The mydriatic effect of multiple doses of tropicamide.

PURPOSE: We investigated whether two drops of 0.5% tropicamide produced a wider pupillary dilation when compared with a single drop and saline control in subjects with dark-colored irides. METHODS: Twelve young adult subjects with dark irides and who were free from ocular disease participated in the study. One eye of each subject, selected at random, was designated as experimental and the fellow eye as control. A single drop of 0.5% tropicamide was instilled in the lower cul-de-sac of each eye in turn. Immediately after, a second drop of 0.5% tropicamide was instilled in the experimental eye and a single drop of unpreserved saline into the control eye. A double-masked experimental protocol was followed. Digital images of both pupils of each subject were taken at baseline (predrug instillation) and then every 5 minutes up to 30 minutes postdrug instillation and at 40, 50, and 60 minutes. The images were subsequently viewed on a PC monitor, and pupil size was measured using a calibrated millimeter scale. RESULTS: Pupil diameter increased as a function of time for both conditions reaching a maximum between 20 and 30 minutes after drop instillation. Pupil diameter was greater under the experimental condition compared with the control (analysis of variance p < 0.001). Pupil diameter reached at least 6 mm under both the experimental and control conditions. CONCLUSION: In young healthy subjects, compared with a single drop of tropicamide, two drops were associated with a greater degree of pupillary dilation on average over the 60-minute study period. However, the magnitude of the difference was small and not clinically significant. A single drop of tropicamide produced a pupillary diameter of at least 6 mm, which should be sufficient for the conduct of a thorough dilated fundus examination.     

Phacoemulsification without preoperative topical mydriatics: Induction and sustainability of mydriasis with intracameral mydriatic solution

Context:

Intracameral mydriatic solution can eliminate the disadvantages of repeated eye drop instillation regimen and provide adequate mydriasis for phacoemulsification with added advantages.

Aims:

Evaluating the role of intracameral irrigating solution (0.5% lignocaine + 0.001% epinephrine) in initiating and maintaining the pupillary mydriasis during phacoemulsification. Secondary aims were to observe the effect of surgical time, nucleus density and ultrasound time on mydriasis during the procedure.

Settings and Design:

The study is a prospective interventional case series, conducted at tertiary care institution.

Materials and Methods:

Thirty patients underwent phacoemulsification under topical anesthesia for visually significant cataract. Pupillary dilatation was achieved by intracameral irrigation of mydriatic solution alone. Pupillary diameter was measured serially during surgery and ultrasound time and total surgical time were noted.

Statistical Analysis Used:

Paired samples student–t test was done to compare means. Spearman correlation coefficient was used to study the effect of various parameters on mydriasis.

Results:

Thirty eyes completed the study. The pupil size increased from 2.1 mm (Range 2-3.5 mm SD ± 0.32) to 6.9 mm (Range 5-9 mm SD ± 1.02) in 30 seconds time after intracameral mydriatic solution delivery, and was 7.0 mm (Range 3.5 - 9 mm SD ± 0.20) at the end of surgery. Duration of surgery, grade of nucleus and ultrasound time had statistically insignificant effect on mydriasis.

Conclusions:

Intracameral solution containing 0.5% lignocaine and 0.001% epinephrine provides rapid mydriasis which is adequate for safe phacoemulsification and is unaffected by other parameters.     

The effect of topical anesthesia on the rat electroretinogram

Topical anesthetics are recommended when electroretinograms (ERGs) are recorded using contact lens electrodes. However, these drugs act by blocking voltage-gated Na⁺ channels. Since such channels have been located in both the inner and outer retina of many species, topical anesthesia could affect the ERG recordings in these subjects. The purpose of this study was to evaluate the effects of oxybuprocaine, a commonly used ester local anesthetic, on the rat ERG. Full-field scotopic and pattern ERGs (PERGs) were recorded successively from both eyes of seven rats. One eye was randomly treated with oxybuprocaine 15 min prior to recording. In 10 rats unilateral full-field photopic ERG recordings were conducted prior to, and 15 min after, treatment. B-wave amplitude ratios of the experimental/control eyes were 1.13, 1.30, and 1.35 for the three intensities used to record scotopic ERG responses, and 1.04 for the photopic ERG responses. PERG amplitude ratios of the experimental/control eyes were 1.10, 1.21, 1.21, 1.24, and 1.26 for the five patterns used. Treatment had no significant negative effect on signal amplitude or implicit time of the full-field ERG or PERG. In fact, amplitudes of signals from treated eyes tended to be (insignificantly) higher, though this might reflect better position of the active electrode rather than a biological effect. We conclude that oxybuprocaine has no negative effect on the rat ERG.     

