A Case of Retained Descemet's Membrane after Penetrating Keratoplasty

PURPOSE: To report a case of retained Descemet's membrane after penetrating keratoplasty (PKP). CASE SUMMARY: A 64-year-old man visited our clinic, complaining of visual disturbance and corneal opacity in his right eye 40 years in duration. On the first visit, his best corrected visual acuity was hand movement on the right eye, and he underwent an uneventful PKP. On the postoperative first day, the patient's visual acuity was 20/200 and slit lamp examination showed a retained Descemet's membrane and pseudo-chamber behind the corneal graft. The corneal graft was edematous, but no intraocular inflammation was observed. The retained Descemet's membrane was surgically removed a quarter at a time. Sutures in one quadrant were removed; the retained Descemet's membrane was lifted with forceps, removed with scissors and knife, and then sutured again. Two months after PKP, the corneal graft remained clear and no intraocular inflammation was observed. An extracapsular cataract extraction (ECCE) was then successfully performed with posterior chamber lens implantation for the senile cataract in his right eye. After the 1-year follow-up, the status of the corneal graft remained clear with a single anterior chamber and best corrected visual acuity improved to 20/100. CONCLUSIONS: Careful post-operative slit-lamp examination is considered important for diagnosis of retained Descemet's membrane after undergoing PKP, and surgical removal can be helpful for maintaining the corneal graft clear.

Clinical Course of Submacular Hemorrhage Due to Various Chorioretinal Diseases According to Pneumatic Displacement

PURPOSE: To assess the clinical course of submacular hemorrhage (SMH) due to various chorioretinal diseases with or without pneumatic displacement and the factors related with the final visual outcome. METHODS: The authors of the present study retrospectively reviewed the charts of 12 eyes (group 1) which underwent pneumatic displacement for SMH and the charts of 14 eyes (group 2) which did not receive pneumatic displacement. Best-corrected visual acuity (BCVA) at baseline was compared with the BCVA at 1, 3, and 6 months and on the final visit. Association between final BCVA and other clinical features was analyzed including age, baseline BCVA, duration of symptoms, and size of SMH. RESULTS: In group 1, log MAR BCVA was 1.22 +/- 0.66 at baseline and there was a significant BCVA improvement of 0.77 +/- 0.57 at 6 months compared with baseline (p = 0.045). On the final visit, 6 eyes (50%) had gained 2 Snellen lines or more. In group 2, BCVA was significantly improved from 1.29 +/- 0.70 at baseline to 1.06 +/- 0.84 at 1 month (p = 0.045). Ten eyes (71.4%) had gained 2 Snellen lines or more on the final visit. In group 1, there were no factors correlated with final BCVA (p > 0.05), while the final BCVA was significantly correlated with age and baseline BCVA in group 2. CONCLUSIONS: Clinicians may expect conservative treatment to lead to significant improvement of BCVA in patients with SMH due to various chorioretinal diseases who did not undergo any procedures to displace the hemorrhage.

Photodynamic Therapy of Choroidal Neovascularization in Age-Related Macular Degeneration with Verteporfin: An Analysis of 10 Years of Clinical Results

PURPOSE: To analyze the long-term results of photodynamic therapy (PDT) for exudative age-related macular degeneration (AMD). METHODS: The clinical data of patients treated with photodynamic therapy for exudative age-related macular degeneration between April 2000 and December 2000 were analyzed. Patients were followed-up for at least 10 years after PDT. RESULTS: Twenty-nine eyes of 29 patients were enrolled. Mean visual acuity on the logarithm of the minimum angle of resolution (log MAR) scale was 0.78 +/- 0.34 at baseline, 1.01 +/- 0.42 at 60 months, and 1.02 +/- 0.41 at 120 months. Predominantly classic, minimally classic, and occult without classic choroidal neovascularization was noted in 51.7%, 17.2%, and 31.1% of patients, respectively. Visual acuity was improved by 1 or more lines in 27.6% of patients and was unchanged in 20.7% of patients, while 51.7% of patients had lost 1 or more lines of visual acuity by 120 months. Baseline visual acuity and age were associated with the final visual prognosis (p < 0.05). Four patients developed neovascular AMD in the contralateral eye. CONCLUSIONS: PDT is safe and effective for neovascular AMD. However, AMD can recur at any time and thus patients should be followed-up for a long period of time.

