Pediatric cataract surgery with hydrophilic acrylic intraocular lens

PURPOSE

To assess the outcomes after hydrophilic acrylic intraocular lens (IOL) implantation during pediatric cataract surgery.

METHODS

This was a retrospective chart review of children who underwent cataract surgery or secondary IOL implantation at Beirut Eye Specialist Centre, Rizk Hospital, between March 2002 and August 2007.

RESULTS

A total of 57 eyes of 40 patients (20 boys) were included in this study. The average age at surgery was 48 ± 40 months (range, 5-172 months). Of these, 54 eyes had congenital or developmental cataracts and 3 eyes had traumatic cataracts. Primary cataract removal and IOL implantation accounted for 45 surgeries, and secondary IOL implantation accounted for 12 surgeries. Hydrophilic acrylic IOLs were implanted in all surgeries. Average follow-up time was 47 ± 21 months (range, 9-97 months). No intraoperative complications were recorded. Of the 57 eyes, 12 (21%) had postoperative complications, but only 7 (12%) required secondary intervention. Average best-corrected visual acuity improved from 2.0 ± 1.0 logMAR preoperatively to 0.8 ± 1.0 logMAR at last follow-up. Improved visual acuity was observed in 47 eyes (82.5%); 31 eyes (54.4%) had a visual acuity of ≥ 20/40 at the last follow-up.

CONCLUSIONS

Hydrophilic acrylic IOLs appear to be suitable for use in pediatric cataract surgery. Results from this study suggest that, compared with hydrophobic IOLs, these IOLs produce similar complication rates, secondary intervention rates, and visual acuity results.

Modern cataract surgery: unfinished business and unanswered questions

We summarize information, based on clinicopathologic studies over the past decade, on various cataract intraocular lens (IOL) procedures and modern "specialized" IOLs, that will help surgeons continuously improve long-term results for cataract patients. Although most operations do initially provide excellent refractive correction and visual rehabilitation, late complications occur. These sometimes are missed because they are outside of the routine period of follow-up care. We have tried to determine if the various techniques and IOLs truly deliver the long-term results that we desire. Most safety and efficacy information is derived from the manufacturer and is passed through the U.S. Food and Drug Administration (FDA). This is often based on limited, relatively short-term observations made by the manufacturer. After a lens receives FDA approval, there are few means to assess the outcome of each procedure and lens years later. We rarely hear of a 10- or 20-year follow-up study. We have found that one of the best means to assess long-term results is pathologic analyses. We discuss recently studied aspects of pathologic reactions, such as posterior capsule opacification, intracapsular fibrosis, glistenings, intralenticular opacification, and other issues with the various IOL platforms; we then present a clinicopathological overview of tissues and IOLs from our database. These include hydrophobic and hydrophilic acrylic designs, plate lenses, and a dual optic lens.

Safety assessment of a new single-use small-incision injector for intraocular lens implantation

PURPOSE

To evaluate the safety of a new injector, the Raysert R-INJ-04/18, for implantation of the C-flex intraocular lens (IOL).

SETTING

Ophthalmology Department, Kaplan Medical Center, Rehovot, Israel.

DESIGN

Experimental study.

METHODS

Sixty IOLs were subdivided into 2 equally sized groups. Group A IOLs were injected using the established R-INJ-04 injector, and those in Group B were injected with the new injector. The IOLs were injected into a Petri dish. Subsequently, all IOLs and injectors were evaluated macroscopically and microscopically and then photographed under light microscopy (LM). Two IOLs in each group were randomly chosen and sent for evaluation by scanning electron microscopy (SEM) and energy dispersive analysis of x-ray. All remaining IOLs were sent for power and modulation transfer function (MTF) analysis.

RESULTS

All Group B IOLs were successfully injected without evident signs of scratching, cracks, or deposits on LM and SEM examination. In Group A, findings were confined to a singular incidence of a small deposit detected on the periphery of the posterior optical surface of the IOL, with corresponding findings detected on the injector nozzle. No signs of scratching, cracks, or deposits were found in the rest of the IOLs or injectors. The power and MTF analyses were within the normal range for all IOLs.

CONCLUSION

The new 1.8 mm external diameter soft-tipped injector for 2.4 to 2.2 mm incisions was shown to be safe for the implantation of the C-flex 21.0 diopter IOL.

A New Classification of Calcification of Intraocular Lenses

OBJECTIVE

To define and classify the major types of intraocular lens (IOL) calcification.

DESIGN

Retrospective observational case series with clinicopathologic correlation.

PARTICIPANTS

More than 400 IOLs explanted because of opacification.

METHODS

The authors reviewed the clinical information and histologic findings of all IOLs that had been explanted because of opacification or calcification of the IOLs accessioned in their laboratory between January 1999 and December 2004.

MAIN OUTCOME MEASURE

The proposed mechanism that led to calcification of each IOL design.

RESULTS

Three major types of calcification were identified: (1) primary calcification, (2) secondary calcification, and (3) false-positive calcification or pseudocalcification. The primary form refers to calcification that is inherent in the IOL, that is, is based on possible inadequate formulation of the polymer, fabrication of the IOL, or issues with its packaging process. The calcification presumably occurs in otherwise normal eyes and generally is not associated with preexisting diseases. The secondary form refers to deposition of calcium onto the surface of the IOL most likely the result of environmental circumstances (e.g., changes in the aqueous milieu surrounding the implanted IOL associated with preexisting or concurrent diseases or indeed any condition that has disrupted the blood-aqueous barrier). By definition, it is not related to any problem with the IOL itself. The false-positive or pseudocalcification refers to those cases in which other pathology is mistaken for calcification or false-positive staining for calcium occurs.

