Neodymium:yttrium-aluminum-garnet capsulotomy and intraocular pressure in pseudophakic patients with glaucoma

Intraocular pressure increase after Nd:YAG laser capsulotomy and anterior segment optical coherence tomography analysis

This study is to determine whether post-procedure intraocular pressure (IOP) increase is associated with the anterior chamber angle in cases of Neodymium: yttrium-aluminum garnet (Nd: YAG) laser capsulotomy. The study included 51 eyes with posterior capsule opacification. Initial IOP values of the patients were compared with IOP values without intraocular pressure-lowering administration at the end of the 1st hour, 1st day, 3rd day, and 7th day after Nd:YAG laser capsulotomy. The anterior segment angle configuration was evaluated using anterior segment optical coherence tomography analysis without dilatation before the procedure. The anterior chamber angle (ACA) and angle opening distances of 500 and 750 μm (AOD500 and AOD750) in the nasal and temporal quadrants were examined. The mean pre-laser IOP value only increased significantly at 1st hour post-laser (13.02 ± 3.02 mmHg vs 14.16 ± 4.07 mmHg, p = 0.016). In eyes with ACA below 40° in both the nasal and temporal quadrants, mean IOP increased significantly at 1st hour post-laser (p = 0.025 and p = 0.032, respectively), while it was not significant in eyes with ACA above 40° (p > 0.05). No correlation was found between ACA, AOD500, and AOD750 values and IOP changes at the first hour (p > 0.05). Except for the first hour after Nd:YAG laser capsulotomy, no significant increase in IOP was observed. This elevation was higher in eyes with ACA less than 40°. In patients with a narrow ACA, first-hour follow-up may be beneficial in terms of susceptibility to increased IOP.

Refractive Changes Following Premature Posterior Capsulotomy Using Neodymium:Yttrium–Aluminum–Garnet Laser

We aimed to determine the timing of neodymium:yttrium–aluminum–garnet (Nd:YAG) laser capsulotomy on corrected-distance visual acuity (CDVA), intraocular pressure (IOP), and spherical equivalent (SE) in patients with posterior capsular opacification (PCO). There were 59 patients with unilateral PCO and a history of Nd:YAG laser capsulotomy enrolled and further divided into the early Nd:YAG group (timing < 12 months, n = 25) and late Nd:YAG group (timing > 12 months, n = 34) depending on the elapsed months from phacoemulsification to Nd:YAG laser capsulotomy. The primary outcomes were CDVA, IOP, and SE before (immediately before Nd:YAG laser capsulotomy) and after (weeks one and four after the laser treatment). The independent t test was applied to analyze the difference in CDVA, IOP, and SE between the two groups, while the generalized estimating equation with Bonferroni adjustment was conducted to evaluate the effect of all the parameters on the change in SE with adjusted odds ratio (aOR) and 95% confidence interval (CI). The CDVA showed significant improvement in both the early Nd:YAG group (p = 0.005) and the late Nd:YAG group (p = 0.001), and hyperopic change occurred in both the early Nd:YAG group (p = 0.003) and the late Nd:YAG group (p = 0.017). The early Nd:YAG group revealed more significant hyperopic change compared with the late Nd:YAG group four weeks after Nd:YAG treatment (p < 0.001), which was still significant after multivariable analysis (aOR: 0.899, 95% CI: 0.868–0.930, p = 0.011). In addition, a deeper ACD (aOR: 0.764, 95% CI: 0.671–0.869, p = 0.019) was significantly correlated with hyperopic change. In conclusion, Nd:YAG laser capsulotomy performed within one year after cataract surgery may lead to significant hyperopic change, in which the ACD alteration affects the hyperopic shift significantly.

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.

Resident-performed laser peripheral iridotomy in primary angle closure, primary angle closure suspects, and primary angle closure glaucoma

Purpose

To investigate the power use and complication frequency of resident-performed laser peripheral iridotomy (LPI).

Methods

A retrospective analysis of 196 eyes from 103 patients who underwent neodymium: yttrium-aluminum-garnet laser iridotomy performed by resident physicians from January 1, 2010 through April 30, 2015 at a university-based county hospital was done. All patients were treated for primary angle closure, primary angle closure suspects, and primary angle closure glaucoma. Data were collected on pre- and post-laser intraocular pressure (IOP), ethnicity, laser parameters and complications. Mean power use and frequency of complications were evaluated. Complications included elevated post-laser IOP at 30–45 minutes (≥8 mmHg), hyphema, aborted procedures, and lasering non-iris structures. The number of repeated LPI procedures, was also recorded.

Results

Mean total power used for all residents was 78.2±68.7 mJ per eye. Power use by first-year trainees was significantly higher than second- and third-year trainees (103.5±75.5 mJ versus 73.7±73.8 mJ and 67.2±56.4 mJ, respectively, p=0.011). Complications included hyphema or microhyphema in 17.9% (35/196), IOP spikes in 5.1% (10/196), aborted procedures in 1.1% (3/196) and lasering non-iris structures in 0.5% (1/196). LPI was repeated in 22.4% of cases (44/196) with higher incidence of repeat LPI among non-Caucasian compared to the Caucasian subjects (p=0.02). Complication rates did not differ with increased training (p=0.16).

