Long-Term Outcomes of Phototherapeutic Keratectomy for Bullous Keratopathy.

PURPOSE: To report the long-term outcomes after phototherapeutic keratectomy (PTK) for the treatment of bullous keratopathy. METHODS: This is a retrospective medical record review of all patients with symptomatic bullous keratopathy who underwent PTK between June 2005 and March 2019 at the Royal Victorian Eye and Ear Hospital who were followed up for at least 12 months after the procedure. Medical records were used to extract demographic data, etiology of bullous keratopathy, complication rates, and subsequent procedures after PTK. The main outcomes recorded were pain and recurrence of bullae, which were assessed according to three time periods: 0 to 3 months, 4 to 12 months, and greater than 12 months after PTK. RESULTS: During the study period, 64 eyes of 64 patients underwent PTK for bullous keratopathy. The mean follow-up duration was 51 months (range 12-140). The most common indication was pseudophakic bullous keratopathy (44% of cases). Pain had resolved in 88% of eyes within 0 to 3 months, 77% of eyes between 3 and 12 months (P = 0.031, compared with 0-3 months), and 70% of eyes with greater than 12-month follow-up (P = 0.131, compared with 3-12 months). Bullae recurred in 17% of eyes within 0 to 3 months, 22% of eyes between 3 and 12 months (P < 0.001 compared with 0-3 months), and 33% of eyes after the 12-month follow-up (P < 0.001 compared with 3-12 months). Eighty-six percent of patients undergoing PTK had no postoperative complications, and 73% of cases did not require subsequent procedures. CONCLUSIONS: PTK is effective in providing long-term symptom relief from bullous keratopathy in most of the treated patients.

Comparison of culture, confocal microscopy and PCR in routine hospital use for microbial keratitis diagnosis.

AIMS: To evaluate the sensitivity and specificity of polymerase chain reaction (PCR), in vivo confocal microscopy (IVCM) and culture for microbial keratitis (MK) diagnosis. METHODS: Retrospective review of PCR, IVCM and culture results for MK diagnosis at Moorfields Eye Hospital between August 2013 and December 2014. RESULTS: PCR results were available for 259 MK patients with concurrent culture for 203/259 and IVCM for 149/259. Sensitivities and specificities with 95% confidence intervals [95% CI] were calculated for Acanthamoeba keratitis (AK) and fungal keratitis (FK), by comparison with culture, for both IVCM and PCR. For AK, FK and bacterial keratitis (BK) sensitivities were calculated, for each diagnostic method, by comparison with a composite reference standard (a positive result for one or more of culture, PCR or IVCM having a specificity of 100% by definition). For the latter, sensitivities with [95% CI] were: for AK, IVCM 77.1% [62.7-88.0%], PCR 63.3% [48.3-76.6%], culture 35.6 [21.9-51.2]; for FK, IVCM 81.8% [48.2-97.7%], PCR 30.8% [9.09-61.4%], culture 41.7% [15.2-72.3%]; for BK, PCR 25.0% [14.7-37.9%], culture 95.6% [87.6-99.1%]. CONCLUSION: IVCM was the most sensitive technique for AK and FK diagnosis but culture remains our gold standard for BK. These findings reflect results to be expected from service providers to UK ophthalmology units and demonstrates the need at our centre for ongoing diagnostic result audit leading to the potential to improve PCR diagnosis. Both FK and AK are now common in the UK; ophthalmology units need to have all these techniques available to optimise their MK management.

A randomized intraindividual comparison of the accommodative performance of the bag-in-the-lens intraocular lens in presbyopic eyes.

PURPOSE: To compare the accommodative performance of the Morcher BioComFold Type 89A bag-in-the-lens intraocular lens (IOL) with a conventional in-the-bag control IOL in presbyopic eyes. DESIGN: Prospective, randomized clinical trial with intraindividual comparison. SETTING: Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom. STUDY POPULATION: Fifty-two eyes of 26 patients with bilateral age-related cataracts. INTERVENTION: Phacoemulsification cataract extraction with implantation of a bag-in-the-Lens and a control IOL, the Alcon AcrySof SA60AT (Alcon Laboratories, Fort Worth, Texas, USA), randomized to either eye. MAIN OUTCOME MEASURES: Axial IOL shift stimulated by physiologic (near visual effort) and pharmacologic (pilocarpine and cyclopentolate) accommodative stimulation was measured objectively with partial coherence interferometry. Other outcome measures were objective and subjective accommodation, logarithm of the minimal angle of resolution distance-corrected near visual acuity, and defocus curves. RESULTS: Three months after surgery, axial IOL shift stimulated by near visual effort measured -5.9 ± 10.3 µm in bag-in-the-lens eyes versus -8.4 ± 12.8 µm in control eyes (P = .37), that stimulated by pilocarpine measured 20.2 ± 165.6 µm versus 50.4 ± 164.4 µm (P = .36), and that stimulated by cyclopentolate measured -65.8 ± 64.3 µm versus -54.0 ± 37.5 µm (P = .34), respectively (n = 25). Objective accommodation measured 0.03 ± 0.18 diopters (D) in bag-in-the-lens eyes versus 0.08 ± 0.21 D in control eyes (P = .40), whereas subjective accommodation measured 2.48 ± 0.72 D versus 2.45 ± 0.80 D (P = .75), respectively. Distance-corrected near visual acuity and defocus curves showed no difference between IOLs. CONCLUSIONS: The bag-in-the-lens IOL demonstrated negligible axial shift and objective accommodation with physiologic near visual stimulation. The IOL shift demonstrated with pilocarpine also was clinically insignificant. The bag-in-the-lens IOL showed no accommodative or near visual advantage over a conventional in-the-bag IOL, despite its unique capsular fixation method. This provides further evidence that the focus-shift principle fails to produce clinically significant IOL movement.

