Apraclonidine and anterior segment laser surgery. Comparison of 0.5% versus 1.0% apraclonidine for prevention of postoperative intraocular pressure rise

Prophylaxis against intraocular pressure spikes following uncomplicated phacoemulsification: a systematic-review and meta-analysis

BACKGROUND

To investigate the effect of perioperative intraocular pressure (IOP) lowering medications on controlling postoperative IOP following uncomplicated phacoemulsification.

METHODS

Ovid MEDLINE, EMBASE, and Cochrane CENTRAL databases were searched up until November 2022. Randomised controlled trials (RCTs) that assessed IOP change via applanation tonometry in medicated and control arms following uncomplicated cataract surgery in healthy eyes were included. The primary outcome was the weighted mean difference (WMD) of IOP at 2-8 h, 12-24 h, and 1-7 days postoperatively within each medication class or common fixed-combination formulations. Risk of bias was assessed using the revised risk of bias in randomised trials (RoB-2). Level of evidence was rated using the Grading of Recommendation, Assessment, Development and Evaluation (GRADE) RESULTS: From 702 screened articles, 30 RCTs involving 2986 eyes were included. There was a statistically significant reduction in IOP favouring treatment arms at 2-8 h (WMD = -3.87 mmHg; 95% CI [-4.75, -3.00]; p < 0.001) and 12-24 h (WMD = -2.69 mmHg; 95% CI [-3.36, -2.02]; p < 0.001), with the effect wearing off beyond 1 day (p = 0.18). Between medication classes, the largest effect at both 2-8 h and 12-24 h was observed with intracameral cholinergics or fixed-combination carbonic anhydrase inhibitor-beta-blocker (FCCB) formulations. Conversely, the smallest effect was observed with prostaglandin analogues, alpha-agonists, and topical carbonic anhydrase inhibitors (CAIs).

CONCLUSION

Prophylaxis against acute IOP elevations following uncomplicated cataract surgery is effective. FCCB and intracameral cholinergics are the most effective ocular antihypertensive agents, while alpha-agonists, prostaglandin analogues, and topical CAIs were found to be the least effective. These findings may inform future surgical guidelines.

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.

Perioperative medications for preventing temporarily increased intraocular pressure after laser trabeculoplasty

BACKGROUND

Glaucoma is the international leading cause of irreversible blindness. Intraocular pressure (IOP) is the only currently known modifiable risk factor; it can be reduced by medications, incisional surgery, or laser trabeculoplasty (LTP). LTP reduces IOP by 25% to 30% from baseline, but early acute IOP elevation after LTP is a common adverse effect. Most of these IOP elevations are transient, but temporarily elevated IOP may cause further optic nerve damage, worsening of glaucoma requiring additional therapy, and permanent vision loss. Antihypertensive prophylaxis with medications such as acetazolamide, apraclonidine, brimonidine, dipivefrin, pilocarpine, and timolol have been recommended to blunt and treat the postoperative IOP spike and associated pain and discomfort. Conversely, other researchers have observed that early postoperative IOP rise happens regardless of whether people receive perioperative glaucoma medications. It is unclear whether perioperative administration of antiglaucoma medications may be helpful in preventing or reducing the occurrence of postoperative IOP elevation.

OBJECTIVES

To assess the effectiveness of medications administered perioperatively to prevent temporarily increased intraocular pressure (IOP) after laser trabeculoplasty (LTP) in people with open-angle glaucoma (OAG).

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 11), MEDLINE Ovid (1946 to 18 November 2016), Embase.com (1947 to 18 November 2016), PubMed (1948 to 18 November 2016), LILACS (Latin American and Caribbean Health Sciences Literature Database) (1982 to 18 November 2016), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com); last searched 17 September 2013, ClinicalTrials.gov (www.clinicaltrials.gov); searched 18 November 2016 and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en); searched 18 November 2016. We did not use any date or language restrictions.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) in which participants with OAG received LTP. We included trials which compared any antiglaucoma medication with no medication, one type of antiglaucoma medication compared with another type of antiglaucoma medication, or different timings of medication.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened records retrieved by the database searches, assessed the risk of bias, and abstracted data. We graded the certainty of the evidence using GRADE.