CONCLUSIONS

When evaluating the pathogenesis and nature of IOL calcification in or on any given design, one should categorize it according to these types. Primary calcification is IOL related and the IOL should be withdrawn or modified to correct the problem. After the cause is identified and the lens is implanted again, patients should be followed up for up to 2 years to be sure the problem is alleviated. Secondary calcification is by definition not IOL related; it may occur with virtually all IOL designs implanted under various adverse circumstances. No IOL, hydrophilic or hydrophobic, is immune to secondary calcification. The false-positive form is recognized readily in the laboratory and this erroneous diagnosis is avoided.

Nicholas Harold Lloyd Ridley. 10 July 1906 — 25 May 2001

Sir Harold Ridley invented and refined the modern miracle of replacing lenses obscured by cataracts with plastic optical lenses, thus rendering a complete cataract cure. This operation, broadly termed the cataract–intraocular lens (IOL) operation, has since brought sight to many millions of people throughout the world, and continues to improve the quality of life of more than 10 million patients worldwide each year.

Three-hundred-sixty degree barrier effect of a square-edged and an enhanced-edge intraocular lens on centripetal lens epithelial cell migration Two-year results

PURPOSE

To study the 360-degree barrier effect of an intraocular lens (IOL) with a square edge at the optic and an enhanced square edge at the optic-haptic junctions (Rayner 570C C-flex) on centripetal migration of lens epithelial cells (LECs) over a 2-year period.

SETTING

Department of Ophthalmology, Scarborough Hospital, Scarborough, United Kingdom.

METHODS

In a prospective study of 40 consecutive eyes, a C-flex IOL was implanted in the bag after phacoemulsification surgery. Eyes with intraoperative complications, requiring additional procedures, without 360-degree overlap of the optic, or with capsule block syndrome were excluded. Follow-up was at 6, 10, 18, and 24 months. At each visit, high-magnification retroillumination digital photographs were taken using a slitlamp-attached digital camera. The barrier effect to LEC migration across the optic edge and the enhanced square edge at the optic-haptic junction was graded as complete (no epithelial pearls or sheet), partial (few epithelial pearls without sheet), and minimal/none (epithelial sheet behind the IOL optic).

RESULTS

Twenty-four patients came to the final follow-up at 24 months. Fifteen of these eyes (63%) had a complete barrier effect throughout the 360 degrees of the IOL. Three eyes (13%) had a partial barrier effect throughout the 360 degrees of the IOL. Three eyes had a complete optic barrier effect but a partial optic-haptic junction barrier effect. Three eyes had a partial optic barrier effect but a complete optic-haptic junction barrier effect. No eye had epithelial sheets extending behind the optic at any location.

CONCLUSIONS

This study showed the barrier effect of the edge design of the C-flex IOL and the efficacy of the enhanced edge in preventing LEC migration at the optic-haptic junction. The enhanced edge was as effective as a sharp square edge in restricting the LEC migration.

Current concepts of ocular manifestations in Marfan syndrome

Marfan syndrome is a widespread disorder of connective tissue. It is characterized by systemic and ocular features due to mutations in the fibrillin gene. Awareness and prompt recognition of the ocular complications of Marfan syndrome may enable improvement and preservation of sight. Studies have been performed in the last few years that enable a better understanding of the genetics of the syndrome, earlier diagnosis, and improvement in the surgical techniques and options.

Postoperative surface deposits on intraocular lenses in children

PURPOSE

To report the clinicopathologic features of 4 intraocular lenses (IOLs) composed of 3 different hydrophilic biomaterials explanted from children who had postoperative opacification of the IOL optic.

SETTING

David J Apple, MD, Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, USA.

METHODS

The IOLs were explanted 20, 11, 22, and 25 months postoperatively from children aged 10, 3, 36, and 20 months old, respectively, at IOL implantation. Clinical data were obtained to correlate the findings with possible associated risk factors. The explanted IOLs were examined by gross and light microscopy. They were further analyzed with a stain for calcium, alizarin red 1%. Scanning electron microscopy and energy dispersive X-ray spectroscopy (EDS) were also performed.

RESULTS

The primary reason for cataract surgery in Case 1 and Case 2 was persistent hyperplastic primary vitreous (PHPV); 1 patient received a B-Lens IOL (Hanita) and the other a Centerflex IOL (Rayner). The primary reason in Case 3 was familial bilateral congenital cataract and in Case 4, rubella cataract; both patients received a Hydroview IOL (Bausch & Lomb). All 4 IOLs had surface deposits on the optic, but the morphology of the deposits on the B-Lens and Centerflex IOLs was different than that in previously reported cases. The deposits in all four cases stained positive with alizarin red and consisted of calcium and phosphorus when imaged with EDS.

CONCLUSIONS

Calcified deposits on 2 Hydroview IOLs explanted from children were similar to those seen in adults with the same IOL. The deposits on the B-Lens and Centerflex IOLs were probably secondary to a breakdown of the blood-aqueous barrier caused by preexisting PHPV.

Evaluation of a new soft tipped injector for the implantation of foldable intraocular lenses

AIM

To evaluate the R-INJ-04 soft-tipped injector, a new injector with an integral round nozzle manufactured by Rayner Intraocular Lenses, England.

METHODS

16 Rayner C-flex intraocular lenses (IOLs; Rayner Intraocular lenses, England) ranging between +10 and +30 D (2 for each power) were tested. An ophthalmic viscoelastic device (Healon, AMO, Santa Ana, California, USA) was applied to the injectors. The IOLs were loaded according to the company injector's instructions for use and were injected into a Petri dish. After the injection, all the IOLs and nozzles were evaluated by gross (macroscopic) and microscopic analyses and photographed under a light microscope. One lens of each power and the cartridge used for the implantation were then sent for further analysis by scanning electron microscopy (SEM). The rest of the IOLs were tested for power and modulation transfer function (MTF).

