Chemical preparation of the eye in ophthalmic surgery. I. Effect of conjunctival irrigation.

We investigated the effect on bacterial flora of conjunctival irrigation as part of the chemical preparation of the eye before surgery. Forty consecutive patients underwent conjunctival irrigation with a saline solution in one randomly selected eye. Aerobic and anaerobic bacterial conjunctival cultures were taken in masked fashion before and after the preparation. In nonirrigated eyes, the colony counts before and after the preparation were virtually identical; the species count increased 23%. In irrigated eyes, the colony count increased 18% and the species count increased 46%. The increase in the species count was significant. Our findings suggest irrigation with a saline solution does not reduce the bacterial flora of the conjunctiva.

Chemical preparation of the eye in ophthalmic surgery. II. Effectiveness of mild silver protein solution.

Although a mild silver protein solution (Argyrol) has been used for a number of years and is still used by many ophthalmic surgeons, its efficiency as an antibacterial agent on the conjunctiva has not been scientifically evaluated as part of the preoperative chemical preparation of the eye. We studied the effectiveness of a mild silver protein solution on the conjunctival flora of 32 patients in a masked fashion. By bacteriologic analysis, the mild silver protein solution was found to be no more effective in reducing the number of species and colonies in the treated eye than in the untreated eye. While the mild silver protein solution does stain mucus and other debris on the eye to facilitate irrigation, this study did not demonstrate a significant bactericidal effect.

Unsuspected glove perforation during ophthalmic surgery.

OBJECTIVES: To determine the rate of perforation of surgical gloves after ophthalmic surgery and to identify factors that contribute to the development of perforations. DESIGN: Case-control study of used and unused surgical gloves collected during a 7-month period. SETTING: The ophthalmology surgical suites of a major teaching hospital. MAIN OUTCOME MEASURES: Development of glove perforations as measured by five different techniques. RESULTS: We tested 103 pairs of latex surgical gloves before use and 454 pairs of gloves after use. Of five techniques used to test for pinholes, air inflation with water submersion and compression was found to be the most sensitive, yielding a 6.80% prevalence in control glove pairs and a 21.81% prevalence in study glove pairs (P = .0005). When examined by subspecialty area, the lowest perforation rate (11.39%; P = .00009) occurred in cataract and intraocular lens surgery and the highest rate (41.67%; P = .003) occurred in oculoplastic surgery. Factors that correlated significantly with the development of perforations as determined by multiple logistic regression analysis included pediatric ophthalmology and strabismus surgeries, oculoplastic surgeries, level of training of the surgeon, duration of operation, and larger glove size. The thumb and index fingers of the nondominant hand contained the largest numbers of pinholes. CONCLUSIONS: The rate of surgical glove perforation after ophthalmic surgery is relatively high. Recommendations for reducing the rate of glove perforation are discussed.

Chemical preparation of the eye in ophthalmic surgery. III. Effect of povidone-iodine on the conjunctiva.

A half-strength povidone-iodine (Betadine) solution was used topically as part of the preoperative chemical preparation of the eye. Aerobic and anaerobic bacterial cultures of the conjunctiva were taken before and after the chemical preparation in 30 consecutive patients; the second eye served as a control. In the control eyes, no significant change in the number of colonies or species of bacteria was found. In the povidone-iodine-treated eyes, the numbers of colonies decreased 91% and the number of species decreased 50% (statistically significant). We therefore recommend that a half-strength povidone-iodine solution be used as part of the chemical preparation of the eye for surgery.

Chemical preparation of the eye in ophthalmic surgery. IV. Comparison of povidone-iodine on the conjunctiva with a prophylactic antibiotic.

