Prophylactic use of apraclonidine for intraocular pressure increase after Nd:YAG capsulotomies.

We evaluated the prophylactic effect of 1% apraclonidine HCl in controlling the increase in intraocular pressure after Nd:YAG posterior capsulotomy in a large, multicenter double-masked clinical trial. One hundred sixty-four patients were enrolled into the apraclonidine-treated group, and 165 into the vehicle-treated group. The incidence of increase in intraocular pressure (greater than 5 mm Hg) in the apraclonidine-treated group (7%, 11 of 163 patients) was significantly less than that in the vehicle-treated group (39%, 64 of 164 patients). Similarly, the mean maximal change in intraocular pressure in the apraclonidine-treated group (1.3-mm Hg decrease) was significantly different from the increase in the vehicle-treated group (5.3-mm Hg increase). Few adverse reactions were observed. The risk for significant loss of visual function after Nd:YAG laser posterior capsulotomy, combined with the efficacy and relative safety of prophylactic apraclonidine, suggest its addition to the treatment armamentarium.

Prevention and emergency field management of venomous snakebites during military exercises.

Summer exercises in the continental United States bring many military personnel in contact with our four types of indigenous venomous snakes. Personnel with a knowledge of these snakes, their habits, and habitat, and who exercise common sense are much less likely to fall victim to a venomous bite. When a bite does occur, timely and appropriate first aid can help to reduce the sequelae of an envenomation. Military medical personnel should be prepared to discuss snakebite prevention and field management with all personnel taking to the field this summer.

ALO 2145 reduces the intraocular pressure elevation after anterior segment laser surgery.

The effect of an alpha adrenergic agonist, ALO 2145 (para-amino-clonidine [PAC]), was examined in a double-masked, multicenter study on the postoperative intraocular pressure (IOP) elevation after laser surgery in 165 patients (83 trabeculoplasty, 36 iridotomy, and 46 capsulotomy). One drop of 1.0% ALO 2145 or vehicle was instilled 1 hour before and immediately after laser surgery. The mean IOP increase in the ALO 2145-treated group was lower (P less than 0.05) than in the placebo group at each of the first three postoperative hours. Overall, 18% of placebo-treated eyes experienced IOP increases greater than or equal to 10 mmHg as compared with 4% of ALO 2145-treated eyes (P less than 0.003). Ocular and systemic side effects were minimal and did not differ between the treatment groups. ALO 2145 safely and effectively reduced the incidence and magnitude of potentially harmful IOP elevations after anterior segment laser surgery.

The safety and efficacy of topical 1% ALO 2145 (p-aminoclonidine hydrochloride) in normal volunteers.

We prospectively evaluated the efficacy and safety of the twice-daily application of 1% ALO 2145 (p-aminoclonidine hydrochloride, a topical alpha 2-agonist) in 21 normal volunteers for one month. Criteria measured included intraocular pressure (IOP), basal tear secretion, pupillary size, corneal sensitivity, heart rate, and blood pressure; urinalysis and blood chemistry studies were also performed. The mean (+/- SD) IOP fell 38.7%, from 17.5 +/- 3.9 mm Hg to 10.7 +/- 3.4 mm Hg, in five hours. The mean IOP remained between 23% and 30% below the pretreatment level when checked 12 hours after the last drop's instillation from day 8 through day 28 of the study. No clinically significant changes in mean systolic blood pressure, blood chemistry values, urinalysis results, basal tear secretion, or corneal sensitivity were noted. The mean heart rate and diastolic blood pressure were each significantly decreased at only one of nine time intervals. Dry mouth was noted at some time in 52% of volunteers. ALO 2145 seems to be effective in lowering IOP in normal volunteers, without marked cardiovascular effects.

Effects of topical ALO 2145 (p-aminoclonidine hydrochloride) on the acute intraocular pressure rise after argon laser iridotomy.

A prospective, randomized, double-masked pilot study compared topical 1% ALO 2145 (p-aminoclonidine hydrochloride, a topical alpha 2-agonist) with a placebo to determine its ability to minimize any acute postoperative intraocular pressure (IOP) increase after argon laser iridotomy. Twenty-eight eyes (21 patients) with chronic narrow angle glaucoma underwent argon laser iridotomy. Fourteen eyes were treated with ALO 2145; the remainder received a placebo. All eyes received one drop of the appropriate medication one hour before and following the iridotomy. Six eyes (43%) treated with the placebo and no eyes treated with ALO 2145 experienced an IOP increase greater than 10 mm Hg over baseline. The mean IOPs and mean IOP changes from baseline were significantly lower during the first three postoperative hours in the eyes treated with ALO 2145. No significant difference was noted in the ease of iridotomy formation, rate of iridotomy closure, visual acuity, anterior segment inflammation, or mean heart rate.

