Effect of in-the-bag intraocular lens fixation on the prevention of posterior capsule opacification

PURPOSE: To compare the incidence of posterior capsule opacification (PCO) after extracapsular cataract extraction (ECCE) and phacoemulsification and to evaluate the role of posterior chamber intraocular lens (PC IOL) haptic fixation and biomaterial/design in reducing the incidence. SETTING: Postgraduate Institute of Medical Education and Research, Chandigarh, India; Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: This study comprised 278 eyes of 263 patients having ECCE and 318 eyes of 297 patients having phacoemulsification with PC IOL implantation. Posterior capsule opacification leading to a decrease in Snellen visual acuity of 2 or more lines was considered visually significant. The presence of PCO and IOL haptic fixation were evaluated postoperatively using slitlamp biomicroscopy. Haptic position was noted as in-the-bag (B-B), 1 haptic in the bag and 1 in the sulcus (bag-sulcus [B-S]), or both haptics out of the bag (sulcus-sulcus [S-S]). In addition, the rate of visually significant PCO was compared among 3 IOL biomaterials: poly(methyl methacrylate), silicone, and hydrophobic acrylic.Results: Visually significant PCO occurred in 42.45% of eyes having ECCE and 19.18% of eyes having phacoemulsification (P <.001, chi-square test) after a mean follow-up of 2.4 years +/- 0.7 (SD). In both groups, visually significant PCO was significantly less in eyes with B-B fixation than in those with B-S or S-S fixation (P <.001). The rate of visually significant PCO in all eyes in the phacoemulsification group with B-B fixation was low (11.90%) and was significantly lower in eyes with a hydrophobic acrylic IOL (2.22%; P <.05, chi-square test). CONCLUSIONS: In-the-bag PC IOL fixation is required to consistently reduce the incidence of PCO. Thorough removal of lens substance, including hydrodissection-assisted cortical cleanup, and in-the-bag PC IOL fixation seem to be the most important factors in reducing PCO, regardless of surgical procedure or IOL type used. Intraocular lens biomaterial and design also help prevent PCO.     

Prevention of postoperative infections in ophthalmic surgery

Postoperative endophthalmitis is a serious, vision-threatening complication of intraocular surgery. Better instrumentation, surgical techniques, prophylactic antibiotics and better understanding of asepsis have significantly reduced the incidence of this complication. Postoperative endophthalmitis may occur as an isolated event or as a cluster infection. Topical antibiotics, preoperative periocular preparation with povidone-iodine combined with a sterile operating room protocol significantly reduce the incidence of isolated postoperative endophthalmitis. The role of antibiotics in the irrigating fluid and subconjunctival antibiotics remains controversial. Cluster infections on the other hand are more likely to occur due to the use of contaminated fluids/viscoelastics or a breach in operating room asepsis. Prevention of postoperative endophthalmitis requires strict adherence to operating room norms, with all involved personnel discharging their assigned roles faithfully.     

Neodymium:YAG capsulotomy rates following phacoemulsification with implantation of PMMA, silicone, and acrylic intraocular lenses

BACKGROUND AND OBJECTIVE: Posterior capsular opacification (PCO) is the most common visually disabling sequela of modern cataract surgery. Methods of reducing its incidence include the development of newer surgical techniques and intraocular lens (IOL) materials and designs. The aim of this study was to compare the incidence and time interval of development of PCO, and the requirement of laser capsulotomy in patients implanted with a polymethylmethacrylate (PMMA), silicone, or acrylic IOL. PATIENTS AND METHODS: The data of 340 consecutive patients who underwent phacoemulsification and implantation ofa PMMA, silicone, or acrylic intraocular lens were analyzed. The aim of this study was to compare the incidence and time interval of development of PCO, and the requirement of laser capsulotomy in patients implanted with a PMMA, silicone, or acrylic IOL. RESULTS: The incidence of PCO was found to be significantly less in the acrylic group (6.5% as compared to 21.74% and 26.6% in the PMMA and silicone groups, respectively; P = 0.01297 and 0.0039). Most patients (65%) exhibiting PCO in the PMMA group developed it within the first six months. In the silicone group, development of PCO was delayed. In 60% of patients, it appeared 18 months after surgery. Neodymium:YAG capsulotomy was required in 45% and 60% of patients developing PCO in the PMMA and silicone groups, respectively, while it was required in only 1 of the 4 patients developing PCO in the acrylic group. CONCLUSION: This study indicates that implantation of an acrylic IOL helps reduce the incidence of PCO as well as the need for Nd:YAG capsulotomy. PMMA IOLs require Nd:YAG capsulotomy earlier in the postoperative period as compared to silicone IOLs.     

Elevated IgG anti-histone antibodies in a subgroup of medicated schizophrenic patients.

A total of 57 schizophrenic patients (of which 17 were first-episode, neuroleptic naive) and 76 healthy controls were screened for anti-histone IgG antibodies using an enzyme immunoassay (ELISA). All patients had significantly higher anti-histone antibody titers than controls (t = 3.1, p less than 0.003). Previously medicated patients had significantly higher titers than neuroleptic-naive first episode patients (t = 2.87, p less than 0.006). This study suggests that neuroleptic medications are associated with anti-histone antibodies.     

