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PubMed1999

Unilateral intraocular lens implantation during the first six months of life.

PURPOSE: The purpose of this study was to determine the incidence of postoperative complications and the occurrence of myopic shift in infantile eyes after cataract surgery and implantation of an intraocular lens (IOL). METHODS: Cataract surgery and IOL implantation was performed on 11 infants with unilateral congenital cataracts who had a mean age of 10+/-6 weeks at 5 clinical centers. IOLs with a mean power of 26.2+/-2.3 D were implanted using a standardized protocol. The infants were then followed up for a mean of 13+/-6 months for postoperative complications and longitudinal changes in their refractive error. RESULTS: Eight of the 11 eyes had postoperative complications and were treated with a reoperation. Complications included open-angle glaucoma (n = 2), lens reproliferation into the visual axis (n = 2), pupillary membranes (n = 2), and corectopia (n = 2). A younger age at the time of surgery was positively correlated with the development of a postoperative complication requiring a reoperation (P = .03). A mean myopic shift of 5.49 D occurred in these eyes a year after surgery. No preoperative factors could be identified that correlated with the magnitude of the myopic shift. CONCLUSION: IOL implantation during infancy is associated with a high complication rate frequently requiring reoperation. A large myopic shift typically occurs that necessitates an initial or a late overcorrection with spectacles or a contact lens, depending on the power of the IOL implanted. Until ongoing randomized trials are completed, we recommend that surgeons exercise caution before implanting IOLs in the eyes of infants.

Age Factors↗
PubMed1999

Rupture of the anterior lens capsule in Alport syndrome.

Alport syndrome is an inherited disorder of type IV collagen, a major constituent of basement membranes. Eighty-five percent of cases are transmitted through X-linked dominant inheritance, although autosomal dominant and autosomal recessive inheritance has also been reported. Clinical manifestations of Alport syndrome include progressive glomerulopathy, sensorineural deafness, anterior lenticonus, posterior corneal dystrophy, and abnormal retinal pigmentation. Anterior lenticonus may lead to loss of vision because of progressive myopia or cataract formation. We report 2 cases of unusual cataract formation in adolescent boys who had a rupture of the anterior lens capsule. One rupture was spontaneous, and the other was traumatic.

Adolescent↗
PubMed1998

Contrast sensitivity after extracapsular and intracapsular cataract extraction.

Contrast sensitivity function after cataract extraction and intraocular lens implantation has been mainly correlated to the type or the material of the intraocular lens. Our purpose was to identify other possible factors, like posterior capsule, to contrast sensitivity alterations after cataract surgery, comparing patients operated for cataract by techniques that mainly differed on the posterior capsule's integrity. The intraocular lens implanted was either a posterior or an anterior chamber one, always monofocal and made of PMMA. We measured contrast sensitivity function at four spatial frequencies in two groups of operated individuals (group A and B) and in one group of healthy control individuals. Each group consisted of 42 eyes. Group A comprised eyes with intact, clear posterior capsule and posterior chamber monofocal intraocular lens. Group B comprised eyes with ruptured or removed posterior capsule and anterior chamber monofocal intraocular lens. Control group comprised healthy control eyes. A pair matched design was used to compare contrast sensitivity values among the individuals of the three groups. No statistically significant differences in contrast sensitivity values were found when group B patients were compared to healthy controls (p >0.05). Patients of group A exhibited contrast sensitivity function impairment at intermediate and high spatial frequencies when compared to patients of group B (p <0.05) and to controls (p <0.01). It seems that intact posterior capsule provides inferior visual function, in spite of relatively good visual acuity and apparently satisfactory results.

Aged↗
PubMed1999

Visual recovery in unilateral traumatic pediatric cataracts treated with posterior chamber intraocular lens and anterior vitrectomy in Pakistan.

