared to WT mice, the lens opacity of Grx2 KO mice appeared earlier, the nucleus density of the lens increased, and the opacity increased in the first week after UVB irradiation. Meanwhile, the lenses of Grx2 KI mice remained transparent. The experiment showed that the content of ROS increased, the level of glutathione (GSH) decreased, the content of 8-OHdG increased, and the expression of BCL2 decreased after UVB irradiation. Compared to WT mice, these changes were more significant in Grx2 KO mice. ConclusionThis experiment found that knocking out the Grx2 gene accelerated the occurrence and development of UVB-induced cataracts in mice and that Grx2 plays an important role in the oxidative damage caused by UVB radiation by repairing the antioxidant enzymes of the lens. This study provides a new animal model and research ideas for the study of cataract pathogenesis.

Activation of Nrf2/HO-1 Antioxidant Pathway by Heme Attenuates Calcification of Human Lens Epithelial Cells.

Cataract, an opacification in the crystalline lens, is a leading cause of blindness. Deposition of hydroxyapatite occurs in a cataractous lens that could be the consequence of osteogenic differentiation of lens epithelial cells (LECs). Nuclear factor erythroid 2-related factor 2 (Nrf2) controls the transcription of a wide range of cytoprotective genes. Nrf2 upregulation attenuates cataract formation. Here we aimed to investigate the effect of Nrf2 system upregulation in LECs calcification. We induced osteogenic differentiation of human LECs (HuLECs) with increased phosphate and calcium-containing osteogenic medium (OM). OM-induced calcium and osteocalcin deposition in HuLECs. We used heme to activate Nrf2, which strongly upregulated the expression of Nrf2 and heme oxygenase-1 (HO-1). Heme-mediated Nrf2 activation was dependent on the production of reactive oxygens species. Heme inhibited Ca deposition, and the OM-induced increase of osteogenic markers, RUNX2, alkaline phosphatase, and OCN. Anti-calcification effect of heme was lost when the transcriptional activity of Nrf2 or the enzyme activity of HO-1 was blocked with pharmacological inhibitors. Among products of HO-1 catalyzed heme degradation iron mimicked the anti-calcification effect of heme. We concluded that heme-induced upregulation of the Nrf2/HO-1 system inhibits HuLECs calcification through the liberation of heme iron.

The E3 Ligase RNF157 Inhibits Lens Epithelial Cell Apoptosis by Negatively Regulating p53 in Age-Related Cataracts.

PurposeAge-related cataract (ARC) is a major cause of vision impairment worldwide. The E3 ubiquitin ligase RING finger protein 157 (RNF157) is involved in regulating cell survival and downregulated in human cataractous lens samples. However, the function of RNF157 in cataracts remains unclear. This study aimed to determine the role of RNF157 in ARC.MethodsReal-time polymerase chain reaction (PCR) and Western blotting were used to analyze the expression of RNF157 in clinical lens capsules, rat cataract models, and oxidative stress cell models. Western blot analysis and flow cytometry were used to evaluate cell apoptosis. Co-IP assay, protein stability assay, and ubiquitination assay were used to detect the interaction between RNF157 and its substrate p53.ResultsThe expression of RNF157 was downregulated in human cataract samples, UVB-induced rat cataract model, and H2O2-treated human lens epithelial cells (LECs). Ectopic expression of RNF157 protected LECs from H2O2-induced apoptosis. In contrast, knockdown of RNF157 enhanced oxidative stress-induced apoptotic cell death. Moreover, silence of RNF157 in the rat ex vivo lens model exacerbated lens opacity. Mechanistically, RNF157 causes ubiquitination and degradation of the tumor antigen p53. Overexpression of p53 eliminated the antiapoptotic effects of RNF157, whereas p53 knockdown rescued RNF157 silencing-induced cell death.ConclusionsOur findings revealed that reduced RNF157 expression promoted LEC apoptosis by upregulating p53 in cataracts, suggesting that the regulation of RNF157 expression may serve as a potential therapeutic strategy for cataracts.

Comparing surgical efficiencies between phacoemulsification systems: a single surgeon retrospective study of 2000 eyes.

