Long-term effect of Nd:YAG laser posterior capsulotomy on intraocular pressure

Prevalence and clinical characteristics of uveitic glaucoma: multicentric study in Bogotá, Colombia

OBJECTIVES

To describe the clinical features of patients diagnosed with uveitic glaucoma (UG) and ocular hypertension secondary to uveitis (OHT-SU).

METHODS

A multicentric cross-sectional study using medical records of patients with uveitis between 2013 and 2021. Uveitis and glaucoma specialists examined all patients. Variables were analyzed using the chi-square or Fisher's exact test for categorical variables. Additionally, t test, Mann-Whitney, and Kruskal-Wallis variance analysis were used for continuous variables. Finally, a Kaplan-Meier survival analysis for UG and OHT-SU development over time was done.

RESULTS

Of the 660 clinical records reviewed of patients with uveitis, 191 (28.9%) had OHT-SU in at least one visit, and 108 (16.4%) of them developed UG. In all ages, females were more affected than males. Anterior uveitis was the main anatomic localisation, and non-granulomatous, recurrent, and inactive uveitis were the most frequent clinical features. The mean final visual acuity was 0.3 (0.0-1.0) LogMAR. Also, 95.8% of the patients had additional sequelae related to uveitis regardless of UG and OHT-SU. Interestingly, males had earlier affection, with statistical significance in OHT for adults (P = 0.036) and UG for children (P = 0.04). Of all patients, 81.1% received topical hypotensive treatment and 29.8% required a surgical procedure.

CONCLUSIONS

UG and OHT-SU are common complications of uveitis in the Colombian population. These sight-threatening conditions were more common and appeared sooner in men at any age. Our results suggest that earlier and more aggressive treatment with topical hypotensive agents could positively influence the visual outcomes and the requirement of surgical procedures.

Nd:YAG Laser Capsulotomy: Efficacy and Outcomes Performed by Optometrists

SIGNIFICANCE

An increasing number of optometrists are performing Nd:YAG laser capsulotomy procedures; however, there is limited published information on the outcomes of these procedures.

PURPOSE

This study aimed to assess the efficacy and safety of capsulotomy procedures performed by optometrists.

METHODS

Subjects diagnosed with posterior capsule opacification causing reduced vision and subjective visual complaints were recruited for this study. A baseline examination was performed to ensure that the subjects met all the necessary criteria. The procedure was performed by a licensed doctor of optometry at six different clinics, and each subject was monitored for visual outcome and any potential complications.

RESULTS

Subjects' Snellen visual acuity improved from an average of 20/40 to 20/23 ( P < .001) with no complications of increased intraocular pressure, inflammation, visually significant lens pitting, macular edema, or retinal detachment. Of 78 subjects who responded to a post-procedure survey, 77 (99%) reported subjective improvement in vision after capsulotomy.

CONCLUSIONS

Based on the outcomes of this study, YAG laser capsulotomies are effective treatments to improve patient vision that can be safely and effectively performed by optometrists.

Clinical Features Associated with Acute Elevated Intraocular Pressure After Intravitreal Anti-VEGF Injections

Purpose

To study the effects of intravitreal injection (IVI) of anti-VEGF (vascular endothelial growth factor) agents on intraocular pressure (IOP) and find associations with acute pressure spikes.

Methods

This was a three-month, prospective study of patients receiving outpatient IVI of anti-VEGF agents for diabetic retinopathy (DR), age-related macular degeneration (AMD), and retinal vein occlusion (RVO) at the Acuity Eye Group Medical Centers. IOP was measured pre- and post-injection at 10-minute intervals up to 50 minutes after injection with a handheld tonometer. Patients with an IOP greater than 35 mmHg at 30 minutes received an anterior chamber paracentesis (ACP), while patients below 35 mmHg were monitored without intervention.

Results

A total of 617 patients (51% female, 49% male) received IVI for DR (n = 199), AMD (n = 355), and RVO (n = 63). ACP was performed in 17 patients. Average pre-injection IOP was 16 ± 4 compared to 24 ± 7 mmHg for the non-ACP vs ACP group, respectively (mean ± standard deviation), p < 0.0001. IOP returned to baseline in 98% of patients at 50 minutes. A diagnosis of glaucoma and glaucoma suspect was more prevalent in the ACP group compared to the non-ACP group, 82.3% vs 14.2% and 17.6% vs 9.0%, respectively, p < 0.0001 and p > 0.05. Patients with a pre-injection IOP >25 mmHg and a history of glaucoma had a 58.3% rate of ACP. A 31-gauge needle had a higher mean increase in IOP from baseline compared to 30-gauge needle, p < 0.0001.

Conclusion

IOP spikes are most significant in the first 10 minutes after IVI but typically resolve within the first hour. However, utilizing a smaller 31-gauge IVI in patients with a glaucoma history and pre-injection IOP >25 mmHg may be associated with significant IOP spikes lasting longer than 30 minutes.

Evaluation of Nd:YAG laser capsulotomy results in patients who underwent cataract extraction and intraocular lens implantation with the endocapsular phacoemulsification method