Comparison of Choroidal Thickness in Eyes with Central Serous Chorioretinopathy, Asymptomatic Fellow Eyes and Normal Eyes

PURPOSE: To compare the choroidal thickness in central serous chorioretiopathy (CSC) patients and normal controls using spectral domain optical coherence tomography (SD-OCT). METHODS: The authors compared the choroidal thickness in eyes with CSC, fellow eyes and in normal eyes. In addition, the authors attempted to determine any correlation between choroidal thickness and other factors such as age, height of serous retinal detachment, and spherical equivalent. Choroidal thickness was measured using a perpendicular line from the outer margin of the subfoveal retinal pigment epithelium to the inner surface of the sclera. RESULTS: Twenty-five eyes of 25 CSC patients, 17 fellow eyes and 29 age-matched normal eyes were examined and categorized as group 1, group 2 and group 3, respectively. Subfoveal choroidal thickness was 370.64 +/- 58.06 microm in group 1, 301.85 +/- 47.83 microm in group 2, and 261.84 +/- 48.22 microm in group 3. The choroidal thickness in group 1 was significantly greater than those in group 2 and group 3, and the choroidal thickness in group 2 was significantly greater than that in group 3 (p = 0.001, p < 0.001, p = 0.004, respectively), where the choroidal thickness showed a negative correlation with age (p = 0.015). CONCLUSIONS: The choroidal thickness was greater in eyes with CSC and in their fellow eyes compared to that in normal eyes. The results suggest that CSC may be caused by choroidal vascular hyperpermeability and increased hydrostatic pressure in the choroid.

Evaluation of the Central Macula in Commotio Retinae Not Associated with Other Types of Traumatic Retinopathy

PURPOSE: To report on the anatomical and functional changes to the macula in nine patients suffering from commotio retinae not accompanied by any other types of traumatic retinopathy. METHODS: Nine injured eyes with commotio retinae were evaluated soon after ocular trauma with ophthalmic examination, including Spectral-domain optical coherence tomography (SD-OCT). In 12 eyes of 6 patients, Humphrey visual field (HVF) and multifocal electroretinogram (mfERG) were performed. Re-examinations were periodically performed for a mean of 26 days. Data from 9 injured eyes were collected and compared to data collected from the 9 non-affected eyes of the same patients. RESULTS: SD-OCT revealed no significant differences in the foveal thickness and total macular volume between traumatized and intact eyes in all 9 patients. Only 3 out of the 9 injured eyes showed abnormal findings in SD-OCT images such as discontinuity of the inner/outer segment (IS/OS) junction or abnormal hyper-reflectivity from the IS/OS and retinal pigment epithelium (RPE) lines in the macula. HVF and mfERG results did not show any functional deterioration in the injured eyes compared with intact eyes. During follow-up, the commotio retinae resolved in all 9 eyes. The changes to the outer retinal region detected in 3 patients by SD-OCT were also resolved. CONCLUSIONS: Acute retinal changes in commotio retinae, not associated with other retinal pathologies, were resolved without histological and functional sequelae. In a few cases of commotio retinae, SD-OCT revealed transient abnormalities mainly observed at the IS/OS and RPE complexes.

A Case of Retinal Detachment in Colobomatous Macrophthalmos With Microcornea Syndrome

We report a rare case of retinal detachment in colobomatous macrophthalmos with microcornea syndrome. A 25-year-old female who had suffered from poor vision in her left eye since early childhood and high myopia in her right eye (-11 D) visited our clinic because of a sudden deterioration of vision. Examination of the anterior segment showed microcornea with coloboma of the inferior pupil margin in the left iris. Fundus examination of the left eye revealed an inferior choroidal coloboma extending from the optic disc and macula. The patient also had total bullous retinal detachment. Pars plana vitrectomy with silicone oil tamponade was performed, and the retina was reattached. In the very rare condition of colobomatous macropthalmos with microcornea, retinal detachment may develop. Pars plana vitrectomy with additional silicone oil tamponade may be performed to treat this condition.