We previously found that half-strength (5%) povidone-iodine solution significantly reduced the bacterial flora of the conjunctiva. To compare the antibacterial effect of a topical combination antibiotic (Neosporin ophthalmic solution) given three times daily for three days preoperatively with that of half-strength povidone-iodine solution given as part of the preoperative preparation, conjunctival cultures were studied from 35 patients undergoing ocular surgery. When used individually, the antibiotic and povidone-iodine solutions caused a similar and substantial decrease in the number of colonies and species of bacteria cultured. When both drugs were used together, the decrease was even more striking, making 83% of the conjunctivae sterile. To minimize bacterial flora before ocular surgery, we recommend that a broad-spectrum topical antibiotic be given for three days preoperatively and that half-strength povidone-iodine solution be used as part of the preoperative preparation.

Development of tearing in preterm and term neonates.

BACKGROUND: Although term and preterm infants have the capacity to secrete tears, the relative contribution of basal and reflex secretion of tears has not been previously assessed together in a prospective study. This information potentially has practical clinical importance. OBJECTIVES: To measure basal and reflex tear secretion in preterm (30-37 weeks after conception) and term (38-42 weeks) newborns and to determine the developmental pattern of tear production. METHODS: Tear secretion was evaluated by applying Schirmer tear test strips to the inferior fornix for 5 minutes before (reflex plus basal secretion) and after (basal secretion) applying a topical anesthetic agent. RESULTS: Seventy infants (36 preterm and 34 term) were tested. Mean (+/- SD) basal tear secretion was 6.2 (+/- 4.5) mm in preterm and 9.2 (+/- 4.3) mm in term infants and increased progressively with increasing weight (P<.001) for all newborns. Mean (+/- SD) reflex tear secretion was 7.4 (+/- 4.8) mm in preterm and 13.2 (+/- 6.5) mm in term infants and also increased with increasing weight (P<.001) for all newborns. CONCLUSIONS: Preterm infants have reduced reflex and basal tear secretion. This may mask the diagnosis of a nasolacrimal duct obstruction, concentrate topically applied medications, and allow corneas to quickly become dry during ophthalmological examination and treatment. By term, tear production in newborns is similar to that in adults.

An improved scleral spatula needle.

I devised a new spatula needle (DO-5) that improves the performance of the established DO-1 needle of the Davis and Geck Co. The diamond-shaped tip of the needle was lengthened to improve its penetration force through the sclera and the widened shoulder of the point was narrowed to enable the needle to pass through the sclera more easily and to provide closer contact between suture and scleral tissue.

Pupillary dilatation with single eyedrop mydriatic combinations.

We studied the mydiatic effect of three solutions containing a combination of two mydriatic drugs in 80 adult patients. The solutions tested were cyclopentolate HCl 0.5% with phenylephrine 2.5%, tropicamide 0.5% with phenylephrine 2.5%, and tropicamide 1.0% with phenylephrine 2.5%. We evaluated the effect of prior instillation of proparacaine 0.5% eyedrops. All three mydriatic combination solutions evaluated produced pupillary dilatation of about 7 mm within 60 minutes. Additional pupillary dilatation of 1 mm occurred when proparacaine was instilled before the mydriatic combination eyedrop. Mydriasis was resistant to bright light during indirect ophthalmoscopy in all patients. Pupils of younger patients dilated better than those of older patients, but sex and iris color were factors in the amount of pupillary dilatation obtained. Wide and sustained pupillary dilatation can be obtained for satisfactory indirect ophthalmoscopy by the instillation of one drop of proparacaine solution followed by a single drop of any of the three mydriatic combination solutions evaluated. By eliminating the need for multiple instillations of drugs, the use of a single eyedrop mydriatic combination is convenient in terms of time saved and also lessens the change of systemic drug toxicity.

Eye position of strabismus patients under general anesthesia.

We studied the change in eye position under general anesthesia in 317 patients undergoing strabismus surgery. We used the prism cover test to measure preoperative eye position, and the prism reflex test (Krimsky's method) to measure the eye position under general anesthesia. Almost all patients had divergence under anesthesia. We calculated a linear equation and curve to relate the eye position under anesthesia to the preoperative eye position. Patients with a normal amount of divergence (within one standard deviation of the mean) had a higher rate of successful surgical results than those with an abnormal amount of divergence under anesthesia (greater than one standard deviation from the mean).

