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PubMed2007

Safety and efficacy of micro-incisional cataract surgery with bimanual phacoemulsification for white mature cataract.

BACKGROUND: To evaluate the safety and efficacy of micro-incisional cataract surgery (MICS) with bimanual phacoemulsification for the management of white mature cataract. METHODS: Twenty-five eyes in 25 patients with mature cataract were prospectively recruited to undergo MICS with bimanual phacoemulsification. Serial changes in best-corrected visual acuity (BCVA), central corneal thickness (CCT) and endothelial cell density (ECD) were compared using the Wilcoxon signed-rank test. RESULTS: MICS was successfully performed in 24 (96%) of the 25 eyes, with 1 eye requiring conversion to extracapsular cataract extraction due to radial tear during continuous curvilinear capsulorhexis. The median preoperative BCVA was hand movement. On day 1 postoperatively, the median BCVA improved to 0.6 (p < 0.001 compared with baseline). All patients had BCVA of 0.6 or better at 3 months after surgery (p < 0.001 compared with baseline). The mean increase in CCT at day 1 and week 1 postoperatively was 11.5 and 7.1%, respectively. The change in mean CCT was no longer significant at month 3 postoperatively (p = 0.82). The mean reduction in ECD at 3 months postoperatively was 7.8% (p = 0.037). None of the patients developed any postoperative complications. CONCLUSIONS: MICS with bimanual phacoemulsification appeared to be a promising alterative for the management of white mature cataract.

Aged↗

PubMed1996

Calpains in the human lens: relations to membranes and possible role in cataract formation.

Calpains are Ca-activated neutral proteases present in all cells together with an endogenous inhibitor, calpastatin. Proposed substrates are; cytoskeletal proteins like microtubules and actin, protein kinases such as PKC and membrane-bound enzymes like Ca-ATPase and the Ca-channel. In lenses from different species calpains have been detected in decreasing amounts from the epithelium to the cortex to the nucleus. Several substrates for calpain in the lens have been demonstrated: crystallins, vimentin, actin, beaded filaments and MP26 among others. Both studies on animal models and capsulorhexis indicate that calpains are mainly involved in cortical cataract.

Calcium↗

PubMedDate not supplied

Decentration of posterior chamber IOL: effects of loop material and fixation technique.

A prospective study was conducted on 90 eyes undergoing extracapsular cataract extraction and posterior chamber IOL implantation. Postoperative IOL decentration was evaluated with respect to the loop material, either polypropylene (prolene) or polymethylmethacrylate (PMMA), and the IOL fixation technique, either in the capsular sac (in-the-bag) after capsulorhexis, or in the ciliary sulcus after "can-opener" capsulotomy. More decentration was observed with IOL having polypropylene loops than with those having PMMA loops (0.80 +/- 0.735 mm versus 0.373 +/- 0.299 mm). IOL implanted in the bag showed greater decentration than those implanted in the sulcus, but the difference was not significant. Our findings confirm the recommendation to use an IOL with PMMA loops when placing the implant in the capsular sac.

Aged↗

PubMed2005

[Anophthalmia and congenital cataract: case report].

The authors report a case of anophthalmia, congenital cataract and systemic malformations. Male patient, 6 months old, left anophthalmia and congenital posterior polar cataract in the right eye. The patient was treated with manual aspiration of the crystalline lens, with no intraocular lens implantation with primary posterior capsulorhexis and anterior vitrectomy through a small incision. The association of anophthalmia and congenital cataract is rare. The early diagnosis and management in these cases is very important for the best visual rehabilitation.

Abnormalities, Multiple↗

PubMed1993

The effect of extracapsular cataract extraction using nucleus dislocation into anterior chamber on the corneal endothelium.