Growth hormone synthesis and secretion by a somatomammotroph cell line derived from normal adult pituitary of the rat

A somatomammotroph cell line derived from male rat anterior pituitary (rPCO) has been established without the use of transforming agents and has been maintained in culture for more than 1 yr (45 passages) using Minimum Essential Medium supplemented with 10% horse serum, 5 nM T3, 2 nM corticosterone, and 0.1 nM GH-releasing hormone (GRH). Peroxidase and immunofluorescent staining revealed immunoreactive GH in 99% of rPCO cells and immunoreactive PRL in 72% of cells. Within individual cells, GH and PRL appear to be colocalized. The storage capacity for GH in rPCO cells represented 40% of the daily hormone production. In serum-free medium containing 5 nM cortisol, GH secretion was stimulated 10- and 25-fold by 50 pM and 50 nM T3, respectively. GRH (1 nM) stimulated GH secretion 8-fold in the absence of T3, although no effect was observed in the presence of 50 nM T3. Qualitatively similar changes occurred in GH mRNA responses to T3 and GRH. Other secretory proteins were detected on sodium dodecyl sulfate-polyacrylamide gel electrophoresis of culture medium, several of which were present in concentrations similar to that of GH. Nine separate cell lines were cloned from rPCO cells by limiting dilution, all of which secreted GH and PRL. GH secretion varied 6-fold between clones, and the GH to PRL ratio varied more than 200-fold. These rPC cell lines provide a new model for studying the control of GH and PRL gene expression, including hormone synthesis, processing, and secretion. They may also be useful for identifying other pituitary secretory products and as a source for the production of protein hormones.     

Relationship of systolic/diastolic ratios from umbilical velocimetry to fetal heart rate

We assessed the relationship between systolic/diastolic ratios as determined by umbilical velocimetry to fetal heart rate. Umbilical velocimetry was performed with continuous-wave Doppler ultrasound and systolic/diastolic ratios and fetal heart rate for the corresponding cardiac cycles were calculated in four groups of patients. Group 1 consisted of 30 patients undergoing antepartum fetal testing; systolic/diastolic ratios were found to be significantly lower (mean +/- SD, 2.0 +/- 0.15) during an evoked fetal heart rate acceleration with an artificial larynx than either before (2.4 +/- 0.14) or after the acceleration (2.35 +/- 0.10, p less than 0.01). In 20 patients with pyelonephritis (group 2), systolic/diastolic ratios were significantly lower during initial fetal tachycardia (1.6 +/- 0.21) as compared with those obtained after its resolution (2.1 +/- 0.12, p less than 0.08). In the 25 patients with chorioamnionitis in group 3, systolic/diastolic ratios were significantly higher during initial fetal tachycardia (1.4 +/- 0.21) than after its resolution (1.9 +/- 0.15, p less than 0.05). Twenty patients in labor (group 4) had 10 serial measurements at 1 to 2-hour intervals of systolic/diastolic ratio and FHR. Least-squares regression of each patient showed a negative slope that differed statistically from zero (p less than 0.05). There were no patients with elevated systolic/diastolic ratios greater than 3.0 in any group and all patients delivered fetuses appropriate for gestational age. These findings suggest an inverse relationship between systolic/diastolic ratio and fetal heart rate. Additionally, an alteration in fetal heart rate within the range studied does not itself produce abnormal ratios. Therefore normalization of the systolic/diastolic ratio for heart rate may be considered in clinical studies for statistical analysis and comparison but may have little practical or clinical relevance when the ratios are abnormal.     

An Evaluation of Neurotoxicity Following Fluoride Exposure from Gestational Through Adult Ages in Long-Evans Hooded Rats

Antibiotics such as gentamicin (an aminoglycoside) and penicillin (a beta-lactam antibiotic) are routinely used in retinal cell and explant cultures. In many cases, these in vitro systems are testing parameters regarding photoreceptor transplantation or preparing cells for transplantation. In vivo, milligram doses of gentamicin are neurotoxic to the retina. However, little is known about the effects of antibiotics to retina in vitro and whether smaller doses of gentamicin are toxic to retinal cells. To test toxicity, retinal cells were dissociated from tiger salamander, placed in culture, and treated with either 20 μg/ml gentamicin, 100 μg/ml streptomycin, 100 U/ml antibiotic/antimycotic, 0.25 μg/ml amphotericin B, or 100 U/ml penicillin G. All dosages were within manufacturer’s recommended levels. Control cultures had defined medium only. Cells were fixed at 2 h or 7 days. Three criteria were used to assess toxicity: (1) survival of retinal neurons, (2) neuritic growth of photoreceptors assessed by the development of presynaptic varicosities, and (3) survival and morphology of Mueller cells. Rod cells were immunolabeled for rod opsin, Mueller cells for glial fibrillary acidic protein, and varicosities for synaptophysin. Neuronal cell density was reduced with all pharmacological treatments. The number of presynaptic varicosities was also significantly lower in both rod and cone photoreceptors in treated compared to control cultures; further, rods were more sensitive to gentamicin than cones. Penicillin G (100 U/ml) was overall the least inhibitory and amphotericin B the most toxic of all the agents to photoreceptors. Mueller cell survival was reduced with all treatments; reduced survival was accompanied by the appearance of proportionally fewer stellate and more rounded glial morphologies. These findings suggest that even microgram doses of antibiotic and antimycotic drugs can be neurotoxic to retinal cells and reduce neuritic regeneration in cell culture systems.     

Challenges of caring for homeless patients with inflammatory arthritis: 12-month follow-up observations and identification of certain barriers to care

Clinical Rheumatology - Homelessness is a public health crisis and there is a paucity of information about patients with rheumatic disease experiencing homelessness. We sought to develop approaches...