Intraocular Lens Power Calculation in the Absence of Pre-PRK Data in Moderate Myopic Eyes

PURPOSE: To evaluate the correlation between the conventional method and the clinical history method for intraocular lens power calculation for cataract surgery in eyes with previous photorefractive keratectomy in the absence of pre-PRK data. METHODS: The medical records of 38 eyes in 23 patients who had been treated with PRK for myopia and were followed up for more than 1 year were reviewed. The IOL powers by conventional method using post-PRK keratometric value and by clinical history method were compared. RESULTS: The mean values of IOL powers by conventional method, and by clinical history method were +20.58 +/- 1.10D (range, +16.37~+22.80D) and +21.06 +/- 0.85D (range, +18.85~+22.8D), respectively. The following equation describes the regular relationship between the two METHODS: IOLCHM (clinical history method)= 0.683*IOLCM (conventional method) +7.005 (r=0.878, p<.01). When the IOL powers by conventional method were applied to this equation, the mean difference of value between the IOL powers calculated from this equation and those of the clinical history method was?0.01 +/- 0.41D (range, -0.99~+0.76D). CONCLUSIONS: This equation will be helpful to calculate the IOL power for cataract surgery in eyes with previous PRK in the absence of pre-PRK data.

Corneal Endothelial Protection of Ascorbic Acid against Free Radicals during Phacoemulsification

PURPOSE: To evaluate corneal endothelial protection effect of ascorbic acid (AA) at the most appropriate concentration, and determine the synergistic effect of glutathione in irrigation solution during phacoemulsification. METHODS: Phacoemulsification was performed in the anterior chamber of 30 rabbit eyes for 5 minutes without damage to other ocular structures. Thirty rabbit eyes were divided into 6 groups, of 5 eyes each, according to the following irrigation solutions in phacoemulsification.: BSS(R) in group 1, BSS(R) with 1 mM AA in group 2, BSS Plus(R) in group 3, BSS Plus(R) with 0.1 mM AA in group 4, BSS Plus(R) with 1 mM AA in group 5 and BSS Plus(R) with 10 mM AA in group 6. Corneal endothelial loss was measured with specular microscopic photographies taken before and 1 week after surgery. RESULTS: Postoperatively endothelial counts were reduced by 592.0 +/- 100.0, 275.9 +/- 51.9, 658.2 +/- 107.1, 466.3 +/- 88.6, 259.3 +/- 61.6 and 451.6 +/- 63.7 (mean cells/mm2 +/- SD) in groups 1-6, respectively. Endothelial cells in group 2 were less reduced than in group 1 (P=0.009), but there was no difference between groups 2 and 5. Though the reduction of endothelial cells in groups 4, 5, and 6 were less than in group 3 (P<0.05), group 5 showed more significant endothelial protection effect than groups 4 and 6 (P=0.009, 0.009). CONCLUSIONS: AA in irrigation solution showed endothelial protection effect against free radicals during phacoemulsification, and 1 mM was the most effective concentration. Combination of glutathione with AA did not show any synergistic endothelial protection effect.

Subconjunctival Juvenile Xanthogranuloma Involving the Limbus Associated with Neurofibromatosis

PURPOSE: To report a case of isolated subconjunctival juvenile xanthogranuloma invading the corneal limbus in a patient with neurofibromatosis. METHODS: A 2-year-old boy visited the hospital with a conjunctival yellow-brown, non-tender mass of the left eye, which had been found 2 months earlier. Anterior segment examination revealed a 9 x 7 mm-sized subconjunctival elevated mass with an ill-defined border, invading the supero-temporal limbus. Additional ophthalmic examinations did not show any abnormal findings. In the trunk and extremities, there were multiple soft nodules and brown macules. An excisional biopsy of the subconjunctival mass, histopathologic and immunohistochemical examinations were performed. RESULTS: The mass was adhered to the episcleral tissue, without scleral or conjunctival involvement. The histological examination showed a granulomatous lesion consisting of multiple lipid-laden macrophages and other inflammatory cells. The immunohistochemical study showed positive staining for CD68 and negative staining for S100 protein. The multiple soft nodules and brown macules in the trunk and extremities were identified as neurofibromas and caf -au-lait macules by a dermatologist, and the patient was diagnosed with neurofibromatosis. CONCLUSIONS: We report a rare case of subconjunctival juvenile xanthogranuloma involving the limbus, associated with neurofibromatosis.