When the continuous circular capsulorhexis (CCC) is being performed, the nucleus delivery using nucleus dislocation into the anterior chamber is safer and easier than using conventional "push and pull" method to maintain an intact lens capsule. This method include such procedures that after CCC, the nucleus being freed in the capsular bag by hydrodissection and hydrodelineation, then hooked with a Sinskey hook and drawn out to the anterior chamber by rotation. It may damage the corneal endothelium because of the manipulation in the anterior chamber. To investigate an effect of this method on the corneal endothelium, we performed two months time analysis of changes of the central corneal endothelial cell density (CECD) in two groups--a group with an extracapsular cataract extraction (ECCE) using nucleus dislocation into the anterior chamber and a group with a conventional ECCE. Eighteen eyes of 18 cataract patients who were operated on with ECCE using nucleus dislocation into the anterior chamber method, and ten eyes of 10 cataract patients who were operated on with a conventional ECCE method were included. The CECD was measured by specular microscopy, preoperatively, postoperatively at 1 month and 2 months. The average endothelial cell loss at postoperative 1 month was 7.20 +/- 2.98% in the experimental group and 7.88 +/- 2.93% in the control group, and at postoperative 2 months was 9.05 +/- 2.96% in the experimental group and 9.34 +/- 2.95% in the control group. The change in CECD between two groups was not statistically significant.

Adult↗

PubMed2000

Bilateral anterior lenticonus: Scheimpflug imaging system documentation and ultrastructural confirmation of Alport syndrome in the lens capsule.

BACKGROUND: Alport syndrome is a combination of proteinuria, hematuria, and neurosensory high-frequency deafness. Bilateral anterior lenticonus may be a late sign. Diagnosis relies on characteristic electron microscopy changes of glomerular basement membranes in renal biopsy specimens. PATIENT: A 38-year-old man was seen for progressive visual acuity loss (20/400 OU; best-corrected visual acuity, 20/60 OD and 20/50 OS). Findings from slitlamp examination included bilateral anterior lenticonus and central posterior subcapsular cataract, documented using a modified Scheimpflug imaging system. Retinal pathology was not present. On detailed questioning, a history of microhematuria and proteinuria since childhood and progressive high-frequency deafness for years were discovered. The family history was negative for nephropathies, deafness, or eye diseases. Cataract extraction rehabilitated the patient's vision. RESULTS: Electron microscopy of a fragile capsulorhexis specimen showed typical thinned basal lamina with basement membrane disruptions. CONCLUSIONS: Anterior lenticonus is a rare bilateral progressive developmental anomaly. More than 90% of cases are associated with Alport syndrome. For diagnosis of Alport syndrome, the presence of 3 of 4 criteria is required: family history positive for Alport syndrome, progressive intra-auricular deafness, characteristic eye anomalies, and positive findings from glomerular ultrastructural examination. We believe that ultrastructural proof of anterior lenticonus may also be provided in the lens capsule. Arch Ophthalmol. 2000;118:895-897

Adult↗

PubMed2000

[Modern therapeutic approach to congenital abnormalities of the anterior eye segment in pediatric patients].

Modern functional and anatomic tests allow a reproducible approach of congenital abnormalities of the anterior segment in pediatric patients. Bidimensional ultrasonography allows to perform accurate IOL determination based on precise localization of the macula. In congenital glaucoma, it allows to evaluate optic disc cupping when retinal biomicroscopy is not possible. Color doppler ultrasonography enables to assess blood flow of intra-ocular vessels (in case of persistence of primitive vitreous) or of retrobulbar vessels (in eyes with congenital glaucoma). Miniaturization has allowed to adapt a great number of devices, such as an automatic refractometer, a tonometer, a retinograph or an angiograph, for the use in patients in prone position. These techniques have allowed to assess the anatomic and functional status of eyes undergoing surgery for congenital cataract, which is based on an anterior and posterior capsulorhexis followed by central vitrectomy, for congenital glaucoma, using modern goniotomy or external trabeculotomy, or for anterior persistence of primitive vitreous treated with membranectomy.

Age Factors↗

PubMedDate not supplied

[Cataract surgery in children].