The effect of preoperative topical antibiotics in cataract surgery

PURPOSE: We studied whether topical antibiotics prevent endophthalmitis after cataract surgery. METHODS: Cefmenoxime hydrochloride (CMX) or artificial tears (AT) were randomly instilled 72 hours before surgery. Conjunctival swab samples were taken before the instillation of eye drops (1) and after the instillation of eye drops (2). Aqueous humor (3) was cultured intraoperatively. RESULTS: Positive cultures were found in the CMX group of eyes in 76.3% of (1) samples, 58.1% of (2) samples, and 6.0% of (3) samples. In the AT group of eyes, positive cultures were found in 78.6% of (1) samples, 63.8% of (2) samples, and 2.9% of (3) samples. CMX was not effective. In the CMX group of eyes, Staphylococcus epidermidis was found in 59 eyes of group (1), 5 eyes of group (2), and 0 eyes of group (3). In the AT group of eyes, S. epidermidis was found in 70 eyes of group (1), 26 eyes of group (2), and 1 eye of group (3). In the cases where S. epidermidis was decreased by CMX topical use Propionibacterium acnes was increased. CONCLUSIONS: There is a possibility that preoperative topical use of CMX can reduce S. epidermidis. On the other hand, it might increase P. acnes. Considering these results and the fact that there was no difference in effectiveness in the aqueous humor cultures, preoperative CMX topical use may not prevent postoperative endophthalmitis except for endophthalmitis due to S. epidermidis.     

利多卡因注射液滴眼用于激光角膜原位磨镶术表面麻醉的效果研究

目的探讨2％利多卡因注射液滴眼用于准分子激光角膜原位磨镶术（LASIK）表面麻醉的效果。方法100例（200眼）随机分成利多卡因组和奥布卡因组,每组50例（100眼）。两组分别在两种药物的表面麻醉下进行LASIK,根据术中患者对疼痛和触觉的感受评价麻醉效果。结果利多卡因组中98眼能顺利完成手术,2眼稍感疼痛,追加滴利多卡因1滴后顺利完成手术。奥布卡因组99眼顺利完成手术,1眼稍感不适,未做处理,也顺利完成手术。结论2％利多卡因注射液滴眼用于LASIK表面麻醉效果良好。     

表面麻醉下白内障超声乳化手术中的镇痛效果

目的　客观评价表面麻醉下白内障超声乳化手术的止痛效果。方法　在铺巾前、开睑后滴“0 .4%爱尔卡因”表麻剂二次后做白内障超声乳化手术。随机选择角膜切口组、巩膜切口组各 12 0例 ,手术结束后根据病人主观疼痛感觉 ,按疼痛分类记录 ,分析镇痛效果。结果　本研究手术时间范围 5～ 2 5分钟 ,平均 7.2分钟。角膜切口组疼痛感觉 : 级 11只眼 (9.1%) , 级 12只眼 (10 %) , 级 7只眼 (5 .8%) , 6只眼 (5 .0 %) ;巩膜切口组疼痛感觉 : 级 5只眼 (4.2 %) , 级 9只眼 (7.5 %) , 级 8只眼 (6 .7%) , 级 4只眼 (3.3%)。两组间差异无显著性 (P >0 .0 5 ) ;手术并发症 :角膜切口组环行撕囊失败 8只眼 (6 .7%) ,后囊膜破裂 4只眼 (3.3%) ,巩膜切口组环行撕囊失败 6只眼 (5 .0 %) ,后囊膜破裂 5只眼 (4.2 %) ,无晶体核坠入玻璃体内和眼内大出血等严重并发症。结论　表面麻醉方式行超声乳化镇痛效果良好 ,手术安全、舒适。     

先天性泪囊炎表麻下泪道探通术疗效分析

目的探讨先天性泪囊炎泪道探通术的疗效。方法对75例（82眼）2～10个月婴儿先天性泪囊炎泪道探通疗效观察分析。结果一次探通率90．24％。结论门诊表麻下成功率高,并发症少,复发率低。     

