The removal of 10/0 polyester (Mersilene) sutures after small incision congenital cataract surgery.

PURPOSE: To evaluate the use of 10/0 polyester (Mersilene) sutures for closure of small corneal incision after congenital cataract surgery. METHODS: The authors retrospectively reviewed the medical records of 58 cases (42 patients) who underwent congenital cataract extraction and intraocular lens implantation between 1999 and 2004, using Mersilene sutures. An examination looking for suture-related complications and retinoscopy was done 1 week after surgery and then every month for 6 months. The sutures were removed in cases of local tissue reaction, but not due to high postoperative astigmatism. Paired t-test was used to compare patients' age and astigmatism level in those cases who had suture removal (Group 1) as opposed to those who did not (Group 2). RESULTS: In 10 cases (17%) corneal vascularization, necessitating suture removal, was found during 6-month follow-up period, without the trigger of loose suture. Patient age was 3.5+/-3.3 years and 4.4+/3.3 years in Groups 1 and 2, respectively. At 1 week postoperatively the astigmatism value was 1.7+/-1.7 diopter (D) and 2.3+/-2.2 D in Groups 1 and 2, respectively, and it reduced to 0.9+/-0.8 in both groups at 6 months postoperatively. One case of endophthalmitis was encountered 2 days after suture removal. CONCLUSIONS: Removal of Mersilene sutures after congenital cataract surgery is required in cases of corneal vascularization, occurring during the first months postoperatively. Owing to the risk of general anesthesia and infection, suture removal should be considered with caution in cases of postoperative astigmatism.

The iab-7 polycomb response element maps to a nucleosome-free region of chromatin and requires both GAGA and pleiohomeotic for silencing activity.

In the work reported here we have undertaken a functional dissection of a Polycomb response element (PRE) from the iab-7 cis-regulatory domain of the Drosophila melanogaster bithorax complex (BX-C). Previous studies mapped the iab-7 PRE to an 860-bp fragment located just distal to the Fab-7 boundary. Located within this fragment is an approximately 230-bp chromatin-specific nuclease-hypersensitive region called HS3. We have shown that HS3 is capable of functioning as a Polycomb-dependent silencer in vivo, inducing pairing-dependent silencing of a mini-white reporter. The HS3 sequence contains consensus binding sites for the GAGA factor, a protein implicated in the formation of nucleosome-free regions of chromatin, and Pleiohomeotic (Pho), a Polycomb group protein that is related to the mammalian transcription factor YY1. We show that GAGA and Pho interact with these sequences in vitro and that the consensus binding sites for the two proteins are critical for the silencing activity of the iab-7 PRE in vivo.

Molecular mapping of genetic and chromomeric units in Drosophila melanogaster.

We have used a set of overlapping cloned segments defining a 315 kb (X 10(3) base-pairs) region of Drosophila melanogaster chromosomal DNA to map the sequences associated with the polytene band-interbands (chromomeric units) and with the lethal complementation groups contained within this region. The molecular map positions of the 13 +/- 1 chromomeric units from the 87D5-6 to 87E5, 6 region of the third chromosome were determined by in situ hybridization of selected segments to the polytene chromosomes. The length of the largest chromomeric unit within the 315 kb region is approximately 160 kb, while that for the smallest is less than 7 kb and may be as short as 3 kb. By mapping the breakpoints of deletions within the 315 kb region, we have located its 12 lethal complementation groups, which include the genes coding for acetylcholinesterase (Ace) and xanthine dehydrogenase (rosy). Comparison of the two molecular maps indicates a one-to-one topographical correlation between the genetic and chromomeric units.

Molecular Genetics of the ROSY-ACE Region of DROSOPHILA MELANOGASTER.

Three hundred and fifteen kilobases of DNA from the rosy-Ace region on chromosome 3R of D. melanogaster have previously been cloned and extensively characterized. We describe the isolation of nine new deficiency mutants that break within the 315-kb interval. The position of these breakpoints on the DNA map was determined by in situ and Southern hybridization. Further, we more precisely mapped the breakpoints of several deletions previously analyzed. The results permit us to delimit sequences essential to the known complementation groups in the region within approximately 20 kb in most cases. However, one gene, B16-1, is shown to contain essential sequences that span about 50 kb. Also, we demonstrate by overlapping deficiencies that a 45-kb DNA segment from the region, which includes one known complementation group, allows limited survival when deleted.

Specific inhibition of Pseudomonas aeruginosa elastase injected intracorneally in rabbit eyes.