Background/Aim: Posterior capsular opacification (PCO) is a common complication that develops after cataract surgery, and it can be treated neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy. In this study, we aimed to investigate the effects of different intraocular lenses (IOLs) on the development of posterior capsule opacification (PCO), to determine the time between surgery and Nd:YAG laser capsulotomy, and to evaluate the efficacy, effectiveness, and complications of capsulotomy in patients who underwent cataract surgery with the phacoemulsification method and subsequently developed PCO. Methods: The cohort study included one eye of each of 153 cases (63 males, 90 females) who underwent cataract surgery with the phacoemulsification method in our clinic from August 1, 2006, through August 1, 2008, and subsequently developed PCO. According to the type of IOL implanted, the cases were divided into three groups: polymethylmethacrylate IOL (Group 1), hydrophilic acrylic IOL (Group 2), and hydrophobic acrylic IOL (Group 3). The control examinations of the patients who underwent Nd:YAG laser capsulotomy were undertaken before capsulotomy and at the first week, first month, and third month after capsulotomy. Results: Visual acuity improvement was detected in 96.7% of the 153 cases. It was determined that 9.1% of the cases had an intraocular pressure (IOP) increase of more than 5 mmHg at the third hour after capsulotomy and approached baseline values at the end of 1 week. The mean   total energy used in all the cases was 37.20 (14.70) mjl. The mean total energy used in 14 patients with an IOP elevation of above 5 mmHg was 71.07 (10.59) mjl. Nd:YAG laser capsulotomy was performed at an average of 6.29 (4.91) months in Group 1, 7.81 (4.35) months in Group 2, and 17.7 (12.35) months in Group 3. After capsulotomy, clinically significant cystoid macular edema was observed in 1.9% of the cases, IOL damage in 3.9%, and vitreous hemorrhage in 0.6%. Conclusion: In this study, the incidence of PCO development was found to be lower in the patients who underwent hydrophobic acrylic IOL implantation; therefore, this type of lens should be preferred for implantation. Although Nd:YAG laser capsulotomy is an outpatient treatment method that can be applied quickly and can increase visual acuity, it can also lead to complications. To eliminate most of these complications, it would be beneficial to minimize the energy used during the laser procedure.

Costs and Healthcare Resource Utilization Associated with Posterior Capsule Opacification After Cataract Surgery with Five Different Intraocular Lenses: An Economic Analysis for Spain

Purpose

Materials and Methods

Results

Conclusion

Clinical implications of energy used in Neodymium: Yttrium Aluminum Garnet posterior capsulotomy on intraocular pressure

Purpose

To study the trend of the rise of intraocular pressure (IOP), with the energy used during Neodymium: Yttrium Aluminum Garnet (Nd: YAG) posterior capsulotomy.

Methods

This is a prospective interventional study undertaken at a tertiary care center. The study was conducted on 221 non-glaucomatous eyes that underwent Nd: YAG posterior capsulotomy, of which 181 patients completed the study. IOP was recorded before laser and at 1, 2, 3, 4 hours, one day, one week, and one month during the post-laser period. Patients were grouped, depending on the amount of energy used, into Group 1 (≤ 40 mJ), Group 2 (40-80 mJ), and Group 3 (>80 mJ).

Results

Raised IOPs were noted in all the groups at various time points; however, such cases were more in Group 3 (P = <0.001). IOP was noted to peak at the fourth hour and declined to reach baseline by one week in Group 2 and by one month in Group 3.

Conclusion

There exists a relationship between the quantum of energy used and the amount of rising of IOP following Nd: YAG laser capsulotomy. In uncomplicated cases without preexisting glaucoma, if the amount of energy for posterior capsulotomy is limited to 40 mJ, routine use of ocular hypotensive medication can be avoided.

Influence of the "Inverted U Method" Nd: YAG Laser Posterior Capsulotomy on Anterior Segment Parameters, Decentration and Tilt of Intraocular Lens in Patients after Phaco-vitrectomy

PURPOSE

To investigate the effects of the "inverted U method" Nd:YAG laser posterior capsulotomy on anterior segment parameters, decentration and tilt of intraocular lens (IOLs) and visual acuity in posterior capsular opacification (PCO) patients after combined phaco-vitrectomy.

METHODS

Seventy-six patients (76 eyes) were enrolled in this study, who were diagnosed as PCO and underwent "inverted U method" Nd:YAG laser posterior capsulotomy. All patients had undergone previous combined phaco-vitrectomy for rhegmatogenous retinal detachment. The parameters including IOL decentration, angle of IOL tilt, anterior chamber angle (ACA), anterior chamber depth (ACD), anterior chamber volume (ACV), central corneal thickness (CCT), keratometry, pupil size, axial length (AL), intraocular pressure (IOP), refractive status, corrected distance visual acuity (CDVA), objective scattering index (OSI) and Chinese version of Visual Function 14 (VF-14) index were obtained before and 3 months after capsulotomy.

RESULTS

After capsulotomy, the tilt angle and decentration of the IOLs at both vertical (tilt: p = .004, decentration: p = .029) and horizontal meridian (tilt: p = .001, decentration: p = .017) were significantly decreased, ACA increased (p = .015), CDVA (p = .000), VF-14 score (p = .000) and OSI (p = .000) were significantly improved. There were a significant decrease in cylindrical error (p = .001) and a myopic shift in spherical error (p = .001) after the capsulotomy. No significant differences in ACD, ACV, CCT, keratometry, pupil size, AL and IOP were detected (p > .05 for all).

CONCLUSION

The "inverted U method" Nd: YAG laser posterior capsulotomy decreases tilt and decentration of the IOL, increases ACA and causes no change in ACD, ACV, CCT and IOP in patients after phaco-vitrectomy. These changes make a decrease in cylindrical error and a myopic shift in spherical error. Laser capsulotomy significantly improves visual acuity.

Study of Intraocular Pressure following Neodynium Yttrium Aluminium Garnet Laser Capsulotomy with the Use of Brimonidine: A Descriptive Cross-sectional Study

Introduction:

Posterior capsular opacification is a common complication after cataract surgery. Neodynium Yttrium Aluminium Garnet laser capsulotomy is still the preferred treatment for posterior capsular opacification. This study was done to determine the use of Brimonidine eye drop in preventing the rise of intraocular pressure post-Neodynium Yttrium Aluminium Garnet laser capsulotomy.