Mydriatic effect of anticholinergic drugs used during reversal of nondepolarizing muscle relaxants.

Large doses of anticholinergic drugs (atropine, glycopyrrolate) produced mydriasis in a group of adults with no eye abnormalities except strabismus, though the usual intramuscular and intravenous doses of these drugs do not have this tendency. Such large doses are often given intravenously during general anesthesia to prevent the side effects of neostigmine methylsulfate, which is used to reverse the effect of nondepolarizing muscle relaxants. Neostigmine methylsulfate (Prostigmin) reduced the mydriatic effect when given intravenously in conjunction with atropine or glycopyrrolate. Mydriasis was more likely to occur in lightly pigmented eyes than in eyes with dark irides. Pilocarpine eyedrops instilled at the beginning of anesthesia caused miosis that persisted after the large intravenous doses of atropine or glycopyrrolate were given. To prevent an attack of acute angle-closure glaucoma in any patient who is to receive large doses of anticholinergic drugs during general anesthesia, miotic drug therapy should be continued before, during, and after anesthesia at the same frequency as when awake.

Generalized fibrosis of the extraocular muscles.

We studied four patients with the general fibrosis syndrome. One patient had bilateral inguinal hernias and unilateral cryptorchism; the other patients had no other congenital abnormalities. The patients developed normally both neurologically and metally. We successfully treated amblyopia and achieved good functional and cosmetic results with strabismus and blepharoptosis surgery. Histopathologic study revealed fibrous infiltration of extrinsic eye muscle and Tenon's capsule without inflammatory changes.

Inferior oblique muscle recession.

Surgical recession of the inferior oblique muscle is simpler to perform if the inferior rectus muscle, rather than either the lateral rectus muscle or the inferior oblique muscle insertion, is used as a landmark. We measured 200 consecutive autopsy eyes to determine the distance from the commonly used 8-mm recession site determined by the Fink technique to the lateral border of the inferior rectus muscle insertion. It was easier to reach this point by measuring 4.0 mm posterior and 4.4 mm superior to the lateral insertion of the inferior rectus muscle, or 2.9 mm superior (on a line parallel to the corneoscleral limbus) and 5.1 mm posterior (on the line perpendicular to the corneoscleral limbus) to the lateral insertion of the inferior rectus muscle. We made anatomical studies to grade the amount of inferior oblique muscle recession and to evaluate the proper placement of the posterior border of the recessed inferior oblique muscle.

The effect of anterior transposition of the inferior oblique muscle.

The effect of anterior transposition of the insertion of the inferior oblique muscle was compared with the results from conventional inferior oblique muscle recession in 50 patients. Even though both groups of patients had a similar degree of overaction preoperatively, postoperative inferior oblique muscle action was weaker (P < .01) and upgaze more limited P < .01) in the anterior transposition group. These data suggest that anterior transposition serves to convert the inferior oblique muscle from an elevator to a depressor on attempted elevation. Because anterior transposition is such a powerful weakening operation, we suggest that it be reserved for patients with moderate to severe inferior oblique muscle overaction. To avoid postoperative hypotropia in upgaze, anterior transposition should be performed in both eyes for bilateral inferior oblique muscle overaction and not unilaterally.

Absent meibomian glands in the ectrodactyly, ectodermal dysplasia, cleft lip-palate syndrome.

A 27-year-old woman with the syndrome characterized by ectrodactyly, ectodermal dysplasia, and cleft lip-palate had an absent lacrimal punctum in each eye, with signs and symptoms of nasolacrimal obstruction during childhood. Examination disclosed bilateral corneal vascularization and opacification, with diffuse superficial punctate staining of the ocular surface epithelium by fluorescein, an instantaneous tear film break-up time, and normal Schirmer tear measurements. A full-thickness biopsy specimen of the eyelid confirmed the absence of meibomian glands that had been suspected because of absent meibomian gland orifices and secretions. The total absence of meibomian gland secretions in this patient may be a primary feature of this case and may contribute to a lipid-deficient and unstable tear film with resultant desiccation and destruction of the ocular surface epithelium. Breakdown of the corneal epithelium in association with obstruction and infection of the nasolacrimal system may be a particularly disastrous combination for the cornea that resulted in the recurrent, severe bacterial corneal ulcers found in our patient.

