Veva De Groot

Bag-in-the-lens implantation of intraocular lenses

Purpose: To report a new intraocular lens (IOL) and an IOL implantation concept, the bag‐in‐the‐lens implantation technique, designed to prevent posterior capsule opacification (PCO). Setting: The University of Antwerp, Department of Ophthalmology, Edegem, Belgium, and the Netherlands Ophthalmic Research Institute, Department of Morphology, Amsterdam, The Netherlands. Methods: After identical curvilinear capsulorhexes are created in both the anterior and posterior capsules, the capsules are inserted in a flange of the IOL, thus the term bag‐in‐the‐lens as opposed to the currently used lens‐in‐the‐bag technique. The IOL was implanted in an in vitro human capsular bag model and in 10 eyes of 9 patients with cataract. Lens epithelial cell (LEC) outgrowth and PCO formation were observed. Results: When both capsular blades were well stretched around the IOL optic, the in vitro capsular bag model showed LEC proliferation only within the space of the remaining lens bag. The LEC proliferation was limited, and there was no tendency toward proliferation approaching the visual axis. In all 10 eyes, the optical axis remained clear during a follow‐up between 4 and 15 months. Conclusions: This new IOL prevented LEC proliferation in vitro and seems promising in vivo. Target patients are those at risk of PCO including those with congenital cataract, uveitis, diabetes, or cataract extraction combined with vitrectomy.

Continuous positive airway pressure therapy is associated with an increase in intraocular pressure in obstructive sleep apnea

PURPOSE Several reports have demonstrated an association between glaucoma and obstructive sleep apnea (OSA), though the origin of this association remains unknown. In the present study, the influence of OSA and continuous positive airway pressure (CPAP) therapy on intraocular pressure (IOP) and ocular perfusion pressure (OPP) was examined. METHODS IOP, blood pressure, and pulse rate were measured every 2 hours during 24-hour sessions in 21 patients with newly diagnosed OSA. A first series of measurements was performed before CPAP therapy, and a second series was performed 1 month after the initiation of CPAP therapy. OPP was then calculated. RESULTS Baseline measurements showed a significant nycththemeral fluctuation in the average IOP, with the highest IOPs at night. After 1 month of CPAP therapy, the average IOP was significantly higher than baseline. The increase in overnight IOP was also significantly higher. A 24-hour IOP fluctuation of > or =8 mm Hg was found in 7 patients at baseline and in 12 patients during CPAP therapy. The mean difference between trough and peak IOP was 6.7 +/- 1.5 mm Hg at baseline and 9.0 +/- 2.0 mm Hg during CPAP therapy. Thirty minutes after CPAP cessation a significant decrease in IOP was recorded. There was a statistically significant decrease in mean OPP during CPAP therapy. CONCLUSIONS Patients with OSA demonstrated significant 24-hour IOP fluctuations, with the highest values at night. CPAP therapy causes an additional IOP increase, especially at night. Regular screening of visual fields and the optic disc is warranted for all patients with OSA, especially those treated with CPAP.

Secondary closure of posterior continuous curvilinear capsulorhexis in normal eyes and eyes at risk for postoperative inflammation