Effectiveness of Preoperative Intravitreal Bevacizumab Injections in Pars Plana Vitrectomy for Proliferative Diabetic Retinopathy

PURPOSE: To evaluate the efficacy of preoperative intravitreal bevacizumab (Avastin(R); Genetech, San Francisco, CA, USA) injections of pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR). METHODS: Thirty patients (30 eyes) who underwent PPV for treatment of PDR and received a preoperative intravitreal bevacizumab injection of 1.25 mg were retrospectively analyzed. The study group (group 1, 30 patients, 30 eyes) was compared with a control group (group 2, 29 patients, 30 eyes and matched with the study group for preoperative parameters) who underwent PPV without preoperative intravitreal bevacizumab injection. RESULTS: In both groups, visual acuity improved but there was no statistical significance. Intraoperative vitreous hemorrhage occurred in 14 eyes (46.7%) from group 1 and 11 eyes (36.7%) from group 2. There was no statistical significance of intraoperative bleeding occurrence (p=0.3). Postoperative vitreous hemorrhage occurred in 4 eyes from group 1 and 14 eyes from group 2. The group 1 had a lower incidence of postoperative hemorrhage than group 2 (p=0.005). CONCLUSIONS: Preoperative intravitreal bevacizumab injection appears effective in decreasing early postoperative vitreous hemorrhage and maybe technically helpful in PPV for PDR.

Effectiveness of Preoperative Intravitreal Bevacizumab Injections in Pars Plana Vitrectomy for Proliferative Diabetic Retinopathy

PURPOSE: To evaluate the efficacy of preoperative intravitreal bevacizumab (Avastin(R); Genetech, San Francisco, CA, USA) injections of pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR). METHODS: Thirty patients (30 eyes) who underwent PPV for treatment of PDR and received a preoperative intravitreal bevacizumab injection of 1.25 mg were retrospectively analyzed. The study group (group 1, 30 patients, 30 eyes) was compared with a control group (group 2, 29 patients, 30 eyes and matched with the study group for preoperative parameters) who underwent PPV without preoperative intravitreal bevacizumab injection. RESULTS: In both groups, visual acuity improved but there was no statistical significance. Intraoperative vitreous hemorrhage occurred in 14 eyes (46.7%) from group 1 and 11 eyes (36.7%) from group 2. There was no statistical significance of intraoperative bleeding occurrence (p=0.3). Postoperative vitreous hemorrhage occurred in 4 eyes from group 1 and 14 eyes from group 2. The group 1 had a lower incidence of postoperative hemorrhage than group 2 (p=0.005). CONCLUSIONS: Preoperative intravitreal bevacizumab injection appears effective in decreasing early postoperative vitreous hemorrhage and maybe technically helpful in PPV for PDR.

The Efficacy of Photodynamic Therapy With Verteporfin for Polypoidal Choroidal Vasculopathy: Retrospective Multi-Center Case Study

PURPOSE: To evaluate the efficacy of photodynamic therapy (PDT) with verteporfin for polypoidal choroidal vasculopathy (PCV) in Korean patients. METHODS: Clinical data of patients who were treated with PDT for PCV and followed up for more than 6 months were collected from 14 hospitals around the country. The changes in the best corrected visual acuity, angiographic outcome, retinal thickness measured by optical coherence tomography (OCT), and adverse effects of treatment were evaluated. RESULTS: Eighty six patients (86 eyes) were recruited (male: 75.6%, age: 65.9+/-8.3 years, mean follow-up: 14.8+/-10.2 months). The mean logMAR visual acuity at baseline was 0.55+/-0.32 and did not show any statistically significant difference from the final mean logMAR visual acuity (0.53+/-0.54) (p=0.639). The mean treatment session number of PDT was 2+/-1.2. Visual acuity stabilized or improved in 70.9% of patients. Visual acuity improved by more than 2 lines in 33 eyes (38.4%) and worsened by more than 2 lines in 21 eyes (24.4%) of patients. Vascular leakage decreased in 62.5% of patients in fluorescein angiography and polypoidal lesions disappeared or were reduced in 57.3% of patients in indocyanine green angiography. There was no systemic adverse effect of PDT, but increased subretinal hemorrhage after PDT occurred in 10 eyes (11.6%). CONCLUSIONS: In polypoidal choroidal vasculopathy, photodynamic therapy with verteporfin is safe and effective for preserving visual acuity and reducing vascular leakage and retinal thickness.

