Clinical Result of Planned Posterior Continuous Curvilinear Capsulorrhexis in Adult Patients

PURPOSE: Following planned posterior continuous curvilinear capsulorrhexis (PCCC) during cataract surgery in adults, we evaluated the clinical effects of visual acuity and prevention of posterior capsule opacity. METHODS: The clinical results were studied retrospectively by comparing 43 eyes of 43 patients who underwent cataract surgery with PCCC (the experimental group) and 46 eyes of 31 patients who underwent cataract surgery without PCCC (the control group). Preoperative and postoperative best corrected visual acuities (BCVAs) of patients were measured. BCVA (using log MAR) and the occurrence of posterior capsule opacity were closely monitored in both groups preoperatively, two months postoperatively, and at each group's final visit (14.6 months postoperatively for the experimental group and 15.7 months for the control group). One-piece plate intraocular lens was used in cataract surgery. RESULTS: Preoperative BCVA was lower in the control group but not significantly. The 2-month mean postoperative BCVA showed improvement in vision in both the control and experimental groups. In both groups, the BCVA was decreased at the final examination compared with the 2-month postoperative BCVA, and significant differences between the two groups were not observed. Under slit lamp examination, anterior hyaloid opacity was observed in 13 of 43 eyes that underwent PCCC. The decrease in BCVA in 13 eyes with anterior hyaloid opacity was significantly different (p < 0.05) compared with the 2-month postoperative BCVA. CONCLUSIONS: Considering the effort and operation skills required for PCCC, the clinical benefits are negligible. Since cataract surgery with PCCC can cause reduced vision due to anterior hyaloid opacity, side effects should be disclosed before PCCC is performed.

Modified Surgical Technique for Transscleral Fixation of a Single-Piece Acrylic Intraocular Lens in the Absence of Capsular Support

PURPOSE: To introduce a new surgical method of transscleral intraocular lens (IOL) fixation using a foldable, single-piece acrylic IOL with 4 loop haptics and to report the surgical results. METHODS: After a single-piece acrylic IOL with 4 loop haptics was injected into the anterior chamber and positioned on top of the iris diaphragm, a 10-0 Prolene STC-6 straight needle and a 27-gauge needle were used to string the prolene thread through the haptic openings from front to back fixating the IOL to the sclera, resulting in a transscleral "1 loop 4 points" fixation. Twenty-eight eyes of 28 patients who had received transscleral fixation via this new technique were retrospectively reviewed. The best corrected vision acuity (BCVA) was measured after a postoperative period of at least 6 months. Intraoperative and postoperative complications were investigated. RESULTS: In 27 out of 28 eyes (96.4%), the postoperative BCVA was better than 0.5 (Snellen chart). The only complication found was 1 case of choroidal detachment (3.6%). CONCLUSIONS: The new transscleral "1 loop 4 points" fixation technique of a foldable, single-piece acrylic IOL in the absence of capsular support is an easy procedure and reduces surgical time and hastens visual rehabilitation due to excellent IOL positioning stability. Additionally, the technique described in the present study may be a safe procedure with minimal complications.

Modified Surgical Technique for Transscleral Fixation of a Single-Piece Acrylic Intraocular Lens in the Absence of Capsular Support

PURPOSE: To introduce a new surgical method of transscleral intraocular lens (IOL) fixation using a foldable, single-piece acrylic IOL with 4 loop haptics and to report the surgical results. METHODS: After a single-piece acrylic IOL with 4 loop haptics was injected into the anterior chamber and positioned on top of the iris diaphragm, a 10-0 Prolene STC-6 straight needle and a 27-gauge needle were used to string the prolene thread through the haptic openings from front to back fixating the IOL to the sclera, resulting in a transscleral "1 loop 4 points" fixation. Twenty-eight eyes of 28 patients who had received transscleral fixation via this new technique were retrospectively reviewed. The best corrected vision acuity (BCVA) was measured after a postoperative period of at least 6 months. Intraoperative and postoperative complications were investigated. RESULTS: In 27 out of 28 eyes (96.4%), the postoperative BCVA was better than 0.5 (Snellen chart). The only complication found was 1 case of choroidal detachment (3.6%). CONCLUSIONS: The new transscleral "1 loop 4 points" fixation technique of a foldable, single-piece acrylic IOL in the absence of capsular support is an easy procedure and reduces surgical time and hastens visual rehabilitation due to excellent IOL positioning stability. Additionally, the technique described in the present study may be a safe procedure with minimal complications.