Source of the conjunctival bacterial flora at birth and implications for ophthalmia neonatorum prophylaxis.

To understand better the source of conjunctival bacteria in neonates, we studied 106 infants immediately after birth before any eyedrops were applied. The 50 infants delivered by cesarean section had significantly fewer species (0.50 +/- 0.85 vs 1.84 +/- 1.33) and colony forming units (272 +/- 1,019 vs 1,790 +/- 3,779) cultured per subject than the 56 infants delivered vaginally. In infants delivered by cesarean section within three hours of membrane rupture, 24 of 30 (80%) of the conjunctival cultures were sterile, while the rest bore a few cutaneous bacteria (0.23 +/- 0.50 species and 2 +/- 9 colony forming units per subject). The conjunctivae of infants delivered vaginally bore significantly more bacteria characteristic of vaginal flora: microaerophilic as Lactobacillus or truly anaerobic as Bifidobacterium. Neonates delivered by cesarean section more than three hours after membrane rupture showed a bacteriologic flora mixture quantitatively and qualitatively midway between those two groups. Infants delivered by cesarean section within three hours of membrane rupture may not need prophylactic eyedrops because of the type and scarcity of conjunctival bacteria.

Povidone-iodine for ophthalmia neonatorum prophylaxis.

PURPOSE: The agents currently used to prevent ophthalmia neonatorum are less than optimal, with reports indicating evidence of bacterial resistance, ineffectiveness, and toxicity. Povidone-iodine ophthalmic solution, which has been shown to be effective in the preoperative preparation of the eye, generates no resistance, is an effective antimicrobial agent, and has low toxicity. We evaluated the effectiveness and safety of povidone-iodine for ophthalmia neonatorum prophylaxis. METHODS: A bacterial culture was taken from the conjunctiva of each eye of 100 infants within 30 minutes of birth. A drop of 2.5% povidone-iodine solution was then placed on one eye, while the other eye received either one drop of silver nitrate 1% ophthalmic solution or 0.5% erythromycin ointment. Conjunctival bacterial cultures were again taken two to four hours after birth. At each culture and at 24 hours after birth, the eyes were examined for toxic changes. To measure the effectiveness of the medications, the number of bacterial colony-forming units and species from each culture was compared. RESULTS: All three agents significantly reduced the number of colony-forming units, but povidone-iodine caused the most significant decrease. The number of species was reduced significantly by povidone-iodine (P = .00051) and silver nitrate (P = .007), with povidone-iodine yielding the most significant decrease. Erythromycin did not significantly reduce the number of species. Silver nitrate demonstrated more ocular toxicity at the 24-hour determination point than did either of the other two medications (P < .001). CONCLUSIONS: Povidone-iodine 2.5% ophthalmic solution is an effective antibacterial agent on the conjunctiva of newborns and causes less toxicity than silver nitrate.

The effect of povidone-iodine solution applied at the conclusion of ophthalmic surgery.