Methods:

A descriptive cross-sectional study was conducted in Lumbini eye institute and research center, Bhairahawa, Nepal, in 200 eyes with posterior capsular opacification using Brimonidine from Feb 1, 2019, to July 30, 2019. The Institutional Review Committee approved the study with approval number 0237. A convenient sampling method was used. Pre-capsulotomy best-corrected visual acuity, slit-lamp examination of the anterior segment, and dilated fundus examination were done. Intraocular pressure was measured with Goldmann Applanation Tonometer. Post capsulotomy patients were evaluated after one hour, two hours, and two weeks for intraocular pressure and any complications. The statistical analysis was done using Statistical Package of Social Sciences version 20.0 statistical analysis software. The descriptive statistical analysis of the study was done after the collection of the data.

Results:

Mean age of patients at presentation was 61.61 ±SD 1.09. The mean intraocular pressure following Neodynium Yttrium aluminum garnet laser capsulotomy using brimonidine at 1 hour was 12.73±3.3 mmHg. and two hours was 11.98±3.2 mmHg. The mean energy per pulse was 2.3 ±SD 0.3 mJ. The mean duration of posterior capsular opacification from cataract surgery was 22.28 weeks.

Conclusions:

Neodynium Yttrium Aluminium Garnet laser capsulotomy had lower intraocular pressure after the Brimonidine eye drop procedure. The maximum mean reduction in intraocular pressure was observed after two hours.

Effect of Phacoemulsification on Intraocular Pressure in Healthy Subjects and Glaucoma Patients

BACKGROUND

We investigated how cataract surgery might influence long-term intraocular pressure (IOP) change in both healthy subjects and glaucoma patients.

METHODS

A retrospective analysis of patients who had had clear corneal phacoemulsification with a minimum of 12 months of follow up was performed. Glaucoma patients with medically controlled open-angle glaucoma and healthy subjects with no glaucoma were included in the analysis. The change of IOP after phacoemulsification and factors associated with postoperative IOP change were investigated.

RESULTS

In total, 754 eyes of 754 patients, specifically 106 patients with glaucoma and 648 patients with no glaucoma (i.e., healthy subjects) were enrolled. The phacoemulsification effected a reduction of IOP: 1.03 ± 3.72 mmHg in healthy subjects and 1.08 ± 3.79 mmHg in glaucoma patients at postoperative 1 year (P = 0.656). There were negative coefficients of IOP until 1 year of follow up (all P < 0.001), but the IOP change gradually showed a less steeply decreasing slope (correlation coefficient: -0.993), compared with those for 1 week and 1 month of follow up (correlation coefficients: -1.893 and -1.540, respectively). In the multivariate analysis, age and preoperative IOP showed significant associations with postoperative IOP change (regression coefficients: -0.034 and 0.419 respectively, all P < 0.001).

CONCLUSION

Phacoemulsification resulted in IOP reduction, which effect regressed in healthy subjects and glaucoma patients over the course of long-term follow up. Therefore, long-term monitoring of IOP change is needed. In cases of higher preoperative IOP and young patients, phacoemulsification alone is a reliable option for IOP control.

Comparing the long-term impact on health care resources utilization and costs due to various single-piece acrylic monofocal intraocular lens implantation during cataract surgery: a cost-consequence analysis for the United Kingdom, Italy, and Denmark

PURPOSE

The objective of this study was to estimate the cost impact of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy and its complications due to single-piece acrylic monofocal intraocular lenses (IOLs) in the healthcare setting of United Kingdom, Italy, and Denmark.

MATERIALS AND METHODS

A hypothetical cost-consequence model was developed to estimate economic burden of Nd:YAG laser capsulotomy due to different single-piece acrylic monofocal IOLs. Cumulative incidence of Nd:YAG laser capsulotomy at 3 years after cataract surgery with five single-piece monofocal acrylic IOLs was sourced from retrospective data analysis of electronic medical records of cataract patients in the United Kingdom. Risk probability of post-Nd:YAG laser complications, ie, retinal detachment, glaucoma, and cystoid macular edema at 3 years was derived using published literature. Unit costs were taken from publicly available sources with all costs converted to euro (€). Number of cataract procedures per year for each country was sourced from Eurostat statistics.

RESULTS

For the estimated cataract procedures carried out nationally every year, single-piece monofocal hydrophobic AcrySof IOL was associated with substantially lower cases of Nd:YAG laser capsulotomy procedures and subsequent complications in 3 years after cataract surgery when compared to other single-piece monofocal acrylic IOLs. The total cost savings with the use of AcrySof over other IOLs in countries assessed ranged from €0.5 to €4.7 million (vs AMO Tecnis) and €2.1 to €17.9 million (vs Rayner C-/Super-flex).

CONCLUSION

Incidence of Nd:YAG capsulotomy due to the choice of IOL could significantly affect healthcare budgets in the post-cataract surgery period. Our analysis indicates that single-piece monofocal AcrySof IOLs is the most cost-saving treatment option for health care systems when compared to other acrylic single-piece IOLs.

Intraocular Pressure Spikes following Neodymium-doped Yttrium Aluminum Garnet Laser Capsulotomy: Current Prevalence and Management in Israel

Aim

The current treatment for posterior capsular opacification (PCO), neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy, may lead to increased intraocular pressure (IOP). Our aim was to survey routines in the management of IOP spikes and to identify the rate of IOP spikes following prophylactic apraclonidine treatment.

Materials and methods

A survey questionnaire among ophthalmologists and a retrospective registry review was used. Patients were administered apraclonidine 0.5% prior to capsulotomy. The IOP was measured before and 1 hour postprocedure.

Results

A total of 71% of responders (n = 45) routinely prescribe topical IOP-lowering medication and 82% routinely measure IOP before or after capsulotomy. The registry analysis included 87 eyes of 75 patients. Mean IOP decreased by 0.9 ± 3.3 mm Hg (p = 0.01, range: -6 to 10) following capsulotomy. No patient reached IOP values above 21 mm Hg following the procedure, with 3.4 and 1.1% of patients demonstrating an IOP elevation of more than 3 and 5 mm Hg respectively. No association was found between number of laser shots, mean laser power, or comorbid conditions, such as diabetes, hypertension, or glaucoma status with posttreatment IOP.