PURPOSE: To evaluate visual recovery in unilateral traumatic cataracts in children treated with posterior chamber intraocular lens implantation and anterior vitrectomy. METHODS: Sixteen children with unilateral traumatic cataract between ages 3-10 years (mean, 5 years 8 months) were treated with posterior chamber intraocular lens implantation and anterior vitrectomy. Surgery was performed between 2 weeks and 7 months (mean, 7.75 weeks) after injury. Follow up was between 9 and 29 months (mean, 17.9 months). RESULTS: The most common postoperative complication was fibrinous uveitis, which developed in 4 children (25%). All eyes had a clear visual axis postoperatively; none required capsulotomy. The mean postoperative refraction was +0.9 diopters (range, +3.50 to -2.75 diopters). Three eyes (18.75%) had visual acuity of 6/9, 8 eyes (50%) had visual acuity of 6/12 or better, and 11 eyes (68.75%) had visual acuity of 6/18 or better. The cause of poor visual acuity was cystoid macular edema in one eye, macular scars in two eyes, and amblyopia in one eye. CONCLUSIONS: Unilateral traumatic cataracts in children in whom aphakia is corrected with posterior chamber lens implantation combined with anterior vitrectomy result in good visual outcome, and we recommend this treatment modality in traumatic cataract in children.

Capsulorhexis↗
PubMed2000

Factors leading to lens implant decentration and exchange.

PURPOSE: To examine the intra- and post-operative factors leading to posterior chamber intraocular lens (IOL) decentration in patients requiring IOL exchange, and to identify avoidable causes of IOL decentration. METHODS: Case records of 17 patients who had undergone posterior chamber IOL exchange were examined for: (i) any complication or alteration to the original intended surgical procedure, (ii) IOL type and position at the completion of initial surgery, (iii) IOL position at the time of re-operation. RESULTS: The decentred lens implants were injected silicone plate-haptic IOLs in 10 patients, small (5.5 mm) optic diameter PMMA IOLs in 4 patients and large (7 mm) optic diameter PMMA IOLs in 3 patients. In all cases, decentration was due to IOL subluxation. Early decentration of the injected lenses was due to IOL implantation in eyes without a continuous capsulorrhexis. In contrast late decentration was due to subluxation associated with capsule fibrosis. Decentration of small optic PMMA IOLs was found to be associated with an anterior capsule tear and haptic malposition in the ciliary sulcus. Decentration of large optic PMMA IOLs was associated with posterior displacement of one haptic through a posterior capsule defect, zonule dehiscence or fixation of one haptic in the sulcus and one in the capsule bag. CONCLUSION: Clinically significant post-operative subluxation of injected silicone IOLs may be minimised by implanting only into a lens capsule bag with an intact capsulorrhexis. The risk of decentration of small optic PMMA IOLs may be minimised by positioning the haptics at 90 degrees to any capsulorrhexis tear. After cataract surgery complicated by posterior capsule rupture or zonule dehiscence, it is important to assess the remaining capsule support and, where sufficient, implant a large optic diameter posterior chamber IOL in the ciliary sulcus.

Adult↗
PubMed2003

A histological analysis of lens capsules stained with trypan blue for capsulorrhexis in phacoemulsification cataract surgery.

PURPOSE: Staining of anterior lens capsules with dye to facilitate completion of continuous curvilinear capsulorrhexis is now being used more frequently in phacoemulsification of white and mature cataracts with poor red reflexes. This study examined the histological characteristics of anterior lens capsules stained with trypan blue. The layer(s) of the lens capsule that stained with dye and the extent of accumulation of dye in these layers of the lens capsule were determined. To the best of our knowledge this has not been described before. METHODS: A series of 10 stained lens capsules were analysed histologically. The dye used in this study consisted of a standard sterile, noninflammatory, nonpyrogenic, 2 ml solution containing 0.6 mg/ml of trypan blue. Following capsulorrhexis, samples were sent to the laboratory for histological analysis. Frozen sections (8 microm) were prepared and examined with the light microscope. All 10 capsules were cut by frozen section to preserve trypan blue staining (which would be leached by processing) and then subjected to immunohistochemistry for collagen IV. Immunohistochemical analysis using markers for type IV collagen were done on formalin-fixed specimens for morphological comparison with the frozen sections. A counterstain highlighted the epithelium. RESULTS: Continuous curvilinear capsulorrhexis was successfully and easily completed in all cases without any complications. Frozen section analysis using light microscopy demonstrated accumulation of trypan blue dye in the basement membrane of the lens capsule. Staining was concentrated in the portion of the membrane adjacent to the lens epithelium. The lens epithelium could not be clearly identified on the frozen sections. Consequently, immunohistochemical analysis with markers for type IV collagen was performed. A counterstain highlighted the epithelium. This confirmed that the layer staining with trypan blue was the basement membrane, a consistent feature on all the specimens. CONCLUSION: Trypan blue selectively stains the basement membrane of the anterior lens capsule. There is a concentration of dye in the basement membrane adjacent to the lens epithelial cell layer. The lens cortex does not appear clinically to stain with trypan blue. This enables surgeons to distinguish the lens capsule from the cortex and provides sufficient contrast for successful completion of continuous curvilinear capsulorrhexis during cataract surgery.