MAIN RESULTS

We included 22 trials that analyzed 2112 participants and identified no ongoing trials. We performed several comparisons of outcomes: one comparison of any antiglaucoma medication versus no medication or placebo, three comparisons of one antiglaucoma medication versus a different antiglaucoma mediation, and one comparison of antiglaucoma medication given before LTP to the same antiglaucoma medication given after LTP. Only one of the included trials used selective laser trabeculoplasty (SLT); the remaining trials used argon laser trabeculoplasty (ALT). Risk of bias issues were primarily in detection bias, reporting bias, and other potential bias due to studies funded by industry. Two potentially relevant studies are awaiting classification due to needing translation.In the comparison of any medication versus no medication/placebo, there was moderate-certainty evidence that the medication group had a lower risk of IOP increase of 10 mmHg or greater within two hours compared with the no medication/placebo group (risk ratio (RR) 0.05, 95% confidence interval (CI) 0.01 to 0.20). This trend favoring medication continued between two and 24 hours, but the evidence was of low and very low-certainty for an IOP increase of 5 mmHg or greater (RR 0.17, 95% CI 0.09 to 0.31) and 10 mmHg or greater (RR 0.22, 95% CI 0.11 to 0.42). Medication was favored over placebo/no medication with moderate-certainty in reducing IOP from the pre-LTP measurements for both within two hours and between two and 24 hours. At two hours, the mean difference (MD) in IOP between the medication group and the placebo/no medication group was -7.43 mmHg (95% CI -10.60 to -4.27); at between two and 24 hours, the medication group had a mean reduction in IOP of 5.32 mmHg more than the mean change in the placebo/no medication group (95% CI -7.37 to -3.28). Conjunctival blanching was an ocular adverse effect that was more common when brimonidine was given perioperatively compared with placebo in three studies.In our comparison of brimonidine versus apraclonidine, neither medication resulted in a lower risk of increased IOP of 5 mmHg or greater two hours of surgery; however, we were very uncertain about the estimate. There may be a greater mean decrease in IOP within two hours after LTP. We were unable to perform any meta-analyses for other review outcomes for this comparison.In our comparison of apraclonidine versus pilocarpine, we had insufficient data to perform meta-analyses to estimate effects on either of the primary outcomes. There was moderate-certainty evidence that neither medication was favored based on the mean change in IOP measurements from pre-LTP to two hours after surgery.In the comparison of medication given before LTP versus the same medication given after LTP, we had insufficient data for meta-analysis of IOP increase within two hours. For the risk of IOP increase of 5 mmHg or greater and 10 mmHg or greater at time points between two and 24 hours, there was no advantage of medication administration before or after LTP regarding the proportion of participants with an IOP spike (5 mmHg or greater: RR 0.82, 95% CI 0.25 to 2.63; 10 mmHg or greater: RR 1.55, 95% CI 0.19 to 12.43). For an IOP increase of 10 mmHg or greater, we had very low-certainty in the estimate, it would likely change with data from new studies.

AUTHORS' CONCLUSIONS

Perioperative medications are superior to no medication or placebo to prevent IOP spikes during the first two hours and up to 24 hours after LTP, but some medications can cause temporary conjunctival blanching, a short-term cosmetic effect. Overall, perioperative treatment was well tolerated and safe. Alpha-2 agonists are useful in helping to prevent IOP increases after LTP, but it is unclear whether one medication in this class of drugs is better than another. There was no notable difference between apraclonidine and pilocarpine in the outcomes we were able to assess. Future research should include participants who have been using these antiglaucoma medications for daily treatment of glaucoma before LTP was performed.