RESULTS

All the injections were successful. No damage to the IOLs or to the injectors was found by gross examination, light microscopy and SEM. No deposits were found on the IOL optical surfaces or haptics. Power and MTF analysis showed a close match with the original measurements.

CONCLUSION

Our results suggest that the R-INJ-04 soft-tipped injector is safe for the implantation of the C-flex IOL with power range from 10 to 30 D. No structural damage to the IOLs or to the injectors was found, and the lens power and light transmission properties were not damaged in any way by the injection process.

Hydroview lens implant calcification: 186 exchanges at a district general hospital

AIM

This paper describes the experience at a district general hospital of coping with an abrupt onset of calcification of Hydroview intraocular lens (IOL) implants requiring exchange surgery mostly for symptoms of glare, even though the visual acuities were relatively good.

METHODS

In this retrospective study, the operative details of 174 consecutive lens exchanges by one surgeon were retrieved from the surgeon's notes. Of these, pre and post-operative details of 106 consecutive patients were obtained from the hospital notes.

RESULTS

Of the 174 lens exchanges, all were sutureless except one and 31 eyes (18%) had had previous capsulotomies. Of 143 eyes with intact posterior capsules, eight (5.6%) needed anterior vitrectomy. Lens replacements were in the bag in 136 (95%), in the sulcus in five (3.5%), and in the anterior chamber in two (1.5%). Of the 31 eyes with previous capsulotomies, 10 (32%) needed anterior vitrectomy. Lens replacements were in the bag in 22 (71%) and in the sulcus in the remaining nine cases (29%). Postoperatively the best-corrected visual acuity was improved in 53%, remained the same in 35%, and deteriorated in 12%.

CONCLUSION

The lens exchange procedure was mostly predictable with satisfactory visual results allowing preoperative counselling of risks to be similar to that for cataract surgery. The onset and resolution of the period of implantation of lenses requiring exchange has not been explained.

Experimental studies on nonpenetrating filtration surgery using the CO2 laser

BACKGROUND

This study evaluated the use of a CO2 laser for performing deep sclerectomy in nonpenetrating filtration surgery.

METHODS

Three experimental models were performed: enucleated sheep and cow eyes (n=18) to determine optimal irradiation parameters, live rabbit eyes (n=20) to test feasibility, and cadaver eyes (40 procedures in 20 eyes) to study effects in human eyes tissue. After a half-thickness scleral flap was created, deep sclerectomy was performed by CO2 laser applications on the scleral bed down to the trabeculo-Descemet's membrane.

RESULTS

Fluid percolation was repeatedly achieved without penetration in sheep and cow eyes using scanned laser energy of 5-10 W at a pulse duration of 200 micros and a working distance of 35 cm. In live rabbits, deep sclerectomy was achieved without perforation in 19/20 eyes. Intraocular pressure was significantly decreased on the first postoperative day (10.3+/-5.1 mmHg lower, on average, than in the nonoperated fellow eye; P<0.001), and this persisted for 21 days. Operations on all cadaver eyes resulted in effective fluid percolation. Penetration of the scleral wall occurred in five cases only after repeated laser applications with high energy. Histologically, a thin sclerocorneal intact wall was demonstrated at the sclerectomy bed. Collateral tissue damage did not extend beyond 100 microm, and adjacent structures remained unharmed.

CONCLUSIONS

CO2 laser-assisted deep sclerectomy is a feasible and apparently safe procedure.

Clinical presentation of intraocular lens schisis

PURPOSE

To analyze the clinical presentation and implications of cavity or schisis formation in the MemoryLens (CIBA Vision) intraocular lens (IOL) optic.

SETTING

Eye Department, Red Cross Hospital, Munich, Germany.

METHODS

This study was a retrospective chart review and slitlamp photography analysis of IOL schisis.

RESULTS

Four patients with IOL schisis were identified and their charts analyzed. Clinically, the schisis presented as a sharply demarcated round structure. The aspect was clear on coaxial illumination, but on tangential illumination the schisis area was opaque. Patients experienced glare, foggy vision, and deteriorated visual function or had no symptoms. One patient lost visual acuity, and the IOL was explanted.

CONCLUSIONS

Clinically, IOL schisis was easily differentiated from cases of IOL opacification due to calcification. The clinical implication was not uniform, ranging from no symptoms to great visual disturbance leading to explantation of the IOL. The cause of this complication remains unclear. A possible explanation is the impact of solvent-induced tensile stress on the IOL optic material during the manufacturing process.

Evaluation of lens epithelial cell migration in vivo at the haptic-optic junction of a one-piece hydrophobic acrylic intraocular lens

PURPOSE

To evaluate the pattern of lens epithelial cell (LEC) ingrowth behind the intraocular lens (IOL) optic in patients implanted with the AcrySof SA60AT one-piece IOL.

DESIGN

Retrospective case series.

METHODS

Patients implanted with the AcrySof SA60AT one-piece IOL with complete overlap of the capsulorrhexis and IOL optic and no ocular pathology were selected from the practices of six surgeons. High-resolution digital images of the distribution of LECs were captured. Circumferential location and extent of LEC growth behind the optic were measured.

RESULTS

Mean +/- SD follow-up was 13.2 +/- 1.7 months for 40 patients (mean age 72 years). LEC migration beyond the edge of the IOL optic was displayed by 57.5% (23/40) of patients. LECs migrated into the visual axis in 22.5% (9/40) of patients, leading to a visual acuity of <6/9 (20/30) in 10% (4/40) of patients. Cell migration was located preferentially at the optic-haptic junction. Serial photographs were used to monitor LEC migration over time. In some cases, LECs extended from the opposing optic-haptic junctions to converge in the center of the IOL, creating a path across the optic.

