Scleral suturing of intraocular lenses

This paper describes a simple, safe, and reproducible method for scleral suturing intraocular lenses. The method uses standard tools and equipment.     

An evaluation of the biocompatibility of intraocular lenses

BACKGROUND AND OBJECTIVE: The degree of cell adhesion to intraocular lenses (IOLs) was studied through the cell culture system and the morphology of adhering cells was studied using a light electron microscope and a scanning electron microscope. MATERIALS AND METHODS: Human lens epithelial cells were used as materials. The IOL materials were classified into four groups: polymethylmethacrylate (PMMA), heparin surface modified PMMA, surface passivated PMMA, and silicone. RESULTS: PMMA showed greater adhesion than did the other materials. Cells hardly adhered to silicone. Use of a light electron microscope and a scanning electron microscope revealed that cells adhered uniformly to the surface of PMMA and were elongated, but did not adhere uniformly to IOLs of other materials. Only a few cells without the tendency of elongation were noted on the silicone the second day after culture. The 14th day after culture, the surfaces of IOLs, except those of silicone, were covered with cells. CONCLUSION: Such differences in the surface adhesion and morphology of cells adhering to the IOL surface are important in evaluating IOL biocompatibility.     

Secondary implantation of scleral-fixated intraocular lenses

PURPOSE: To evaluate the results of a large series of secondary implantations using scleral-fixated posterior chamber intraocular lenses (IOLs). SETTING: Bellevue Eye Hospital, Kiel, Germany. METHODS: This retrospective review comprised 624 consecutive patients who had secondary implantation of a posterior chamber IOL with scleral fixation between 1988 and 1995. All patients had been aphakic for at least 1 year. An ab interno or ab externo suture technique through the ciliary sulcus was used. Visual outcome and complications 1 year after surgery were determined. RESULTS: Best corrected visual acuity improved or remained unchanged in 92.0% of eyes; 8.0% lost one or two lines. Intraocular lens decentration of more than 1.5 mm occurred in 1.9% of eyes. Suture erosion was observed in 17.9%, cystoid macular edema in 5.8%, retinal detachment in 1.4%, and vitreous hemorrhage in 1.0%. Severe uveitis occurred in 0.5%. CONCLUSION: Secondary IOL implantation with scleral fixation was a safe procedure. Although there was a small risk of significant complications, more than 90% of patients regained or improved their preoperative visual acuity.     

Randomised controlled trial of anterior-chamber intraocular lenses

BACKGROUND: There are an estimated 16 million people blind in both eyes with cataracts. Most live in rural areas of developing countries where surgical resources are scarce. There is no consensus on the most appropriate type of intraocular lens in situations where high-volume low-cost surgery is required. This study was undertaken to evaluate the safety of multiflex open-loop anterior-chamber lenses (ACIOLs). METHODS: 2000 people attending Lahan Eye Hospital, southern Nepal, with bilateral cataracts reducing vision to 6/36 or less were randomly allocated to receive standard surgery--intracapsular extraction (ICCE) with aphakic correction--or ICCE with an ACIOL in their first operated eye. The primary outcome was a visual acuity of less than 6/60 in the operated eye at 1 year follow-up. Visual acuity was measured for 91% of the cohort at 1 year. The sample size was estimated to detect a doubling in poor visual outcome from an estimated rate of 4% in the standard surgery (control) group. FINDINGS: The median (range) time taken to do the surgery was 6.0 (3.0-17.2) min for the ACIOL group and 4.1 (2.4-10.3) min for the control group. 1 year after surgery, 5.0% of the ACIOL group and 5.4% of controls had functional vision less than 6/60 (OR 0.93 [0.60-1.43], p = 0.71). The causes of poor vision in the ACIOL and control groups were: correctable refractive error (22 and 29), uveitis/secondary glaucoma (13 and two), endophthalmitis (four and seven), pre-existing eye disease (four and five), retinal detachment (none and four), cystoid macular oedema (two and none), corneal ulcer (one and one), and corneal decompensation (none and one). INTERPRETATION: This study provides evidence that, in rural areas of developing countries, multiflex open-loop ACIOLs can be implanted safely by experienced ophthalmologists after routine ICCE, avoiding the disadvantages of aphakic spectacle correction. Further follow-up is planned.     

Endoscope-assisted transscleral suture fixation of intraocular lenses

We describe a new method for placing transscleral sutures when fixating posterior chamber intraocular lenses to the sulcus. An intraocular microendoscope with an 18 gauge probe is used for direct sulcus observation and needle position assessment. The straight needle of a 10-0 polypropylene suture and the tip of the probe are placed in a 16 gauge silicone rubber tube to hold them together. Fixing the needle to the endoscope allows a direct view of its tip and requires only one hand. The other hand is used to grasp the tip of the needle when it comes out under the scleral flap after passing through the sulcus. Assessment of needle position with an endoscope avoids surgically induced iris root or ciliary body damage. Fixing the needle to the endoscope simplifies the surgical technique.     

