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Biomedical subjects

S Basti

Publications and source records attributed to S Basti.

At least 19 recordsLinked to original sources

Capsular bag distension after optic capture of a sulcus-fixated intraocular lens.

Capsular bag distension from occlusion of the circular anterior capsule opening by the intraocular lens (IOL) optic is a rare complication of capsulorhexis. The nature and source of fluid remain unclear. We report a case of capsular bag distension in an eye with an optic-captured, all-poly(methyl methacrylate), sulcus-fixated IOL. The fluid behind the IOL optic was visible on the first postoperative day and resolved spontaneously by the sixth postoperative week. We believe that retained viscoelastic material in the capsular bag was a major contributor to the fluid.

Aged

Different faces of the white cataract: a phaco surgeon's perspective.

PURPOSE: To develop a system of categorizing white cataracts so that the salient features, as would be pertinent to phaco-emulsification surgery, could be recognized pre-operatively. METHODS: Patients with total cataracts were carefully evaluated using slit-lamp biomicroscopy and slit-lamp photography. An attempt was made to determine whether pre-operative evaluation could ascertain the presence or absence of features of these cataracts that often cause surgical difficulties, namely, increased intralenticular pressure (ILP), milky cortex and brown nuclear colour. RESULTS: Using a standardized method of biomicroscopic evaluation, it was found that the status of the ILP, cortex and nuclear colour could be determined consistently. Surgical strategies based on such a system of categorization has permitted white cataracts to be consistently managed using phacoemulsification. CONCLUSIONS: Systematic pre-operative evaluation and categorization of white cataracts based on the ILP, status of the cortex and nuclear colour can permit proper surgical planning and successful management of such cases with phacoemulsification.

Cataract

Familial subepithelial corneal amyloidosis (gelatinous drop-like corneal dystrophy): exclusion of linkage to lactoferrin gene.

PURPOSE: Because corneal tissue with familial subepithelial corneal amyloidosis (FSCA; gelatinous drop-like dystrophy of the cornea) contains lactoferrin the possibility that the FSCA gene was the human lactoferrin (hLF) gene was investigated. Due to contradictory published information we also mapped the hLF gene. METHODS: We mapped the hLF gene using a genomic clone of the entire hLF gene as a probe by fluorescence in situ hybridization (FISH). Utilizing PCR primers that are specific to the hLF gene, we also mapped the hLF via radiation somatic cell hybrid analysis. Linkage of the FSCA gene to the hLF gene was evaluated by genetic linkage analysis using polymorphic markers within and in the vicinity of the hLF gene. RESULTS: The hLF gene mapped to the short arm of chromosome 3 at 3p21. Linkage analysis using polymorphic markers for hLF and haplotype analysis of the 3p21 loci indicates that the FSCA gene is not linked to the 3p21 locus. CONCLUSIONS: The gene for FSCA is not the hLF gene in these families.

Amyloidosis

Autosomal dominant zonular cataract with sutural opacities is associated with a splice mutation in the betaA3/A1-crystallin gene.

PURPOSE: Congenital cataracts constitute a morphologically and genetically heterogeneous group of diseases that are a major cause of childhood blindness. Autosomal Dominant Zonular Cataracts with Sutural Opacities (CCZS) have been mapped to chromosome 17q11-q12 near the betaA3A1-crystallin gene (CRYBA1). The betaA3A1-crystallin gene was investigated as the causative gene for the cataracts. METHODS: The betaA3/A1-crystallin gene was sequenced in affected and control individuals. Base changes were confirmed and assayed in additional family members and controls using NlaIII restriction digestion of PCR amplified DNA sequences. Base changes were assessed for their effects on splicing by information analysis. RESULTS: The cataracts are associated with a sequence change in the 5' (donor) splice site of intron 3: GC(g->a)tgagt. The sequence change also creates a new NlaIII site. This base change cosegregates with the cataracts in this family, being present in every affected individual. Conversely, this base change was not seen in 140 chromosomes examined in 70 unaffected and unrelated individuals. Information theory mutational analysis shows that the base change lowers the information content of the splice site from 6.0 to -6.8 bits, so that splicing would not be expected to occur at the altered site. CONCLUSIONS: Taken together, these observations suggest that the observed mutation might be causally related to the cataracts in this family.

Amino Acid Sequence

Prospective evaluation of corneal endothelial cell loss after pediatric cataract surgery.