CONCLUSIONS

The optic-haptic junction of the AcrySof one-piece IOL is a point of weakness in the barrier effect of the square-edge IOL design that provides migrating LECs access to the posterior capsule.

Long-term capsular bag survival without functional lens epithelial cells

PURPOSE

To evaluate the survival of the capsular bag without the support of functional lens epithelial cells (LECs).

SETTING

David J. Apple, MD, Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, USA.

METHODS

One hundred slides of cadaver pseudophakic eyes (from 1991 to 2000) stained with hematoxylin and eosin were analyzed to determine the presence of Soemmering's ring, integrity of the capsular bag, fixation configuration of the haptics, and presence and functionality of the LECs.

RESULTS

A Soemmering's ring was present in 69% of cases. The capsular bags were intact in 100% of cases. In-the-bag fixation was seen in 44% of cases. In 89% of cases, either no cells or nonfunctional LECs were found.

CONCLUSION

Results suggest the capsular bag can survive anatomically without the support of functioning LECs.

Hydrophilic acrylic intraocular lens as a drug-delivery system for fourth-generation fluoroquinolones

PURPOSE

To evaluate the ability and safety of a hydrophilic acrylic intraocular lens (IOL) as a drug-delivery system for commercially available gatifloxacin and moxifloxacin.

SETTING

David J. Apple, MD, Laboratories for Ophthalmic Research, John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, USA.

METHODS

Thirty rabbits were divided into 2 similar groups. In Group A (15 rabbits, 30 eyes), hydrophilic acrylic IOLs (C-flex, Rayner Intraocular Lenses, Ltd.) presoaked for 24 hours in commercially available solutions of gatifloxacin 3 mg/mL or moxifloxacin 5 mg/mL were implanted after evacuation of the crystalline lens. Group B (15 rabbits, 30 eyes) had topical preoperative and postoperative cataract prophylaxis with gatifloxacin 3 mg/mL or moxifloxacin 5 mg/mL; IOLs that were not presoaked were also implanted after evacuation of the crystalline lenses. In both groups, aqueous humor samples were taken 4, 8, or 12 hours after IOL implantation (5 eyes at each time point) to determine the antibiotic concentrations. Clinical examinations were performed 24 hours postoperatively.

RESULTS

The antibiotic concentrations in Group A (presoaked IOLs) were statistically significantly higher than those in Group B (topical) for both antibiotics in all postoperative samples except moxifloxacin at 12 hours. In both groups, there was no statistically significant difference between the concentrations of the 2 antibiotics. No eye showed signs of clinical toxicity.

CONCLUSION

Results show the C-flex IOL is a safe and effective drug-delivery system for fourth-generation fluoroquinolones.

Recurrent iritis after implantation of an iris-fixated phakic intraocular lens for the correction of myopia

The iris-claw intraocular lens (IOL) was recently approved by the U.S. Food and Drug Administration for the correction of refractive disorders. Previous reports are not uniform regarding its potential to induce inflammatory reaction. We report the case of a young healthy patient who experienced persistent and intolerable iritis after implantation of an iris-claw IOL. The iritis was resolved only after explantation of the IOL.

Two opacification patterns of the same hydrophilic acrylic polymer: case reports and clinicopathological correlation

We report 2 intraocular lenses (IOLs) manufactured from the same hydrophilic acrylic polymer by Ioltech that developed optic opacification. In both cases, the postoperative course after implantation of the IOLs was complicated by significant inflammatory reaction with fibrin formation in the anterior chamber. Pathologic analyses of the explanted IOLs were consistent with dystrophic calcification leading to optic opacification, but the pattern was different between the 2 IOL designs. Patient-related factors might have been responsible for this complication.

Hydrophilic acrylic intraocular lens as a drug-delivery system: Pilot study

PURPOSE

To evaluate the ability of a hydrophilic acrylic intraocular lens (IOL) to serve as a drug-delivery system for commercially available gatifloxacin and moxifloxacin.

SETTING

David J. Apple, MD, Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.

METHODS

Hydrophilic acrylic IOLs (C-flex, Rayner Ltd.), presoaked for 24 hours in commercially available solutions of gatifloxacin (Zymar) or moxifloxacin (Vigamox), were implanted in the capsular bag of 6 rabbits for a total of 12 eyes (6 in each group). Aqueous humor samples were taken 2, 4, and 6 hours after implantation. One rabbit served as a control and had nonpresoaked C-flex IOLs implanted. At the end of the operation, 1 drop of Vigamox was applied to the right eye and 1 drop of Zymar was applied to the left eye of the control rabbit.

RESULTS

High concentrations of both antibiotics were found in all the samples of the eyes implanted with the presoaked IOLs. The concentrations of the antibiotics decreased over time, but even the 6-hour sample concentrations were markedly higher than the concentrations found in the control rabbit after 4 hours.

CONCLUSION

The results suggest that the Rayner C-flex IOL can be effective as a drug-delivery system for fourth-generation fluoroquinolones.

New Endoscopic Technique to Analyze Various Modern Specialized Intraocular Lenses in Research Eyes and Human Eyes Obtained Postmortem

PURPOSE

To describe a new modification of the Miyake-Apple posterior video photographic technique and its 2 variations. We have developed a new endoscopic technique that is especially amenable for observation of modern specialized intraocular lenses (IOLs).

DESIGN

Laboratory study.

PARTICIPANT

Three cadaver eyes obtained postmortem.

METHODS

Human eyes obtained postmortem were prepared according to our modified preparation technique used for analyses of whole globes. An intraocular endoscope was utilized to demonstrate all aspects of the interior of an experimentally implanted IOL, with specialized reference to anterior segment structures, obtaining posterior, oblique, and side view images.

MAIN OUTCOME MEASURES

Different interior dynamic views of the anterior segment structures before and after implantation of an IOL.