Use of Autologous Tenon's Capsule Graft for Repair of Traumatic Scleral Perforation

PURPOSE: To report the use of autologous Tenon's capsule graft for repair of scleral defects caused by traumatic scleral perforation. CASE SUMMARY: An 81-year-old man presented with loss of vision in his right eye after a perforating injury caused by a cow horn. Examination showed a laceration of the sclera at 12 o'clock approximately 5~6 mm in length, and a uveal tissue was prolapsed into the wound. The best corrected visual acuity was 0.1. Primary repair of the eye was insufficient because of tissue loss. The inferonasal Tenon's capsule graft was carefully dissected from the sclera and tailored to fit the defect. The graft was covered with a conjunctival flap. The scleral defect was successfully closed with the autologous Tenon's capsule graft. Three months after grafting, phacoemulsification with intraocular lens implantation was performed. CONCLUSIONS: Autologous Tenon's capsule graft is an effective measure to repair traumatic scleral defects and is useful when patch grafts are unexpectedly needed.

Photodynamic Therapy With Verteporfin for Choroidal Neovascularization in Patients with Angioid Streaks

PURPOSE: To evaluate the functional and anatomic outcomes of photodynamic therapy (PDT) for choroidal neovascularization (CNV) in patients with angioid streaks. METHODS: The authors retrospectively evaluated 6 consecutive patients (6 eyes) with CNV secondary to angioid streaks. All patients were treated with standard PDT with verteporfin protocol. Standardized protocol refraction, visual acuity testing, ophthalmologic examination, color photographs, fluorescein angiograms and indocyanin angiograms were used to evaluate the results of PDT with verteporfin. Main outcome measures were visual acuity and CNV size. RESULTS: Their mean age was 61.3+/-5.50 years (range, 53-68 years). Follow-up time ranged from 12 to 38 months with mean of 20.5+/-10.91 months. The mean visual acuity at baseline was 20/100 (range 20/25-20/500), and the mean visual acuity at the last examination was 20/320(range 20/125-counting finger). The mean greatest linear dimension (GLD) at baseline was 2400+/-766.81 micrometer, and the mean GLD at the last examination was 3483+/-444.59 micrometer. CONCLUSIONS: PDT for CNV associated with angioid streaks seemed to slow down but not prevent the progression of the disease and associated visual loss.

Cancer-associated Nummular Loss of the Retinal Pigment Epithelium

PURPOSE: To report a case of cancer-associated nummular loss of the retinal pigment epithelium. METHODS: A 47-year-old man with a history of hepatocellular carcinoma presented with three weeks of bilateral visual loss. His best-corrected visual acuity was 20/40 in each eye. He had multiple round confluent grayish-brown patches at the level of retinal pigment epithelium, and no pigmented choroidal lesions. Fluorescein angiography showed circular areas of transmission defect and indocyanine green angiography showed early hyperfluorescence, corresponding with the multiple round confluent patches. CONCLUSIONS: We report a case of visual paraneoplastic syndrome which showed nummular loss of the pigment epithelial cells which distinguishes the clinical component of BDUMP syndrome.

Photodynamic Therapy for Choroidal Neovascularization Secondary to Age-Related Macular Degeneration

PURPOSE: To investigate the effects of repeated photodynamic therapy (PDT) for subfoveal choroidal neovascularization secondary to age-related macular degeneration (AMD) in Korean patients. METHODS: Clinical data of patients who were treated with repeated (3 times or more) PDT for subfoveal choroidal neovascularization secondary to AMD and followed up for more than 6 months were collected from 17 hospitals around the country. Visual outcomes at 12 and 24 months, follow-up were compared between subtypes of choroidal neovascularization. The factors related to final visual prognosis and PDT-related adverse effects were evaluated. RESULTS: 244 patients (244 eyes) were recruited (male: 60%, age: 67.7+/-9.1 years). The portion of patients with predominantly classic, minimally classic, and occult without classic choroidal neovascularization was 57%, 13%, and 24%, respectively and that of patients with visual improvements or less than moderate visual loss at 24 months follow-up were 28%, 38%, 30% and 47%, 56%, and 65%, respectively. Baseline visual acuity and age were significantly related to the final visual prognosis (p<0.05). PDT-related adverse events developed in 15 (6.1%) patients, but most were mild and transient. CONCLUSIONS: Repeated PDT for subfoveal choroidal neovascularization secondary to AMD has effects comparable to those of previous prospective, controlled trials without any significant safety concerns in Korea.

