Bilateral pediatric cataract surgery: outcomes of 390 children from Nepal and Northern India.

PURPOSE: To report the outcomes of bilateral pediatric cataract surgery from eastern Nepal and northern India. METHODS: Preoperative, intraoperative, and postoperative data of 390 children who underwent surgery bilaterally between 2007 and 2009 were analyzed. RESULTS: Forty-two (10.8%) children came from Nepal and 348 (89.2%) from India (mainly Bihar State). Intraocular lens (IOL) implantation with posterior capsule opening and anterior vitrectomy were achieved in 386 (99.0%) children bilaterally. Median age at surgery was 7 years and 69.2% were male. At first presentation, 243 (62.3%) of the children were blind (< 3/60 in the better eye). After more than 1 year, 53.5% had a normal visual status (range: 6/6 to 6/18), 5.6% of children were still blind, and mean refractive error spherical equivalent was +1.0 ± 2.4 diopters. Astigmatism changed from suture-induced with the rule at discharge to against the rule within 3 weeks of surgery. Mean long-term astigmatic error was 1.0 ± 0.9 diopters after 1 year. Glaucoma was rare. CONCLUSIONS: Even in a setting with limited resources, successful, cost-effective, high-volume surgery for pediatric cataract is possible. Despite late presentation and limited follow-up, more than half achieved good outcomes after more than 1 year. Only 5.6% remained blind due to amblyopia or eye anomalies. Bilateral surgery during one hospital stay, IOL implantation with undercorrection according to age, aggressive surgery to prevent secondary cataract, intensive anti-inflammatory therapy, and provision of durable, high-quality spectacles to take home all proved beneficial because many children cannot attend for regular follow-up.

Myeloperoxidase deficiency preserves vasomotor function in humans.

AIMS: Observational studies have suggested a mechanistic link between the leucocyte-derived enzyme myeloperoxidase (MPO) and vasomotor function. Here, we tested whether MPO is systemically affecting vascular tone in humans. METHODS AND RESULTS: A total of 12 135 patients were screened for leucocyte peroxidase activity. We identified 15 individuals with low MPO expression and activity (MPO(low)), who were matched with 30 participants exhibiting normal MPO protein content and activity (control). Nicotine-dependent activation of leucocytes caused attenuation of endothelial nitric oxide (NO) bioavailability in the control group (P < 0.01), but not in MPO(low) individuals (P = 0.12); here the MPO burden of leucocytes correlated with the degree of vasomotor dysfunction (P = 0.008). To directly test the vasoactive properties of free circulating MPO, the enzyme was injected into the left atrium of anaesthetized, open-chest pigs. Myeloperoxidase plasma levels peaked within minutes and rapidly declined thereafter, reflecting vascular binding of MPO. Blood flow in the left anterior descending artery and the internal mammary artery (IMA) as well as myocardial perfusion decreased following MPO injection when compared with albumin-treated animals (P < 0.001). Isolated IMA-rings from animals subjected to MPO revealed markedly diminished relaxation in response to acetylcholine (P < 0.01) and nitroglycerine as opposed to controls (P < 0.001). CONCLUSION: Myeloperoxidase elicits profound effects on vascular tone of conductance and resistance vessels in vivo. These findings not only call for revisiting the biological functions of leucocytes as systemic and mobile effectors of vascular tone, but also identify MPO as a critical systemic regulator of vasomotion in humans and thus a potential therapeutic target.

Electrophysiological characterization of chloride secretion across the jejunum and colon of pigs as affected by age and weaning.

Hypersecretion of chloride can cause diarrhea, a disease frequently occurring in young pigs, particularly around weaning. We investigated the contribution of different channels to intestinal Cl(-) secretion as influenced by age and weaning. Jejunal and colonic epithelia from 4-month-old pigs and 4-week-old piglets were incubated in Ussing chambers and stimulated by carbachol and forskolin. Changes in short-circuit currents were taken as measure of electrogenic net Cl(-) secretion. DIDS or NPPB served to inhibit Ca-activated Cl(-)-channels and outwardly rectifying Cl(-)-channels (ORCC) or cystic fibrosis transmembrane regulator (CFTR), respectively. Depolarizing the basolateral membrane allowed to examine the influence of K(+)-channels on Cl(-) secretion. Forskolin-stimulated Cl(-) secretion was mediated by CFTR. ORCC were not involved. Carbachol-induced Cl(-) secretion could be ascribed to an enhanced driving force due to the opening of K(+)-channels, whereas Ca-dependent Cl(-) channels seemed not to be involved. In jejunum, piglets showed higher Cl(-) secretion than pigs. Two days after weaning forskolin induced an I (sc) overshoot and a faster increase in G (t). In colon, Cl(-) secretion was neither influenced by age nor by weaning. The data suggest a disposition of porcine jejunum for a higher Cl(-) secretion in young and freshly weaned piglets, which might be a natural defense mechanism as well as a predisposing factor for diarrhea.