Simplifying scleral fixation of posterior chamber intraocular lenses

We describe a surgical modification for primary scleral fixation of posterior chamber intraocular lenses. The technique keeps intraocular surgical manipulation at a minimum and allows fixation of the lens during accidental rupture of the posterior lens capsule.     

Scanning electron microscopic characteristics of small-incision intraocular lenses

PURPOSE: To evaluate the surface characteristics of commonly used, small-incision, intraocular lenses (IOLs). METHODS: Representative samples of five groups of foldable IOLs (4 silicone and 1 acrylic) underwent surface and edge-finish examination using a slit lamp. The IOLs were folded using a folding block and forceps. All the IOLs then were examined using a scanning electron microscope. A one-piece polymethylmethacrylate IOL was used for comparing surface-finish characteristics. The IOLs were examined for optic surface quality, edge finish, haptic, haptic/optic junction, and possible post-folding modifications. RESULTS: Slit-lamp evaluation of the surface quality of all of the silicone lenses demonstrated a smooth finish of the optic surface, edge, and haptics. Scanning electron microscopic analysis of the IOLs demonstrated adequately finished haptics or footplates and optics. Excess molding flash was seen on the edges of the some of the silicone IOLs, and no molding flash was observed on others. The acrylic IOL had a somewhat sharper optic edge. Irregular finish of the haptic/optic junctions of some of the IOLs (both silicone and acrylic) was noted. CONCLUSIONS: Currently available foldable IOLs have demonstrated adequate lens finish. However, irregularities of the haptic/optic junctions and molding flash are present on most IOLs evaluated, indicating room for improvement in the finish of foldable IOLs. Phacoemulsification with capsular bag IOL placement may decrease the clinical significance of these relatively subtle lens finish irregularities.     

Contrast sensitivity in patients with silicone intraocular lenses

Meningococcal clone ET-15/37, which appeared as a new one in the Czech Republic in 1993, caused an emergency epidemiological and clinical situation in invasive meningococcal disease, characterized by a high fatality rate (20%) compared to the "normal" fatality rate due to "non ET-15/37" strains. Morbidity rate increased since the first year of the new clone occurrence and reached the peak in 1995. This clone has spread all over the country and investigation of the epidemiological markers of Neisseria meningitidis allowed to quickly recognize the emergency situation and subsequently to provide a targeted vaccination with A + C polysaccharide meningococcal vaccine which prevented the spread of the disease caused by Neisseria meningitidis C. The most frequent phenotype of ET-15/37 clone was C:2a:P1.2(P1.5) and its percentage achieved 80% of group C Neisseria meningitidis strains tested. This antigenic shift of Neisseria meningitidis was associated with the age shift in invasive meningococcal disease morbidity: teenagers started to be the most affected age group and later age group of 1-4 olds followed with high morbidity rates. In 1995 B variant of ET-15/37 clone, B:2a:P1.2(P1.5), appeared, causing a high fatality rate, too. Some data are indicative of a possible decrease in the invasive meningococcal disease incidence in the Czech Republic; nevertheless, the active surveillance and detailed investigation of meningococci have to be continued. After four years following the vaccination and chemoprophylaxis strategy recommended in the Guidelines, set up by the National Reference Laboratory for Meningococcal Infections in 1993, it is possible to conclude, that there have been practically no secondary cases of invasive meningococcal disease in the Czech Republic.     

Corneal endothelial damage from previously implanted intraocular lenses

Intraocular lenses which had been surgically removed from human eyes were compared to new uncoated IOLs with regard to damage caused by dynamic and static contact with fresh rabbit corneal endothelium. Previously implanted IOLs caused consistently less endothelial damage. Possible mechanisms and the implications of these findings for the corneal surgeon doing pseudophakic keratoplasty are discussed.     

A new program for calculating intraocular lenses]

A principally new programme is described which overcomes the disadvantages of the usual calculation methods. It is based on the application of each surface of the optical system. The point for the anterior chamber lens is chosen in dependence on the anterior chamber depth; for the posterior chamber lens on the posterior surface of the eye lens. The programme is able to calculate 12 different cases. In each case calculations are made for intraocular lens power, aniseikonia and anisometropia. The calculations are made for possible emmetropia as well as for intended myopia or hypermetropia corresponding to the other eye. The programme can also be used to estimate the effect of mistakes made by measuring the single parameters, for instance: refraction, corneal curvature, eye length, anterior chamber depth. Compared to the SRK II-equation the results of the new programme are much more precise.     

Deposits on the surface of intraocular lenses: a pathologic study

The clinical course of implanted intraocular lenses is frequently complicated by the formation of deposits or "precipitates" on the lens surfaces. These lesions are related to the amount of inflammation in the eye, the use of pilocarpine, and the presence of lens cortex in extracapsular procedures. Corticosteroids cause the lesions to diminish or disappear. Similar lesions seen in the course of lens implantation in laboratory animals are found on histologic examination to be accumulations of inflammatory cells. In the chronic state the cells are macrophages, epithelioid cells, and giant cells, accompanied in the early stages by acute inflammatory leukocytes. The relationships between these cells, inflammation, the presence of the foreign body, and the chemistry of methacrylate are difficult to sort out.     

