Posterior Surface Opacification of a Silicone Intraocular Lens in a Patient with Asteroid Hyalosis

PURPOSE: In the present study, a case of posterior surface opacification of a silicone intraocular lens (IOL) in a patient with asteroid hyalosis (AH) is reported. CASE SUMMARY: 76-year-old male was referred to our clinic with IOL opacification in his left eye. The patient had uneventful cataract surgery 7 years prior with the same silicone IOL implanted in both eyes. Three years after surgery, posterior capsular opacity was observed in his left eye and neodymium:YAG (Nd:YAG) laser capulotomy was performed. After posterior capsulotomy, opacification of the IOL's posterior surface was observed on slit lamp examination. IOL exchange was performed and the explanted IOL was analyzed using a light microscope and a scanning electron microscope with energy dispersive X-ray spectroscopy for elemental analysis of the deposits. The calcification was on the posterior surface of the IOL and composed mainly of calcium and phosphorus, the main components of AH. The right eye showed clear IOL with intact posterior lens capsule. CONCLUSIONS: Surgeons performing cataract surgery should consider the possibility of surface calcification of silicone IOLs in eyes with AH before IOL selection for implantation.

Morphological Changes in Extraocular Muscle of Rabbit Eye Produced by Subtenon's Botulinum A Toxin Chemodenervation

PURPOSE: Currently, when injecting botulinum a toxin into the extraocular muscle, EMG (Electromyography) is used for accurate location. In this study, we examined the effects of subtenon botulinum toxin injection without EMG guidance by quantifying the morphological changes of the extraocular muscle fibers in rabbits. METHODS: Using 10 New Zealand white rabbits, 10 units of botulinum a toxin in 0.1 ml of normal saline was injected into the subtenon space of the superior rectus muscles, 5 mm from the muscle insertion in right eyes. As a control, 0.1 ml of normal saline was injected into the subtenon space of the superior rectus muscles in left eyes. At 3 weeks after injections, the bilateral superior rectus muscles of each rabbit were carefully dissected from the globe. Cross-sections of 5 micrometer thickness were obtained at the site, 5 mm from the insertion of each superior rectus muscle. Sections were stained with Masson's trichrome and observed by light microscopy. Using Image-Pro Plus software, the diameter of the orbital layer myofibers was measured and statistical analysis was done using the Kruskal-Wallis test. RESULTS: The average diameter of the orbital layer fiber cells after botulinum toxin injection was 11.5+/-2.26 micrometer at 3 weeks, whereas that of the control was 14.4+/-3.77 micrometer. The difference was statistically significant (p<0.01). CONCLUSIONS: The diameter of myofibers in the orbital layer was reduced after subtenon botulinum a toxin injection. Further studies on the duration of botulium toxin in subtenon space and the change in the size of myofibers depending on the dosage of botulinum toxin will be necessary.

A Case of Inadvertent Anterior Chamber and Corneal Stromal Injection with Antibiotics during Cataract Operation

PURPOSE: To report a case of inadvertent anterior chamber and cornea stromal injection with high dose antibiotics and steroids during cataract operation. METHODS: During cataract operation on a 78 year-old female patient, high dose gentamicin (20 mg/0.5 ml) and dexamethasone (2 mg/0.5 ml) were inadvertently injected into the anterior chamber and cornea stroma when making cornea edema for sealing of the incision sites. Anterior chamber irrigation with balanced salt solution (BSS) was immediately administered. On postoperative day one, extensive cornea edema was noted, and best-corrected visual acuity was 0.2. Descemet's membrane folds were observed around the corneal incision sites. Topical 5% NaCl and 1% prednisolone were started. RESULTS: Four weeks postoperatively, corneal edema began to reduce significantly. At four months postoperatively, corneal edema fully resolved, and best-corrected visual acuity was 0.8. However, some Descemet's membrane folds still remained, and a decrease in the number of endothelial cells was noted by specular microscope. CONCLUSIONS: In this case involving anterior chamber and cornea stromal injection with high dose antibiotics and steroids, immediate anterior chamber irrigation with balanced salt solution seemed an appropriate management, and the patient's long-term visual acuity appears good. To prevent such mistakes, precise labeling of all solutions and use of different syringe needles should be considered.