Basement Membrane↗
PubMed2006

Phacoemulsification in true exfoliation of the lens capsule: a case series.

PURPOSE: We report five cases (seven eyes) of true exfoliation during an 18-month period. Of the two bilateral cases, the first was identified immediately before cataract surgery and the second spontaneously developed a split in the anterior capsule just before capsulorrhexis, mimicking a partial capsulorrhexis. In the three unilateral cases, true exfoliation was noted during the first examination. METHODS: Vision blue aided uneventful capsulorrhexis differentiating its edge from the true exfoliation edge, and in the first two cases, the anterior capsule was sent for histopathology and ultrasound of the fellow eye was requested. RESULTS: Ultrasound and histopathology demonstrated lamellar separation of the anterior portion of the lens capsule, confirming the diagnosis of true exfoliation. Cataract surgery by phacoemulsification was uneventful in all cases. CONCLUSION: True exfoliation of the lens capsule can masquerade as a partial capsulorrhexis and should be looked for before surgery and immediately before capsulorrhexis to avoid creating a partial thickness capsulorrhexis and its related surgical complications. No zonule weakness was appreciated in our cases. To our knowledge, the spontaneous occurrence of a curvilinear lamellar capsular dehiscence with a flap before capsulorrhexis has not been reported before. This series highlights that cataracts associated with true exfoliation of the lens capsule can be safely operated, with the help of vision blue, by routine phacoemulsification without having to convert to the extracapsular technique.

Aged↗
PubMed2000

Effect of lens style on postoperative refractive astigmatism after small incision cataract surgery.

PURPOSE: To evaluate the astigmatic results of two popular foldable intraocular lenses when standard surgical approaches are used in rural private practice in Australia. METHODS: Four hundred consecutive cataract operations were followed in a prospective study. The refractive results of patients receiving the Alcon Acrysof MA30 lens were compared to those receiving the Allergan silicone S140 lens. All patients were over 60 years of age and had no intercurrent ocular disease. Refractive and keratometric astigmatism was analysed both by vector analysis and as an absolute measure. RESULTS AND CONCLUSION: The Acrysof lens is associated with less postoperative astigmatism (P = 0.01), than the Silicone S140 lenses.

Acrylates↗
PubMed2002

A comparison of cataract surgery under topical anaesthesia with and without intracameral lignocaine.

PURPOSE: To compare the efficacy of intracameral unpreserved lignocaine with placebo during cataract surgery under topical anaesthesia. METHODS: One hundred and thirty-five consecutive cases undergoing clear corneal phacoemulsification were enrolled in this single surgeon, prospective, double-masked, controlled trial. Patients were randomized into two groups, receiving either intracameral unpreserved lignocaine 1% or placebo (balanced salt solution). Systolic and diastolic blood pressure, pulse rate and peripheral oxygen saturation were recorded preoperatively and during phacoemulsification. The level of intraoperative pain was assessed by a numerical analogue scale ranging between 0 (no pain) and 10 (unbearable pain). Data were compared by Student t-test. RESULTS: Sixty-seven cases received lignocaine (group 1) and 68 received placebo (group 2). Average age was 75 years and 74 years, respectively. Systolic blood pressure, pulse rate, oxygen saturation and pain score showed no statistical difference (P = 0.241, 0.542, 0.712, 0.237, respectively). Diastolic blood pressure showed a weakly significant change (P = 0.023). Patients reported minimal discomfort during surgery in both groups. CONCLUSION: This study found no additional benefit of intracameral unpreserved lignocaine when performing routine clear corneal phacoemulsification under topical anaesthesia.