Conclusion

Most ophthalmologists surveyed routinely prescribe prophylactic IOP-lowering medication and measure IOP before or after capsulotomy. Mean IOP remained clinically stable following capsulotomy with prophylactic apraclonidine instillation, and no patient reached IOP values above 21 mm Hg. Differences in laser delivery or comorbid conditions were not associated with posttreatment IOP. Considering that no patient demonstrated a clinically significant IOP spike following prophylactic apraclonidine instillation, perhaps routine measurement of IOP following primary Nd:YAG laser may be reserved for high-risk patients only.

Clinical significance

In this work, we showed the prophylactic effect of apraclonidine 0.5% and suggest that measuring IOP after the procedure is necessary only in certain high-risk cases, possibly helping to reduce workload and patient waiting time and improving quality of service.

How to cite this article

Achiron A. Intraocular Pressure Spikes following Neodymium-doped Yttrium Aluminum Garnet Laser Capsulotomy: Current Prevalence and Management in Israel. J Curr Glaucoma Pract 2017;11(2):63-66.

Collective Migration of Lens Epithelial Cell Induced by Differential Microscale Groove Patterns

Herein, a micro-patterned cell adhesive surface is prepared for the future design of medical devices. One-dimensional polydimethylsiloxane (PDMS) micro patterns were prepared by a photolithography process. We investigated the effect of microscale topographical patterned surfaces on decreasing the collective cell migration rate. PDMS substrates were prepared through soft lithography using Si molds fabricated by photolithography. Afterwards, we observed the collective cell migration of human lens epithelial cells (B-3) on various groove/ridge patterns and evaluated the migration rate to determine the pattern most effective in slowing down the cell sheet spreading speed. Microgroove patterns were variable, with widths of 3, 5, and 10 µm. After the seeding, time-lapse images were taken under controlled cell culturing conditions. Cell sheet borders were drawn in order to assess collective migration rate. Our experiments revealed that the topographical patterned surfaces could be applied to intraocular lenses to prevent or slow the development of posterior capsular opacification (PCO) by delaying the growth and spread of human lens epithelial cells.

Bleb failure and intraocular pressure rise following Nd: Yag laser capsulotomy

Background

To report the negative effect of Nd: Yag (Neodymium-doped: Yttrium Aluminium Garnet) laser capsulotomy on the intraocular pressure (IOP) and the trabeculectomy bleb integrity, in a small series of eyes, both trabeculectomised and pseudophakic, following the laser application for the management of posterior capsular opacification (PCO).

Methods

This is a retrospective, non-comparative interventional case series study, in which 20 trabeculectomised and pseudophakic eyes from 15 patients, with otherwise well functioning blebs, were presented with uncontrolled IOP, in a variable distance of time following the application of YAG laser capsulotomy. Student paired t-test confirmed a statistically significant difference (P < 0.05) between IOP before Nd: YAG laser capsulotomy (16 mmHg ± 3 mmHg) and the respective one, 2 to 6 months after Nd: Yag capsulotomy (34.5 ± 11 mmHg).

Results

All of the cases failed to respond to conservative treatment and were successfully managed with the implantation of Ahmed drainage devices. All patients showed flat filtering bleb and uncontrolled IOP (34.5 ± 11 mmHg), under maximum topical treatment, in a period of 2 to 6 months following Nd: YAG laser caspulotomy. The implantation of Ahmed valve proved to be effective treatment for these patients (IOP < 21 mmHg).

Conclusions

Although Nd: Yag laser capsulotomy is considered a safe surgical procedure and usually is done without second thought, in this series of eyes, it is postulated that it may be responsible for the deregulation of the filtering bleb and subsequent loss of IOP control. We consider that laser capsulotomy should be performed with caution, especially in eyes with previous trabeculectomy. Also close monitoring of the intraocular pressure and assessment of eventual bleb morphology variations in the follow-up period is mandatory. Further studies are needed in order to confirm our findings.

Pathogenesis of Uveitic Glaucoma

Uveitic glaucoma consists one of the most serious complications of intraocular inflammation and, despite its rarity, is considered as one of the leading causes of preventable loss of vision worldwide. It has been associated with a wide spectrum of inflammatory diseases, but its pathogenesis is still not fully comprehended. It appears that the type of inflammation, the steroid-response and the anatomical alterations of the anterior chamber play a pivotal role. To our knowledge, the mechanisms may be both acute and chronic. The main targets of the treatment are to control the inflammation and reduce the intraocular pressure (IOP). The management of glaucoma associated with uveitis remains an extremely challenging condition for ophthalmologists. The successful treatment of uveitic glaucoma is inextricably correlated with prompt and immediate therapeutic decisions. Very often a solid collaboration between clinicians from different specialties may be required for treating the underlying disease.

Further understanding of its pathogenesis can indicate therapeutic targets and may lead to the development of new and more efficient therapeutic approaches. New glaucoma surgical modalities may ameliorate the prognosis after surgical intervention, but this calls for further evaluation. This study aims to highlight the complexity of uveitic glaucoma analyzing the main pathogenetic mechanisms and the correlations with the inflammatory response.

Study of Variation in Intraocular Pressure Spike (IOP) Following Nd- YAG Laser Capsulotomy

INTRODUCTION

Posterior Capsular Opacifications (PCO) is a frequent complication of cataract surgery following posterior chamber intraocular lens implantation. Nd -Yag laser capsulotomy is the treatment of choice for PCO and is known to be associated with complications like Raised Intraocular Pressure (IOP), Intraocular lens pitting, intraocular lens cracks, cystoid macular oedema, retinal detachment, corneal burns. Raised IOP is the most common complication and prescribing anti-glaucoma drugs post capsulotomy is a common practise. Our study helps us to anticipate the post procedural IOP rise in specific patients and treat only selected group of patients with anti- glaucoma medications.