Effect of central corneal thickness and corneal hysteresis on tonometry as measured by dynamic contour tonometry, ocular response analyzer, and Goldmann tonometry in glaucomatous eyes.

PURPOSE: The dynamic contour tonometer (DCT; Pascal tonometer) and the Ocular Response Analyzer (ORA) are novel tonometers designed to measure intraocular pressure (IOP) independent of corneal properties and central corneal thickness (CCT), respectively. We wanted to compare the corneal compensated IOP (IOPcc) as measured by ORA with IOP values measured by DCT and Goldmann applanation tonometry (GAT) with respect to IOP readings and the influence of corneal hysteresis (CH) and CCT in glaucoma patients. PATIENTS AND METHODS: In a study of 94 glaucomatous eyes, IOP measurements by ORA, DCT, and GAT were compared, and the effects of CCT and CH were analyzed. All measurements were taken by 1 of the authors only. RESULTS: The Mean CCT was 550+/-44 mum and mean CH 10.24+/-3.3 mm Hg. The mean value for IOPcc was 17.94+/-5.9 mm Hg, 15.14+/-3.7 mm Hg for DCT, and 14.3+/-4.3 mm Hg for GAT. The mean difference was 3.65+/-3.85 mm Hg between IOPcc and GAT and 2.80+/-4.9 mm Hg between IOPcc and DCT (P<0.001) and -0.85+/-3.3 mm Hg between GAT and DCT (P=0.015). None of the methods was related to CCT. In contrast, CH was highly statistically significant related to IOPcc (P<0.0001), whereas GAT and DCT showed only weak relation to CH (P=0.05). CONCLUSIONS: IOP measurements with the ORA are significantly higher than DCT or GAT with no apparent linear correction factor. To date, we cannot estimate the impact of differences in CH in relation to IOP and its measurement.

Changes in corneal hysteresis after clear corneal cataract surgery.

PURPOSE: To assess the changes in corneal hysteresis (CH) as measured by the Ocular Response Analyzer (ORA; Reichert Ophthalmic Instruments, Buffalo, New York, USA) to describe the influence of clear corneal cataract surgery on corneal viscoelastic properties and intraocular pressure (IOP) measured by noncontact tonometry (NCT) and Goldmann applanation tonometry (GAT). DESIGN: Retrospective, interventional, comparative study. METHODS: One hundred and one eyes of 101 consecutive patients who underwent routine clear corneal cataract surgery were evaluated. CH, NCT, and central corneal thickness (CCT) were measured by ORA before surgery and at postoperative day 1. A control group of 48 pseudophakic eyes (surgery >3 months previously) was included. RESULTS: CCT increased from 556.82 +/- 32.5 microm before surgery to 580.26 +/- 45.5 microm after surgery (P < .001; control, 555.16 +/- 42.33 microm). Mean CH decreased from 10.35 +/- 2.5 mm Hg before surgery to 9.20 +/- 1.9 mm Hg after surgery (P < .001; control, 10.47 +/- 1.63 mm Hg). NCT values rose from 17.85 +/- 3.8 mm Hg before surgery to 20.10 +/- 6.3 mm Hg after surgery. GAT values were 14.85 +/- 2.8 mm Hg before surgery and 15.24 +/- 4.1 mm Hg after surgery (P = .52). There was no significant difference of CCT or CH between the preoperative values and the values of the control group (CCT, P = .986; CH, P = .166), in contrast to the difference between postoperative values and the values of the control group (CCT, P = .005; CH, P = .031). CONCLUSIONS: At day 1 after clear corneal cataract surgery, CH is diminished, whereas CCT is increased significantly. Postoperative corneal edema leads to a change of corneal viscoelastic properties, resulting in a lower damping capacity of the cornea. It is supposed that GAT and NCT measurements are significantly different because of postoperative changes in viscoelastic properties of the cornea.

Effect of orally administered probiotic E. coli strain Nissle 1917 on intestinal mucosal immune cells of healthy young pigs.

Several beneficial effects of probiotics have been described in studies using rodent disease models and in human patients; however, the underlying mechanisms remained mostly unclear. Only a few studies focused on the effects of probiotics on the intestinal mucosal immune system. Here, we studied the effect of the probiotic strain E. coli Nissle 1917 (EcN) administered orally to young pigs at two concentrations (10(9) and 10(11)CFU/d for 21 days) on the gut-associated lymphatic tissue. This probiotic strain was shown recently to reduce recurrence of inflammation in ulcerative colitis patients. We quantified the number and distribution of intestinal immune cells (granulocytes, mast cells, CD4+, CD8+, CD25+, IgA+ lymphocytes) and the mucosal mRNA expression of cytokines (IFN-gamma, TNF-alpha, TGF-beta, IL-10) and antimicrobial peptides (PR-39, NK-lysin, prepro-defensin-beta 1, protegrins). The number and distribution of cells were highly different between small intestinal and colon segments in all groups, but were not influenced by EcN, except high dose EcN fed pigs (10(11) CFU/d) showing an increase in mucosal CD8+ cells in the ascending colon. The mRNA analysis revealed no changes associated with EcN feeding. In conclusion, according to our analyses EcN has only minor effects on the distribution of mucosal immune cells in the gut of healthy individuals. The well-established preventive effects of EcN might therefore be relate to other mechanisms than simple modulation of immune cell distribution.