A Case Report of Human Thelaziasis / 감염과화학요법

The authors report a case of infection with Thelazia callipaeda in a Korean man. The patient was a 47 year-old man. He experienced epiphora and foreign body sensation of the right eye since 3 weeks ago. Total of 2 worms were removed from the conjunctival sac; one by himself 1 day prior to examination and the other by an ophthalmologist. The worm was slender creamy white in color which was fixed in a 10% formaline solution. The worm was 17.38 mm in length, 0.45 mm in body width, 0.026 mm in length of buccal cavity, 0.63 mm in length of anterior end to vaginal opening, 0.76 mm in length of anterior end to the esophagointestinal junction and 0.06 mm in length of posterior end to the anus. There were numerous striations on surface of worms and vaginal opening was located anterior to the esophagointestinal junction. Based on aforementioned findings, it was confirmed as a female worm of Thelazia callipaeda, and the authors report it with literature.

A Case Report of Human Thelaziasis / 감염과화학요법

The authors report a case of infection with Thelazia callipaeda in a Korean man. The patient was a 47 year-old man. He experienced epiphora and foreign body sensation of the right eye since 3 weeks ago. Total of 2 worms were removed from the conjunctival sac; one by himself 1 day prior to examination and the other by an ophthalmologist. The worm was slender creamy white in color which was fixed in a 10% formaline solution. The worm was 17.38 mm in length, 0.45 mm in body width, 0.026 mm in length of buccal cavity, 0.63 mm in length of anterior end to vaginal opening, 0.76 mm in length of anterior end to the esophagointestinal junction and 0.06 mm in length of posterior end to the anus. There were numerous striations on surface of worms and vaginal opening was located anterior to the esophagointestinal junction. Based on aforementioned findings, it was confirmed as a female worm of Thelazia callipaeda, and the authors report it with literature.

Analysis of Preferential Hyperacuity Perimeter Results in Maculopathy Caused by Various Retinal Diseases

PURPOSE: The Preferential Hyperacuity Perimeter (PHP) is a device designed to monitor the development of choroidal neovascularization in age-related macular degeneration (AMD) patients. Recent studies have reported the efficacy of the PHP in early detection of AMD. To evaluate hyperacuity, a dot deviation signal is flashed to the central 14 degrees of the macular visual field and the patient's perceived hyperacuity defect is recorded. The purpose of our study was to identify the role of the PHP in analyzing visual functions of patients with maculopathy caused by retinal diseases other than AMD. METHODS: Seventy-four eyes of 55 patients with macular abnormalities caused by various retinal diseases (44 eyes of diabetic retinopathy, 6 eyes of central serous chorioretinopathy, 24 eyes of other retinal diseases) underwent PHP, Optical Coherence Tomography (OCT) and fluorescein angiography (FAG). RESULTS: Of the 74 eyes with maculopathy, 60 eyes (81%) were positive on the PHP. By disease, 40 eyes (40/44, 91%) with diabetic retinopathy, 3 eyes (3/6, 50%) with central serous chorioretinopathy and 17 eyes (17/24, 71%) with other retinal diseases were positive. Among them, the location of hyperacuity defect lesions determined by PHP correlated well with the location shown on OCT and FAG in 6 eyes (6/40, 15%) with diabetic retinopathy, 1 eye (1/3, 33%) with central serous chorioretinopathy and 5 eyes (5/17, 29%) with other retinal diseases. CONCLUSIONS: Many retinal diseases that lead to maculopathy revealed a hyperacuity defect on PHP when the lesion was located not only in the retinal pigment epithelium but also in the outer retinal layer. Special attention to the patient's visual acuity and visual field defects is required when analyzing PHP results since these factors can influence the PHP evaluation.

Correlation of OCT and Preferential Hyperacuity Perimeter in Exudative Age-related Macular Degeneration