AIM

To study and correlate the effect of energy used and number of shots with post procedural IOP spike following Nd-YAG laser capsulotomy cases.

MATERIALS AND METHODS

All patients with PCO presenting to Ophthalmology Out Patient Department at Sri Siddhartha Medical College between November 2014 to November 2015 were included. All the patients with glaucoma, uveitis and high myopia were excluded from the study. Data relevant to history, ocular examination and IOP were recorded.

RESULTS

Significant correlation of IOP spike with the number of Nd- YAG Laser shots delivered was found by One-way ANOVA Post-Hoc Tukeys Test. The p-value was significant for shots more than 40, provided the energy was restricted to 20 mJ and below. Correlation of energy with IOP spike was not significant as found by One-way ANOVA, Post-Hoc Tukey test. Predictability of 2 hours post-procedure IOP regarding persistent IOP rise was significant.

CONCLUSION

It was observed that all pseudophakic patients may not require anti-glaucoma medication pre, or post Nd YAG laser capsulotomy. Only patients who required more than 40 shots during the procedure would need a close observation and if persistent rise is documented, ocular hypotensives may be advised.

The Pathogenesis of Raised Intraocular Pressure in Uveitis

AIM

To analyze current understanding of the factors that contribute to raised intraocular pressure (IOP) in patients with uveitis.

METHODS

A pubmed literature review was carried out using words including "uveitic glaucoma", "IOP AND uveitis", "ocular hypertension AND uveitis", "inflammation AND glaucoma", "aqueous dynamics" AND "glaucoma/uveitis".

RESULTS

Of the two studies looking at the aqueous dynamics in experimentally induced uveitis, both found aqueous flow decreased acutely, and one found that uveoscleral outflow increased. This is likely to reflect the types of uveitis that present acutely with hypotony. A study examining patients with Fuch's heterochromic cyclitis found no difference in aqueous flow or uveoscleral outflow. No studies have examined aqueous dynamics in types of uveitis that present with acutely raised IOP. Levels of prostaglandins rise in acute uveitis, which has been shown to increase uveoscleral and trabecular outflow, without affecting aqueous flow. Studies have demonstrated that raised levels of trabecular protein reduce trabecular outflow. Steroid treatment, inflammatory cells, free radicals and enzymes are also likely to contribute to the development of raised pressure. When considering the impact of the pathogenesis of raised pressure in uveitis on its treatment, prostaglandins may provide good intraocular pressure control, but there are concerns regarding their theoretical ability to worsen the inflammatory response in uveitis. Studies have not conclusively proven this to be the case. Surgical success rates vary, but trabeculectomy plus an antimetabolite, deep sclerectomy plus an antimetabolite, and Ahmed valve surgery have been used.

CONCLUSIONS

Uveitic glaucoma is caused by a number of different diseases, some of which present with acute hypotony, others with acutely raised IOP, and others which demonstrate an increase in IOP over time. Further studies should be carried out to examine the differing pathogenesis in these types of diseases, and to establish the best treatment options.

Prevention of posterior capsular opacification

Posterior capsular opacification (PCO) is a common complication of cataract surgery. The development of PCO is due to a combination of the processes of proliferation, migration, and transdifferentiation of residual lens epithelial cells (LECs) on the lens capsule. In the past decades, various forms of PCO prevention have been examined, including adjustments of techniques and intraocular lens materials, pharmacological treatments, and prevention by interfering with biological processes in LECs. The only method so far that seems effective is the implantation of an intraocular lens with sharp edged optics to mechanically prevent PCO formation. In this review, current knowledge of the prevention of PCO will be described. We illustrate the biological pathways underlying PCO formation and the various approaches to interfere with the biological processes to prevent PCO. In this type of prevention, the use of nanotechnological advances can play a role.

A new technique for Nd:YAG laser posterior capsulotomy

AIM

To investigate the effects of a new opening pattern in neodymium:yttrium-aluminum-garnet (Nd:YAG) laser posterior capsulotomy on visual function.

METHODS

This technique was conducted along a circular pattern. The energy ranged between 0.8 and 1.2 mJ/pulse was consumed and mean total energy levels were 74±21 mJ (mean±standard deviation: SD, from 40 to 167) and laser shots aimed at 150 µm away behind a datum point and went along an imaginary line which extends 0.5 mm inside from optic margin and into the circular en bloc pattern. Vitreous stands were attached with fragment and then they were cut off by the laser after circular application. The circular fragment was completely separated from vitreous, and then this fragment was quickly sunk in intravitreal space.

RESULTS

The follow-up period ranges from at least a week to 40mo, making 15.8mo on average. The procedural outcome showed 96% (74 eyes out of the 77 eyes) enhancement in patients' visual acuity. Cystoid macular edema or retinal detachment was not observed in any of the patients during follow-up periods.

CONCLUSION

This new technique is expected to improve the weaknesses that the conventional procedures have by adding the process to cut off vitreous stands attached with the fragment by the laser to the circular application.

The Effect of ND:YAG Laser Posterior Capsulotomy Size on Refraction, Intraocular Pressure, and Macular Thickness

Purpose. The aim of this study is to examine the influence of capsulotomy size on, spherical equivalent (SE), intraocular pressure (IOP), and macular thickness. Materials and Methods. Sixty-eight patients were examined preoperatively and 1, 4, and 12 weeks after Nd:YAG capsulotomy. Patients were divided into two groups based on the postoperative capsulotomy size. Changes in SE, IOP, and macular thickness were compared between two groups. Results. We found a higher hyperopic shift in large capsulotomy group. In both groups 1 and 2, IOP increased 1 week postoperatively. Intraocular pressure rise in group 2 was higher than in group 1. Both groups had increased macular thickness at 1 week postoperatively. The degree of macular thickening was similar in group 1 and group 2. Comment. Patients who underwent a larger capsulotomy have a higher hyperopic shift and IOP elevation. Rise in macular thickness was similar in large and small capsulotomy groups.