The relationship between rod perimetric thresholds and full-field rod ERGs in retinitis pigmentosa.

Dark-adapted static perimetric fields and rod full-field electroretinograms (ERGs) were measured in normal subjects and 15 patients with retinitis pigmentosa. Psychophysical thresholds for short-wavelength stimuli were obtained from 76 locations across the retina on a modified Octopus 201 perimeter; threshold differences to short- and long-wavelength stimuli were used to determine whether rods were mediating threshold at each retinal location. Full-field rod ERG peak-to-peak amplitude as a function of retinal illuminance was analyzed by determining the parameters of the best-fit Naka-Rushton equation. Rod ERG thresholds and mean rod perimetric thresholds were significantly correlated with a slope of approximately 1.0. Log k was positively correlated with threshold elevation in the region of peak field sensitivity and log Vmax was positively correlated with log rod visual field area. These results demonstrate correspondence between parameters derived from rod visual fields and parameters derived from the Naka-Rushton analysis of the full-field rod ERG.

Reduction of pupillary constriction during cataract surgery using suprofen.

The efficacy of a new nonsteroidal anti-inflammatory agent, suprofen, for reducing pupillary constriction during cataract surgery was ascertained in a double-masked, multicenter, clinical study. Prior to surgery 1.0% suprofen or a placebo was instilled; the surgeon's normal regimen of mydriatics and cycloplegics was used. Suprofen (209 patients) was far more effective than the placebo (203 patients) in maintaining a dilated pupil prior to intraocular lens (IOL) implantation (or instillation of a miotic). The mean pupillary area prior to IOL implantation was 6.3 sq mm larger (20% larger) in patients treated with suprofen than in patients receiving the placebo. The investigators' subjective evaluations of the adequacy of pupil size for IOL implantation and of the difficulty of IOL implantation favored patients treated with suprofen over those receiving the placebo.

A double-masked comparison of ocular decongestants as therapy for allergic conjunctivitis.

A prospective, randomized, double-masked study of three commercially available ocular decongestant products was conducted to compare their relative efficacies in the treatment of allergic conjunctivitis. All three products contained a vasoconstrictor (naphazoline hydrochloride) and an antihistamine (antazoline phosphate or pheniramine maleate) in varying concentrations. Eighty-nine (89) patients presenting the ocular signs and symptoms of allergic conjunctivitis were enrolled and randomly distributed among the three treatment groups. Patients were evaluated for three ocular signs (lid swelling, bulbar conjunctival inflammation and palpebral conjunctival inflammation) and three ocular symptoms (itching, tearing and discomfort). An overall follow-up impression of treatment results was also recorded. The treatment period lasted one week. The three preparations were found to vary greatly in patient comfort and acceptability but were not different in their ability to ameliorate the itching, tearing, redness, edema and discomfort when dosed topically for the relief of allergic conjunctivitis.

Use of steroid/antibiotic prophylaxis in intraocular lens implantation: a double-masked study v placebo.

A prospective, randomized, double-masked study was conducted to compare the efficacy of steroid/antibiotic treatment to placebo in reducing postoperative ocular inflammation. Patients undergoing planned extracapsular cataract extraction with intraocular lens implantation were treated with either placebo or a combination product containing dexamethasone, neomycin, and polymyxin B for three days prior to surgery and three weeks following surgery. Five of thirteen (38%) patients treated with placebo developed significant iritis postoperatively, while none of ten (0%) patients treated with the combination product developed excessive inflammation (P = 0.027). Two patients treated with the steroid/antibiotic combination product experienced a broken suture postoperatively followed by iris prolapse, as compared to none in the placebo group (P greater than 0.10). More types and significant numbers of bacteria were isolated from the eyes of the placebo-treatment group after therapy than were found in the steroid/antibiotic-treatment group.

Safety evaluation of BSS plus in pediatric intraocular surgery.

An open-label study was conducted to determine the safety of a new intraocular irrigating solution, BSS Plus, when used during pediatric ophthalmic surgery. BBS Plus is a modified glutathione-bicarbonate-Ringer's solution which contains the necessary ions, buffers, and substrates for maintenance of normal cellular metabolism, function, and structural integrity when used as a perfusate during ophthalmic surgical procedures. At three centers, 30 patients undergoing lens aspiration or anterior segment reconstruction using vitrectomy instrumentation were enrolled in this study. Transient postoperative increases in intracellular pressure and internal or external ocular inflammatory signs were seen which were consistent with the trauma produced by the surgical procedure. The solution was judged to be safe when used in these surgical indications.