Purpose: To observe the posterior continuous curvilinear capsulorhexis (PCCC) after cataract surgery in control eyes and eyes with an increased risk for postoperative inflammation. Setting: Department of Ophthalmology, University Hospital Antwerp, Belgium. Methods: After phacoemulsification, a PCCC was performed before intraocular lens (IOL) implantation in 20 eyes of 18 patients with ocular or systemic conditions that predisposed them for increased postoperative inflammation; e.g., diabetes, uveitis, retinitis pigmentosa (inflammation group). These eyes were compared with 20 eyes of 16 patients who had the same surgical procedure but did not present a history of medical or ocular pathology (control group). The postoperative follow‐up was 6 months to 3 years. Reclosure of the PCCC was evaluated by anterior segment photographs. The reclosure was classified as partial when newly formed tissue was present at the PCCC margin and total when the proliferation covered the entire PCCC area. Results: Three types of PCCC reclosure were found: fibrotic, Elschnig pearl or multilayer, and monolayer. All 3 were seen within or at the margin of the PCCC area. Reclosure (total and partial) occurred in 8 eyes (40%) in the control group and 10 (50%) in the inflammation group. Total reclosure was more frequent in the inflammation group (4 eyes [20%]) than in the control group (1 eye [5%]). Monolayered or multilayered cellular proliferation was present in 8 eyes (40%) in the control group and 4 eyes (20%) in the inflammation group; fibrotic proliferation was found in the inflammation group only (7 eyes [35%]). Conclusion: Reclosure of the PCCC occurred in both groups, although the frequency of reclosure was slightly higher in the inflammation group. Although PCCC does not prevent posterior capsule opacification in all cases, it is useful in specific situations.

A new glaucoma hypothesis: a role of glymphatic system dysfunction

In a recent review article titled “A new look at cerebrospinal fluid circulation”, Brinker et al. comprehensively described novel insights from molecular and cellular biology as well as neuroimaging research, which indicate that cerebrospinal fluid (CSF) physiology is much more complex than previously believed. The glymphatic system is a recently defined brain-wide paravascular pathway for CSF and interstitial fluid exchange that facilitates efficient clearance of interstitial solutes, including amyloid-β, from the brain. Although further studies are needed to substantiate the functional significance of the glymphatic concept, one implication is that glymphatic pathway dysfunction may contribute to the deficient amyloid-β clearance in Alzheimer’s disease. In this paper, we review several lines of evidence suggesting that the glymphatic system may also have potential clinical relevance for the understanding of glaucoma. As a clinically acceptable MRI-based approach to evaluate glymphatic pathway function in humans has recently been developed, a unique opportunity now exists to investigate whether suppression of the glymphatic system contributes to the development of glaucoma. The observation of a dysfunctional glymphatic system in patients with glaucoma would provide support for the hypothesis recently proposed by our group that CSF circulatory dysfunction may play a contributory role in the pathogenesis of glaucomatous damage. This would suggest a new hypothesis for glaucoma, which, just like Alzheimer’s disease, might be considered then as an imbalance between production and clearance of neurotoxins, including amyloid-β.

Cumulative neodymium:YAG laser rates after bag-in-the-lens and lens-in-the-bag intraocular lens implantation: comparative study.

PURPOSE: To study the cumulative neodymium:YAG (Nd:YAG) laser rate after bag‐in‐the‐lens implantation (Morcher 89A) and lens‐in‐the‐bag implantation (Morcher 92S) of 2 intraocular lenses (IOLs) of the same biomaterial. SETTING: Department of Ophthalmology, University Hospital of Antwerp, Edegem, Belgium. METHODS: This study comprised 100 eyes of 87 patients who had the bag‐in‐the‐lens IOL implantation between January 2000 and August 2004. The postoperative follow‐up ranged between 17 and 72 months. One hundred eyes of 94 patients of the same age and with the same follow‐up period received the lens‐in‐the‐bag IOL. The cumulative Nd:YAG laser frequency rates in both groups were calculated, and the cumulative incidence rates were defined by Kaplan‐Meier survival analysis. RESULTS: No Nd:YAG laser capsulotomy was performed in eyes having bag‐in‐the‐lens IOL implantation. A laser capsulotomy was performed in 20 eyes having lens‐in‐the‐bag IOL implantation; the cumulative frequency in this group was 2% at 1 year and 20% at 71 months, with a plateau beginning at 42 months. The cumulative incidence rate of Nd:YAG posterior capsulotomy was approximately 2% at 1 year, increasing to approximately 28% at 42 months. CONCLUSIONS: The cumulative Nd:YAG laser rate after bag‐in‐the‐lens implantation was zero. A zero rate has not been reported with lens‐in‐the‐bag implantation of an IOL of the same biomaterial or of other biomaterials, as published in the literature. Thus, it can be concluded that the bag‐in‐the‐lens implantation technique has 100% effectiveness against posterior capsule opacification.