Aged↗
PubMed2002

Phacoemulsification in filtered chronic angle closure glaucoma eyes.

PURPOSE: To report the results of phacoemulsification in eyes with chronic angle closure glaucoma having a functional filtering bleb. METHODS: A prospective and non-comparative study was undertaken in 60 consecutive eyes of 44 patients having a functional filtering bleb for chronic angle closure glaucoma and undergoing cataract surgery. Only those cases who had intraocular pressure 0.05 using paired t-test). The central anterior chamber depth was statistically significant (P = 0.002) when preoperative (1.90 +/- 1.27 mm) was compared to postoperative at 6 months (2.11 +/- 1.27 mm). CONCLUSION: Phacoemulsification in eyes with a functional filtering bleb for chronic angle closure glaucoma is challenging. However, with slight modifications in technique, it can be accomplished without compromising the functioning of the bleb.

Capsulorhexis↗
PubMed1997

[Intraocular pressure after extracapsular cataract extraction with posterior chamber lens implantation--sulcus versus capsular bag fixation].

BACKGROUND: In this retrospective study the postoperative alteration of intraocular pressure after cataract extraction and posterior chamber lens implantation was analyzed statistically. The influence on intraocular pressure between different positions of the loops (sulcus versus bag) was compared. PATIENTS AND METHOD: The posterior chamber lens implantation was performed on 267 eyes with 129 sulcus implanted and 138 in-the-bag implanted intraocular lenses. The average age of the patients was 74.8 respectively 71.9 years, with an equal ratio of sex. In surgery the viscoelastic experimentation of the nucleus was done via corneoscleral cut. A x-crossed suture sealed the corneoscleral wound followed by subconjunctival injection of corticosteroids. The postoperative medication for 4-6 weeks consisted of a corticosteroid and antibiotic combination. RESULTS: The average intraocular pressure of the sulcus implanted respectively in the bag implanted intraocular lenses increased from 15.4 mm Hg respectively 15.9 mm Hg preoperatively to 16.3 respectively 15.8 mm Hg at the first postoperative day. After two months the intraocular pressure decreased to 14.6 respectively 14.1 mm Hg. That means a pre- to postoperative difference of -0.8 respectively -1.8 mm Hg. CONCLUSIONS: In summary both groups showed a slight decrease in average intraocular pressure after two months. In comparison to the sulcus implanted intraocular lens the decrease of intraocular pressure was more than 1 mm Hg in case of the in the bag implanted lens. This decrease was statistically significant but may be considered of less clinical interest.

Aged↗
PubMed1997

[Extent of damage to different intraocular lenses by neodymium:YAG laser treatment--an experimental study].