RESULTS

High-magnification images of different intraocular structures both before and after device insertion as well as the device itself were obtained. Oblique and side view images from different locations were also available and informative. These images helped to create a 3-dimensional view of these objects and their relations to the surrounding structures.

CONCLUSION

The combination of the intraocular endoscope with the closed-system technique is a useful addition to our 3 previously described techniques: (1) the original Miyake-Apple posterior video/photograph technique and the (2) closed system and (3) side/oblique view (keyhole technique) modifications.

Suturing a tear of the anterior capsulorhexis

AIM

To describe a new technique of suturing a tear in the anterior capsulorhexis.

METHODS

Continuous curvilinear capsulorhexis (CCC) with lens removal was done in five fresh cadaver eyes. The diameter of the CCC was measured with a calliper. Using the same calliper a tear of the CCC was created while opening the calliper's arms. The distance between the calliper's arms needed to tear the CCC was documented. Using 9-0 Ethilon 9011, CS 160-6 sutures in two eyes, 9-0 Prolene, D-8229, CTC-6L sutures in two eyes, and 10-0 Prolene, 9090, CTC-6 suture in one eye, the tears were sutured. A tear in the CCC was created again in the same way as the first tear. The distance between the calliper's arms needed to tear the CCC was documented again.

RESULTS

Suturing of the tear restored some of the strength/elasticity of the CCC. Better results were found while using the 9-0 Prolene, D-8229, CTC-6L sutures than with the two others sutures.

CONCLUSIONS

Suturing of a broken CCC can restore at least some of the strength/elasticity of the CCC. This can be important before intraocular lens (IOL) implantation for the safety of the implantation or after the implantation to ensure proper fixation of the IOL.

"Special" intraocular lens designs: why do they sometimes fail?

A variety of new "special" intraocular lens models to optimize the visual performance after cataract surgery have been introduced. The majority of these new intraocular lens designs require a good centration within the capsular bag and/or capsular elasticity. Today, the main post-operative complications after cataract surgery still arise from retained lens epithelial cells within the capsular bag, resulting mainly in anterior and posterior capsule opacification. Some special intraocular lenses are not designed to be effective against proliferating lens epithelial cells. Although lens epithelial cells can never be completely removed from the capsular bag, surgical quality is a major factor for success or failure of these intraocular lens designs.

Histology of AlphaCor skirts: evaluation of biointegration

PURPOSE

To report histologic findings in 14 AlphaCor artificial corneas implanted during clinical trials and subsequently explanted from human subjects following complications, so as to evaluate biointegration within the device skirt.

METHODS

Explants were fixed and sectioned in paraffin. Histologic findings related to the device skirt were compared with earlier histologic results from animal studies and correlated with clinical histories.

RESULTS

Two devices had been removed due to complications related to the optic alone, 11 following stromal melting overlying the biointegratable sponge skirt and 1 due to a retroprosthetic membrane. All devices demonstrated normal skirt porosity. Biointegration was similar to that found in animal studies but qualitatively appeared reduced in the affected areas in patients with overlying stromal melting prior to explantation. Patients with a longer history of melting prior to explantation demonstrated presence of inflammatory cells around the device.

CONCLUSIONS

Histologic findings of the AlphaCor skirt in humans are consistent with earlier animal studies. This study confirms that biointegration by host fibroblastic cells, with collagen deposition occurs after AlphaCor implantation in humans. In cases in which stromal melting had occurred, biointegration is seen to be reduced. On correlating preoperative clinical factors with biointegration observed histologically, preoperative vascularization appears not to be required for AlphaCor biointegration.

Linear deposits on the surfaces of intraocular lenses implanted through a hexagonal cartridge which mimic scratches/cracks on the lenses

AIM

To describe unique linear deposits on the surface of posterior chamber intraocular lenses (IOLs) occurring after implantation through a hexagonal cartridge.

METHODS

Five ACR6D SE IOLs (Corneal Laboratories, Pringy, France) were injected/implanted through hexagonal cartridges. Two of these were injected into a petri dish and the remaining three were inserted into the evacuated capsular bag of cadaver eyes. In addition, three other ACR6D SE IOLs were injected into a petri dish through round cartridges. The latter served as controls.

RESULTS

All lenses that were injected/implanted through the hexagonal cartridges demonstrated linear deposits on the posterior surface of the IOL optic component. The IOLs that were injected through the round cartridges had no deposits. All the hexagonal cartridges showed signs of internal cracking. None of the round cartridges were cracked.

CONCLUSION

Implantation of at least one IOL model, the ACR6D SE IOL, through a hexagonal cartridge can result in linear deposits on the posterior optical surface of the IOL. The shape of the cartridge appears to be a significant factor in causing the depositions.

Cocooning of an iris-fixated intraocular lens in a 3-year-old child after perforating injury: Clinicopathologic correlation

We present a 3-year-old patient who developed extensive noninflammatory fibrous membrane formation in the anterior chamber involving the present iris-fixated intraocular lens (IOL), with subsequent need for explantation. The child had had repair of a corneal injury, crystalline lens extraction and Artisan iris-claw IOL (Ophthec) implantation after a penetrating injury 2 months before. Histopathologic analyses were consistent with a retrocorneal membrane that originated from the corneal stroma and formed a "cocoon" membrane on the iris-claw IOL.