INTRODUCTION: Cataract extraction in children has improved and became more popular over the past few decades but, due to particular features of children's eyes, still remains controversial--especially regarding the intraocular lens implantation. INDICATIONS FOR OPERATION: In contrast to adults, indications for cataract surgery in children are much more difficult to determine. Since subjective visual acuity cannot be obtained, greater reliance must be placed on the morphology and location of the lens opacity, and the behavior of the child. Forced preferential looking and visual evoked potentials can be helpful, but they should not be the only criteria. CORRECTION OF POSTOPERATIVE APHAKIA: In management of pediatric cataract, correction of postoperative aphakia is still an incompletely resolved problem. Conventionally, optical correction is achieved by spectacles or contact lenses. The power of both spectacles and contact lenses can be readily adjusted to compensate for ocular growth. The success of both depends significantly on parental compliance and the child's acceptance. Hutchinson reported that 44% children with aphakia stopped wearing glasses or contact lenses 2 months after surgery. Contact lens wearing can also result in a number of corneal complications, including infectious keratitis, corneal vascularization and hypoxic corneal ulceration. IOL implantation is theoretically superior to glasses and contact lenses since it provides almost immediate optical correction which is much more reliable because it does not depend on parental or child's compliance. Still, there are many controversies about IOL implantation in infants and young children like IOL-size, material, IOL power calculation, prevention and management of secondary cataract, as well as long term safety of IOLs in children's eyes. Although short-term anatomic results after cataract extraction and primary IOL implantation in children are excellent and stable, long-term follow-up is necessary to answer questions about the long-term safety of implants in children's eyes. POSTOPERATIVE COMPLICATIONS: A higher incidence of postoperative inflammation and opacification of the optical axis has been reported after pediatric cataract surgery. Posterior capsular opacification is almost an unavoidable complication in children's eyes if the posterior capsule is left intact. Several methods have been proposed in order to keep the optical axis clear in infants and young children. Comparison of posterior capsulectomy with and without anterior vitrectomy showed that posterior capsular opacification rates are diminished only after combined posterior capsulectomy and anterior vitrectomy and not after capsulectomy alone. Posterior capsulorhexis with optic capture seems to effectively prevent posterior capsular opacification. This technique eliminates the need for anterior vitrectomy and ensures the centration of the intraocular lens. Glaucoma and retinal detachment are late complications of pediatric cataract surgery. On average glaucoma develops 6.8 years after cataract operation. Retinal detachment develops several decades after cataract extraction. AMBLYOPIA: The functional results after pediatric cataract surgery depend not only on the anatomic success of the operation and postoperative maintenance of a clear optical axis, but even more on aphakic visual rehabilitation. Children's eyes with cataract severe enough to require cataract extraction usually have some degree of amblyopia already present prior to surgery. In unilateral pseudophakia amblyopia develops postoperatively unless the fellow eye is occluded or optically and/or pharmacologically penalized. Immediate optical correction is desirable because prevention and/or therapy of amblyopia should be initiated directly after surgery. Parental compliance with occlusion therapy and not successful surgery are major determinants of a good visual outcome in unilateral aphakic/pseudophakic children.

Aphakia, Postcataract↗

PubMed2000

[Foldable Hydroview (H60m) intraocular lens: functional results and postoperative findings].

PURPOSE: To study visual quality and postoperative complications after phacoemulsification and hydrogel (Hydroview, H60M) IOL implantation, at one year postoperatively. METHODS: Prospective study of 60 patients. After capsulorhexis and phacoemulsification, patients received a foldable hydrogel lens or a PMMA IOL. Postoperative examinations were made on 7, 30, 60, 180 and 360 th day. We measured distance visual acuity, contrast sensitivity, keratometry, anterior capsule fibrosis and the presence of other postoperative complications. RESULTS: Small incision and foldable IOL provided faster visual rehabilitation, however visual acuity was better with PMMA lens (F=4.33, p<0.5) at 12 months after surgery. Contrast sensitivity at high spatial frequencies was significantly better in PMMA lens group. Anterior capsule fibrosis is more important in hydrogel IOL group (chi(2) = 10.87, gl = 3, p<0.025). Other complications in the two groups were few and comparable. CONCLUSIONS: Hydrogel IOL provided good visual results and rapid visual recovery. However visual results are unstable. Anterior capsule fibrosis and on anterior intraocular lens surface fibrosis are common complications with hydrogel lens.