The effect of phacoemulsification on intraocular pressure in medically controlled open-angle glaucoma patients

PURPOSE

To evaluate intraocular pressure (IOP) after phacoemulsification in patients with medically controlled open-angle glaucoma (OAG), and examine the association of biometric variables to IOP changes.

DESIGN

Retrospective case series.

METHODS

Open-angle glaucoma patients without prior incisional glaucoma surgery undergoing phacoemulsification by a single surgeon between January 1997 and October 2011 were evaluated. Patient charts were reviewed to obtain demographic information, preoperative glaucoma medications, severity and treatment measures, and preoperative and postoperative IOP.

RESULTS

A total of 157 eyes (157 patients) were included in the study. The average preoperative IOP of 16.3 ± 3.6 mm Hg decreased to 14.5 ± 3.4 mm Hg at 1 year (P < .001). Sixty eyes (38%) required additional medications or laser for IOP control within the first year postoperatively, or had a higher IOP at postoperative year 1 without medication change. Among eyes without postoperative medication changes (n = 102), higher preoperative IOP (P < .001), older age (P = .006), and deeper anterior chamber depth (P = .015) were associated with lower postoperative IOP.

CONCLUSIONS

Phacoemulsification resulted in a small average decrease in IOP in patients with OAG. A sizeable proportion of medically controlled glaucoma patients with open angles undergoing phacoemulsification experienced an increase in IOP or required more aggressive treatment to control IOP postoperatively.

[Effect of posterior neodymium:YAG capsulotomy. Safety evaluation of macular foveal thickness, intraocular pressure and endothelial cell loss in pseudophakic patients with posterior capsule opacification]

OBJECTIVE

To determine the effect of posterior capsulotomy on macular thickness, intraocular pressure and endothelial cell loss in pseudophakic patients with posterior capsule opacification using the other eye of every patient as a control.

METHODS

An observational prospective study was conducted on 31 pseudophakic patients with posterior capsular opacification in one eye, using the other eye as a control. Patients did not suffer any other ocular pathology. All patients were treated by posterior capsular opacification with Nd:YAG capsulotomy, and followed up for a three-month period. The ocular examination included, best corrected visual acuity (BCVA), intraocular pressure (IOP), macular optical coherence tomography (OCT), and endothelial cell assessment (including densitometry, cell size and coefficient of variation, hexagonal cell percentage and pachymetry), which were determined in both eyes before treatment, and one week, one month and 3 months after capsulotomy.

RESULTS

Generalized estimating equations (GEE) were used to assess the capsulotomy effect adjusted by corresponding baseline measurements and time. No association was found between capsulotomy and IOP (P=.597), macular thickness (P=.085) or ECA (densitometry (P=.422), average size of cells (P=.299), variation coefficient (P=.495), hexagonal cell percent (P=.093) and corneal pachymetry (P=.423). A significant increase of 0.15 Snellen units in BCVA was found during the 3-month follow-up period (P<.001).

CONCLUSION

This study shows that after Nd:YAG capsulotomy, BCVA improves significantly without any IOP, OCT or ECA changes during the three-month follow-up. Nd:YAG capsulotomy is a safe procedure in pseudophakic patients without any other ocular pathology.

Fixed combination brimonidine-timolol versus brimonidine for treatment of intraocular pressure elevation after neodymium:YAG laser posterior capsulotomy

PURPOSE

To evaluate the efficacy of fixed combination brimonidine-timolol (FCBT) in comparison with brimonidine tartrate 0.2% and control for the treatment of intraocular pressure (IOP) spikes after neodymium:YAG (Nd:YAG) laser posterior capsulotomy.

METHODS

One hundred five eyes of 105 patients were enrolled in the study. Patients were randomized to 3 groups (each group, including 35 patients): the FCBT group that received 1 drop of FCBT, the brimonidine group that received 1 drop of brimonidine tartrate 0.2%, and the control group that received 1 drop of artificial tear, 1 h before the laser procedure. Postoperative IOP measurements were performed at 1st, 2nd, 3rd, 24th hours, and seventh day.

RESULTS

The mean IOP changes from baseline were statistically different between the study groups at first, second, and third hours (all P<0.001). Pairwise comparisons showed that although the mean IOP changes of the treatment groups were similar at 1st and 24th hours and seventh day (all P>0.05), the IOP levels of the brimonidine group were less reduced from baseline than the FCBT group at second and third hours (P=0.01 and P=0.03, respectively). The differences among the study groups concerning the incidence of IOP elevations of ≥5 or ≥10 mmHg were statistically significant (P=0.007, P=0.04, respectively). However, the differences between the treatment groups were not statistically significant (both P>0.05).

CONCLUSION

This study has shown that preoperative instillation of 1-drop FCBT was safe and effective for preventing IOP spikes after Nd:YAG laser posterior capsulotomy. FCBT may be a better option than brimonidine tartrate 0.2%, which is one of the current standard prophylaxes for these spikes.

Persistent ocular hypertension following intravitreal bevacizumab and ranibizumab injections

PURPOSE

To study ocular hypertension (OHT) following intravitreal injections of bevacizumab and/or ranibizumab in patients with age-related macular degeneration (AMD).

METHODS

Retrospective case series. Patients with AMD who were treated at a tertiary referral center with intravitreal bevacizumab and/or ranibizumab injections from January 1, 2006 to December 31, 2008 were studied. The development of OHT following these injections was investigated.