PURPOSE: To study the alterations in endothelial cell count and morphology after pediatric cataract surgery using currently practiced techniques. SETTING: L.V. Prasad Eye Institute, Hyderabad, India. METHODS: In a prospective nonrandomized series comprising 20 eyes of 14 children with congenital or developmental cataract, endothelial cell loss from cataract surgery was evaluated. Mean patient age was 9.3 years (range 5 to 15 years). Extracapsular cataract extraction (ECCE) with intraocular lens (IOL) implantation was performed in 11 eyes (Group 1). Primary posterior capsulotomy and anterior vitrectomy were performed with ECCE and IOL implantation in 9 eyes (Group 2). Noncontact specular microscopy was done preoperatively and 6 to 8 and 24 to 36 weeks postoperatively. Endothelial cell loss, alteration in the coefficient of variation, and the change in the number of hexagonal cells were determined by semiautomated analysis of endothelial pictures. RESULTS: Mean endothelial cell loss was 198.39 cells/mm2 (5.28%) in Group 1 and 295.17 cells/mm2 (7.50%) in Group 2 at 24 to 36 weeks. There was no statistically significant difference in alteration in endothelial cell count and morphology between the 2 groups. CONCLUSIONS: The results suggest that endothelial cell loss with currently practiced techniques of pediatric cataract surgery is within acceptable limits.

Adolescent

Results of bilateral cataract extraction with posterior chamber intraocular lens implantation in children.

OBJECTIVE: A retrospective study was undertaken to evaluate long-term anatomic and visual outcomes in eyes of children who underwent bilateral intraocular lens implantation. DESIGN: The study design was a review of medical records of 24 children operated on for bilateral cataracts and posterior chamber-intraocular lenses. PARTICIPANTS: Twenty-four children operated on for bilateral cataracts by 1 surgeon between February 1980 and February 1995 were studied. INTERVENTION: Cataract extraction with bilateral posterior chamber-intraocular lens implantation was performed. MAIN OUTCOME MEASURES: Best-corrected visual acuity, visual acuity without correction, intraocular pressure, manifest refraction, and any intraoperative or postoperative complications were measured. RESULTS: At last follow-up (mean follow-up, 50.8 months; range, 10-149 months), the intraocular lens was in good position and the intraocular pressure was normal without medication in all eyes. Four years after surgery, 79.2% (19 of 24) of first eyes achieved a best-corrected visual acuity of 20/40 or better compared to 66.7% (16 of 24) of second eyes. No eye had any loss in best-corrected visual acuity. In first eyes of 3- to 8-year olds at the time of surgery, 73.3% (11 of 15) achieved a spherical equivalent within 2 diopters of the intended at 4 years after surgery compared to 80% of second eyes. In the 9- to 18-year-old group, 88.9% (8 of 9) of first eyes and 100% of second eyes achieved a spherical equivalent within 2 diopters of the intended at 4 years after surgery. Intraoperative and postoperative complications were minimal. CONCLUSIONS: Long-term anatomic and visual results have been gratifying in this series of patients with bilateral implants.

Adolescent

Secondary capsule-supported intraocular lens implantation in children.

PURPOSE: To evaluate surgical problems, postoperative complications, and visual results of secondary posterior chamber intraocular lens (IOL) implantation in children. SETTING: L.V. Prasad Eye Institute, Hyderabad, India. METHODS: A retrospective study was done of secondary IOL implantation in 27 children (35 eyes) who were not satisfied with aphakic glasses and were intolerant of or reluctant to use contact lenses. The extent of posterior capsular support was assessed prior to surgery. Additional surgical procedures were posterior synechiolysis (11 eyes), anterior vitrectomy (8 eyes), pupilloplasty (2 eyes), and membranectomy (2 eyes). RESULTS: Postoperative complications included wound leak (1 eye), uveitis (5 eyes), peripheral anterior synechias (2 eyes), and retinal detachment (1 eye). Visual acuity improved or remained at the preoperative level in 34 eyes. CONCLUSION: Secondary posterior chamber IOL implantation is an effective optical modality for managing pediatric aphakia. Observation must continue to determine the long-term safety of the procedure.

Adolescent

Computerized topography of selective versus all-suture release to manage high astigmatism after cataract surgery.

PURPOSE: To compare the efficacy of selective suture release (SSR) with all-suture release (ASR) in controlling corneal astigmatism after cataract surgery. SETTING: Sight Saver's Cornea Training Centre, L.V. Prasad Eye Institute, Hyderabad, India. METHODS: This prospective, randomized study evaluated the effect on astigmatism of two techniques of suture release in 30 patients with more than 3.00 diopters (D) of corneal astigmatism after cataract surgery. All patients had interrupted sutures with well-healed wounds. Fifteen patients had ASR irrespective of the location of the steep meridian. In the other 15, only the suture located in the steep meridian was selectively released. The pattern of decay of astigmatism after suture release was studied using computerized videokeratography. RESULTS: Mean pretreatment corneal cylinder was 6.30 D +/- 2.72 (SD) in the ASR group and 6.95 +/- 1.67 D in the SSR group. In the ASR group, corneal cylinder dropped to 3.70 +/- 1.15 D immediately after suture release and further decreased to 1.82 +/- 0.66 D at 1 week (P < .001). In the SSR group, astigmatism swung erratically to the adjoining sutures and decreased unpredictably at an average of 1.32 +/- 2.00 D with each suture release. CONCLUSION: The ASR technique was more predictable and less cumbersome than the SSR method.