Adult↗

PubMed2000

Influence of intraocular lens material and design on postoperative intracapsular cellular reactivity.

PURPOSE: To evaluate the influence of intraocular lens (IOL) material and design on the outcome of postoperative lens epithelial cell proliferation within the capsular bag after cataract surgery. METHODS: A total of 5,079 human globes containing rigid and foldable posterior chamber IOL styles commonly implanted in the United States (n = 8) were analyzed in this study. Each globe, fixated in 10% formalin, was sectioned at the equator and analyzed using the Miyake-Apple posterior technique. The study consisted of 3 parts: First, to evaluate posterior capsule opacification (PCO); the Nd:YAG laser posterior capsulotomy rate (%) was documented and plotted on a monthly basis, creating a computerized trend line for each IOL style. Second, to evaluate anterior capsule opacification (ACO); 460 globes were processed for histologic examination. Anterior capsule fibrosis was scored from 0 to III, according to the thickness of proliferative tissue/cells on the inner surface of the anterior capsule at the capsulorhexis margin. Third, interlenticular opacification (ILO) was studied by analysis of 3 pairs of acrylic piggyback lenses that had been explanted because of opacification between their optics. Each IOL pair was processed for histologic examination, and scanning electron microscopy was performed on 1 of the lenses. RESULTS: In the first study, relatively higher Nd:YAG laser posterior capsulotomy rates (19.1% to 32.8%) were noted with the 4 oldest IOL designs in this study (2 foldable lenses, 1 3-piece polymethyl methacrylate [PMMA] design, and 1 single-piece all-PMMA design). Four modern lenses, 1 acrylic lens, and 3 silicone foldable IOL designs had Nd:YAG rates ranging from 1.3% to 14.6% (P < .0001). In the second study, mean ACO scores were highest with silicone-plate lenses (1.77 +/- 0.86 and 1.28 +/- 0.77). The lowest mean score was observed with the acrylic lens (0.51 +/- 0.52; P < .0001). In study 3, the analyses of the 3 pairs of explanted acrylic piggyback lenses showed that the opacification between them (ILO) may have different forms. CONCLUSIONS: Control of postoperative intracapsular cellular proliferation is important in avoiding 3 significant clinical complications. Postoperative lens epithelial cell proliferation is involved in the pathogenesis of PCO, ACO, and ILO, the latter being a newly described form of opacification within the capsular bag related to piggyback IOL implantation. IOL material and design are important factors influencing the outcome of these complications.

Acrylates↗

PubMed2001

[Intraocular lens implantation in the first year of life].

We evaluated 36 eyes in 23 infants between one and eleven months old who had primary posterior chamber intraocular lens implantation for congenital cataracts. All eyes had a capsulorhexis of anterior and posterior capsulae and anterior vitrectomy. In order to obtain an emmetropia at age 5 years, we chose a 35% undercorrection of lens power for infants less than six months old, and 25% for infants between seven and eleven months old. The average follow-up was 15.3 months. Nine eyes developed posterior synechiae and eight developed a posterior opacification. The average postoperative refraction was +5.81 dioptries at one month, +4.56 at four months, +1.5, at one year, and +0.19 at two years. There was a marked subjective visual improvement in 34 eyes.

Cataract↗

PubMed2000

Revolutions in ophthalmology.

Cataract is the major cause of blindness worldwide. The transition of couching of cataract to most modem phaco-emulsification gained popularity with more scientific capsulorhexis. Ongoing research is taking place with laser technologies for removal of cataract. Surgery has an important role in advanced corneal diseases. Corneal transplantation is the most successful form. The refractive errors can be corrected by laser-assisted in-situ keratomileusis, intrastromal corneal rings and phacic intra-ocular lenses. Current research is going on to identify the gene responsible for glaucoma and once this is identified, medical therapy can be developed to control the disease. Thermocautery or photocoagulation and indenting the globe so as to bring the choroid nearer the break by scleral buckling forms the basis of modern surgery of retinal detachment. Vitreoretinal diseases, macular degeneration, diabetic retinopathy are no longer considered problematic. We are optimistic that more clinical breakthroughs are expected in the 21st century with new advances of ophthalmic researches.