RESULTS

Four out of 116 patients with AMD (3.45%) developed sustained elevated intraocular pressure (IOP) after multiple intravitreal injections of bevacizumab 1.5 mg/0.06 mL and/or ranibizumab 0.5 mg/0.05 mL. An analysis of 4 cases revealed: None of the patients had a previous diagnosis or family history of glaucoma/OHT. Two patients had both bevacizumab and ranibizumab injections. Two patients developed OHT after recent intravitreal ranibizumab and 2 patients after recent intravitreal bevacizumab injection. Two patients were pseudophakic with a history of YAG capsulotomy. The range of preinjection IOP was 8-15 mmHg (mean, 13 mmHg). The range of postinjection IOP was 28-36 mmHg (mean, 31.75 mmHg). The range of IOP increase was 17-21 mmHg (mean, 18.75 mmHg). Mean number of pan-anti-VEGF injections prior to OHT was 13.3 (range, 3-19). A disrupted posterior capsule might predispose patients to the development of OHT.

CONCLUSIONS

Persistent OHT may occur after intravitreal anti-VEGF injection in patients with no previous diagnosis of glaucoma or OHT. OHT may persist across several visits and patients may require IOP-lowering therapy. Sustained elevation in IOP usually occurs after multiple injections.

Three and Five Year Changes in Intraocular Pressures After Clear Corneal Phacoemulsification in Open Angle Glaucoma Patients, Glaucoma Suspects, and Normal Patients

PURPOSE

This study evaluates the change in intraocular pressure (IOP) and glaucoma medication requirements after clear corneal phacoemulsification in open angle glaucoma patients, glaucoma suspects, and normal patients at 3 years and last follow-up (mean 5 y).

PATIENTS AND METHODS

This study represents a retrospective analysis of patients who had clear corneal phacoemulsification and at least 3 years of follow-up. The patients were classified into 3 groups: glaucoma (G), glaucoma suspects (GS), and no glaucoma (NG). No patient had a history of previous intraocular surgery. Single factor analysis of variance, Fisher exact tests, 2-tailed paired Student t tests and Kaplan-Meier analysis were applied.

RESULTS

Forty-eight patients (55 eyes) in the glaucoma group, 41 patients (44 eyes) in the GS group, and 59 patients (59 eyes) in the NG group met the above criteria. At 3 years follow-up IOP was significantly decreased in all groups; (G) group decreased 1.4+/-3.3 mm Hg (P = 0.0025), GS 1.4+/-4.2 mm Hg (P = 0.004), and NG 1.7+/-3.1 mm Hg (P = 0.0005). At the final follow-up visit (mean near 5 y for all groups) the IOP was significantly decreased in all groups, (G) group 1.8+/-3.5 mm Hg (P = 0.005), GS 1.3+/-3.7 mm Hg (P = 0.025), and NG 1.5+/-2.5 mm Hg (P < 0.0001). The number of preoperative and postoperative glaucoma medications in the (G) group did not show any significant change at 3 and 5 years (P = 0.36, P = 0.87). Kaplan-Meier analysis shows that at 3 years, 85% of the (G) group, 81% of GS, and 90% of the NG had IOPs less than or equal to their preoperative IOP, with the same number of glaucoma medications or less. At 5 years the percentages were 76%, 79%, and 85%, respectively.

CONCLUSIONS

This study demonstrates that cataract removal by clear cornea phacoemulsification in glaucoma patients, glaucoma suspects, and normal patients results in a small but significant decrease in IOP that is sustained at 3 years and a mean of 5 years in all groups. This study does not imply that cataract removal by phacoemulsification is a substitute for a combined procedure but may be an appropriate procedure for certain patients based on medication requirements and extent of optic nerve damage.

Outcome of posterior capsulotomy in late capsular block syndrome with posterior capsular opacification

BACKGROUND

To examine the results of neodymium:yttrium-aluminium-garnet (Nd:YAG) laser posterior capsulotomy in eyes with late or previously unrecognized capsular block syndrome (CBS) presenting with deterioration of vision owing to posterior capsular opacification (PCO).

METHODS

Patients, who underwent uneventful phacoemulsification with intraocular implantation and were referred for Nd:YAG laser capsulotomy owing to PCO, were prospectively examined for the presence of CBS. When indicated, Nd:YAG laser posterior capsulotomy was carried out. Prospective follow-up examinations were performed for the next 6 months. The outcome measures were post-laser change in best corrected visual acuity, refraction, change in intraocular pressure, inflammation and complication rate.

RESULTS

Of 655 patients referred for capsulotomy, eight had an associated CBS in that eye. These eight eyes comprised the study cases. The presence of CBS had not been recognized before the development of PCO. Best corrected visual acuity improved in all cases. In seven out of eight (87.5%) eyes refraction was unchanged throughout the follow up. Ocular hypertension, inflammation or other complications did not develop.

CONCLUSION

Nd:YAG laser capsulotomy in eyes with PCO and late or previously unrecognized CBS is a safe procedure, resulting in improved visual acuity without refractive change.

Evaluation of the effects of hydrodissection with antimitotics using a rabbit model of Soemmering's ring formation

BACKGROUND

Regeneration/proliferation of lens material within the capsular bag still is the most frequent complication after cataract surgery. We aimed to evaluate the effects of hydrodissection with low doses of antimitotics on the overall regeneration/proliferation of lens material in rabbit eyes, using a model allowing the lens material to be confined to the equatorial region of the capsular bag, facilitating its quantification.

METHODS

Twelve albino rabbits underwent bilateral phacoemulsification. Their eyes were randomized to receive 0.4 cc of balanced salt solution, 5-fluorouracil (12.5 mg/mL) or mitomycin C (0.1 mg/mL) during hydrodissection. They were left aphakic, so the capsulorhexis would fuse with the posterior capsule postoperatively. After 4 weeks, killing/enucleation was performed. Regeneration/proliferation of lens material within the equatorial capsular bag (Soemmering's ring) was graded from the Miyake-Apple view (0-4). Its area was also calculated (microm(2)) from direct measurements performed on histological sections.

RESULTS

The capsulorhexis margin fused with the peripheral posterior capsule, so the central posterior capsule remained clear. There was no significant difference among the groups (Kruskal-Wallis test) regarding Soemmering's ring gross grading (P = 0.511), number of lens epithelial cell layers lining the inner surface of the capsular bag (P = 0.310) and Soemmering's ring microscopic cross-sectional area (P = 0.638).

