Analysis of elements of interlenticular opacification

PURPOSE: To report the histopathologic and ultrastructural features of three cases of interlenticular opacification (ILO) between piggyback intraocular lenses. DESIGN: Interventional case series with clinicopathologic correlation. METHODS: Three pairs of acrylic piggyback lenses were explanted due to decrease in visual acuity associated with ILO. Lenses were evaluated with gross and light microscopic examinations in all cases. The anterior lens in one case was examined with scanning electron microscopy and energy dispersive x-ray spectroscopy. RESULTS: The material opacifying the interlenticular space was composed mostly of retained/regenerative cortical material in all cases. From the peripheral interface towards the central interface, the opacifying material changed as the interlenticular space was progressively narrower. The material attached to the peripheral interface, where the interlenticular space was wider, was very thick. At the midperipheral interface, the thick cortical material was broken into multiple globules due to liquefactive degeneration. At the paracentral zone, compression of the globules formed a flat, compact layer of an amorphous material. At the central interface (contact zone), almost no material could be found between the piggyback lenses. CONCLUSIONS: Analyses of ILO cases where all the components of the opacifying material were in situ allowed us to confirm that the pathogenesis of this complication is similar to that of posterior capsule opacification; thus, careful removal of lens epithelial cells and cortical material is mandatory in piggyback implantation.     

Effect of hydrodissection on intraoperative performance: randomized study

PURPOSE: To evaluate the effect of hydrodissection on intraoperative performance during phacoemulsification of age-related nuclear cataracts. SETTING: Iladevi Cataract & IOL Research Centre, Ahmedabad, India, and Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: In a prospective study, 86 eyes were randomly assigned to have multiquadrant hydrodissection (+HD, n = 48) or no hydrodissection (-HD, n = 38) during phacoemulsification of a grade 1 to 3 nuclear cataract. Excluded were patients with grade 4 or 5 nuclear sclerosis, a poorly dilating pupil, or associated ocular/systemic disease. Parameters assessed were nucleus and cortex removal time, the amount of fluid used for cortex removal, and the total amount of fluid used. The ease of nucleus rotation and cortical cleanup was also evaluated and graded subjectively as very easy, difficult, or very difficult. Data were analyzed using the Student t test and the chi-square test. RESULTS: The mean nucleus removal time was 355 seconds +/- 237 (SD) and 474 +/- 212 seconds in the +HD and -HD groups, respectively (P =.09). The mean cortex removal time was significantly less in the +HD group than in the -HD group (79 +/- 51 seconds and 220 +/- 222 seconds, respectively) (P =.007). Significantly less fluid (43%) was used for cortex removal in the +HD group than in the -HD group (mean 70 +/- 45 mL and 123 +/- 82 mL, respectively) (P =.013), and significantly less total fluid (35%) was used in the +HD group (312 +/- 132 mL and 422 +/- 80 mL, respectively) (P =.002). Nucleus rotation was easy in all eyes in the +HD group; 68.43% of eyes in the -HD group failed to achieve rotation (P =.001). Cortex removal was very easy in 52.08% of eyes in the +HD group and easy in 47.90%; it was easy in 52.63% in the -HD group, difficult in 36.84%, and very difficult in 10.52%. CONCLUSION: The use of multiquadrant cortical-cleaving hydrodissection made removal of the lens nucleus and cortex easier and faster during phacoemulsification of age-related nuclear cataracts.     

Permanent blue discoloration of a hydrogel intraocular lens by intraoperative trypan blue

A 79-year-old white man had cataract surgery in the right eye with implantation of an Acqua intraocular lens (IOL) (Mediphacos). Trypan blue 0.1% was used during surgery to stain the anterior capsule and enhance the contrast during capsulorhexis. Seven days after surgery, the patient presented with "dark and double" vision (monocular diplopia). The IOL was decentered superiorly and appeared dark blue. The lens was explanted 2 months after surgery and sent for gross and microscopic analyses in a dry state and after hydration. The same analyses were performed on 2 unused lenses of the same design that had been immersed in diluted trypan blue solutions (0.01% and 0.001%). On the explanted lens, the dark blue staining was denser in the optic, especially in its periphery. The blue discoloration could not be removed after 24 hours of lens immersion in a balanced salt solution at 37 degrees C. Permanent staining of the unused lenses was also obtained after immersion in the trypan blue solutions.     

Association of HLA class I and II alleles and extended haplotypes with nasopharyngeal carcinoma in Taiwan

BACKGROUND: Nasopharyngeal carcinoma (NPC), which occurs at a disproportionately high rate among Chinese individuals, is associated with Epstein-Barr virus (EBV). Human leukocyte antigen (HLA) polymorphisms appear to play a role in NPC, because they are essential in the immune response to viruses. We used high-resolution HLA genotyping in a case-control study in Taiwan to systematically evaluate the association between various HLA alleles and NPC. METHODS: We matched 366 NPC case patients to 318 control subjects by age, sex, and geographic residence. Participants were interviewed and provided blood samples for genotyping. High-resolution (polymerase chain reaction-based) genotyping of HLA class I (A and B) and II (DRB1, DQA1, DQB1, and DPB1) genes was performed in two phases. In phase I, 210 case patients and 183 control subjects were completely genotyped. In phase II, alleles associated with NPC in the phase I analysis were evaluated in another 156 case patients and 135 control subjects. Extended haplotypes were inferred. RESULTS: We found a consistent association between HLA-A*0207 (common among Chinese but not among Caucasians) and NPC (odds ratio [OR] = 2.3, 95% confidence interval [CI] = 1.5 to 3.5) but not between HLA-A*0201 (most common HLA-A2 allele in Caucasians) and NPC (OR = 0.79, 95% CI = 0.55 to 1.2). Individuals with HLA-B*4601, which is in linkage disequilibrium with HLA-A*0207, had an increased risk for NPC (OR = 1.8, 95% CI = 1.2 to 2.5) as did individuals with HLA-A*0207 and HLA-B*4601 (OR = 2.8, 95% CI = 1.7 to 4.4). Individuals homozygous for HLA-A*1101 had decreased risks for NPC (OR = 0.24, 95% CI = 0.13 to 0.46). The extended haplotype HLA-A*3303-B*5801/2-DRB1*0301-DQB1*0201/2-DPB1*0401, specific to this ethnic group, was associated with a statistically significantly increased risk for NPC (OR = 2.6, 95% CI = 1.1 to 6.4). CONCLUSIONS: The restriction of the association of HLA-A2 with NPC to HLA-A*0207 probably explains previously observed associations of HLA-A2 with NPC among Chinese but not Caucasians. The extended haplotypes associated with NPC might, in part, explain the higher rates of NPC in this ethnic group.     

Muscle fiber type-specific myofibrillar Ca(2+) ATPase activity after spinal cord injury

Biopsies of the vastus lateralis muscle were analyzed to determine if increased energy demand of contraction, as indirectly reflected by myofibrillar Ca(2+) adenosine triphosphate activity (qATPase), contributes to greater fatigue in affected muscle of spinal cord injured (SCI) patients. The qATPase activity showed a fiber-type effect, IIax + IIx > IIa > I. Average fiber qATPase and fiber specific qATPase activities were not different between SCI and able-bodied controls, nor did they change over time. We suggest greater fatigue in SCI subjects early after injury does not reflect increased energy demand of contraction.