Cataract↗

PubMed2001

[A new predictive formula for anterior chamber depth for pseudophakia].

PURPOSE: To develop a new predictive formula of the anterior chamber depth(ACD) of the pseudophakic eyes for more accurate intraocular lens(IOL) power calculation with the Ray Tracing method. METHODS: We studied a series of 149 phacoemulsificated eyes with capsulorhexis and in-the-bag fixation of IOL. ACD was measured with a Jaeger type depth measuring unit which was attached to a slit-lamp biomicroscope. We developed the formula with 3 variables: preoperative anterior corneal curvature with keratometer, and ACD and crystalline lens thickness with preoperative ultrasonography. We named the derived formula "formula H". We compared formula H with Olsen's predictive formula for the ACD(Olsen 92, Olsen 95). RESULTS: Mean absolute error between the predicted and postoperatively measured ACD was 0.174 +/- 0.133, 0.280 +/- 0.235, 0.229 +/- 0.200 mm in formula H, Olsen 92, and Olsen 95, respectively. Formula H was significantly more accurate than both Olsen formulas(p < 0.001, p < 0.05, respectively). CONCLUSIONS: The accuracy of IOL power calculation can be improved with the new formula using the Ray Tracing method, using the new ACD predictve formula.

Aged↗

PubMed2001

[A new theoretical formula for the intraocular lens power calculation by the Ray Tracing Method].

PURPOSE: To study the mathematical properties of the intraocular lens(IOL) power calculation with the Ray Tracing method and to investigate its clinical results. METHODS: We first obtained a ray focusing equation with the Ray Tracing method, and then derived an emmetropizing equation and an equation for postoperative refraction. The exact calculation of these equations was investigated. A new IOL power calculation formula was consequently developed and named "formula H", combining it with the predictive formula for the postoperative anterior chamber depth of pseudophakic eyes in another report by us. A series of 150 phacoemulsificated eyes with capsulorhexis and in-the-bag fixation of IOL were studied. The cases were divided into 3 groups; 16 short eyes(< 22 mm), 103 normal eyes(22 < or = and < 24.5 mm), and 31 long eyes(> or = 24.5 mm). The predictive error of formula H was compared with that of SRK-T, Holladay, and SRK II in each group. RESULTS: The exact calculation of emmetropizing power in taking account of a IOL design was mathematically impossible, or generally difficult. In the latter case, however, we could calculate it by solving a cubic or quartic equation. Exact and easy predictive calculation of postoperative refraction for any IOL design was possible if we knew such data as anterior and posterior curvature and thickness of each power of IOL. The mean absolute error of formula H was 0.38, 0.34, 0.36, 0.44 diopter, in all eyes, short eyes, normal eyes, and long eyes, respectively. Formula H was significantly more accurate than all other formulas in all eyes, in short eyes and normal eyes. CONCLUSIONS: For clinical use, predictive calculation of postoperative refraction should be recommended but calculation of emmetropizing power should be abandoned. But emmetropizing calculation is useful and important for the fundamental study of IOL power calculation. Formula H was more accurate than all other formulas and very useful for clinical use.

Anterior Chamber↗

PubMed2001

[Total anterior opacification on the anterior surface of hydrophilic acrylic implanted lens].

We report a case of cloudiness occurring on the anterior surface of a hydrophilic acrylic foldable intraocular lens 1 year following implantation. This was not a case of phimosis of the capsulorhexis; the dondiness seemed secondary to fibroepithelial proliferation. Successful reopening was obtained with YAG laser. No recurrence was observed during the six months of follow-up.

Acrylic Resins↗

PubMed2002

Neodymium: YAG capsulotomy rates after phacoemulsification with hydrophobic and hydrophilic acrylic intraocular lenses.