Aged

Silicone oil adhesion to intraocular lenses: an experimental study comparing various biomaterials.

PURPOSE: To perform an in vitro experimental study comparing the degree of adherence of silicone oil to various rigid and foldable intraocular lens (IOL) designs and to the human lens capsule. SETTING: Center for Research on Ocular Therapeutics and Biodevices, Department of Ophthalmology, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: Seven IOL styles comprising various biomaterials were studied: fluorine-treated (Fluorlens), heparin-surface-modified (HSM), hydrogel, Memory-Lens, Poly(methyl methacrylate) (PMMA), soft acrylic, and silicone lenses; the human crystalline lens was also studied. Each lens was immersed in silicone oil for 12 hours, than photographed, studied by scanning electron microscopy (except the crystalline lens), and subjected to computer-generated image analysis to determine the silicone oil coverage. RESULTS: Silicone oil coverage of dry silicone lenses was 100% and of lenses immersed in normal saline, 82.5%. The least coverage was on the heparin-surface-modified lens (mean score 9.4%). Coverage of the other four lenses ranged from approximately 15.1% to 33.7%. Mean coverage of the human lens capsule was 10.9%. CONCLUSION: Although a silicone IOL shows maximal adherence to silicone oil, other lens biomaterials are not immune to this complication. Silicone oil coverage was related to the dispersive energy component of the surface charge of the IOL biomaterial. Low dispersive energy materials had less silicone oil coverage, while those with higher dispersive energy had more oil coverage.

Adhesiveness

Globe rupture during digital massage after peribulbar anesthesia.

A 75-year-old woman developed globe rupture with extrusion of intraocular contents during digital massage after periocular injection of an anesthetic. The rupture was repaired. At the last follow-up 6 months after surgery, visual acuity was 20/160. The retina was attached, and the vitreous hemorrhage was resolving. This complication of peribulbar anesthesia and digital massage highlights the importance of using quantitative techniques to induce hypotony during peribulbar anesthesia.

Aged

Physical and mechanical principles of phacoemulsification and their clinical relevance.

A clear understanding of the physical and mechanical principles that govern phacoemulsification can facilitate usage of this technique for effective and efficient cataract removal in a variety of clinical situations. This article addresses separately, concepts pertaining to the three essential components of phacoemulsification, namely, irrigation, aspiration and emulsification. Machine settings are suggested for the various techniques presently in use. Finally, alternative approaches for lens removal that are currently being investigated are briefly discussed.

Biomechanical Phenomena

Autosomal dominant zonular cataract with sutural opacities in a four-generation family.

PURPOSE: We identified and examined four generations of a family with coexisting autosomal dominant zonular cataracts and sutural opacities and sought to determine their genetic basis. METHODS: Twenty-four of the 48 members in the family were examined. Systemic and ocular histories were obtained, and a detailed ophthalmic examination was performed. From each individual, 20 ml of blood was drawn for linkage studies with microsatellite markers in regions to which zonular cataracts had previously been localized (chromosomes 1, 2, and 16). RESULTS: Individuals of the first generation were reportedly asymptomatic. Several members of the second generation had morphologically identical zonular cataracts. Affected members of the third generation showed morphologic heterogeneity, with the zonular opacity varying from a uniform lamella to a segregation of dots. A high degree of consanguinity in the second generation suggested recessive inheritance with a pseudodominant inheritance pattern. However, examination of one member of the asymptomatic first generation disclosed senile cataractous changes superimposed on a faint zonular cataract enclosing sutural opacities and a pulverulent fetal nucleus. The latter findings were reconfirmed to be present in affected members of all generations, suggesting an autosomal dominant mode of inheritance. Initial efforts at linkage analysis excluded the gene locus causing this cataract from the Duffy, haptoglobin, and gamma-crystallin regions. CONCLUSIONS: The cataract in this family is both phenotypically and genetically distinct from previously described and mapped cataracts.

Adolescent

Results of a prospective evaluation of three methods of management of pediatric cataracts.

