Group Of Cataract Patients Research Articles

Antibacterial effect of povidone iodine disinfectant and antibiotic eye drops before cataract surgery

Objective: Investigate the distribution of bacteria in the conjunctival sac of two groups of cataract patients with different preoperative aseptic treatments, and compare the clinical effects of 0.5% povidone-iodine (PI) and antibiotic eye drops on killing conjunctival sac bacteria.Methods: 400 cases of patients (400 eyes) who underwent cataract surgery in the Department of Ophthalmology of Baogang Hospital in Inner Mongolia from October 2019 to October 2020 were selected in a randomized controlled study. They were randomly divided into the experimental group (group A) and the control group (group B), with 200 cases in each group. Group A: the patients were given Gatifloxacin Eye Gel (3 times/day, 1 drop/time) combined with Diclofenac Sodium Eye Drops (4 times/day, 1 drop/time) before the operation; 0.5% PI was administered to irrigate the conjunctival sac, with 0.9% SodiumChloride Injection washing after 3 min; 0.5% PI was administered to irrigate the conjunctival sac after operation. The corneal epithelium was observed after each irrigation. Group B: the patients were given Gatifloxacin Eye Gel (3 times/day, 1 drop/time) combined with Diclofenac Sodium Eye Drops (4 times/day, 1 drop/time) 2 days and 1 day before the operation; 0.9% Sodium Chloride Injection was administered to irrigate the conjunctival sac before and after surgical disinfection. Conjunctival sac specimens were collected for bacterial culture 2 hours before the operation, after irrigation, and after the procedure. The positive rate and the distribution of bacteria were compared between the two groups.Results: The difference in the positive rate of bacteria in the conjunctival sac between the two groups at different time points had a statistical significance (χ2 = 11.498, p < .022). Conjunctival sac specimens were collected on admission and 2 hours before the operation. There was no significant difference in the pathogens with positive results between the two groups (p = .955; p = .073); there was a substantial difference in the distribution of positive pathogens between the two groups before and after surgical disinfection (p < .001); there was a significant difference in the distribution of pathogens between the two groups after the operation (p = .005). For Staphylococcus epidermidis, Corynebacterium, Enterococcus faecalis, Streptococcus, and other Gram-positive bacteria, there was a significant difference in the disinfection methods between the two groups at different time points (p < .001); for Staphylococcus aureus, Gram-positive cocci, and Gram-negative bacteria, there was no significant difference in the disinfection methods between the two groups at different time points (p = .113; p = .224; p = .146). There was no significant difference between the two groups with 0-10 and 101-1000 bacterial colonies at different time points (p = .370 and .071, respectively). When there were 11-100 bacterial colonies, there was a significant difference between the two groups at different time points (p < .001). There was no significant difference in corneal epithelial injury between the two groups at other time points (χ2 = 4.133, p = .127).Conclusions: The combination of 0.5% PI disinfectant and antibiotic eye drops can effectively reduce the bacterial load of the conjunctival sac before operation. At the same time, it is safe and effective to irrigate the conjunctival sac with 0.5% PI disinfectant before the procedure.

Cytokine and Chemokine Concentration in the Tear of Patients with Age-Related Cataract