To compare under similar conditions intraoperative surgical efficiencies metrics between an active fluidics and a gravity based phacoemulsification systems. Adult patients who were diagnosed with a cataract that compromised visual acuity inferior to 20/40 were included in the study. Patients were excluded from the study if they had a history of severe retinal disorders, clinically significant corneal endothelial dystrophy or history of corneal disease. All phacoemulsification surgeries were performed by a single surgeon. Both phacoemulsification systems used the 0.9 mm 45-degree aspiration bypass system Intrepid Balanced tip and the 0.9 mm Intrepid Ultra infusion sleeve. All cataracts were classified using the Lens Opacities Classification System III, cumulative dissipated energy (CDE) and aspiration fluids were measured in each surgery. Totally 2000 eyes were included in the study. Phacoemulsification was performed in 1000 (50%) eyes with an active fluid dynamics system and in 1000 (50%) eyes with a gravity-based fluidic system. Mean CDE until fracture of the lens was 1.1 and 1.9 percent-seconds and total mean CDE used was 5.6 and 7.2 percent-seconds using an active fluidics dynamics system and gravity-based fluidic system, respectively (P<0.001). Mean aspiration fluids used were 70 mL using an active fluidics dynamics system and 85 mL using a gravity-based fluidic system (P<0.001). This study evidences that surgeries performed under similar conditions (same surgeon, phaco tip and sleeve) with the active fluidics dynamics system required significantly lower CDE and aspiration fluids.

Neglected Congenital Rubella Syndrome in 10-Year-Old Boy

Introduction: Cataract, congenital heart defect, and hearing impairment are the three most common manifestations of congenital rubella syndrome (CRS) that lead to developmental delay in the children. CRS usually present during the infant period of three months old as the median age number. Ironically, we found a 10-year-old boy who was diagnosed with CRS and there was no significant plan to improve his condition anymore because of his neglected by family. The purpose of this case report is to alert primary health workers and also ophthalmologists to do our best to prevent blindness due to cataracts in Indonesia with early detection. Case presentation: A 10-year-old boy was brought to the outpatient clinic with a chief complaint of difficulties in focusing the target in the classroom. The grandmother said that her grandson has already had a white plaque in his both eyes since he was born. The boy has also suffered from deaf-mutism. His visual acuity was hand movement and there was lens opacity in his both eyes. He also had posterior uveitis in both eyes followed by the presence of nystagmus. There was retinal detachment in ultrasonography (USG) examination. The patient has no cardiac abnormalities. Rubella infection was confirmed by the high number of IgG rubella serology. His grandmother had just brought the boy to the outpatient clinic because she never thought that the eyes needed therapy until the boy could not do his daily activities as the cataract worsen. Conclusions: The parent’s role is highly crucial for the visual outcome of patient with congenital ophthalmologic problems. Primary health worker also play a significant role in early detection that may prevent such incident. Delayed detection and management of congenital cataracts may cause permanent visual impairment and lead to patient’s poor quality of life.

Association of alkaptonuria and low dose nitisinone therapy with cataract formation in a large cohort of patients.

Homogentisic acid (HGA) lowering, disease modifying off‐label nitisinone therapy has been used in the United Kingdom National Alkaptonuria Centre (NAC) since 2012. This study evaluated the serendipitous observation of cataract in a large cohort of patients with the very rare disease alkaptonuria (AKU), over a 5‐year period. Patients with AKU who attended the NAC since 2012. Standard physical examination and ocular assessment, including photographs of the crystalline lens were taken before commencement of nitisinone 2 mg daily and annually over 5 years. Photographs were randomised and graded by two independent observers using the WHO cataract classification. AKU patients who did not receive nitisinone were included as a control group. HGA was measured on acidified 24 h urine (u‐HGA24) and HGA and tyrosine in fasting acidified serum samples (sHGA, sTYR) at each visit. Patients without suitable lens images were excluded. Cataract (mean grade 1) was noted at baseline in 47 out of 62 (76%) with a mean (SD) age of 44 (14) years. In nitisinone‐treated patients, there were significant increases in the mean grade of nuclear (0.18, p < 0.01) and cortical (0.38, p < 0.01) lens opacities over the mean duration of 4.93 years of the study. Worsening of the nuclear cataract and cortical lens opacities by at least 1 grade was noted in 14 out of 46 (30%) and 11 out of 46 (24%) patients, respectively. There is an increased prevalence and progression of cataract in AKU and a possible association of nitisinone with cataract progression.