The Effect of Low-power Laser on the Murine Hair Growth

Low-power laser(LPL) delivers a small amount of energy without elevation of tissue temperature. LPL has been reported to have biostimulation effects including anti-inflammatory, analgesic, regenerative, immunocorrective, and vasodilative effects. However, the effect of LPL on hair growth has rarely been studied. We investigated the effect of LPL on hair growth in the mouse. After depilation of back skin of mice, we classified the mice into 4 groups: control, laser irradiated group, MoandMore(R) applied group, and Spella 707(R) applied group. Laser irradiation or application of these drugs were performed on the back skin of the mice for 30 days. The results are summarized as follows. Hair growth of control was first observed at 13 days after depilation, and complete hair regrowth was observed at 25 days. Hair growth of both laser irradiation group and MoandMore(R) applied group was first observed at 9 days after depilation, and complete hair regrowth was observed at 20 days. Hair growth of Spella 707(R) applied group was firstly observed at the 9 days after depilation, and complete hair regrowth was observed at the 15 days. Hair growth started at the irradiation site in the laser irradiation group, but it started at the random sites in other groups. In conclusion LPL irradiation have a stimulating effect on the hair growth in the mouse.

The Effect of Repeated Use of the Disposable Blade in Automated Microkeratome on the Corneal Flap Dimensions and Cut Quality

PURPOSE: To evaluate changes in the blade, flap dimensions, and stromal bed with repeated use of disposable blade in LASIK (laser in situ keratomileusis) surgery. METHODS: A keratome was used to make a corneal flap in pig cadaver eyes, with the blades being reused up to five times. The thickness and diameter of each corneal flap was measured. Scanning electron microscopy of the stromal beds and blade cutting edges was performed to determine the effect that repeated use of the blade had on the stromal bed, and on the cutting edge of the blade. RESULTS: The thickness/diameter of flap was 169.73 +/- 7.55 micro meter/8.60 +/- 0.23 mm after single use and 142.93 +/- 13.10 micro meter/8.72 +/- 0.20 mm after being used five times, with both demensions decreasing as the blade was used more. The edge of the blade became blunt and irregular and the cutting surface rough and irregular with continual use. CONCLUSIONS: During LASIK surgery, reused blades became blunt, causing a thin flap, rough cutting face, and complications such as irregular astigmatism clinically.

A Case of Decompression Retinopathy after Glaucoma Surgery

PURPOSE: Acute decompression of the eye in patients with high intraocular pressure (IOP) can lead to development of posterior pole hemorrhages. The courses of this rare syndrome is relatively benign. Herein we report a case of decompression retinopathy that developed diffuse retinal hemorrhages after glaucoma surgery in both eyes. METHODS: A 17-year-old male patient diagnosed with juvenile primary open angle glaucoma (JPOAG) underwent glaucoma surgery on both eyes at five months interval. Visual acuity on presentation was no light perception (NLP) in the right eye and 1.0 in the left eye. On the first postoperative day, IOP was 4 mmHg and diffuse retinal hemorrhages was found in the posterior pole after nonperforating trabecular surgery and triangular reticulated sodium hyaluronidate (SK GEL 3.5) implantation in the right eye. Trabeculectomy with 0.02% mitomycin C soaking (1 minute) was performed in the left eye 5 month after the right eye operation. On the second postoperative day, IOP was 5 mmHg and diffuse retinal hemorrhages was also observed in the posterior pole of the left eye. During the follow-up period (8 weeks), the retinal hemorrhage was absorbed without impairment of visual acuity. RESULTS: Decompression retinopathy developed in the posterior pole of the patient with JPOAG after glaucoma surgery, and the hemorrhages were absorbed over time with no visual impairment.

Long-Term Alignment after Bimedial Rectus Recessions for Infantile Esotropia

PURPOSE: Long-term alignment after bimedial recti recessions for infantile esotropia were evaluated in 51 infantile esotropes with angle less than 55 PD. All patients were followed up for more than 2 years (Mean 4.5+/-2.0 years). METHODS: All the patients'charts were reviewed retrospectively. They were divided into three groups as follows: 1) orthophoria within +/-8PD, 2) esotropia, and 3) exotropia by final alignment. In each group, immediate postoperative angle of deviation, success rate and stereopsis were evaluated. And the relation between final alignment and immediate postoperative angle of deviation were studied. RESULTS: The mean preoperative deviation of all patients was 44.1+/-6.67 PD (22~54 PD). Monocular preference was shown in 49.1% (25 patients) at the initial visit. Twenty-eight patients (54.9%) were aligned within +/-8 PD of orthotropia after initial surgery and forty-three patients (83.4%) after the second operation. The immediate postoperative deviation averaged 1.2+/-5.17% PD of exotropia in 28 patients who were aligned within +/-8 PD of orthotropia at the last visit. The patients with deviation of +/-3PD immediately after surgery were found to be mostly aligned within +/-8 PD of orthotropia at the last visit (51.7%, p=0.07). Thirty-one of 42 patients (73.8%) had measurable stereopsis and 47.6% of these patients favorable stereopsis better than 800 seconds of arc. The most satisfactory results in the obtaining stereopsis was shown in the patients undergoing surgery between 1~2 years of age. CONCLUSIONS: Bimedial recti recessions for infantile esotropia less than 55 PD were effective as an initial procedure in long-term follow-up for more than 2 years. Orthotropia within +/-3 PD in the immediate postoperative period was desirable for the long-term alignment. Binocularity was best obtained by undergoing early surgery between 1~2 years of age.