The compounds benzyloxycarbonyl-L-leucyl-hydroxamate (Z-Leu-NHOH), phosphoryl-L-leucyl-L-phenylalanine (P-Leu-Phe) and 2-mercaptoacetyl-L-phenylalanyl-L-leucine (HSAc-Phe-Leu) strongly inhibit the activity of Pseudomonas elastase in vitro. The capacity of these inhibitors to prevent corneal melting and perforation due to the elastase was examined in rabbit eyes by intrastromal injections of elastase solutions containing the various inhibitors. HSAc-Phe-Leu was substantially more effective than the other two inhibitors. It completely prevented corneal perforation, markedly delayed the appearance of melting and kept the degree of melting at a minimum. Subconjunctival injections of HSAc-Phe-Leu given prior to enzyme administration delayed but did not prevent corneal melting or perforation, whereas frequent topical application with drops of this inhibitor completely prevented corneal melting. It is suggested that HSAc-Phe-Leu or similarly structured inhibitors of the elastase might be helpful in the management of corneal infections with Pseudomonas aeruginosa.

Reattachment of extraocular muscles using fibrin glue in a rabbit model.

PURPOSE: Reattaching extraocular muscles by the conventional suturing method may be complicated by scleral perforation. The attachment of extraocular muscles, using fibrin sealants, avoids such risk. The authors evaluated the use of fibrin sealant in a laboratory rabbit model. METHODS: Fifty-eight eyes of 29 rabbits were used in the study. In both eyes of each rabbit, the superior rectus muscle was disinserted, recessed, and either sutured or reattached to the globe by fibrin sealant. Two groups of eyes were compared. In one group (42 eyes), the recessed muscle was reattached using fibrin sealant. In the second group (16 eyes), sutures were used to reattach the recessed muscle to the globe. The insertion of the superior rectus muscle was examined 14 days after surgery, and histopathologic evaluation was performed 6 weeks after the surgery. RESULTS: Although in the sutured muscle group no slippage from the original placement was found, it was found in the group in which fibrin glue was used. The muscle slippage was greater at the small muscle recessions and smaller at the large muscle recessions. For muscle recession of 6 mm or more, the average muscle slippage was 0.12 +/- 0.28 mm, which was not statistically different from the suture group (P = 0.0828). CONCLUSIONS: Fibrin sealant was found to be effective for extraocular muscle reattachment only in large muscle recessions. However, in small muscle recessions the glue was not strong enough to overcome the contractive strength of the muscle.

Persisting accommodative esotropia.

This report examines the persistence of many cases of accommodative esotropia well beyond the expected time of resolution (age 10 to 12 years) and the potential usefulness of any associated clinical features to predict timely or delayed disappearance. In a series of 202 patients, there was no discrete age of improvement and more than half persisted after age 10 years. The results were similar for both high and normal accommodative convergence/accommodation ratio cases. Initial hyperopia did not predict persistence; subsequent increases prior to age 7 years, and decreases thereafter, were different statistically but were clinically similar. Moreover, the occurrence of inferior oblique overaction and of dissociated vertical deviation, as well as a family history of strabismus, did not predict persistence or delayed improvement.

Adjustment of sutures 8 hours vs 24 hours after strabismus surgery.

PURPOSE: To compare the postoperative results of adjustable-suture strabismus surgery when suture adjustment was performed 8 hours (group 1) and 24 hours (group 2) after surgery. METHODS: A retrospective clinical study was conducted in two hospitals. Strabismus surgery and muscle adjustment were performed in 90 patients. All patients had horizontal strabismus (40 patients had esotropia and 50 patients had exotropia), and they underwent either primary surgery or reoperation. Mean age of the patients was 29.9 +/- 14.1 (range, 14 to 74) years. The angle of deviation was measured in all patients before surgery, after surgery both before and after adjustment, and at the final follow-up examination. The follow-up period was 6 to 40 months (mean, 19.6 months). RESULTS: Preoperative data were similar in the two groups. The mean angle of deviation immediately after muscle adjustment was 0.6 +/- 6. 1 prism diopters in group 1 and 0.4 +/- 6.3 prism diopters in group 2. This similar deviation in the two groups (P =.9) changed during the follow-up period, and at the final examination the measured angles in groups 1 and 2 were -1.0 +/- 7.9 and -2.5 +/- 10.3 prism diopters, respectively (P =.48). The most considerable outcome measure was the calculated drift values. At the last follow-up these values were -1.6 +/- 5.8 for group 1 and -2.9 +/- 11 prism diopters for group 2 (P =.5). Subdividing the patients on the basis of their deviation before surgery, a postoperative drift toward exotropia was found in most patients of group 1. In group 2, however, a greater tendency toward exotropia was shown only by those patients who had displayed exotropia preoperatively, whereas patients with preoperative esotropia showed a greater tendency toward esotropia after surgery. CONCLUSION: In patients undergoing horizontal extraocular muscle surgery with adjustable sutures, suture adjustment 8 hours or 24 hours after surgery did not produce significantly different results.

Measurement of cyclotorsion.