Clinical outcomes of cataract surgery after bag-in-the-lens intraocular lens implantation following ISO standard 11979-7:2006

PURPOSE: To assess the clinical outcomes of bag‐in‐the‐lens intraocular lens (BIL IOL) implantation following the International Organization for Standardization (ISO) 11979‐7:2006 in pediatric eyes and eyes with ocular comorbidities. SETTING: Antwerp University Hospital, Department of Ophthalmology, Antwerp, Belgium. DESIGN: Cohort study. METHODS: This cohort included the first series of patients having IOL implantation using the bag‐in‐the‐lens technique. Surgeries were performed between December 1999 and September 2006. In addition to IOL implantation, the technique comprised creation of a primary posterior continuous curvilinear capsulorhexis (PCCC) equal in size to the anterior capsulorhexis. RESULTS: The study enrolled 807 eyes of 547 patients; 326 of the eyes (40.40%) had ocular comorbidity. In the 481 eyes without ocular comorbidity, the mean decimal corrected distance visual acuity was 0.52 ± 0.24 (SD) (0.276 ± 0.206 logMAR) preoperatively and 0.94 ± 0.18 (−0.012 ± 0.053 logMAR) postoperatively. The mean postoperative achieved spherical equivalent was 0.48 ± 0.83 diopter (D) and the mean targeted refraction, −0.24 ± 0.71 D. The A‐constant was modified from 118.4 to 118.04. Posterior capsule opacification (PCO) did not occur in any adult eye during the follow‐up. Retinal detachment after IOL implantation occurred in 10 eyes (1.24%). In 19 eyes, the iris was captured by the IOL haptics postoperatively. Hypopyon occurred in 3 patients and toxic anterior segment syndrome in 1 patient. CONCLUSION: The BIL IOL met the ISO criteria; that is, primary PCCC was safe in healthy eyes and in eyes with ocular comorbidities and no eye developed PCO over a mean follow‐up of 26.1 ± 21.3 months. Financial Disclosure: Drs. Gobin, Mathysen, Van Looveren, and De Groot have no financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.

One-year follow-up of bag-in-the-lens intraocular lens implantation in 60 eyes

PURPOSE: To report the feasibility and clinical results of implanting a bag‐in‐the‐lens intraocular lens (IOL) designed to prevent posterior capsule opacification after cataract surgery. SETTING: Departments of Ophthalmology, University of Antwerp, Antwerp, Belgium, and University of Munich, Munich, Germany. METHODS: This prospective study comprised 63 eyes (55 patients; 7 children, 48 adults) scheduled for cataract surgery and bag‐in‐the‐lens IOL implantation. A posterior curvilinear capsulorhexis the same size as the anterior capsulorhexis was created for IOL insertion. After surgery, lens epithelial cell (LEC) proliferation was documented every 6 months with a minimum follow‐up of 12 months. RESULTS: Sixty of 63 eyes (95%) had implantation of the bag‐in‐the‐lens IOL. Conversion to a conventional IOL was necessary in 2 cases. In 1 eye, postoperative luxation of the IOL into the vitreous occurred as a result of an oversized anterior and posterior capsulorhexis. Three eyes had early postoperative iris incarceration in the lens groove that required surgery. No LEC proliferation on the optic occurred during a mean follow‐up of 22.7 months (range 12 to 64 months); LEC proliferation was confined to the peripheral capsular bag. CONCLUSION: Lens epithelial cell proliferation was mild and confined to the periphery of the capsular bag during follow‐up, and the bag‐in‐the‐lens IOL optic remained clear.