TOPICAL APRACLONIDINE REDUCES PAIN AFTER INTRAVITREAL INJECTIONS: A Double-Blind Randomized Controlled Trial

PURPOSE

To evaluate the efficacy of topical apraclonidine in reducing pain and subconjunctival hemorrhage (SCH) after intravitreal injections (IViT).

METHODS

A prospective, randomized, double-blinded study. Thirty-nine patients were examined twice, at each monthly IViT of 1.25 mg/0.05 mL bevacizumab. Patients were randomly assigned to receive either topical apraclonidine 0.5% or placebo to the treated eye, 30 minutes before the first IViT. At their second IViT, the intervention was switched. Thirty minutes after the injection, SCH size was measured by a slit lamp, and pain was assessed by the numerical rating scale (NRS-11).

RESULTS

Mean pain score was 1.69 (SD ±1.44) in the apraclonidine group and 3.28 (SD ±2.27) in the control group (P < 0.001). Phakic patients had a greater pain reduction after topical apraclonidine (P < 0.001). Subconjunctival hemorrhage incidence was 41% in the apraclonidine group and 51.3% in the control group (P = 0.503). Mean SCH size was 1.71 mm (SD ±5.83) in the apraclonidine group and 3.25 mm (SD ±6.41) in the control group (P = 0.253). After topical apraclonidine, there was a smaller reduction in SCH size in patients with choroidal neovascularization or hypertension (P = 0.003 and 0.044, respectively), and a greater reduction in phakic patients (P = 0.048).

CONCLUSION

Topical apraclonidine 0.5%, administered 30 minutes before IViT, significantly decreased pain by a factor of 1.94. It did not decrease the incidence or size of SCH in the entire cohort, but only in several subpopulations.

Clinical options for the reduction of elevated intraocular pressure

Elevated IOP in clinical practice is usually seen in glaucoma or ocular hypertension. Glaucoma affects 60 million people worldwide and 8.4 million are bilaterally blind from this chronic disease.1 Options for reducing IOP rely on pharmacological agents, laser treatments and surgery which may be penetrating or non-penetrating. The last twenty years has seen significant changes in all of these strategies. This review aims to cover these clinical options and introduce some of the new technologies currently in development for the clinical lowering of IOP.

Update on the role of alpha-agonists in glaucoma management

Glaucoma is the second most common cause of world blindness (following cataract) with estimated cases reaching 79.6 million by 2020. Although the etiology of glaucoma is multi-factorial, intraocular pressure (IOP) is the only modifiable factor in glaucoma management proven to alter the natural course of the disease. Among various classes of IOP-lowering medications currently available, alpha-adrenergic receptor agonists are used either as monotherapy, as second-line therapy, or in fixed combination with beta-blockers. Non-selective adrenergic agonists such as epinephrine and dipivefrin are infrequently used today for the treatment of glaucoma or ocular hypertension, and have been replaced by the alpha-2-selective agonists. The use of apraclonidine for IOP reduction in glaucoma or OHT is limited due to a high rate of follicular conjunctivitis. The alpha-2-selective agonist in use today is brimonidine. The brimonidine-purite formulations are preferred to brimonidine-benzalkonium chloride (BAC) formulations due better tolerability while maintaining similar efficacy. Brimonidine is also effective when used in combination with a beta-blocker. Using brimonidine-timolol fixed combination (BTFC) as first-line therapy has an added potential for neuroprotection. This would be a valuable strategy for glaucoma treatment, for patients who are intolerant of prostaglandin analogs, or for patients where prostaglandin analogues are contraindicated as first-line therapy, such as in patients with inflammatory glaucoma.

Brimonidine 0.15% versus apraclonidine 0.5% for prevention of intraocular pressure elevation after anterior segment laser surgery

PURPOSE

To compare the efficacy and safety of brimonidine 0.15% with those of apraclonidine 0.5% in preventing intraocular pressure (IOP) elevations after anterior segment laser surgery.

SETTING

Massachusetts Eye and Ear Infirmary, Glaucoma Service, Boston, Massachusetts, USA.