The Effect of Cataract on Color Vision Measurement with the Low-Vision Cambridge Colour Test: Providing an Adjustment Factor for Clinical Trials.

PurposeTo quantify the effect of cataract on color vision as measured by the low-vision Cambridge Colour Test (lvCCT; Cambridge Research Systems) and to understand whether different types and severities of cataract have different effects on color vision.DesignCohort study.ParticipantsPatients aged 18 to 95 undergoing routine cataract surgery at the Oxford Eye Hospital.MethodsThe lvCCT was performed to measure color sensitivity in both eyes both before and after surgery. The crystalline lens was examined and graded according to the Lens Opacities Classification System III to determine the type and severity of cataract. Measures of repeatability were performed for the data to explore test–retest bias using Bland–Altman analysis. The Wilcoxon signed-rank test was performed to assess the effect of cataract on color vision by comparing control and surgical test measurements. Three multiple linear regressions were performed to relate cataract grading or severity to color vision measurements.Main Outcome MeasuresColor discrimination along each of the protan, deutan, and tritan confusion lines.ResultsThe Wilcoxon signed-rank test showed a statistically significant difference in both the protan (P = 0.024) and tritan (P = 0.020) axes on comparison of control and surgical test measurements. As severity of cataract increased, color vision sensitivity was affected more greatly, and nuclear sclerotic cataract showed the most profound effect on color vision sensitivity in the lvCCT; however, the linear regression models showed that these observations did not reach statistical significance.ConclusionsCataract surgery has a statistically significant effect on color vision in both the protan and tritan axes. The effects of specific subtypes of cataract and different severities could not be elucidated because of the high prevalence of patients with mixed cataract. The lvCCT color sensitivity measurements are used regularly as outcome measures in clinical gene therapy trials involving vitreoretinal surgery, and vitrectomy accelerates cataract formation. Therefore, it is important to quantify the effect of cataract on color vision measurements so that it may be taken into account when used as an outcome measure in clinical trials. We were unable to derive a precise correction factor for cataract on color vision measurements.

Commentary

Commentary

Выбор тампонады при хирургическом лечении субмакулярных кровоизлияний при влажной форме возрастной макулярной дегенерации

Purpose. To evaluate the efficacy and anatomical results of surgical treatment of submacular hemorrhages in the exudative age-related macular degeneration with tamponade with air or gas-air mixture. Material and methods. We examined 6 patients (6 eyes) with the diagnosis of submacular hemorrhages. The average age of the subjects was 69.47 ± 3.12 years. The maximum corrected acuity averaged 0.03 ± 0.04. According to the data of optical coherence tomography, a high central detachment of the neuro- and pigment epithelium with hemorrhagic contents was determined in patients. All patients had previously received a course of intravitreal injections of an angiogenesis inhibitor (Aflibercept) in the range from 1 to 5. In the presence of lens opacity, surgical treatment was started with phacoemulsification of cataracts. In the main group, after microinvasive subtotal vitrectomy and subretinal administration of tissue plasminogen activator (Prourokinase)® 500, irrigation fluid was replaced with sterile air; in the control group, the operation was completed with a gas-air mixture tamponade. In the early postoperative period, patients of both groups were recommended a forced head position «face down» two days. The follow-up period for patients was 3 months. Results. The compared groups did not differ in terms of age and gender. The duration of existence of submacular hemorrhages was 6.27 ± 2.67 days. In the early operational period, low visual acuity was explained by tamponade with air or a gas-air mixture. In the main group, air resorption occurred for 10 ± 1.53 days with an increase in visual acuity to 0.25 ± 0.06 and lysis of the submacular clot. The displacement of the blood clot from the central area of the retina by air or gas-air mixture, with the correct positioning of the patient, occurred at the same time (6.87 = 2.13 days). In the control group, an increase in visual acuity to 0.23 ± 0.04 was observed for a longer period – 22 ± 3.12 days due to a longer period of resorption of the gas-air mixture. During the observation period of 3 months, stable results were achieved in all cases in patients of both groups. Conclusion. Microinvasive subtotal vitrectomy and subretinal injection of Prourokinase with air tamponade can achieve a significant improvement in the functional results of treatment in a shorter period. Keyword: submacular hemorrhage, age-related macular degeneration, air tamponade, optical coherence tomography.