Conclusion

Total power used for LPI decreased with increased resident training, while the complication rate did not differ significantly among resident classes. Complication rates were comparable to rates reported in the literature for attending-performed LPIs.

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.

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.

Neodymium-yttrium aluminium garnet laser capsulotomy energy levels for posterior capsule opacification

Purpose:

To study factors affecting laser energy levels required for neodymium: yttrium aluminium garnet (Nd: YAG) laser capsulotomy and to evaluate whether any correlation exists between applied laser energy levels and complications.

Methods:

The present study examined 474 consecutive patients for a number of factors including age, type of posterior capsule opacification (PCO), material and fixation of intraocular lens (IOL) and complication rates, versus energy levels used for Nd: YAG laser capsulotomy.

Results:

Mean patient age was 55.6 ± 8.7 years and mean follow up period was 22.9 ± 4.5 months. IOL biomaterial (KW ANOVA; P = 0.173) and patient's age (P = 0.246) did not significantly influence total laser energy requirement for capsulotomy. However, total laser energy levels were significantly higher (KW ANOVA; P < 0.001) with fibro-membranous and fibrous subtypes of PCO. Complications such as IOL pitting, intraocular pressure (IOP) elevation, uveitis, retinal detachment (RD) and cystoid macular edema (CME) were significantly more common when higher energy levels was used. The mean total energy in patients with RD was 77.7 ± 17.7 mJ as compared to 43.4 ± 26.9 mJ in the rest of the cohort. RD was more common in patients with higher axial length [n = 7 (63%)] (P < 0.001).

Conclusion:

Type of PCO significantly influenced laser energy levels required for capsulotomy, whereas IOL biomaterial and fixation did not. Complications such as IOL pitting, uveitis, IOP elevation, RD and CME was significantly more common when total laser energy was higher. It is recommended that the lowest possible single pulse laser energy be used for capsulotomy to minimize complications.

[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.

Primary lens extraction for glaucoma management: A review article

Recently, primary lens extraction alone gained more acceptance as an alternative surgical approach for glaucoma management. This view was supported by the advances in phacoemulsification and intraocular lenses with greater safety and visual recovery, in addition to a substantial reduction of intraocular pressure and deepening of the anterior chamber and filtration angle. The decrease in IOP after cataract surgery in primary open-angle glaucoma (POAG) is mild, less predictable, related to baseline levels, and may return to presurgical values after an initial period of reduction. Therefore, the IOP-lowering effect of primary cataract extraction in POAG may be insufficient to achieve adequate IOP control. The IOP reduction after lens extraction is consistently greater in eyes with primary angle closure glaucoma (PACG) than in eyes with POAG. Primary lens extraction in acute PACG eliminates, or at least, reduces the risk of recurrence of acute attacks and deepens the anterior chamber and widens the angle which reduces the risk of progression of peripheral anterior synechiae and development of chronic PACG. Primary lens extraction may be more preferable to glaucoma incisional surgery in mild to moderate PACG eyes with appositional angle closure. The decision to do lens extraction as a primary treatment for glaucoma should be individualized based upon several factors other than the effect on IOP. These factors include patients' characteristics, surgeons' skills and preferences, status of glaucoma control, type of cataract and intraocular lens implanted, and potential harm of laser treatment for late capsular opacification and fibrosis.

Macular morphology after cataract surgery with primary posterior capsulorhexis and posterior optic buttonholing

PURPOSE

To evaluate possible changes in macular morphology after cataract surgery with combined primary posterior capsulorhexis and posterior optic buttonholing in comparison to conventional in-the-bag intraocular lens (IOL) implantation.

DESIGN

Prospective randomized study.

METHODS

Fifty consecutive age-related cataract patients with normal macular morphology and function waiting for bilateral cataract surgery were enrolled. Cataract surgery with combined primary posterior capsulorhexis and posterior optic buttonholing was performed in one eye; in the fellow eye cataract surgery was performed with in-the-bag IOL implantation, leaving the posterior lens capsule untouched. Optical coherence tomography measurements were performed one week and one month postoperatively.

RESULTS

During follow-up, no statistically significant changes of macular morphology could be observed in any of the tested patients. Mean central retinal thickness, minimum and maximum retinal thickness, and central retinal volume were all statistically comparable between the eyes with combined primary posterior capsulorhexis and posterior optic buttonholing and the control eyes (P > .05). Best-corrected visual acuity was full in all patients (Snellen 20/25 and better). No cases of subclinical macular edema were observed.

CONCLUSION

Cataract surgery with combined primary posterior capsulorhexis and posterior optic buttonholing apparently does not increase the risk for postoperative macular edema in patients with a normal macula, since no cases of biomicroscopically noticeable macular edema with visual loss were observed in the first 1,000 eyes with primary posterior capsulorhexis/posterior optic buttonholing cataract surgery and no case of subclinical macular edema was found in this prospective randomized study.