METHODS

This double-masked randomized trial 80 eyes of 80 patients who had laser peripheral iridotomy, argon laser trabeculoplasty, or neodymium:YAG laser capsulotomy. Eyes received 1 drop of brimonidine 0.15% or apraclonidine 0.5% before laser surgery. Intraocular pressure, heart rate, and blood pressure were measured before laser surgery and at 1 hour, 3 hours, 24 hours, and 1 week after laser surgery.

RESULTS

Before laser treatment, 41 patients received brimonidine 0.15% and 39 received apraclonidine 0.5%. Thirteen (31.7%) patients in the brimonidine group and 11 (28.2%) in the apraclonidine group had postoperative IOP elevations of 5 mm Hg or more (P = .5). Four patients (9.8%) in the brimonidine group and 3 (7.7%) in the apraclonidine group had IOP increases of 10 mm Hg or more (P = .5). There were no statistically significant changes in mean heart rate or blood pressure in either group except a slight reduction in diastolic blood pressure at 1 hour in the brimonidine group (-4.7 +/- 9.2 mm Hg) compared with that in the apraclonidine group (-0.1 +/- 9.1 mm Hg) (P = .01). No clinically significant side effects were noted in either group.

CONCLUSION

A single preoperative drop of brimonidine 0.15% had similar efficacy and safety as apraclonidine 0.5% in preventing IOP elevations immediately after anterior segment laser surgery.

Brimonidine 0.2% versus apraclonidine 0.5% for prevention of intraocular pressure elevations after anterior segment laser surgery

OBJECTIVE

To compare the efficacy of brimonidine 0.2% with apraclonidine 0.5% in preventing intraocular pressure (IOP) elevations after anterior segment laser surgery.

DESIGN

Double-masked, randomized clinical trial.

PARTICIPANTS

Sixty-six patients underwent either laser peripheral iridotomy, argon laser trabeculoplasty, or neodymium:yttrium-aluminum-garnet laser capsulotomy.

INTERVENTION

Eyes received either one drop of brimonidine 0.2% or apraclonidine 0.5% before laser surgery.

MAIN OUTCOME MEASURES

Intraocular pressure, heart rate, and blood pressure were measured before laser surgery and at 1 hour, 3 hours, 24 hours, and 1 week after laser surgery.

RESULTS

Before the laser treatment, 33 patients (50.0%) received brimonidine 0.2% and 33 patients (50.0%) received apraclonidine 0.5%. Eight of 33 patients (24.2%) in the brimonidine-treated group and 9 of 33 patients (27.3%) in the apraclonidine group had postoperative IOP increases of 5 mmHg or more. This was not statistically different (P = 0.80). By the time of last follow-up examination, 3 of 33 patients (9.1%) in the brimonidine-treated group and 3 of 33 patients (9.1%) in the apraclonidine group had IOP increases of 10 mmHg or more. This was also not statistically different (P > or = 0.95). The mean IOP reduction from baseline in the brimonidine group (-2.8 +/- 2.8 mmHg) was not statistically different (P = 0.55) compared with the mean IOP reduction in the apraclonidine group (-3.6 +/- 3.3 mmHg). There were no statistically significant changes in mean heart rate or blood pressure in either group except for a slight reduction in diastolic blood pressure at 1 hour (P = 0.005) in the brimonidine group (-5.2 +/- 7.4 mmHg) compared with the apraclonidine group (-0.2 +/- 6.4 mmHg). There were no clinically significant side effects noted in either group.

CONCLUSIONS

A single preoperative drop of brimonidine 0.2% is as effective as apraclonidine 0.5% in preventing IOP elevation immediately after anterior segment laser surgery.

Randomised fellow eye comparison of the effectiveness of dorzolamide and apraclonidine on intraocular pressure following phacoemulsification cataract surgery

PURPOSE

To compare the effectiveness of 2% dorzolamide and 0.5% apraclonidine on intraocular pressure (IOP) following phacoemulsification cataract surgery.