ABSTRACT Purpose The present study measured 41 soluble mediators in the tear of 19 patients with age-related cataract and 32 healthy adults as controls. Materials and Methods This was a prospective, case–control study in which, using multiple immunoassays, we measured in tear samples the following molecules: EGF, FGF-2, Eotaxin, TGF-α, G-CSF, Flt-3L, GM-CSF, Fractalkine, IFN-α2, IFN-γ, GRO, IL-10, MCP-3, IL-12p40, MDC, IL-12p70, PDGF-AA, IL-13, PDGF-AB/BB, IL-15, sCD40L, IL-17a, IL-1ra, IL-1α, IL-9, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IP-10, MCP-1, MIP-1α, MIP-1β, RANTES, TNFα, TNFβ, VEGF. Statistical analyses were done by multiple adjusted models and p values were corrected by the Benjamini and Hochberg method. Results We did not find significant differences in the amount of the tested molecules in the tear fluid between cataract patients and controls. Correlation analyses relative to age were carried out for both groups. Analysis of MCP-1 tear levels revealed a direct correlation with age for normal healthy controls as well as for cataract patients. But IL-6 tear levels correlated with age only in the group of cataract patients. In addition, IL1-ra tear levels correlated with cataract nuclear grade; higher grades were associated with higher IL-1ra concentrations. Conclusions Our results suggest that ocular aging is accompanied by increased production of IL-6 and MCP-1, which can be measured in tear fluid. Abbreviations AMD: Age-Related Macular Degeneration; EGF: Epidermal growth factor; Eotaxin: Eosinophil chemotactic proteins; FasL: Fas ligand; FGF-2: Basic fibroblast growth factor 2; Flt-3L: Fms related tyrosine kinase 3 ligand; G-CSF: Granulocyte colony stimulating factor; GM-CSF: Granulocyte macrophage colony stimulating factor; GRO: Growth regulated protein; HGF: Human growth factor; ICAM-1: Intercellular adhesion molecule-1; IFNα2: Interferon alpha 2; IFNγ: Interferon gamma; IL: Interleukin; IL-1ra: Interleukin-1 receptor antagonist; IL-12p40: Interleukin-12 subunit p40; IL-12p70: Interleukin-12 subunit p70; IP-10: Interferon gamma-induced protein 10; MCP-1: Monocyte chemotactic protein 1; MCP-3: Monocyte chemotactic protein 3; MDC: Macrophage derived chemokine; MIG: Monokine induced by gamma interferon; MIP-1α: Macrophage inflammatory proteins 1 alpha; MIP-1β: Macrophage inflammatory proteins 1 beta; MMPs: Matrix metalloproteinases; MMP-9: Matrix metalloproteinase 9; PAI1: Plasminogen activator inhibitor 1; PDGF-AA: Platelet-derived growth factor subunit AA; PDGF-AB/BB: Platelet-derived growth factor subunit AB and BB; PIGF: Placenta growth factor; RANTES: Regulated on activation, normal T cell expressed and secreted; SAA: Serum amyloid A; sCD40L: Soluble CD40 ligand; sTNF-RII: Soluble tumor necrosis factor receptor; TBUT Tear breakup time; TGF-α: Transforming growth factor alpha; TGF-β: Transforming growth factor beta; TNFα: Tumor necrosis factor alpha; TNFβ: Tumor necrosis factor beta; VCAM: Vascular cell adhesion molecule; VEGF: Vascular endothelium growth factor

Correlation between axial length and corneal curvature and spherical aberration

Objective: To discuss the correlation between axial length and corneal curvature and corneal spherical aberration in a group of cataract patients with axial length greater than 24 mm. Methods: Retrospective case series. This study comprised 117 (234 eyes) age-related cataract patients. There were 51 men (43.59%) and 66 women (56.41%) with mean age of (69.0±8.7) years (range from 52.0 to 85.0 years). The average axial length was 27.6±1.8 (range from 24.2 to 31.9 mm). We devided them into four groups according to the axial length. A-scan was used to measure the axial length and Pentacam was used to get the corneal curvature and corneal spherical aberration of both anterior and posterior surface. kolmogorov-smirnov test was used to check the normal distribution. ANOVA test was used to compare eachcorneal parameter among different groups. Pearson correlation analysis was used to obtain the correlation of corneal parameters in groups. Results: There were correlations between the axial length and the anterior and posterior corneal curvature (r=-0.213, r=0.174, respectively, P<0.05). No correlation was found between the axial length and anterior or posterior corneal spherical aberration (r=-0.114, 0.055, respectively, P>0.05). Mean values of corneal anterior surface curvature were (45.26±1.60) D (group 1), (44.17±1.45) D (group 2), (44.40±1.99)D (group 3), and (44.53±1.69) D (group 4) respectively. Mean values of corneal posterior surface curvature were(-6.57±0.26)D (group 1), (-6.40±0.24)D (group 2), (-6.41±0.38)D (group 3), and (-6.43±0.26)D (group 4) respectively. There were significant difference of corneal anterior and posterior surface curvature among 4 groups (P=0.004, P=0.001). There was significant difference of corneal curvature of anterior surface in group 1 compared to group 2 and group 3(P<0.01, P=0.01). There was significant difference of curvature of posterior surface in group 1 compared to group 2 and group 3, respectively (P<0.01). Mean values of anterior surface corneal spherical aberration were (2.09±0.53) μm (group 1), (1.90±0.44) μm (group 2), (2.00±0.74) μm (group 3), and (1.78±0.52) μm (group 4) respectively. Mean values of posterior surface corneal spherical aberration were (2.69±1.15) μm (group 1), (2.46±1.16) μm (group 2), (2.92±2.51) μm (group 3), and (2.69±1.13) μm (group 4) respectively. No correlation was found in anterior and posterior surface corneal spherical aberration(P>0.05) among different groups. Conclusions: The eye with a longer axial length have a flatter cornea. Cornea fails to compensate for axial length elongation when the axial length is longer than 28mm. The corneal spherical aberration varies among individuals, which suggests us to do the customized measurement before cataract surgery to make a decision on choosing the aspherical intraocular lens. (Chin J Ophthalmol, 2017, 53: 255-259).