Learning phacoemulsification. Results of different teaching methods.

We report the learning curves of three eye surgeons converting from sutureless extracapsular cataract extraction to phacoemulsification using different teaching methods. Posterior capsule rupture (PCR) as a per-operative complication and visual outcome of the first 100 operations were analysed. The PCR rate was 4% and 15% in supervised and unsupervised surgery respectively. Likewise, an uncorrected visual acuity of > or = 6/18 on the first postoperative day was seen in 62 (62%) of patients and in 22 (22%) in supervised and unsupervised surgery respectively.

Quantification of recti eye muscle paths in high myopia.

PURPOSE: To elucidate the etiology of an acquired, restrictive motility disorder in patients with high myopia. METHODS: Thirty-three orbits were imaged using a Siemens Magnetom or Siemens Vision (both 1.5 Tesla) MRI (magnetic resonance imaging) scanner, applying a head coil. Coronal T1-weighted, spin-echo images were obtained. Orbits of three different patient groups were analyzed. Group 1 (n = 14): patients with high axial myopia and restricted eye motility (average axial length = 31.4 mm; refractive error more than -15 D). Group 2 (n = 8): subjects with high axial myopia and normal eye motility (average axial length = 29.2 mm). Controls (n = 11): emmetropic subjects with normal eye motility. RESULTS: Highly myopic patients showed significant displacements of recti EOMs in comparison to the controls. Mean displacements as measured in the plane 3 mm anterior to the globe-optic nerve junction in primary gaze were, in group 1: lateral rectus (LR) 2.9 mm (2.5 downward, 1.4 medial), medial rectus (MR) 1.3 mm downward. In group 2: LR 1.4 mm (1.3 downward, 0.6 medial) and MR 1.2 mm downward. In both groups 1 and 2, the inferior rectus (IR) was displaced 1.3 mm medially and upwards. In both groups of myopic patients the superior rectus (SR) was displaced 1.5 mm medially and downwards. CONCLUSIONS: In patients with high axial myopia, displacements of all recti EOMs can be detected by MRI. However, displacement of the LR into the lateral and inferior quadrant of the orbit is significantly greatest. We therefore assume LR displacement to be a major pathophysiological factor for the restrictive motility disorder in high myopia. EOM dislocations can be explained by myopia-associated alterations in the orbital connective tissues confining EOM positions in relation to the orbital wall.

[The predictive value of a classification for proliferative diabetic vitreoretinopathy]. / Klinische Bedeutung einer Stadieneinteilung der proliferativen diabetischen Vitreoretinopathie.

BACKGROUND: Kroll's classification of proliferative diabetic vitreoretinopathy (PDVR) defines stage A (vitreoretinal proliferations without retinal detachment), stage B (partially detached retina not involving the macula), stage C (partially detached macula) and stage D (completely detached macula). The purpose of this study was to analyse the prognostic value of Kroll's classification in respect of the postoperative results of vitreoretinal surgery based on our group of patients. PATIENTS AND METHODS: The charts of 563 patients who underwent vitrectomy because of PDVR between 1990 and 1997 were examined retrospectively. Postoperative visual acuity, possible risk factors, frequencies of silicone oil tamponade and revitrectomies were related to the preoperative staging of PDVR. The influence of possible predictive factors on the postoperative visual outcome were evaluated using multivariate logistic regression analysis. RESULTS: After vitreoretinal surgery mean postoperative visual acuity was significantly better in stage A compared to stage C (p < 0.01) or D (p < 0.0001). In 179 out of 563 eyes (31.7 %) revitrectomy (including silicone oil removal) was required and in 51 eyes (9.1 %) more than one revitrectomy was performed. Silicone oil tamponade was used in 22 out of 253 eyes (8.7 %) classified as stage A, in 27 out of 201 eyes (13.4 %) of stage B, in 17 out of 78 eyes (21.8 %) of stage C and in 10 of 31 eyes (32.3 %) of stage D. Postoperative increase of visual acuity of more than 3 lines was significantly less frequent in stage B (p < 0.014), C (p < 0.039) and D (p < 0.001) compared to stage A. CONCLUSION: Kroll's classification for PDVR has a high prognostic value for the postoperative visual outcome and level of surgical risk management. Thus patients with good prognosis can be identified easily, facilitating the decision for surgery.