METHODS

This prospective, randomised study comprised 54 eyes of 27 consecutive patients with age-related cataract scheduled for cataract surgery in both eyes. In each patient the eye with the higher degree of cataract was randomly assigned to receive one drop of either dorzolamide or apraclonidine immediately after surgery. The fellow eye was operated on later and received the other treatment. Cataract surgery was performed with a superior 6.0 mm sutureless frown incision, phacoemulsification and implantation of a three-piece PMMA intraocular lens. The IOP was measured pre-operatively as well as 6 h and 20-24 h and 1 week post-operatively.

RESULTS

The mean pre-operative IOP was not significantly different between the groups (dorzolamide group, 14.9 +/- 2.3 mmHg; apraclonidine group, 14.6 +/- 2.5 mmHg; p = 0.450). At 6 h post-operatively, the mean IOP was significantly lower in the dorzolamide than in the apraclonidine group (15.6 +/- 3.9 mmHg vs 18.0 +/- 4.0 mmHg; p < 0.001). An IOP increase of more than 5 mmHg at 6 h post-operatively occurred in 3 (12%) eyes in the dorzolamide group and in 9 (36%) eyes in the apraclonidine group (p = 0.034). At 20-24 h post-operatively and at 1 week post-operatively no difference was found between the groups.

CONCLUSIONS

2% Dorzolamide is more effective than 0.5% apraclonidine in preventing the early post-operative IOP increase following phacoemulsification cataract surgery.

Control of intraocular pressure elevations after argon laser trabeculoplasty: comparison of brimonidine 0.2% to apraclonidine 1.0%

OBJECTIVE

To determine whether brimonidine 0.2% can control intraocular pressure (IOP) spikes as well as apraclonidine 1.0% can in those patients undergoing argon laser trabeculoplasty (ALT).

DESIGN

Prospective, randomized, double-masked, clinical trial.

PARTICIPANTS

A total of 56 eyes of 41 patients with open-angle glaucoma or ocular hypertension were entered in the study; 46 eyes of 41 patients were eventually used for the final analysis.

INTERVENTION

Patients were randomized to receive either brimonidine 0.2% or apraclonidine 1.0% before and after 360 degrees ALT. Both patient and physician were masked as to which agent each patient received.

MAIN OUTCOME MEASURES

Intraocular pressure measurements were recorded before surgery and at 1, 2, and 4 hours after surgery. The difference between the preoperative IOP (baseline) and the highest recorded postoperative IOP was recorded as the maximum IOP change. The mean of the maximum IOP change for each group was analyzed using a two-sample, one-tailed t test.

RESULTS

The mean of the maximum IOP change in the brimonidine 0.2% group was -2.6+/-3.6 mmHg, and the mean for the apraclonidine 1.0% group was -2.3+/-3.7 mmHg (P = 0.8). No patient had a pressure spike greater than 10 mmHg.

CONCLUSIONS

Brimonidine 0.2% appears to be as effective as apraclonidine 1.0% in preventing IOP spikes after argon laser trabeculoplasty.

Efficacy of apraclonidine 1% versus pilocarpine 4% for prophylaxis of intraocular pressure spike after argon laser trabeculoplasty

OBJECTIVE

The authors compared the efficacy of apraclonidine 1% versus pilocarpine 4% prophylaxis of post-argon laser trabeculoplasty (ALT) intraocular pressure (IOP) spike.

DESIGN

Prospective randomized clinical trial.

PARTICIPANTS

Two hundred twenty-eight eyes of 228 patients with primary open-angle glaucoma undergoing ALT were studied.

INTERVENTION

Patients were given 1 drop of either apraclonidine 1% (n = 114) or pilocarpine 4% (n = 114) 15 minutes before ALT.

MAIN OUTCOME MEASURES

Peri-ALT IOPs and incidences of post-ALT IOP spikes at 5 minutes, 1 hour, and 24 hours were compared between the two groups.