Intraocular levels of interleukin 17A (IL-17A) and IL-10 as respective determinant markers of toxoplasmosis and viral uveitis.

Uveitis is a potentially blinding inflammatory disease. Thirty to 50% of uveitis cases are considered idiopathic. The present study sought to determine the intraocular cytokine patterns in the different etiological types of uveitis in order to better understand their immunological regulation and to determine whether the cytokine pattern may be a useful diagnostic tool. From a multicenter institutional prospective study, the clinical and biological data from patients with uveitis of various etiologies, determined after a complete workup, were compared with those from a control group of cataract patients. A multiplex assay was used to assess the profiles of 27 cytokines and chemokines in aqueous humor samples from these patients. In total, 62 patients with infectious or noninfectious uveitis and 88 controls were included. After a complete workup, the cause of uveitis remained unknown in 25 patients (40% idiopathic uveitis). Interleukin 1β (IL-1β) levels were markedly increased in viral uveitis, as were IL-10 levels, whereas IL-17A levels were augmented in toxoplasmic uveitis. Based on the cytokine pattern, the patients were reassigned to specific groups. At the end of the study, the diagnosis of idiopathic uveitis was still valid in only 11 patients (18%). The observation that some markers are specific to certain diseases enables a better understanding of the disease pathogenesis and paves the way for new diagnostic methods aimed to identify inflammatory markers, which may perhaps be targeted by therapy.

Hepcidin Prohormone Levels in Patients with Primary Open-Angle Glaucoma

Aims: To assess the levels of hepcidin prohormone (Hep) in aqueous humor and plasma of human eyes with primary open-angle glaucoma (POAG) and to correlate their concentrations with the severity of glaucoma. Methods: Sixty patients with POAG and forty five patients with senile cataract (control group) were enrolled in the study prospectively. Aqueous humor samples were obtained by paracentesis from glaucoma and cataract patients who were undergoing elective surgery. Aqueous humor and corresponding plasma samples were analyzed for Hep concentrations by enzyme-linked immunosorbent assay. Results: Hep levels were significantly lower in aqueous humor of POAG patients with respect to the comparative group of cataract patients (P

Homocysteine and Hydroxyproline Levels in Patients with Primary Open-Angle Glaucoma

Aim: To assess the levels of homocysteine (Hcy) and hydroxyproline (Hyp) in aqueous humor and plasma of human eyes with primary open-angle glaucoma (POAG) and to correlate their concentrations with the severity of glaucoma.Methods: Fifty patients with POAG and 35 patients with senile cataract (control group) were enrolled in the study prospectively. Aqueous humor samples were obtained by paracentesis from glaucoma and cataract patients who were undergoing elective surgery. Aqueous humor and corresponding plasma samples were analyzed for Hcy and Hyp concentrations by high-performance liquid chromatography and spectrometry, respectively.Results: Hcy and Hyp levels were significantly higher in aqueous humor of POAG patients with respect to the comparative group of cataract patients (p < 0.001). No significant difference in the levels of Hcy and Hyp in plasma of POAG and cataract patients. A positive correlation was found between Hcy and Hyp in aqueous humor of POAG patients (p < 0.001). No significant correlation was found between either Hcy or Hyp levels and the severity of visual field loss.Conclusion: Increased levels of aqueous humor Hcy and Hyp may be associated with POAG. In addition, Hcy and Hyp may be useful protein levels in aqueous humor of POAG patients as a consequence of glaucomatous damage.