Professor Peter Choyce: an early pioneer of intraocular lenses and corneal/refractive surgery

Professor Peter Choyce, FRCS, DOMS, MS, was one of the pioneers of intraocular lens implant surgery. He developed an interest in artificial lens implantation following cataract surgery, a procedure that was widely criticized by the ophthalmic establishment in the UK, Europe, North America and other countries. Owing to the opposition to the intraocular lenses, Peter Choyce together with Sir Harold Ridley co-founded the International Intraocular Implant Club in 1966, which was responsible for the gradual acceptance of artificial lens implantation. Peter Choyce developed several models of intraocular lens, but did not patent the majority of them. The Choyce Mark IX, manufactured by Rayner Intraocular Lenses, became the first US Food and Drug Administration-approved intraocular lens in 1981. A review of Peter Choyce's record confirms a significant number of original innovations in the field of anterior segment surgery, including many procedures taken for granted today, but not associated with his name. These include early work on both kerato- and intraocular lens-refractive procedures, keratoprosthesis, pioneering paediatric implant procedures and others. Unfortunately his tenacious adherence to anterior chamber lens technology, while in general clinically sound, caused many to question his influence and hence he remained poorly understood even until after his death. He passed away on 8 August 2001 after a long fight with colon cancer. In this article, we provide evidence and elaborate Peter Choyce's accomplishments, which places him as one of the most innovative ophthalmologist in his surgical field in the twentieth century.

Posterior capsule opacification in rabbit eyes implanted with 1-piece and 3-piece hydrophobic acrylic intraocular lenses

PURPOSE

To evaluate the outcome of posterior capsule opacification (PCO) after implantation in rabbit eyes of currently available 3-piece and 1-piece hydrophobic acrylic intraocular lenses (IOLs) with square optic edges.

SETTING

John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.

METHODS

The 3-piece designs evaluated were the AR40e (Advanced Medical Optics Inc.) and the MA60AC (Alcon, Inc.); the 1-piece designs were the SA60AT and the SA30AT (Alcon, Inc.). Nine lenses of each type were implanted in a randomized manner by the same surgeon in 18 Dutch Belted pigmented rabbits. After a follow-up of 3 weeks, the rabbits were killed and analyses of the enucleated eyes were performed from the posterior or Miyake-Apple view. The intensity of central PCO, peripheral PCO, and Soemmering's ring formation was scored from 0 to 4. The area of Soemmering's ring formation was also scored from 0 to 4 based on the number of quadrants involved. Other parameters analyzed were capsulorhexis coverage of the IOL anterior surface, IOL centration, fixation, and presence of striae. Results from the posterior view were complemented by histopathologic evaluation of the eyes.

RESULTS

No statistically significant difference was found between the 4 groups of IOLs in the parameters analyzed from the posterior view. When cell ingrowth occurred with the 1-piece designs, causing peripheral and central PCO formation, it was more likely to start at the optic-haptic junctions, as observed during the clinical follow-up with slitlamp examination and confirmed by gross and histopathologic analyses of the enucleated eyes.

CONCLUSIONS

The square, truncated optic edge is the most important IOL design feature for PCO prevention. The optic-haptic junctions of the 1-piece designs appear to be sites where the barrier effect of the truncated optic edge is less effective.

Analysis of the capsule edge after Fugo plasma blade capsulotomy, continuous curvilinear capsulorhexis, and can-opener capsulotomy

PURPOSE

To compare the quality of the edges of anterior capsulotomies performed in porcine eyes using 3 different techniques.

SETTING

David J. Apple, MD Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, USA.

METHODS

Four porcine eyes were submitted to the center in 10% neutral buffered formalin. The cornea of the eyes had been removed, and a continuous capsulotomy had been performed in each eye using the Fugo plasma blade. To provide morphologic correlation, 4 additional porcine eyes were used in the study. In 2, a manual continuous curvilinear capsulorhexis (CCC) was performed after the cornea or cornea/iris was removed and in the other 2, a can-opener capsulotomy (COC) was performed. The eyes were then placed in 10% neutral buffered formalin. Gross (macroscopic) and microscopic analysis of each eye was performed, and photographs were taken. One eye in each group was also prepared and analyzed under scanning electron microscopy (SEM).

RESULTS

The capsulotomy margin in the Fugo blade group presented some regularly spaced tags directed centrally with smooth edges at the base. Such a configuration would not interfere with the dynamics of the capsulorhexis sphincter and would generally not lead to radial tears. The smooth and regular nature of the capsulotomy margin in the CCC group was confirmed by gross and microscopic examinations of the eyes. The capsulotomy margin in the COC group presented some sharp notches directed outward, irregularly spaced, and irregular in shape. These are known to have a tendency to extend and form radial tears.

CONCLUSION

Although performance of an anterior capsulotomy with the Fugo blade was associated with some margin irregularities, the geometry of the centrally directed tags prevented them from becoming the site of radial tear formation. The base of the capsulotomy performed with the Fugo blade appeared to be almost as smooth and regular as in the CCC under SEM evaluation.

Removal times for a dispersive and a cohesive ophthalmic viscosurgical device correlated with intraocular lens material

PURPOSE

To investigate the removal times of ophthalmic viscosurgical devices (OVDs) with different intraocular lens (IOL) designs and materials.

SETTING

Center for Research on Ocular Therapeutics and Biodevices, Department of Ophthalmology, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA, and Heidelberg IOL & Refractive Surgery Research Group, Department of Ophthalmology, Ruprecht-Karls-University of Heidelberg, Heidelberg, Germany.

METHODS

In a standardized laboratory setup, the Miyake-Apple posterior view video technique was used to evaluate OVD removal from capsular bags in human autopsy eyes implanted with poly(methyl methacrylate) (PMMA), silicone, and acrylic IOLs. The cohesive OVD ProVisc (sodium hyaluronate 1.0%) and the dispersive OVD Viscoat (sodium hyaluronate 3.0% and chondroitin sulfate 4.0%) were stained with fluorescein for better visualization. The open-sky preparation and an Alcon Series 20000 Legacy phaco machine with a flow rate of 25 mL/min and a vacuum setting of +500 mm Hg (maximum irrigation/aspiration) were used. The time needed for complete removal of the cohesive and dispersive OVDs with each IOL type was measured and analyzed statistically.