In vitro lens capsule model for investigation of posterior capsule opacification.

UNLABELLED: A modified dissection technique of donor eyes for investigating posterior capsule opacification (PCO) that preserves normal capsule and zonule architecture is described. The intact crystalline lens-zonule-ciliary body complex is dissected from the globe in one piece and pinned with 8 entomological pins through the ciliary body to a soft silicone ring with an internal diameter of 12.7 mm. The specimen is iridectomized and cataract extraction performed; the specimen is then placed in culture. The capsule is supported by the native zonules and suspended freely within culture medium. The entire capsular bag is visible, allowing observation of lens epithelial cell (LEC) growth. In 15 eyes of 13 donors, the mean time to LEC confluence was 10.4 days +/- 1.4 [SD]. This technique builds on previous capsular bag models, providing a more physiological model for observation of PCO in vitro. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Pilot study of new focus-shift accommodating intraocular lens.

PURPOSE: To determine the visual and accommodative performance of the OPAL-A focus-shift accommodating intraocular lens (IOL). SETTING: Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom. METHODS: In this study comprising unilateral phacoemulsification and accommodating IOL implantation, patients were followed for 6 months. Corrected distance (CDVA) and distance-corrected near (DCNVA) visual acuities were measured. Objective amplitude of accommodation was measured with an autorefractor and subjective amplitude of accommodation, using push-up tests and defocus curves. Physiological and pilocarpine-stimulated IOL movement was measured by anterior segment optical coherence tomography. RESULTS: The mean values at 1 month, 3 months, and 6 months, respectively, were as follows: CDVA, -0.06 +/- 0.08 (SD), -0.08 +/- 0.09, and -0.05 +/- 0.09; DCNVA, 0.31 +/- 0.15, 0.31 +/- 0.15, and 0.34 +/- 0.16; objective amplitude of accommodation, 0.36 +/- 0.38 diopters (D), 0.12 +/- 0.34 D, and 0.10 +/- 0.34 D; subjective amplitude of accommodation, 2.79 +/- 0.86 D, 2.55 +/- 0.85 D, and 2.50 +/- 0.62 D with push-up test and 0.90 +/- 0.40 D, 0.78 +/- 0.23 D, and 0.93 +/- 0.35 D with defocus curves. The maximum physiologic IOL shift at 1 month (mean 45.2 +/- 63.4 microm) occurred with a 3.0 D accommodative stimulus. At 6 months, the mean pilocarpine-stimulated forward IOL shift was 306 +/- 161 microm. CONCLUSIONS: Objective accommodation and forward axial shift were clinically insignificant with the accommodating IOL. The near visual performance was attributed to depth of focus rather than to true pseudophakic accommodation.

Anterior chamber depth measurements in eyes with an accommodating intraocular lens: agreement between partial coherence interferometry and optical coherence tomography.

PURPOSE: To determine agreement between partial coherence interferometry (PCI) and anterior segment optical coherence tomography (AS-OCT) measurements of anterior chamber depth (ACD) and axial intraocular lens (IOL) movement in eyes with an accommodating IOL. SETTING: Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom. METHODS: In this prospective pilot study of cataract patients, the central ACD was measured by PCI (ACMaster) and AS-OCT (Visante) 6 months after unilateral OPAL-A accommodating IOL implantation. Measurements were performed with a distance target and 1.00 diopter (D) and 2.00 D accommodative targets and after administration of topical pilocarpine 4%. Agreement between PCI and AS-OCT ACD measurements and IOL movement was calculated. RESULTS: Measurements were obtained in 18 patients. There was a consistent and statistically significant bias toward shallower ACD measurements with AS-OCT than with PCI, with the bias most pronounced after pilocarpine (mean 4.117 mm +/- 0.291 [SD] versus 4.054 +/- 0.287 mm; bias 0.063 mm; P<.0001). Limited IOL movement to 1.00 D and 2.00 D accommodative stimuli was detected with both instruments. After pilocarpine, forward IOL movement measurements were statistically significantly greater by AS-OCT than by PCI (mean 0.306 +/- 0.161 mm versus 0.270 +/- 0.155 mm) (P = .017). CONCLUSIONS: The AS-OCT device showed a bias toward underestimation of ACD compared with the PCI device. The bias increased as ACD shallowed with pilocarpine, resulting in overestimation of forward IOL movement by AS-OCT. This may lead to overestimation of the accommodative performance of IOLs. The ACD measurements obtained by the 2 devices are not interchangeable.