Damage of foldable intraocular lenses by incorrect folder forceps

Patients presenting with ischemic chest pain and electrocardiographic evidence of global T-wave inversion are most frequently women with intact left ventricular function and no critical stenosis of major coronary vessels. Hence, this syndrome has a good immediate and long-term prognosis.     

Combined treatment of postoperative inflammations after intraocular lenses implantation

Laser exposure was used for treating some postoperative complications in 11 patients. The results indicate a high efficacy of YAG and argon laser in multiple-modality treatment of exudative reactions developing after implantation of intraocular lenses.     

Management of complications in eyes containing two intraocular lenses

OBJECTIVE: To describe the management of complications in eyes containing two intraocular lenses (IOLs). DESIGN: A retrospective noncomparative case series. PARTICIPANTS: Eight patients having a dislocated posterior chamber intraocular lens (PC IOL) and a secondary anterior chamber intraocular lens (AC IOL) participated. INTERVENTION: Surgical treatment of complications, including mobile dislocated PC IOLs in five eyes and retinal detachment in three eyes, was performed. MAIN OUTCOME MEASURES: Visual acuity and anatomic status were evaluated. RESULTS: Dislocated PC IOLs were removed through a pars plana incision in five eyes and a limbal incision in three eyes. Retinal detachments were repaired in three eyes. With follow-up from 7 months to 6.5 years, visual acuities ranged from 20/25 to 20/40 in five eyes and 20/60 to 20/400 in the three eyes undergoing retinal detachment repair. CONCLUSION: Eyes in which dislocation of a PC IOL occurs during or after cataract surgery may have significant complications develop. Successful surgical repair is more complex in the presence of a secondary AC IOL.     

Capsular management and refractive error in pediatric intraocular lenses

The effects of dietary protein types and methionine supplementation on phospholipid metabolism were investigated to clarify the mechanism of the hypocholesterolemic action of soybean protein in rats fed a cholesterol-free diet. The effect of switching from a casein diet to a soybean protein diet was also investigated. Rats were fed casein, soybean protein or soybean protein + methionine diet for 14 d. Compared with casein diet, feeding of soybean protein diet led to significantly higher proportions of linoleic acid and linoleic acid-containing molecular species, especially 16:0-18:2, in plasma and liver microsomal phosphatidylcholine (PC). In addition, significantly lower plasma cholesterol concentration, hepatic S-adenosylmethionine concentration and liver microsomal PC:phosphatidylethanolamine ratio resulted. These alterations caused by the soybean protein diet were significantly suppressed by supplementing methionine to the level of the casein diet (3.4 g/kg diet). The proportion of the sum of certain plasma PC molecular species, which contain 18:1 or 18:2 in the sn-2 position, increased in response to the switch from the casein diet to the soybean protein diet at a rate similar to the decrease in plasma cholesterol concentration; there was a significant correlation between the two variables (r = -0.992, P < 0.001). These results indicate that about 40% of the hypocholesterolemic action of soybean protein is due to the low methionine content of the protein and might be associated with alterations of the plasma phospholipid molecular species profile.     

Scanning electron microscopy of intraocular lenses (author's transl)

Tolerance of intracular lenses is partly depending of the finishing quality of their different constituents. Several types of intraocular lenses have been studied with scanning electron microscopy: some imperfections of loop insertions and edge finish have been visualized.     

AMO array multifocal versus monofocal intraocular lenses: long-term follow-up

BACKGROUND: Reperfusion therapy by primary coronary angioplasty has been shown to be beneficial for patients who present themselves up to 12 h after the onset of symptoms. However, the relationship between outcome and ischaemic time for patients who present relatively late after the onset of symptoms is still uncertain. The aim of this study was to investigate differences in patient characteristics, left ventricular function and clinical outcome among early (< 3 h), intermediate (3-6 h) and late (6-24 h) treated patients. METHODS AND RESULTS: From August 1990 until December 1995, we studied 496 patients who underwent primary coronary angioplasty for acute myocardial infarction. Patients who underwent reperfusion therapy between 6 and 24 h were more often of female gender and more often had diabetes. Primary coronary angioplasty was less successful with later time to reperfusion. Patients who had reperfusion therapy within 6 h showed recovery of left ventricular function at 6 months follow-up, while the left ventricular function of patients treated late had deteriorated. Reocclusion of the infarct-related vessel at follow-up coronary angiography was highest for patients with an ischaemic time of more than 6 h. They more often suffered a repeat myocardial infarction and had a significantly higher 6 months mortality. After adjustment for age, heart rate at presentation, gender, and the presence of diabetes by multi-variate analysis, ischaemic time remained an independent predictor of both left ventricular function recovery and 6 month mortality. CONCLUSIONS: The time from symptom onset to reperfusion is related to some baseline clinical characteristics, procedural success rate, left ventricular function and clinical outcome.