Moxifloxacin Punctum Plug for Sustained Drug Delivery

To assess the safety and feasibility of a moxifloxacin-loaded punctum plug (MP) in 2 groups of cataract patients. Two prospective, single-arm, Phase I studies were conducted with 20 cataract patients (10 per study) at the Singapore National Eye Center. After cataract surgery, the MP was inserted into the punctum, and follow-up assessments were conducted at 1 h, 24 h, and on days 3, 7, 10, 20, and 30. Study endpoints included MP retention, ease of placement, and moxifloxacin concentrations in the tear fluid. Moxifloxacin concentrations were targeted to be ≥250 ng/mL through 7 days, with detectable levels through day 10. After the course of therapy, the plug would resorb and be absent from the punctum by day 30. Slit lamp evaluations were performed, and intraocular pressure measurements were performed on days 1, 3, 7, 10, 20, and 30. Patients were queried for the presence or absence of several ocular sensations in the operative eye. Due to the variability in tear film antibiotic concentrations observed in the first study, a second study was conducted with more stringent concomitant drop administration and tear sample collection criteria. MP retention in the punctum was 95% (19/20) through day 10, and all plugs were absent at day 30. Average moxifloxacin concentrations in the tear film ranged from 155 to 785 ng/mL for Study 1 and 2,465 to 3,236 ng/mL for Study 2 through day 7. These values were above the target of 250 ng/mL for all time points except for day 1 of Study 1. For both studies, moxifloxacin concentrations in the tear film were above detectable levels at day 10. The plugs were well tolerated, and there were no adverse events as defined by the protocol, and no ocular complaints or findings other than normal post-cataract symptoms. The MP delivered and maintained moxifloxacin tear fluid concentrations at therapeutic levels above the MIC(90) values for common susceptible conjunctivitis pathogens for 7 days (Study 2). The MP also exhibited a favorable safety and tolerability profile and, hence, may be a viable alternative to topical antibiotic drops for the treatment of bacterial conjunctivitis.

Serotonin and hydroxyindolacetic acid levels in aqueous humor of patients with primary open-angle glaucoma

AbstractPurposeTo investigate the levels of 5-HT (serotonin, 5-hydroxytryptamine) and 5-HIAA (5-hydroxyindolacetic acid) in the aqueous humor and plasma of subjects with primary open-angle glaucoma (POAG) and to correlate their concentrations with the severity of glaucoma.MethodsThirty-five patients with POAG and 30 patients with senile cataract (control group) of matched age and gender were included in the study prospectively. Aqueous humor samples were obtained by paracentesis from glaucoma and cataract patients who were undergoing elective surgery. Aqueous humor and corresponding plasma samples were analyzed for 5-HT and 5-HIAA levels by high performance liquid chromatography with electrochemical detection.Results5-HT and 5-HIAA levels were significantly higher in the aqueous humor of POAG patients than in that of the comparative group of cataract patients. There was no significant difference in the 5-HT and 5-HIAA levels in plasma of POAG and cataract patients. A positive correlation was found between 5-HT and 5-HIAA in the aqueous humor of POAG patients. The 5-HT turnover (5-HIAA/5-HT) was higher in POAG than in cataract patients, but the difference was not significant. No significant correlation was found between levels and severity of visual field loss.ConclusionIncreased levels of 5-HT and 5-HIAA aqueous humor may be associated with POAG.