RESULTS

The mean removal times for both OVDs were as follows: Alcon MZ60BD PMMA IOL-25.0 seconds +/- 3.7 (SD) (Viscoat), 15.9 +/- 6.9 seconds (ProVisc); Alcon AcrySof MA60BM IOL-35.5 +/- 10.0 seconds (Viscoat), 25.6 +/- 4.7 seconds (ProVisc); Chiron/Bausch & Lomb C1043 silicone IOL-46.5 +/- 10.5 seconds (Viscoat), 17.3 +/- 2.1 seconds (ProVisc); AMO SI-30 silicone IOL-33.5 +/- 3.1 seconds (Viscoat), 15.3 +/- 6.3 seconds (ProVisc); and Pharmacia 912 silicone IOL-18.3 +/- 5.8 seconds (Viscoat), 19.8 +/- 4.3 seconds (ProVisc).

CONCLUSIONS

Differences in OVD removal times were detected. The removal time for the cohesive OVD correlated with the IOL material. Overall, the time needed for complete removal was significantly longer for the dispersive OVD than for the cohesive OVD.

Late postoperative opacification of a hydrophilic acrylic (hydrogel) intraocular lens: a clinicopathological analysis of 106 explants

PURPOSE

To report clinical, pathologic, histochemical, ultrastructural, and spectroscopic analyses of MemoryLens intraocular lenses (IOLs) explanted from patients who had visual disturbances caused by postoperative opacification of the lens optic.

DESIGN

Noncomparative, large case series with clinicopathologic correlation.

PARTICIPANTS

A total of 106 hydrophilic acrylic IOLs of the same design explanted from 106 different patients. All patients had decreased visual acuity at presentation approximately 2 years after cataract surgery, associated with a whitish fine granularity on the optical surfaces of the IOLs.

METHODS

The explanted IOLs were submitted to the John A. Moran Eye Center and were examined under light microscopy, histochemically, and with scanning electron microscopy (SEM) equipped with an energy dispersive x-ray spectroscopy detector with light element capabilities (EDS).

MAIN OUTCOME MEASURES

The IOLs were examined for distribution, structure, and composition of the deposits causing opacification of their optic components.

RESULTS

The average interval between lens implantation and opacification was 25.8+/-11.9 months. The most frequently associated medical and ophthalmic conditions were diabetes and glaucoma. However, some patients did not have any preexisting medical or ophthalmic conditions. Most of the IOLs had been implanted in 1999 and 2000. Microscopic analyses revealed the presence of multiple fine, granular deposits of variable sizes on the anterior and posterior optic surfaces, especially on the anterior surface. The deposits stained positive for calcium. The EDS confirmed the presence of calcium and phosphate within the deposits.

CONCLUSIONS

The results obtained suggest the surface deposits to be composed, at least in part, by calcium and phosphate. A special polishing technique used in the manufacture of most of these IOLs may have caused changes in the lens surface leading to deposit formation. Further studies should be undertaken to confirm this hypothesis.

Correlation between different measurements within the eye relative to phakic intraocular lens implantation

PURPOSE

To obtain measurements of the white-to-white distance and the anterior chamber and ciliary sulcus diameters in phakic human eyes obtained post-mortem to find a correlation between these measurements.

SETTING

David J. Apple, MD Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.

METHODS

Twenty-two phakic human eyes obtained from eye banks within 24 hours of death were evaluated. The following measurements were performed: white-to-white distance, anterior chamber diameter with a plastic sizer after a small limbal incision, and anterior chamber and ciliary sulcus diameters after fixation and sagittal section of the eyes. The first 10 eyes were studied at the 6 o'clock to 12 o'clock meridian and the last 12 eyes, at the 3 o'clock to 9 o'clock meridian.

RESULTS

A positive correlation was found between the white-to-white measurements and the anterior chamber diameter in the 10 eyes studied at the 6 o'clock to 12 o'clock meridian but not in the 12 eyes studied at the 3 o'clock to 9 o'clock meridian. The latter is the meridian frequently used by surgeons to perform white-to-white measurements and thus choose the overall size of the phakic intraocular lens to be implanted. No correlation was found between the white-to-white measurements and the ciliary sulcus diameter in the 2 meridians.

CONCLUSION

Experimental studies using cadaver eyes are helpful in evaluating sizing techniques for phakic IOL implantation as well as in better understanding the anatomical relationships between ocular structures.

Posterior capsule opacification in rabbit eyes implanted with hydrophilic acrylic intraocular lenses with enhanced square edge

PURPOSE

To evaluate the development of posterior capsule opacification (PCO) after implantation of single-piece hydrophilic acrylic intraocular lenses (IOLs) with an enhanced square edge.

SETTING

John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.

METHODS

The standard 570H Centerflex (Rayner Ltd.) design was compared to 2 new designs with enhanced square edges: the 570E and the 570C. Ten IOLs of each type were implanted in a randomized manner by the same surgeon in 15 pigmented rabbits. After a follow-up of 3 weeks, the rabbits were killed and the eyes were analyzed from the posterior view. The intensity of central PCO, peripheral PCO, and Soemmering's ring formation was graded from 0 to 4. The area of Soemmering's ring was graded from 0 to 4 based on the number of quadrants involved. Other parameters analyzed were capsulorhexis coverage of the IOL edge and IOL centration and fixation. Results from the posterior view were complemented by histopathological evaluation.

RESULTS

Posterior capsule opacification was lowest in the 570C group, highest in the 570H group, and intermediate in the 570E group. There was a statistically significant difference between the 3 groups in peripheral PCO (P = .039). No significant difference was found between the groups in the other parameters analyzed. When cell ingrowth occurred with the 570H, it started at the optic-haptic junctions, as observed during the clinical follow-up and confirmed by gross and histopathological analyses.