Intraocular lens centration and visual outcomes after bag-in-the-lens implantation

PURPOSE: To examine the centration and visual outcomes after cataract surgery using the bag‐in‐the‐lens (BIL) implantation technique. SETTING: University Hospital Antwerp, Department of Ophthalmology, Edegem, Belgium. METHODS: This study comprised 180 eyes of 125 patients who had cataract surgery with implantation of the BIL intraocular lens (IOL) between March 2002 and September 2005. Postoperative data at 5 weeks, 6 months, and 1 year were evaluated. The geometric center of the IOL, measured on a red reflex slitlamp photograph, was compared with the geometric center of the pupil and the limbus. RESULTS: The mean decentration compared with the limbus was 0.304 mm ± 0.17 (SD) at a mean angle of −24.9 ± 113.3 degrees. Compared with the dilated pupil, the mean deviation was 0.256 ± 0.15 mm at a mean angle of −5.2 ± 119.0 degrees. The amount of decentration was stable during the postoperative follow‐up period. There was no correlation between the amount of decentration and the visual outcomes (pupil: r = −0.07, P = .494; limbus: r = 0.11, P = .304). CONCLUSIONS: Surgeon‐controlled BIL centration was predictable 5 weeks and unchanged 6 months and 1 year postoperatively. It can therefore be concluded that capsular bag healing has no influence on BIL IOL centration over time.

Lack of fluorophotometric evidence of aqueous–vitreous barrier disruption after posterior capsulorhexis

Purpose: To evaluate the integrity of the aqueous–vitreous barrier by assessing the flow of fluorescein from the anterior chamber to the anterior vitreous using fluorophotometry in eyes with a posterior continuous curvilinear capsulorhexis (PCCC) and in eyes without a PCCC. Setting: University Hospital Antwerp, Edegem, Belgium. Methods: Ten patients had bilateral extracapsular cataract extraction with implantation of an intraocular lens. In 1 eye, a PCCC was performed; the other eye served as a negative control. The eyes of 2 other patients who had complicated cataract surgery with posterior capsule and anterior hyaloid membrane rupture served as positive controls. All patients had fluorophotometry of both eyes 12 to 18 months after surgery to measure the flow of fluorescein from the anterior chamber to the anterior vitreous. Results: There were no statistically significant differences in the distribution pattern of fluorescein between eyes with PCCC and eyes without PCCC. In contrast, enhanced flow was detected in both eyes with rupture of the posterior capsule and the anterior hyaloid. Conclusions: In this fluorophotometry study, a PCCC did not seem to disrupt the aqueous–vitreous barrier. Results indicate that an intact anterior vitreous membrane is crucial to maintain the barrier function between the anterior and the posterior segments of the eye.

Are intracranial pressure fluctuations important in glaucoma

Glaucoma is one of the leading causes of irreversible blindness. Primary open-angle glaucoma (POAG), the most common type, is a progressive optic neuropathy with characteristic structural changes in the optic nerve head and functional changes in the visual field. Mechanical and vascular theories for the pathogenesis of glaucomatous optic neuropathy have been proposed. Elevated intraocular pressure (IOP) is a strong risk factor, although a subset of POAG patients has normal IOP and is designated normal tension glaucoma (NTG). Clearly, factors other than IOP are likely to be involved in retinal ganglion cell death in glaucoma. An intriguing finding of recent studies is that intracranial pressure (ICP) is lower in patients with POAG and NTG when compared with nonglaucomatous control subjects. It has been suggested that the relationship between IOP and ICP may play a fundamental role in the development of glaucoma. A decreased ICP could result in an increased trans-lamina cribrosa pressure difference (IOP minus ICP) and lead to glaucomatous damage. In the present paper, we raise the question of whether ICP fluctuations also may be important in glaucoma. The effect of ICP fluctuation might be comparable to that of IOP fluctuation, which has been recognized as an independent risk factor for glaucoma progression.