Tumor Necrosis Factor-α and Interleukin-6 Levels in Patients with Primary Open-Angle Glaucoma

Purpose: To investigate the levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the aqueous humor and plasma of human eyes with primary open-angle glaucoma, (POAG) and to correlate their concentrations with the severity of glaucoma. Patients and methods: Thirty five patients with POAG and thirty patients with senile cataract (control group) of matched age and gender were included in the study prospectively. Aqueous humor samples were obtained by paracentesis from glaucoma and cataract patients who were undergoing elective surgery. Aqueous humor and corresponding plasma samples were analysed for TNF-α and IL-6 concentrations by enzyme linked immunosorbent assay. Results: TNF-α and IL-6 levels were significantly higher in aqueous humor of POAG patients with respect to the comparative group of cataract patients (P<0.001). No significant difference in the levels of TNF-α and IL-6 in plasma of POAG and cataract patients. A positive correlation was found between TNF-α and IL-6 in aqueous humor of POAG patients (P<0.001). Significant correlation was found between TNF-α or IL-6 levels and severity of visual field loss in moderate stage (P<0.001). Conclusion: Increased levels of TNF-α and IL-6 aqueous humor may be associated with POAG. In addition, TNF-α and IL-6 may be useful proinflammatory cytokines levels in aqueous humor of POAG patients. TNF-α and IL-6 concentrations in aqueous humor are significant with visual field loss in patients with POAG.

Erythropoietin and soluble CD44 levels in patients with primary open‐angle glaucoma

To investigate the levels of erythropoietin (EPO) and soluble CD44 (sCD44) in the aqueous and plasma of human eyes with primary open-angle glaucoma (POAG), and to correlate their concentration with severity of glaucoma. A total of 30 patients with POAG and 25 patients with senile cataract (control group) of matched age and gender were included in the study prospectively. Aqueous samples were obtained by paracentesis from glaucoma and cataract patients who were undergoing elective surgery. Aqueous and corresponding plasma samples were analysed for EPO and sCD44 concentrations by enzyme-linked immunosorbent assay. The EPO and sCD44 levels were significantly higher in aqueous of POAG patients with respect to the comparative group of cataract patients (P < 0.001). No significant difference in the levels of EPO and sCD44 in plasma of POAG and cataract patients. A high positive correlation was found between EPO and sCD44 in aqueous of POAG patients (P < 0.001). Significant correlation was found between EPO or sCD44 levels and severity of visual field loss in mild and moderate stages (P < 0.001). Increased levels of aqueous EPO and sCD44 may be associated with POAG. In addition, EPO and sCD44 may be useful proteins levels in aqueous of POAG patients as a result of glaucoma damage and not a cause. EPO and sCD44 concentrations in aqueous are a possible biomarkers for visual field loss in patients with POAG.

Oxidative Stress Markers in Patients with Primary Open-Angle Glaucoma

Purpose: To investigate the levels of antioxidant enzymes catalase (CAT), glutathione peroxidase (GPO), superoxide dismutase (SOD), and malondialdehyde (MDA) in human eyes with primary open-angle glaucoma (POAG) and to correlate their concentrations with severity of glaucoma.Design: A prospective cases control study.Patients and Methods: Thirty patients with primary open-angle glaucoma and twenty-five patients with senile cataracts of matched age and gender were included in the study prospectively. Aqueous humor samples were obtained by paracentesis at the time of elective surgery for glaucomatous and cataractous patients. Aqueous humor were analyzed for CAT, GPO, SOD, and MDA status.Results: GPO, SOD, and MDA enzyme levels revealed a high significant increase in aqueous humor of POAG patients with respect to the comparative group of cataract patients (P < 0.001). No significant difference in the activity of CAT enzyme in aqueous humor of POAG and cataract patient (P = 0.201). Significant correlation was found between the MDA enzyme level and severe visual field loss (P < 0.001) in POAG patients.Conclusion: Increased levels of aqueous humor GPO, SOD, and MDA may be associated with POAG. In addition, they may be useful antioxidant enzyme levels in aqueous humor of POAG patients as a result of glaucoma disease and not a cause.

Protein content in aqueous humor from patients with pseudoexfoliation (PEX) investigated by capillary LC MALDI-TOF/TOF MS.

Analysis of proteins in human body fluids is challenging since the composition of the sample often is rather complex. Here we present a method for analysis of proteins in aqueous humor from two groups of cataract patients, with and without pseudoexfoliation (PEX). Aqueous humor is an extracellular fluid contained in the anterior chamber of the eye between the cornea and iris. The limited volume of sample requires sophisticated analysis techniques. Our method is based on a total tryptic digestion of the sample followed by capillary LC-MALDI MS and MS/MS analysis of the peptides. The method is rapid, efficient and suitable as a complement or alternative to more commonly used methods based on gel electrophoretic experiments. With this method we found and unambiguously identified 30 nonredundant proteins. Proteins found include general transport proteins such as albumin and apolipoprotein A1 but also specific proteins involved in immune response, such as complement factors. Cystatin C, clusterin, and crystallins were also found. Although the number of proteins was roughly the same in both groups there was a significant difference in their identities. These findings may give some new insights into the pathophysiology of the PEX syndrome.