PURPOSE: To measure accurately the amount of cyclotorsion. METHODS: A horizontal light beam of the slit lamp is projected on the retina, crossing the fovea. The slit light will normally cross between the middle and lower thirds of the disk. Cyclotorsion of the eye will cause the horizontal slit-light beam to be projected onto a different part of the disk. The slit light is then tilted by the scale mark on the slit lamp in such a way that the slit light is crossing the fovea and the physiologic area on the disk. RESULTS: The amount of slit-lamp tilt needed is obtained from the scale mark on the slit lamp. This test correlated well with other tests used for the appreciation of cyclotorsion: the Maddox double rod test and indirect ophthalmoscopy. CONCLUSION: A simple method for measuring ocular cyclotorsion is described.

Ocular manifestations in multiple endocrine neoplasia type 2b.

PURPOSE: To describe the clinical and laboratory findings in a patient with multiple endocrine neoplasia type 2b. METHOD: Case report. An 8-year-old boy underwent ophthalmic examination, genetic evaluation, total thyroidectomy, and biopsy of a tongue nodule. RESULTS: Ocular features, including previously unreported iris changes, and their probable origin are discussed. Genetic testing detected the point mutation at codon 918 within the RET protooncogene on chromosome 10, characteristic of multiple endocrine neoplasia type 2b. Histologic analysis of excised thyroid tissue disclosed medullary carcinoma. A tongue nodule proved to be neuromatous. CONCLUSION: Ophthalmologists can play an important role in the recognition of multiple endocrine neoplasia type 2b, a potentially lethal condition.

Ocular signs of cocaine intoxication in neonates.

We examined 13 cocaine-intoxicated neonates, proven by urine assay, by slit lamp and found that most had iris blood vessel abnormalities. Using an iris vascularity scale that ranged from Grade 0 with no visible vessels to Grade 4 with dilated and tortuous vessels, we found that the intoxicated infants had increased grades in the iris periphery and collarette (P less than .02) as compared to 36 control newborns who had no cocaine in their urine. Infants with dilated or tortuous iris vessels were more likely to be intoxicated by cocaine (P less than .01). The presence of dilated or tortuous iris vessels in a neonate should signal the physician to rule out cocaine intoxication.

Convergence insufficiency secondary to subdural hematoma.

PURPOSE/METHODS: Symptomatic convergence insufficiency developed in a 56-year-old man after he sustained head trauma and developed subdural hematoma. RESULTS/CONCLUSION: All symptoms resolved after surgical evacuation of the subdural hematoma. Convergence insufficiency developing after head trauma could be the result of a subdural hematoma.

Anterior segment pathology associated with hypermetropia.

Eight children presented who suffered from pathological changes of the anterior chamber as part of Axenfeld-Rieger syndrome. All of them had associated hypermetropia. Hypermetropia in these cases may have resulted from disturbed development of the anterior segment of the eyes during fetal life.

Superior oblique muscle paresis after sub-Tenon's anesthesia for cataract surgery.

A 68-year-old man developed strabismus after having sub-Tenon's anesthesia for cataract extraction and intraocular lens implantation. An ipsilateral hypertropia with superior oblique muscle paresis developed in the operated eye. The hypertropia appeared 1 day after surgery and resolved 1 month later. Although sub-Tenon's anesthesia is considered safer than other methods of local anesthesia, strabismus may occur.

The effect of 2-mercaptoacetyl-L-phenylalanyl-L-leucine, a specific inhibitor of Pseudomonas aeruginosa elastase, on experimental Pseudomonas keratitis in rabbit eyes.

The compound 2-mercaptoacetyl-L-phenylalanyl-L-leucine (HS-Ac-Phe-Leu) is a potent and specific inhibitor of Pseudomonas aeruginosa elastase, effectively inhibiting the elastase activity both, in vitro and within the rabbit cornea. This inhibitor was therefore evaluated as an adjunct to antibiotics (gentamicin) treatment in experimentally induced Pseudomonas keratitis in rabbits. Twenty eight hours after infection, the eyes that received both, gentamicin and HS-Ac-Phe-Leu showed significantly less corneal melting than those treated with the antibiotics alone, demonstrating the beneficial effect of the inhibitor. Forty eight hours after infection, the difference in clinical appearance between the two treatment groups diminished and was statistically insignificant. No adverse effects were noted in the eyes that received the inhibitor in spite of its frequent application. The protective effect of HS-Ac-Phe-Leu, seen on the first day of the experiment suggests further exploration of the therapeutic potential of this or other, similarly structured, specific and potent inhibitors of Pseudomonas elastase.

Inhibition by phosphoramidon of Pseudomonas aeruginosa elastase injected intracorneally in rabbit eyes.