RESULTS

The two groups were similar in age, race, and medical dependency. Post-ALT mean IOPs at 5 minutes, 1 hour, and 24 hours were significantly lower than pre-ALT mean IOPs in both apraclonidine (P < 0.001) and pilocarpine (P < 0.001) groups. Incidences of IOP spikes greater than 1, 3, and 5 mmHg at 1 hour post-ALT were 21.1%, 14.9%, and 8.8% for the apraclonidine group and 12.3%, 5.3%, and 4.4% for the pilocarpine group (P = 0.076, 0.015, and 0.18 chi-square test). In the apraclonidine prophylaxis group, patients on long-term apraclonidine showed significantly higher incidence of post-ALT IOP spike than the patients without such long-term apraclonidine use (35.7%, 15 of 42 eyes, vs. 12.5%, 9 of 72 eyes; P = 0.003). In addition, peri-ALT pilocarpine prophylaxis tended to be less effective in patients undergoing long-term pilocarpine therapy but without statistical significance (17.4%, 8 of 46 eyes, vs. 9.4%, 6 of 64 eyes; P = 0.17).

CONCLUSION

Peri-ALT pilocarpine 4% was at least as effective as, if not more effective than, apraclonidine 1% in post-ALT IOP spike prophylaxis. Peri-ALT apraclonidine prophylaxis was not effective in patients on long-term apraclonidine, and peri-ALT pilocarpine prophylaxis tended to be less effective in patients undergoing long-term pilocarpine therapy. Pilocarpine 4% can be considered as a first-choice drug for post-ALT IOP spike prophylaxis, especially in patients under treatment with apraclonidine.

Chronic use of apraclonidine decreases its moderation of post-laser intraocular pressure spikes

OBJECTIVE

The purpose of the study is to investigate the efficacy of 1.0% apraclonidine in preventing intraocular pressure (IOP) spike after argon laser trabeculoplasty (ALT) in patients on chronic apraclonidine therapy compared with patients not on chronic apraclonidine use.

DESIGN

The study design was a prospective study.

PARTICIPANTS

This study consisted of 231 consecutive eyes of patients with primary open-angle glaucoma undergoing ALT: 70 eyes (30%) were started on a regimen including chronic apraclonidine 0.5% use (group A) and 161 eyes (70%) were started on a regimen without chronic apraclonidine 0.5% use (group B).

INTERVENTION

Both groups received one drop of apraclonidine 1.0% 15 minutes before ALT to 180 degrees of previously untreated trabecular meshwork. Intraocular pressure was measured before the procedure and at 5 minutes, 1 hour, and 24 hours after the laser treatment.

MAIN OUTCOME MEASURES

Incidences of an IOP spike and mean IOPs at 5 minutes, 1 hour, and 24 hours after the laser treatment were compared between the two groups. Multivariate logistic regression analysis also was carried out to identify the significant risk factors for post-ALT IOP spikes despite prophylactic apraclonidine 1.0% treatment.

RESULTS

The incidences of IOP spikes greater than 0 mmHg, greater than 2 mmHg, and greater than 5 mmHg at 1 hour after ALT were 32.9%, 22.9%, and 12.9%, respectively, in group A versus 13.7%, 11%, and 3.1%, respectively, in group B (P = 0.0007, P = 0.009, and P = 0.004). Chronic apraclonidine 0.5% use was found to be the only significant risk factor for IOP spikes at 1 hour after ALT by multivariate logistic regression analysis.

CONCLUSIONS

The incidences of IOP spikes in group A were significantly greater than in group B and approached the reported incidences of IOP spikes without perilaser apraclonidine prophylaxis. This indicates that peri-ALT apraclonidine is relatively ineffective in patients with chronic apraclonidine 0.5% use (group A) compared with patients without chronic apraclonidine use (group B), presumably because of saturation of the ocular alpha-2 receptors with apraclonidine in patients with chronic apraclonidine use. Therefore, in patients receiving chronic apraclonidine therapy, it is especially important to monitor their post-ALT IOPs and to be prepared to treat postlaser IOP spikes using agents other than apraclonidine.