Long-term Experience With Mixing and Matching Refractive Array and Diffractive CeeOn Multifocal Intraocular Lenses

To compare visual performance of the refractive Array SA40N and the diffractive CeeOn 811E multifocal intraocular lenses (IOLs) and to evaluate the potential benefits of combining both multifocal IOLs in the same patient. Two groups of cataract patients were unilaterally implanted with either the CeeOn diffractive (n = 10) or the Array refractive multifocal IOL (n = 10). Another group was bilaterally implanted with one of each multifocal IOLs (mix & match group, n = 10). Visual acuity, spectacle independence, depth of focus, contrast sensitivity, presence of photic phenomena, and patient satisfaction were assessed postoperatively. All eyes achieved good distance visual acuity but better uncorrected near vision was achieved with the CeeOn diffractive design. Contrast sensitivity with either multifocal IOL was at the lower limit of the normal range but when multifocal IOLs were combined in the same patient, contrast sensitivity was not significantly different from phakic controls. Defocus curves revealed a superiority of CeeOn diffractive design for near and Array refractive design for intermediate but mix & match patients performed better overall than the other patients, particularly for intermediate distances, which was reflected by total independence from spectacles in 90% of patients compared to 60% in the other groups. Visual outcomes remained unchanged over time (1 month vs 6 month vs > 3 years). Bilateral implantation with a diffractive multifocal IOL in one eye and a refractive multifocal IOL in the fellow eye is safe and could provide patients with better intermediate vision, increased depth of focus and contrast sensitivity, and also less dependence on spectacles.

Posterior capsule opacification with AcrySof and poly(methyl methacrylate) intraocular lenses: Comparative study with a 3-year follow-up

Purpose: To evaluate whether reports of reduced posterior capsule opacification (PCO) rates with AcrySof® intraocular lenses (IOLs) are applicable to a mixed group of cataract patients in everyday surgical practice. Setting: Department of Ophthalmology, Kärnsjukhuset, Skövde, Sweden. Methods: A retrospective study comparing a study group receiving an AcrySof IOL (n = 145) and a group receiving a poly(methyl methacrylate) (PMMA) IOL (n = 153) was performed. The follow-up was 3 years in both groups. The performance of a neodymium:YAG laser capsulotomy was used as the end point for clinically significant PCO. Results: Nine capsulotomies (6.2%) were performed in the AcrySof group and 34 (22.2%) in the PMMA group. The difference in the capsulotomy rate between the 2 groups was highly significant ( P < .001). The relative risk was 3.6 times higher in the PMMA group. Conclusions: There was a significant difference in the frequency of capsulotomy between AcrySof and PMMA IOLs in a mixed group of cataract patients in everyday clinical practice. This finding indicates the importance of the IOL type in PCO formation.

Age-Related Changes of Human Lens Epithelial Cells in vivo

We examined the density and morphology of lens epithelial cells (LECs) in vivo in a group of normal volunteers and cataract patients by using a newly developed noncontact specular microscope. There was a statistically significant decrease in the cell density of LECs in a group of cataract patients over the age of 80 years. The coefficient of variation of the cell area and the number of large black spots that were observed in the enhanced specular images were not related to aging or cataract formation. Our data indicate that the cell density of LECs decreases after reaching the age of 80, but cataract formation does not affect the cell density or the coefficient of variation of the cell area until the age of 80.

Potential acuity meter results in cataract patients.