The effect of topical cyclosporin A on the rabbit cornea

To investigate the effect of topical cyclosporin A (CSA) on the rabbit cornea, both eyes of 80 animals were treated with CSA 2% eye drops over a 3-week period under various conditions. CSA was dissolved in castor oil or ethanol 13.8 vol. %. Slit-lamp, scanning and transmission electron microscopic examinations were performed. CSA 2% in castor oil given 5 times daily showed no damage to either the corneal epithelium or endothelium. In contrast the solutions containing ethanol revealed considerable epithelial cell damage.Presented at the meeting of the Northwest German Society of Ophthalmology (Nordwestdeutsche Augenarzte), Hamburg, FRG, 2 June, 1985     

The effect of topical steroid medication on experimental candida keratitis

An immunological study was performed to investigate the effect of topical steroid medication on candida keratitis. 15 albino rabbits were used in this study. Candida keratitis was induced by inoculating candida albicans into the corneal stroma on the animals. In the experimental group (9 rabbits), prednisolone ointment was given twice daily for 4 days prior to the inoculation. In the control group (6 rabbits) no medication was given. The clinical course of keratitis was observed and stimulation of peripheral lymphocytes was measured. Candida extract (soluble antigen) and formalin-fixed candida whole cells (insoluble antigen) were used as antigens to stimulate the lymphocytes. Clinical observation was continued up to 21 days after inoculation. Stimulation of peripheral lymphocytes was measured by the stimulation index (SI) at before 4,7,11,14 and 21 days after inoculation. Inflammation was suppressed clinically in the active phase of the experimental group, but the total course of inflammation was longer than in the control group. In the control group, SI against both soluble and insoluble antigens was elevated. The peak SI was reached at 11 days after inoculation. In the experimental group, SI was elevated against soluble antigen but no elevation was observed against insoluble antigen. These results show that cellular immunological response does exist in experimental candida keratitis in rabbits. Since local steroid medication prolonged inflammation and suppressed cellular immunity, cellular immunity seems to play a significant role in the development and recovery of candida keratitis.     

The antibacterial effect of topical anesthetic proparacaine on conjunctival flora

Purpose: To investigate the antibacterial effect of topical anesthetic proparacaine on conjunctival flora.Methods: One hundred and forty-four eyes of 72 patientsawaiting cataract surgery were included in the study. A commercially available solution of proparacaine, preserved with benzalkonium chloride 0.01%, was instilled in one eye of all subjects while the vehicle solution, including the same concentration of preservative in aqueous solution, was administered to the other eye. Conjunctival cultures were taken from all eyes before and 15 minutes after the instillation of proparacaine and the vehicle.Results: Of the 144 eyes, 76 (52.8%) had positive-conjunctival cultures with the most commonly isolated organisms being coagulase-negative staphylococci in each group. Of the 76 culture-positive eyes, 40 (52.6%) received proparacaine and 36 (47.4%) the vehicle preparation. Fifteen minutes after the instillation of proparacaine and the vehicle eyedrops, four eyes (10%) and 12 eyes (33.3%) had culture-positive conjunctival smears, respectively. Proparacaine significantly reduced the number of culture-positive eyes (p = 0.0003), in contrast to the vehicle (p = 0.21).Conclusion: A topicalanesthetic, proparacaine, demonstrates antibacterial effects on the conjunctival flora.     

The effect of topical corticosteroids on laser-induced peripheral anterior synechiae

Purpose : To assess the influence of different topical steroid agents and a non-corticosteroid medication after Argon laser trabeculoplasty (ALT) on the development of peripheral anterior synechiae (PAS) and the reduction of intraocular pressure (IOP).
Method : In two separate prospective, randomised, group-controlled studies, topical fluorometholone 0.1% (FML Liquifilm) was compared with dexamethasone 0.1% (Maxidex) (Study A), or naphazoline hydrochloride 0.1% (Albalon) (Study 6) after ALT for chronic open-angle glaucoma, with particular reference to the formation of PAS and the IOP response.
Results : In Study A ( N =109) eyes treated with Maxidex had a significantly higher incidence of PAS than those treated with FML—45% compared with 22%, P <0.05 (normal deviate test).
In Study B ( N =75) the incidence of PAS was equal in eyes treated with FML or Albalon (23%).
In the two studies combined ( N =184), the development of PAS was associated with a significantly lower mean response of IOP to ALT—1.47 mmHg compared with 3.22 mmHg, 0.01< P <0.05 (Student t -test).
Conclusion : The incidence of PAS after ALT is significantly higher with the post-laser use of Maxidex than with FML, and is the same for Albalon as for FML. The therapeutic benefit of ALT is significantly reduced if PAS develop.