BACKGROUND: Neodymium:YAG laser capsulotomy frequently damages the intraocular lens (IOL). This damage, mainly caused by acoustic shock wave and thermal conduction, results in opacities in the IOL, which may cause glare or image degradation. Because of the introduction of new IOL materials in cataract surgery, investigation of YAG laser resistance of these IOL materials seems to be necessary. MATERIALS AND METHODS: A total of 17 standard IOLs of different types and classes of materials were tested as follows: Class I: Acrylate a) PMMA, compression molding, b) PMMA, compression molding, heparin-surface modified, c) acrylate/methacrylate copolymer; Class II: Silicone: a) Polydimethylsiloxane, b) Polydimethyldiphenylsiloxane; Class III: Hydrogel: a) poly-hydroxyethylmethacrylate (poly-HEMA), b) polyacrylate-hydrogel; Class IV: Thermoset polymer: methylmethacrylate, hydroxyethylmethacrylate, ethylene glycol dimethacrylate. Each IOL was placed in a rectangular transparent acrylic test chamber filled with balanced salt solution and subjected to irradiation from a Q-switched Nd:YAG laser. The laser beam was focused on the posterior surface and inside of the IOLs. The optic of the IOL was divided into four target zones and each zone was subjected to 40 bursts inside the lens and 40 bursts on the posterior surface of the lens. Laser power settings were: 1.1 mJ, 1.1 mJ with 0.4 mm defocus, 2.1 mJ and 4 mJ and one burst was applied (wave length 1064 nm, fundamental mode, duration 7 +/- 2 nanoseconds, spot size 15 microns in air). Following exposure, each lens was examined by light microscopy for the interior damage and by scanning electron microscopy for the posterior surface damage. For quantitative analysis, the extent of each superficial damage was evaluated by an image analysis system using at least original magnification x 1400. RESULTS: Each IOL material demonstrated specific morphologic damage patterns. Intralenticular damage: Class I: cracks with radiating fractures with smaller extent in group Ic; Class II: blistered snowball-like inclusions; Class III: localized small holes, exception: IIIb: with very short radiating fractures; Class IV: stellar pits with short radiating fractures. For silicone superficial posterior damage sites a splash crater pattern with irregular melted edges was observed, while acrylate damage sites demonstrated a melted or stellate crater pattern with slightly raised edges. The silicone, poly-HEMA and the acrylic IOLs containing HEMA presented highest YAG laser resistance with the smallest amount of posterior damage in comparison to PMMA-IOLs. There was no marked increase in damage size in these IOL materials with higher energy exposure in this set-up. CONCLUSION: For each material consistent and characteristic specific morphologic damage patterns were observed. Foldable optic materials were more resistant against Nd:YAG-laser photodisruption than rigid optic materials. Individual laser strategies for each IOL-material and design should be deducted.

Capsulorhexis↗
PubMed2002

Complications in the first year following cataract surgery with and without IOL in infants and older children.

PURPOSE: The optimal role of intraocular lenses (IOLs) in infants remains a controversial topic for many reasons, including concerns about significant complications occurring in young rapidly developing eyes. METHODS: To assess the number and type of significant complications requiring further intervention occurring in the first postoperative year, we reviewed the records of 15 eyes of 13 infants undergoing lensectomy with posterior chamber IOL and pars plana vitrectomy (PPV)/capsulectomy under 6 months (group A) of age as part of an ongoing prospective study of IOL use in infants. This group was compared with a group of 16 children age 10 months to 5 years undergoing an identical procedure (group B) and a group of 33 infants less than 6 months of age undergoing lensectomy/vitrectomy without IOL (group C). RESULTS: Thirteen of 15 eyes in group A required additional surgery in the first postoperative year. Twelve of the 15 eyes (80%) developed secondary opacification across the visual axis posterior to the IOL requiring a second PPV and one eye developed pseudophakic glaucoma. Two patients required a third PPV to keep the visual axis clear. In group B, 0 of 16 (P <.0001) developed secondary opacification of the visual axis. In group C, 4 of 33 (12%; P <.0001) developed pupillary opacification in the first postoperative year. CONCLUSIONS: Intraocular lens implants in infants may be associated with a higher complication rate requiring further surgery during the first postoperative year than is lensectomy/vitrectomy surgery without IOL implant in infants or lensectomy/IOL/vitrectomy surgery in children older than 6 months of age.

Capsulorhexis↗
PubMedDate not supplied

Intraocular lens tolerance in surgery for cataracta complicata: assessment of four implant materials.

PURPOSE: To evaluate various available intraocular lenses (IOL) (PMMA, acrylic, heparin coated PMMA, and silicone) in patients with cataracta complicata and evaluate IOL tolerance, post-operative inflammation, cystoid macular edema, and posterior capsular opacification(PCO) requiring Nd:YAG capsulotomy. DESIGN: randomized, double masked clinical trial. PARTICIPANTS: Patients evaluated in the Ocular Immunology and Uveitis Service of the Massachusetts Eye and Ear Infirmary and deemed to need cataract surgery by standard criteria were asked to participate in the clinical trial. Patients had to have a diagnosis of chronic uveitis, which was inactive for 3 months prior to cataract surgery. RESULTS: Acrylic lenses appeared to provide the best overall results when evaluated for post-operative inflammation, PCO rates, visual acuity, and cystoid macular edema (CME) (compared to PMMA, silicone, and heparin coated PMMA).

Acrylic Resins↗