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.

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.

The Differences in Results of Short Wavelength Automated Perimetry According to Lens Opacities

PURPOSE: Perimetric examination plays an important role in the diagnosis of glaucoma, which is among the leading causes of blindness worldwide. Several examination methods have been developed for early detection of glaucoma. Among those, short-wavelength automated perimetry (SWAP) is the most widely investigated. In this study, the effects of nuclear opacities on SWAP were examined. METHODS: Lens opacities were divided into cortical and nuclear opacity groups ; each group consisted of fifteen eyes. The eyes studied underwent standard white-on-white perimetry and SWAP exams before and after cataract operation. The differences in the results of the examinations were compared between the two opacity groups. The t test was used for comparing the data. RESULTS: In the cortical opacity group, the average difference between the mean deviation before and after the operation was 5.46dB in white-on-white perimetry and 5.02dB in SWAP. In the nuclear opacity group, the average difference between the mean deviation before and after the operation was 4.01dB in white-on-white perimetry and 10.82dB in SWAP. There was no statistically significant difference in the cortical opacity group (p=0.6575). However, there was a statistically significant difference in the nuclear opacity group (p<0.0001). CONCLUSIONS: In clinical situations, more caution should be taken when interpreting the SWAP results of nuclear cataract patients in order to make an accurate decision.

Surgical treatment modalities of thyroid ophthalmopathy

This report presents the use of various surgical treatment modalities in patients who were diagnosed as having thyroid ophthalmopathy. The records of 53 patients who received surgery because of thyroid ophthalmopathy at the Department of Ophthalmology, Yonsei University College of Medicine between Sept. 1996 and Jan. 2000 were retrospectively evaluated. Among the 53 patients, there were 30 females and 23 males. The mean ages of the patients were 40.8 +/- 17.1 years. Orbital wall decompression (52.8%) was the most frequently performed surgery followed by lid surgery (49.1%) and strabismus surgery (26.4%). Only one type of surgery was performed on 86.8% of the patients while 13.2% received more than one type of surgery. Among the many different types of surgeries possible in patients that have thyroid ophthalmopathy, orbital wall decompression, lid surgery, and strabismus surgery are the most commonly used surgical methods for treatment.

Analysis of the factors affecting decentration in photorefractive keratectomy and laser in situ keratomileusis for myopia

To evaluate the relationship between ablation zone demm in PRK and 88.7% were decentered less than 0.75 mm in LASIK. The most meridional displacement was toward the superonasal quadrant; 46% in PRK and 51% in LASIK. There was less decentration in males, in the 2nd-operated eye, in older age, PRK, in larger ablation diameter, and in shallower ablation depth, but these differences were not statistically significant.

Morphologic studies of the retina in a new diabetic model; SHR/N:Mcc-cp rat

The pathogenesis of diabetic retinopathy has not been fully explained. The earliest histological lesion is the loss of intramural pericytes and thickening of the basement membrane. Increased activity of the polyol pathway is a probable mechanism for these two abnormalities. Investigations have suffered from the lack of an exact animal model simulating the human condition. Examination of the retina in the spontaneously diabetic SHR/N:Mcc-cp rat demonstrated degeneration and loss of intramural pericytes, a progressive increase in basement membrane thickness, and microinfarctions with an area of non-perfusion. Therefore, this model may be used to clarify the biochemical mechanisms linking the metabolic abnormalities of diabetes and retinopathy.