PURPOSE: Povidone-iodine 5% solution decreases the incidence of postoperative endophthalmitis when used on the eye for preoperative preparation. We sought to determine whether it also minimized conjunctival bacterial flora immediately after surgery by preventing bacteria present on the surface of the eye from entering surgical wounds. METHODS: In 42 eyes of 40 patients, at the conclusion of surgery, on an alternating basis, each patient received either a drop of a broad-spectrum antibiotic solution (polymyxin B sulfate-neomycin sulfate-gramicidin) or a 5% povidone-iodine solution in the operated-on eye. Bacterial cultures were taken before and after surgery and 24 hours later. The 38 unoperated-on eyes in the unilateral cases served as control eyes. RESULTS: Relative to the control group, povidone-iodine was effective in preventing an increase in the number of colony-forming units (P = .035), while the antibiotic was not. At 24 hours after surgery, the species count was lower in the eyes receiving povidone-iodine than in the antibiotic-treated eyes (P = .034) and was increased in the antibiotic group since the completion of surgery (P = .013), but was lower in the povidone-iodine and antibiotic groups than in the control eyes for both groups (P < .01). CONCLUSIONS: Povidone-iodine 5% solution applied to the eye at the conclusion of surgery was more effective at minimizing the number of colony-forming units and species for the first postoperative day than was a broad-spectrum antibiotic. While not true for the antibiotic, the antimicrobial effect of povidone-iodine lasted for at least 24 hours after the completion of surgery.

Efficacy of topical povidone-iodine during the first week after ophthalmic surgery.

PURPOSE: In the first postoperative day, povidone-iodine ophthalmic solution prevents an increase in conjunctival bacterial colony-forming units and decreases the species compared with antibiotic. We sought to determine whether these beneficial effects of povidone-iodine could be sustained during the first postoperative week. METHODS: In 42 eyes of 35 consecutive patients, one or two drops of either a broad-spectrum antibiotic (polymyxin B sulfate-neomycin sulfate-gramicidin) or povidone-iodine 1.25% to 2.5% were placed in the treated eye or eyes at the conclusion of surgery and three times daily during the first postoperative week. Bacterial cultures were taken from both eyes at the end of surgery before instillation of either of the eyedrops and again 1 week later. Twenty-eight untreated eyes served as a control group. RESULTS: During the first postoperative week, the number of colony-forming units and species increased in both treatment groups. Relative to the control group, both medications effectively reduced the mean number of colony-forming units at 1 week (P < .02), but their effects on colony-forming units did not significantly differ from each other (80 +/- 290 for the povidone-iodine-treated eyes and 75 +/- 90 for the antibiotic-treated eyes). At 1 week, the species count increased 281% in the antibiotic group but only 106% in the povidone-iodine group. Compared to the control group, eyes that received povidone-iodine had a significantly lower species count (P = .0097). CONCLUSION: Povidone-iodine ophthalmic solution is an alternative to postoperative topical antibiotics because of its effectiveness in controlling conjunctival bacterial colony-forming units and species, its relatively low cost, and its availability.

Antimicrobial preparation of the eye for surgery.

An important source of postoperative eye infection is the indigenous flora in and around the eye. Therefore, proper preparation of the operative field is crucial. Through an international survey we determined that ophthalmic surgeons used widely varying techniques in the pre-operative antimicrobial preparation of the eye. On the basis of these survey responses we have studied to date the effect on the bacterial flora of the conjunctiva of three regimens. Irrigation of the conjunctiva with saline tended to increase the ocular flora; instillation of silver protein solution had no significant effect. Povidone-iodine drops (5%) significantly reduced both colony and species counts.

The oculocardiac reflex as a surgical aid in identifying a slipped or 'lost' extraocular muscle.

The oculocardiac reflex during strabismus surgery has generally been regarded as a hazard capable of causing death. Six cases are presented which show a beneficial use of the oculocardiac reflex. Isolation of a previously slipped or 'lost' extraocular muscle can be difficult. In this series identification of the tissue as muscle was substantiated by observing a positive oculocardiac reflex when traction was placed on the suspected tissue. Each of the 6 dislodged extraocular muscles was the medial rectus muscle. Three of the muscles had been resected and 3 either recessed or tenotomised. In one patient, despite 6 previous strabismus operations, including 2 strabotomies on a muscle that slipped, and in another patient, who had a lapse of 6 years since the last strabotomy, when the slipped muscle was isolated, the oculocardiac reflex could still be elicited. To avoid abolishing the oculocardiac reflex during surgery the anaesthetist should be instructed to avoid the use of an intravenous parasympatholytic agent, such as atropine, at the time of induction and during the operation.