Randomized intraindividual comparison of posterior capsule opacification between a microincision intraocular lens and a conventional intraocular lens.

PURPOSE: To evaluate the differences in posterior capsule opacification (PCO) and visual and optical performance between a microincision intraocular lens (IOL) and a conventional IOL. SETTING: Ophthalmology Department, St. Thomas' Hospital, London, United Kingdom. METHODS: Patients with bilateral cataract were prospectively randomized to receive a HumanOptics MC611MI microincision IOL (microlens group) or an Alcon AcrySof MA60AC 3-piece IOL (control group) in either eye and were followed for 24 months. Best corrected visual acuity (BCVA) (logMAR) was measured; PCO was quantified by POCO software analysis of retroillumination images. Aberrations and modulation transfer function (MTF) were measured at the 24-month visit. RESULTS: The study enrolled 32 patients. The mean percentage area PCO was greater in the microlens group than in the control group from 3 months onward and was statistically significant from 12 months onward. The greatest difference in PCO between groups was at 24 months: mean 25.45%+/-34.51% (SD) in the microlens group versus 7.82%+/-13.35% in the control group (P= .029). The BCVA in the control group was slightly better at all time points; the difference between groups was statistically significant at 3, 6, and 12 months. No significant difference in aberrations was detected. The MTF curves were comparable for both IOLs. CONCLUSIONS: Both IOLs provided good visual performance. There was no evidence of distortion of the microincision IOL in the capsular bag. The microincision IOL had poorer PCO performance, which was visually significant and was caused by migration of lens epithelial cells through its broad optic-haptic junctions.

Fellow-eye comparison of posterior capsule opacification with AcrySof SN60AT and AF-1 YA-60BB blue-blocking intraocular lenses.

PURPOSE: To evaluate intraindividual differences in posterior capsule opacification (PCO) and visual performance of AcrySof SN60AT (Alcon Laboratories) and AF-1 YA-60BB (Hoya Corp.) intraocular lenses (IOLs). SETTING: Ophthalmology Department, St. Thomas' Hospital, London, United Kingdom. METHODS: In this prospective single-surgeon standardized-surgical-procedure fellow-eye comparison, an AcrySof SN60AT or an AF-1 YA-60BB IOL was randomized to the first eye of 36 patients and fellow-eye surgery was performed within 4 to 6 weeks. Follow-up was at 1, 3, 6, 12, and 24 months. Best distance- corrected logMAR visual acuity was measured at 100% and 9% contrast. Contrast sensitivity was measured using the Functional Acuity Contrast Test (FACT) on the Optec 3500 instrument (Stereo Optical Company, Inc.). Color vision was assessed with the Farnsworth Munsell 100-hue test. After pupil dilation, digital retroillumination photographs were taken and the percentage area of PCO was calculated using POCO software. RESULTS: Posterior capsule opacification was significantly greater in the AF-1 YA-60BB group than in the AcrySof SN60AT group at all time points (P<.0001), with the difference greatest at 24 months. At 24 months, 100% contrast visual acuity was significantly better in the AcrySof SN60AT group than in the AF-1 YA-60BB group (P = .0313); 9% contrast visual acuity was significantly better in the AcrySof SN60AT group from 6 months onward. There was no significant difference between groups in color vision or contrast sensitivity. Electron microscopy showed the AcrySof SN60AT IOL has a much sharper posterior edge profile. CONCLUSIONS: The AcrySof SN60AT IOL had better PCO performance and thus visual performance than the AF-1 YA-60BB IOL. This is attributable to the differences in optic edge design.

Effect of square-edged intraocular lenses on neodymium:YAG laser capsulotomy rates in the United States.

PURPOSE: To model the effect of the introduction of square-edged intraocular lenses (IOLs) in the United States on neodymium:YAG (Nd:YAG) laser capsulotomy rates and to compare the model with actual capsulotomy rates. SETTING: Ophthalmology Department, St. Thomas' Hospital, London, United Kingdom, and Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA. METHODS: The actual numbers of cataract surgeries and Nd:YAG laser capsulotomies performed in the U.S. were obtained from Medicare claims data for 1993 to 2003. The percentage market share of square-edged IOLs was obtained, and numbers of square-edged and round-edged IOLs implanted were calculated. Predicted laser capsulotomy rates were modeled on published postmortem and clinical data and compared with actual capsulotomy rates. RESULTS: Between 1993 and 2003, the number of cataract surgeries and Nd:YAG laser capsulotomies reimbursed by Medicare rose by 67.4% and 18.9%, respectively. After the introduction of square-edged IOLs in 1995, the market share grew to 48.5% in 2003. The total number of Nd:YAG capsulotomies reimbursed by Medicare in 2003 exceeded the number of capsulotomies predicted by the model by at least 23.9%. The estimated cost generated by the discrepancy between predicted and actual laser capsulotomies in 2003 was at least US $30 million. CONCLUSIONS: After the introduction of square-edged IOLs, Nd:YAG laser capsulotomy rates decreased, but not by as much as predicted. The additional cost to the Medicare system was more than US $30 million higher than the model predicted.