CONCLUSIONS

The effect of different solutions on after-cataract should be assessed in terms of overall regeneration/proliferation of lens material within the capsular bag, in addition to posterior capsule opacification. When administered in low doses during hydrodissection, 5-fluorouracil and mitomycin C did not show a significant inhibitory effect on after-cataract formation in rabbit eyes.

Brimonidine 0.2% Versus Brimonidine Purite 0.15%: Prophylactic Effect on IOP Elevation After Nd:YAG Laser Posterior Capsulotomy

AIMS

The aim of this study was to compare the prophylactic effect of brimonidine 0.2% versus brimonidine Purite 0.15% on intraocular pressure (IOP) increase after Nd:YAG laser posterior capsulotomy.

METHODS

In this prospective, double-masked, randomized, controlled study, 106 patients (106 eyes) who underwent Nd:YAG laser posterior capsulotomy were allocated to a brimonidine 0.2% group (35 eyes), a brimonidine Purite 0.15% group (36 eyes), or a vehicle group (35 eyes). One (1) drop of brimonidine 0.2%, brimonidine Purite 0.15%, or vehicle was instilled 1 h preoperatively and 1 drop immediately after Nd:YAG laser posterior capsulotomy. IOPs were measured preoperatively and at 1, 2, 3, and 24 h postoperatively.

RESULTS

Decreases in IOP from baseline ranged from 2.3 to 2.7 mmHg in the brimonidine 0.2% group and 2.2-2.5 mmHg in the brimonidine Purite 0.15% group (P < 0.05), whereas the vehicle group exhibited a rise in IOP. IOP elevations of less than 5 mmHg occurred in 22.9% of patients in the brimonidine 0.2% group, 27.8% in the brimonidine Purite 0.15% group, and 48.6% in the vehicle group. Spikes of IOP greater than 10 mmHg occurred in 2.9% of patients in the brimonidine 0.2% group, 2.8% in the brimonidine Purite 0.15% group, and 8.6% in the vehicle group. The incidence of IOP elevation was not statistically significant between the brimonidine 0.2% and the brimonidine Purite 0.15% groups (P < 0.05).

CONCLUSIONS

Brimonidine 0.2% and brimonidine Purite 0.15% have similar efficacy in the prevention of IOP elevation after Nd:YAG laser posterior capsulotomy.

Efficacy of various drugs in the prevention of posterior capsule opacification: experimental study of rabbit eyes

PURPOSE

To assess the efficacy of various drugs in the prevention of posterior capsule opacification (PCO) in a closed capsular bag technique.

SETTING

Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida, USA.

METHODS

Lens material was removed using phacoaspiration or phacoemulsification through a microcapsulorhexis according to the hardness of the crystalline lens correlated with the weight and age of the rabbits. A mixture of an ophthalmic viscosurgical device (sodium hyaluronate 1.4% [SHA]) and a drug was injected into the empty capsular bag, allowed to remain inside for 3 minutes, and removed. The capsular bag was rinsed with balanced salt solution (BSS) and refilled with SHA. In a group of rabbits, the capsulorhexis was sealed with a minicapsulorhexis valve (MCV). Rabbits were treated with 1 of the following: SHA (control), BSS, mitomycin-C (MMC, 0.2 mg/mL), ethylenediaminetetraacetic acid (EDTA) (10 mM and 15 mM), 5-fluorouracil (5-FU, 33 mg/mL), acetic acid (3%, 0.3%, and 0.003%), and distilled water.

RESULTS

Upon completion of the study, the control and treated eyes had PCO and new lens material (not residual). Anterior capsule proliferation was observed in eyes treated with 5-FU. The order of PCO appearance (earliest to latest) was as follows: 15 mM EDTA, SHA, MMC, acetic acid 0.3%, acetic acid 3%, BSS, distilled water (small animals; no MCV), acetic acid 0.003%, 5-FU, 10 mM EDTA, and distilled water (large animals; MCV). The earliest appearance was day 1 postoperatively and the latest, day 47.

CONCLUSIONS

Distilled water and 10 mM EDTA treatments were the most efficient in retarding the appearance of PCO.

Use of Nd:YAG laser capsulotomy

Surgery for cataract removal has become successively refined such that posterior capsular opacification is the most common problem presenting after modern cataract extraction. Various techniques and treatments exist to manage patients with posterior capsular opacification using Nd:YAG capsulotomy. There are many possible variations in initial assessment, pre-laser treatments, laser techniques, and follow-up routines. The literature on the use of Nd:YAG laser for capsulotomy was reviewed and interpreted. This article presents the currently available knowledge in a format that allows the practitioner to tailor an evidence-based protocol for treating patients with symptomatic posterior capsule opacification.

Assessment of anterior capsule opacification: photographic technique and quantification

PURPOSE

To develop and evaluate a standardized slitlamp photographic technique to document and quantify anterior capsule opacification (ACO) in the pseudophakic eye.

SETTING

University of Vienna, Medical School, Department of Ophthalmology, Vienna, Austria.

METHODS

In this prospective study, slitlamp photographs were taken in 29 eyes of 19 patients with ACO of varying degrees and intraocular lenses of different materials. Digital slitlamp photographs were taken by 2 examiners using a standardized protocol. The intensity of anterior fibrosis was evaluated using subjective grading by 2 masked examiners and by image analysis.

RESULTS

A standardized protocol was developed for documentation of ACO. The intraexaminer (or short-term) reproducibility (r = 0.96, P < .01) and interexaminer reproducibility (r = 0.93, P < .01) were excellent. The results of image analysis used to objectively quantify ACO correlated with the subjective grading (r = 0.95, P < .01).

CONCLUSION

This standardized technique of slitlamp photography and image analysis provided reproducible documentation and can therefore serve as a basis for the quantification of ACO.