Phosphoramidon (N-(alpha-L-rhamnopyranosyloxyhydroxyphosphinyl)-L-leucyl-L-trypto phan) is a powerful inhibitor of Pseudomonas aeruginosa elastase. The addition of this compound to an elastase solution injected intrastromally in rabbit eyes protected the corneas from the damage of the enzyme for a period of 12 hours. Phosphoramidon is comparable in this respect to the inhibitor 2-mercaptoacetyl-L-phenylalanyl-L-leucine, but is considerably more effective than its analog phosphoryl-L-leucyl-L-phenylalanine (P-Leu-Phe). It is suggested that the rhamnopyranosyl moiety, present in phosphoramidon but not in P-Leu-Phe, is responsible for the difference in the intracorneal activity of the two phosphoramidates. Phosphoramidon as well as the mercaptoacetyl derivative might prove beneficial in the treatment of Pseudomonas aeruginosa corneal infections.

X-irradiation in the prevention of experimental post-traumatic vitreous proliferation.

We created double perforating injuries in both eyes of 22 rabbits. One eye of each animal was given a dose of 600 Rad x-irradiation 24 hours after the injury. The irradiated eyes developed significantly less intraocular proliferation than the non-irradiated eyes.

Evaluation of superior rectus muscle attachment following hang-back recession in rabbit eyes.

PURPOSE: The hang-back suture technique has been advocated to decrease the risk of scleral perforation during strabismus surgery. In this study, we evaluated the muscle insertion site in rabbits 4 weeks after a hang-back recession was performed. METHODS: Twenty-five eyes of 13 rabbits underwent hang-back recessions of between 5 and 8 mm of the superior rectus muscle. Four weeks later, the attachment sites were examined. RESULTS: Four weeks following the surgery, 14 muscles (n=25, 56%) were anteriorly displaced. In the 5 mm recession group, one muscle was anteriorly displaced (n=7, 14.3%). In the 6 mm recession group, 50% of the muscles recessed were displaced anteriorly (n=8). The 7 mm hang-back recession group demonstrated forward displacement in five muscles operated (n=6, 83%) and in the 8 mm recession group, all four muscles (100%) were anteriorly displaced. The magnitude of displacement was positively correlated to the amount of the hang-back recession performed (Pearson correlation p<0.001). CONCLUSIONS: Anterior displacement of muscles using the hang-back technique in the rabbit eye is unacceptably high and occurred in 56% of the cases. A positive, statistically significant correlation exists between the amount of recession performed and the number of muscles displaced from their new insertion. Therefore, when performing large recessions using the hang-back technique displacement should be anticipated.

Strabismus surgery in children with Möbius syndrome.

Möbius syndrome is a congenital disorder of facial diplegia associated with lateral gaze paralysis. Although palsy of the sixth and seventh cranial nerves is the minimum diagnostic finding for Möbius syndrome, neuropathologic evidence indicates that this is a more complex syndrome.(1) Clinically, it is characterized by a total absence of facial expression and severe esotropia. Other anomalies may be associated with this syndrome, especially other cranial nerve palsies and Poland syndrome. The etiology of this syndrome has not been clearly established. Brain stem necrosis resulting from a vascular deficiency has been offered as a possible pathogenetic explanation.(2) The strabismus in Möbius syndrome is congenital esotropia with bilateral limitation in abduction. Even though many reports have described the various features of Möbius syndrome, only a few articles have reported the results of strabismus surgery in children, including bimedial rectus muscle recession. (3-5) Some authors report that bilateral medial rectus muscle recession alone has been disappointing; therefore, a combination of a medial rectus muscle recession and a lateral rectus muscle resection was recommended for satisfactory results. (5-7) In more severe cases, muscle transposition was needed to ensure straight position of the eyes in primary gaze. (8-9)

Refractive status in children after long-term follow up of cataract surgery with intraocular lens implantation.

PURPOSE: To evaluate the resultant refractive status in children 5 to 11 years after cataract surgery with a high power intraocular lens (IOL) implantation. METHODS: Charts of eight patients (10 eyes) who underwent cataract surgery with IOL implantation by the same technique were reviewed. Age at surgery was 2 months to 3 years. High-power IOL of 27.0 to 30.0 diopters (D) was implanted in seven eyes and lower IOL (between 19.0 D to 23.0 D) in three eyes. Follow-up period was between 5 and 11 years. RESULTS: In children who received a high-power IOL, the resultant refraction after 5 to 7 years was found to be between -5.50 and -12.00 D. In the group that had a lower power IOL implanted, the refraction was between -2.50 and +9.00 after 6 to 11 years. The results were plotted on a graph of refraction vs. IOL power and showed that the IOL power that may result in emmetropia in an older child is 23.2D. CONCLUSIONS: The implantation of a high-power IOL (27 D to 30 D) in eight young children resulted in refractive status within 3 D of emmetropia during the first year or two of life and in high myopia at age 5 to 12 years.