CONCLUSIONS

The square optic edge is the most important IOL design feature for PCO prevention. However, it should be present for 360 degrees around the IOL optic to provide an effective barrier effect.

Capsulorhexis ovaling and capsular bag stretch after rigid and foldable intraocular lens implantation

PURPOSE

To compare the amount of capsulorhexis ovaling and capsular bag stretch produced by various intraocular lenses (IOLs) implanted in pediatric human eyes obtained post-mortem.

SETTING

David J. Apple, MD Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, Salt Lake City, Utah, USA.

METHODS

In this nonrandomized comparative study, 16 pediatric human eyes obtained postmortem were divided into 2 groups: Eight eyes were obtained from children younger than 2 years (Group A), and 8 eyes were obtained from children older than 2 years (Group B). All eyes were prepared according to the Miyake-Apple posterior video technique. Six types of rigid and foldable posterior chamber IOLs manufactured from poly(methyl methacrylate) (single-piece), silicone (plate and loop haptics), and hydrophobic acrylic (single-piece and 3-piece AcrySof, Alcon Laboratories) biomaterials were implanted. The capsulorhexis opening and capsular bag diameters were measured before IOL implantation and after in-the-bag IOL fixation with the haptics (or the main axis) at the 3 to 9 o'clock meridian. The percentage of ovaling of the capsulorhexis opening was calculated by noting the difference in the opening's horizontal diameter before and after IOL implantation. The percentage of capsular bag stretch was also calculated by noting the difference in the horizontal capsular bag diameter before and after IOL implantation.

RESULTS

All IOLs produced ovaling of the capsulorhexis opening and stretching of the capsular bag parallel to the IOL haptics. There were significant differences in capsulorhexis ovaling and capsular bag stretch (P<.001, analysis of variance) between the 6 IOL types in each group of eyes. The postimplantation difference was significant only between the single-piece hydrophobic acrylic IOL (AcrySof) and the other IOLs. The single-piece hydrophobic acrylic IOL was associated with significantly less capsulorhexis ovaling and capsular bag stretch in both groups (mean 12.06% +/- 0.59% [SD] and 7.6% +/- 1.47%, respectively).

CONCLUSIONS

Modern rigid and foldable IOLs designed for the adult population implanted in the capsular bag of infants and children produced variable degrees of capsulorhexis ovaling and capsular bag stretch. The Miyake-Apple posterior video technique confirmed the well-maintained configuration of the capsular bag (with minimal ovaling) after implantation of a single-piece hydrophobic acrylic IOL because of its flexible haptic design.

Pathological evaluation of postmortem human eyes implanted with a new single-piece hydrophobic acrylic lens

PURPOSE

To report the pathological findings in 14 human cadaver eyes implanted with a single-piece AcrySof(Alcon Laboratories) posterior chamber intraocular lens (IOL).

SETTING

David J. Apple, MD Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.

METHODS

Fourteen human autopsy eyes implanted with a single-piece AcrySof (SA30AL) IOL were evaluated. The eyes were sectioned at the equatorial plane, and the anterior segment containing the IOL in the capsular bag was evaluated from a posterior perspective (Miyake-Apple view) and from an anterior perspective (surgeon's view) after removal of cornea and iris. They were then processed through paraffin, sectioned, and stained with hematoxylin-eosin, periodic acid-Schiff, and Masson's trichrome and examined under light microscopy.

RESULTS

All IOLs had symmetric in-the-bag fixation. Slight decentration was measured in 1 eye, which also had an anterior capsule tear. Grade 1 anterior capsule opacification was present in 9 eyes. No central posterior capsule opacification or posterior capsule folds were observed in any eye. Soemmering's ring formation was observed in 5 eyes. Zonular stretch caused by different degrees of capsular bag contraction was present in 4 eyes without decentration of the IOL.

CONCLUSIONS

Analyses of pseudophakic cadaver eyes from the posterior (Miyake-Apple) view, complemented by microscopic analyses, proved useful in the evaluation of IOL-capsular bag interaction. These studies are more important in cases of newly introduced lens designs.

Deposits in artificial corneas: risk factors and prevention

PURPOSE

To identify risk factors for calcium deposition and pigmented staining within AlphaCor artificial corneas.

METHODS

Retrospective analysis of data from 72 AlphaCor implantations was conducted. Histological analysis of explants was performed.

RESULTS

Eight cases of either intraoptic calcium or pigment deposition occurred in AlphaCor patients between 2.5 and 21 months after implantation. Four cases had diffuse white deposits, confirmed to be calcium and associated with prior coadministration of topical steroids and beta-blockers. The other four cases had brown deposits, associated with cigarette smoking and topical levobunolol.

CONCLUSION

These findings led to changes in patient management protocols, surgeon training and patient information so as to minimize the risk of further occurrences. No further cases of white deposition have occurred after warning surgeons of the risk associated with certain topical therapy combinations. The risk of brown staining may be difficult to remove completely as it appears that environmental exposure to chemicals may cause deposition in addition to personal smoking habits and topical medications.

Single-piece hydrophobic acrylic intraocular lens explanted within the capsular bag

A 74-year-old woman had uneventful phacoemulsification with implantation of a single-piece hydrophobic acrylic intraocular lens (IOL) (SA30AL) in her left eye. Two weeks after the surgery, the patient presented for ophthalmological consultation reporting pseudophakic dysphotopsia, which she had subjectively noted since surgery. Explantation/exchange of the IOL was performed 3 months after the surgery. The IOL was strongly attached to the capsule, which was fibrotic and contracted; explantation of the capsular bag complex in toto was done. To our knowledge, this is the first case of explantation of this IOL design with clinicopathological correlation.