The Effect of Larger and Blend Zone Ablation on Optical Aberrations in Laser Epithelial Keratomileusis (LASEK)

PURPOSE: The purpose of this study is to investigate the postoperative high order aberration after LASEK and to evaluate the effects of LASEK on high order aberration using larger and blend zone ablation. METHODS: Twenty patients out of 28 patients who received treatment were followed up for 3 months. In each case, one eye received conventional ablation LASEK and the other eye received larger and blend zone ablation LASEK. Preoperative and postoperative RMS (root mean square) of Bille aberration maps measurements were made with WaveScan Wavefront(TM) system (VISX, Santa Clara, U.S.A.). RESULTS: RMS of Bille aberration maps at post operation 1 month and post operation 3 months displayed a statistically significant increase compared with preoperative value. (p<0.05) In post operation 3 month, larger and blend zone ablation LASEK treated eyes displayed a statistically significant lower post operative RMS compared to those of conventional ablation LASEK.(p<0.05) CONCLUSIONS: High order aberrations at post operation 1 month and post operation 3 months increased compared with preoperative value. High order aberration after LASEK with larger and blend zone ablation are less pronounced compared to those associated with conventional ablation LASEK. By using larger and blend zone ablation it is possible to minimize the high order aberration of the eye and improve visual results for patients undergoing LASEK.

The Clinical Significance of Bone Scan in Orbital Wall Fracture

PURPOSE: Occasionally it is necessary to differentiate an old fracture of orbit from newly developed one, especially when surgery is considered or legal problem is involved. In this study, we evaluated the efficacy of bone scan in differentiating old fracture from new one. METHODS: Patients who had orbital wall fracture but did not fit into operative indication were included. After intravenous injection of 99mTc-MDP, bone scan was taken using Single Photon Emission Computed Tomography (SPECT) immediately after injury and with 2 month intervals afterwards. We analyzed the change of tracer uptake on the fracture sites. RESULTS: Sixteen out of 19 patients showed hot uptake on initial bone scan. In 3 patients, no hot uptake was observed on initial bone scan, which led us to believe that they were old fractures. Among 7 patients who had been followed up for more than 4 months, 5 patients showed disappearance of hot uptake in 6 months and 2 patients in 4 months. CONCLUSIONS: We concluded that bone scan is useful in differentiating old fracture of orbit from newly developed one.

Necrotizing Conjunctival Ulceration following Subconjunctival Atropine Depot Injection

PURPOSE: To report a case of severe conjunctival necrosis associated with scleral melting following subconjunctival atropine depot injection in treating posterior synechiae associated with uveitis. METHODS: A 31-year-old male patient visited our clinic after subconjunctival injection of 1% atropine, 0.4 ml, in treating circular posterior synechiae associated with uveitis in his left eye. The marked conjunctival injection and chemosis around the limbus were noted. Three days after first visit to our clinic, remarkable necrosis had developed around the whole limbus, and newly developed whitish necrotic tissue was noted over sclera and episclera. We debrided the necrotic conjunctiva and episclera, and the exposed sclera was grafted with amniotic membrane. REUSLTS: After 4 weeks, the complete re-epithelization of necrotized defect was shown and there were no evidence of inflammation, symblepharon, or scleral melting. CONCLUSIONS: In usage of atropine, especially to eyes locally, subconjunctival injection should be avoided due to direct toxicity to the conjunctiva and sclera to form necrosis and melting. The damaged lesions of conjunctiva and sclera due to usage of this drug generally cause chronic inflammation and persistent surface defect. In order to restore and re-epithelize the necrotic defect, more aggressive treatment such as an amniotic membrane transplantation would be needed.