PURPOSE: To retrospectively evaluate the incidence of neodymium: YAG (ND:YAG) laser capsulotomies for posterior capsule opacification (PCO) seen with hydrophobic and hydrophilic acrylic intraocular lens implants 18 months after surgery. METHODS: One hundred and five eyes that had phacoemulsification with a continuous curvilinear capsulorhexis and implantation of either a hydrophobic or a hydrophilic acrylic posterior chamber IOL were evaluated in order to assess the incidence of PCO. Fifty-six eyes received a hydrophobic IOL (Acrysof-Alcon) and forty-nine eyes received a hydrophilic IOL (Galand-Visional). A standardized surgical protocol was performed by a single surgeon. All surgical complications were excluded and all patients had standardized postoperative medication and follow-up. RESULTS: With an average follow-up of 18 months in both groups, the incidence of posterior Nd:YAG laser capsulotomy for PCO was 8.9% in the hydrophobic group and 24.4% in the hydrophilic group, respectively (p = 0.03). CONCLUSION: Intraocular lenses made from hydrophobic acrylic material are associated with a significantly reduced rate of Nd:YAG laser capsulotomies as compared with intraocular lenses made from hydrophilic acrylic material.

Acrylic Resins↗

PubMed2002

[Anterior chamber inflammation following cataract surgery in patients with non-insulin-dependent diabetes mellitus].

PURPOSE: The aim of the study was to estimate the early breakdown of the blood-aqueous barrier (BAB) following uneventful cataract surgery in patients with non-insulin dependent diabetes mellitus. MATERIAL AND METHODS: Aqueous flare was estimated in 54 diabetic eyes before and after cataract surgery. Fifteen eyes underwent uneventful ECCE (extracapsular cataract extraction with "can opener" capsulotomy) and 39 phacoemulsification with continuous curvilinear capsulorhexis. All procedures were performed by experienced surgeons. Fifty six eyes of age-matched healthy patients undergoing uncomplicated cataract surgery served, as control. Anterior chamber flare was quantified preoperatively, 1 and 3 days postoperatively, using laser-flare meter (Kowa FM-500). Laser flare values were expressed in photon counts/millisecond. RESULTS: Mean preoperative anterior chamber flare in diabetes type 2 was as follows: normal fundus--6.7, background retinopathy--8.6 and proliferative retinopathy--14.1 (p < 0.01 vs NF group). Significantly lower anterior chamber flare measurements following phacoemulsification (25.0-1 day, 17.8-3 days post surgery), than after ECCE (63.7 and 45.6, respectively) (p < 0.01) were observed in diabetic eyes. In phaco group, we noted lower flare values in eyes without retinopathy; 25.2-1 day, 14.0-3 days post surgery, than in proliferative retinopathy (31.5 and 28.4, respectively) (p < 0.05 vs no retinopathy group). CONCLUSIONS: Phacoemulsification, as a less traumatising technique produces less BAB breakdown and seems to be more suitable than ECCE in diabetic eyes. Following phacoemulsification, eyes with proliferative retinopathy had significantly higher flare values than eyes without retinopathy.

Aged↗

PubMed2002

[A study of human lens epithelial cells by light and electron microscopy and by immunohistochemistry in different types of cataracts].

PURPOSE: To evaluate the characteristics of cataract changes in lens epithelial cells (LECs), in different types of human cataract. MATERIAL AND METHODS: Anterior capsules for the study were obtained from patients with different types of cataracts during extracapsular cataract extraction, or phacoemulsification using continuous curvilinear capsulorhexis. LECs attached to the anterior capsules were analyzed for morphological changes by light and electron microscopy, and for cellular characteristics by immunohistochemistry. The reactivity to cytokeratins 5,6,8,17 and 19 (arker for epithelial cells) and to vimentin (arker for mesenchymal cells) was determined. RESULTS: The consecutive degenerative changes were observed in most of the cells: multilayered cells, nuclei of abnormal diameters and shapes, vacuolation of nuclei and cytoplasm. LECs were immunohistochemically positive for cytokeratin and vimentin, or only for vimentin in all types of cataract. Some of LECs showed morphological and immunohistochemical characteristics of mesenchymal cells. CONCLUSIONS: Lens epithelial cells show similar degenerative changes in different types of cataract and may have the ability to transdifferentiate into mesenchymal cells.

Adult↗