To determine the ability of the potential acuity meter (PAM) to predict potential visual acuity through lenticular opacities in a group of cataract patients without significant other ocular pathology. This prospective study undertook PAM measurements on each eye of 84 subjects during preoperative hospital visits to either A Scan or Primary Care clinics. PAM results were compared to best corrected visual acuity findings obtained at least 6 weeks post-cataract extraction. Comparison of PAM result to visual outcome showed poor correlation (rho = 0.41, P = 0.0005). Using predictive estimates, 49% of subjects' PAM results underestimated visual outcome as determined by a difference of greater than 2 Snellen acuity lines in these results. Factors such as preoperative vision level, cataract type and pupil dilation did not significantly influence the predictive power of the PAM. Preoperative pinhole results were also correlated with visual outcome (rho = 0.42, P = 0.0006). Vison in the fellow eye of subjects with 6/9 or better was correlated to the PAM result indicating a moderate to good predictive power in 'normal' eyes. PAM results were considered to be poor for a clinical test. The results of this study indicate that this instrument has only a limited usefulness as part of the standard preoperatve examination in patients undergoing cataract extraction.

Intraocular lens prediction and oculometric harmony

The oculometric features have been analysed in two groups of cataract patients, each comprising 30 subjects. All had undergone ECCE and insertion of biconvex Rayner 2 Superflex posterior chamber IOL. Using Binkhorst and SRK II routinely, the groups were given by a good fit between methods (discrepancy between emmetropia predictions numerically < 1 D) and a poor fit (actual discrepancy range 1.6-4.1 D, all with the same sign, the lower values being predicted by Binkhorst). A certain overlapping between groups was found regarding axial length and corneal curvature radius, the ranges being 21.5-25.1/22.7-29.9 mm and 7.3-8.5/7.2-8.1 mm, respectively. In contrast there was no overlapping regarding the ratio between axial length and corneal curvature radius; the ranges were 2.80-3.05 and 3.06-3.90 in the two groups. Evaluating the actual prediction errors by the two methods (follow-up after at least 4 months), they did not primarily pertain to very short or very long eyes, as usually advanced. Skew ratios between axial length and corneal curvature appeared more decisive. Possible implications for the current IOL prediction formulas, including the newer generations, are discussed.

Comparison of postoperative astigmatism with incisions of varying length closed with horizontal sutures and with no sutures

Four groups of cataract patients having phacoemulsification with a scleral tunnel incision were studied. Three groups had incision lengths of 5.0, 6.0, and 6.5 min closed with a single horizontal suture. The fourth group of patients had 5.0 mm incisions without suture closure. We found no statistical difference between these groups in the vector astigmatic changes over a four week period and subsequently over a 6.9 ± 3.7 week period. The patients in all groups returned to their preoperative astigmatic values within one to two weeks within the statistical significance achieved in this study.

Relating vernier acuity and Snellen acuity in specific clinical populations.

The relationship between vernier acuity and Snellen acuity in a group of cataract patients was examined. The vernier stimulus consisted of two small spots of light, vertically separated by a variable-sized gap. The Snellen stimulus was a standard projected Snellen chart. The form of the relation between vernier and Snellen acuity was found to depend upon the vernier gap size used. Specifically, when the smaller gaps of 4 or 8 min of arc are used, the two types of acuity are linearly related. When the gap is 16 or 32 min of arc, (or if best vernier performance irrespective of gap is considered) vernier acuity is related to Snellen acuity by a power function with an exponent less than one, within this clinical population. Thus, with increasing degrees of retinal image degradation caused by cataract, optimum vernier acuity is impaired at a slower rate than Snellen acuity. Our results in cataract patients are compared to results obtained by others within a population of strabismic and anisometropic amblyopes.

Visual functioning in cataract patients. Methods of measuring and results.

An Index for measuring Visual Functioning on the basis of self-assessment is presented and evaluated clinically and statistically. The construct validity and the reliability are shown to be sufficient. The 'Visual Functioning Index' has been applied to a group of cataract patients. In bilateral cataract patients visual functioning is, of course, correlated to visual acuity in the best eye, but this correlation is not straight forward. So, for the assessment of visual impairment both visual acuity and visual functioning must be measured. Application of the Index to a group of monaphakic cataract patients indicates a good improvement of visual function obtained even by first cataract extraction. Ideally cataract surgery should be performed before the total visual functioning and social integration is severely damaged. On this basis about 20% of the patients in this study should have been operated at an earlier stage, which among other things suggests a need for additional surgical capacity.