BACKGROUND: Although a variety of approaches to manage cataracts in children have been studied, no consensus exists on the optimum approach. The authors, therefore, conducted a prospective, nonrandomized, consecutive study to evaluate three most commonly adopted methods of management of pediatric cataracts. METHODS: Lensectomy anterior vitrectomy (LAV), extracapsular cataract extraction with intraocular lens implantation (ECCE + IOL) and ECCE, primary posterior capsulotomy, anterior vitrectomy with IOL (ECCE + PPC + AV + IOL) were the surgical procedures performed. Aphakia in the LAV group was corrected with spectacles or contact lenses. Intraoperative and postoperative results were analyzed. Discrete variables among the three groups were compared using chi square test. RESULTS: One hundred ninety-two eyes were included in the study. There was no statistically significant difference in the intraoperative complications in the three groups. During a mean follow-up period of 11.3 months, postoperative obscuration of the visual axis was seen in 43.7% of eyes in the ECCE + IOL group and in 3.65% of eyes in the ECCE + PC + AV + IOL (p < 0.001). Two of the seven patients in the LAV group in whom contact lenses were prescribed developed corneal infiltrates. Severe postoperative anterior uveitis occurred in 15.9% and 13.8% of eyes in the ECCE + PPC + AV + IOL and ECCE + IOL groups, respectively. None of the eyes that underwent LAV developed this complication (P < 0.001). There was no statistically significant difference in the incidence of retinal detachment, endophthalmitis, or glaucoma in the three groups. CONCLUSION: Of the three approaches, ECCE + PPC + AV + IOL was conducive to at least short-term maintenance of a clear visual axis, provided optimum refractive correction, and was not associated with increased risk of short-term complications. Continued follow-up of these eyes is necessary to conclude on the long term results of this technique.

Cataract

Experience during the learning curve of laser in situ keratomileusis.

PURPOSE: To identify pitfalls and offer hints on achieving a successful outcome during the early laser in situ keratomileusis (LASIK) learning process. SETTING: Gimbel Eye Centre, Calgary, Alberta, Canada. METHODS: This was a retrospective review of the preoperative planning, surgical procedure, intraoperative and postoperative problems, and early postoperative anatomic and refractive results in the first 73 eyes that had LASIK. RESULTS: Intraoperative complications included failure of the keratome to make a cut, excessively thin cap, repositioning difficulty, and inadequate intraocular pressure elevation. Early postoperative complications included excessive central and peripheral wrinkling of the cap, peripheral lipid deposits, and central edema of the cap. One month postoperatively, mean spherical equivalent refraction was -0.90 diopters (D) (range +1.75 to -6.00 D), and 45 eyes had a best corrected visual acuity between 20/15 and 20/40. CONCLUSION: Our retrospective review of the problems experienced during the early LASIK learning process should help novice lamellar refractive surgeons avoid such problems and shorten the learning curve.

Adult

Co-occurring adenoviral keratitis and hemorrhagic cystitis. A case report.

Adenoviruses are ubiquitous viruses, commonly causing ocular infections. They are also known to cause multisystem infections. External ocular infections caused by adenovirus are most often due to contaminated secretions. We report a patient in whom genitourinary symptoms developed and subsided along with ocular symptoms. Adenovirus was isolated on ocular culture. This is the first reported case of concurrent adenoviral keratitis and hemorrhagic cystitis. Eliciting a history of genitourinary and respiratory symptoms is important in patients with ocular adenoviral infections.

Adenoviridae Infections

Conjunctival transplantation for corneal surface reconstruction--case reports and review of literature.

Corneal persistent epithelial defects (PED) can occur due to various causes. In diffuse ocular surface disease, they often occur secondary to depletion of limbal stem cells. A number of complications occur secondary to PED and successful treatment usually requires conjunctival surgeries for corneal surface reconstruction. We report two cases of chemical injury successfully treated by two such procedures. This report highlights the encouraging results of limbal transplantation and reviews the literature in the management of PED with limbal stem cell loss.

Adult

Autosomal dominant zonular cataract with sutural opacities localized to chromosome 17q11-12.

Congenital cataracts constitute a morphologically and genetically heterogeneous group of diseases that are a major cause of childhood blindness. Different loci for hereditary congenital cataracts have been mapped to chromosomes 1, 2, 16, and 17q24. We report linkage of a gene causing a unique form of autosomal dominant zonular cataracts with Y-sutural opacities to chromosome 17q11-12 in a three-generation family exhibiting a maximum lod score of 3.9 at D17S805. Multipoint analysis gave a 1-lod confidence interval of 17 cM. This interval is bounded by the markers D17S799 and D17S798, a region that would encompass a number of candidate genes including that coding for beta A3/A1-crystallin.

Adolescent