PURPOSE: Preferential hyperacuity perimeter (PHP) is a device that measures metamorphopsia in the central 14 degrees of the macular visual field which is presented by hyperacuity defect. We elucidated a hyperacuity defect lesion of PHP in exudative age-related macular degeneration (AMD) by Optical coherence tomography (OCT). METHODS: Nineteen eyes of 18 patients with exudative AMD diagnosed by fundus examination and fluorescein angiography (FA) underwent PHP. We then elucidated any hyperacuity defect lesion of PHP by fundus photography, FA and OCT. For a control, 20 eyes of 10 age-matched persons who had no ophthalmological abnormality underwent PHP and OCT to determine if hyperacuity defect would appear. RESULTS: Hyperacuity defect lesion appeared in 18 eyes (95%) of AMD patients. There was good locational correlation between the hyperacuity defect lesions and lesions in the fudoscopic examination in 16 eyes of 18, but there was a counterpart relation at the superior-inferior and left-right in 2 eyes. Hyperacuity defect lesion in PHP was of smooth or irregular elevation of the retinal pigment epithelium (RPE) in OCT. In the control, hyperacuity defect lesion appeared in 1 eye (5%) and it was normal in OCT. CONCLUSIONS: PHP showed a highly positive rate in detecting AMD-related lesion. The hyperacuity defects that are noted by the PHP are produced from elevation of the RPE.

The Optical Coherence Tomography Analysis of Hyperfluorescence by Scanning Laser Ophthalmoscope in Central Serous Chorioretinopathy

PURPOSE: To analyze the optical coherence tomography (OCT) result at the area of hyperfluorescence by scanning laser ophthalmoscopy (SLO) in central serous chorioretinopathy. METHODS: We investigated sensory detachment, pigment epithelial detachment (PED), choroidal neovascularization (CNV), and retinal pigment epithelial atrophy using OCT in the area of hyperfluorescein by scanning laser ophthalmoscopy (SLO) in 29 eyes of 29 patients with CSC. RESULTS: Of 29 eyes, no specific finding was noted in 19 eyes. Small PED corresponding to the leaking point was noted in 3 eyes, large serous PED with leaking point in 2 eyes, hemorrhagic PED in 1 eye, subretinal precipitate and PED in 1 eye, and retinal pigment epithelial atrophy in 2 eyes. CONCLUSIONS: OCT provided intuitive and objective information on the pathophysiologic state of the retinal pigment epithelial layer at the area of hyperfluorescence by SLO in CSC.

The Evaluation of Retinal Sensitivity using SLO Microperimetry in Diabetic Patients

PURPOSE: Microperimetry with the scanning laser ophthalmoscope (SLO) allows precise point-to-point correlation between visual functions and retinal pathology. The aim of this study was to evaluate the retinal sensitivity in patients with diabetic retinopathy. METHODS: We divided 15 eyes into 3 study based on the severity of the diabetic retinopathy and 5 healthy eyes as a control. Twenty eyes of 20 patients were prospectively examined with static manual microperimetry using the SLO (Scanning laser microscope 101, Rodenstock, Munich, Germany) to compare the retinal sensitivity according to the severity of retinal pathology. RESULTS: We observed a generalized decrease in retinal sensitivity in diabetic retinopathy patients. There was a significant decrease in retinal sensitivity over 5degrees in non-proliferative diabetic retinopathy and proliferative diabetic retinopathy (p<0.05). CONCLUSIONS: Results indicate that the higher the degree of diabetic retinopathy, retinal sensitivity decreased. A decreased in retinal sensitivity was also observed with retinal hemorrhage, exudate and neovascularization. It may help in making management decisions in diabetic patients by offering sensitive parameters in addition to the visual acuity.

The Results in LASIK According to The Use of The Fixation Ring and The Accuracy of The Focusing Beam

PURPOSE: In order to know the effects of inaccurate laser shot of vertical or horizontal direction, we evaluated the clinical results of LASIK according to the use of fixation ring and the accuracy of the focusing beam on the corneal stromal bed. METHODS: LASIK was performed in 73 eyes with one surgeon between April, 2001 and January, 2002 were divided into two groups: those who exceeded -6.00D were high myopia group (37 eyes), and those who did not were low myopia group (36 eyes). We retrospectively analyzed the results of the LASIK in two methods, the one is the evaluation of the vertical directional error with the accuracy of the focusing beam and the other is the horizontal error with the use of fixation ring. We measured the preoperative and postoperative uncorrected visual acuity, spherical equivalent, and the postoperative predictability. RESULTS: There was no significant statistical difference in the spherical equivalent, uncorrected visual acuity, postoperative predictability between the use and nonuse of fixation ring and good and bad accuracy of focusing beam in high myopia and low myopia (P>0.05). CONCLUSIONS: These results suggest that a little difference in the accuracy of focusing beam on the corneal stromal bed and the use of fixation ring would not affect the clinical result after LASIK.