Ten-year Results after Conventional Corneal Cross-linking in Korean Patients with Progressive Keratoconus

Purpose@#To evaluate the long-term effects of conventional corneal cross-linking in patients with progressive keratoconus. @*Methods@#A total of 18 eyes of 9 patients diagnosed with keratoconus were analyzed retrospectively. One eye was diagnosed with progressive keratoconus and conventional corneal crosslinking was performed. The other eye was classified as non-progressive and remained untreated. All patients were assessed with best corrected visual acuity (BCVA), maximum keratometry (Kmax), mean keratometry (Kmean), corneal astigmatism, and corneal thickness. Clinical data were collected before the procedure and at 1, 3, 6 months and 1 to 10 years after the procedure. @*Results@#The BCVA significantly improved from 0.63 ± 0.18 logarithm of the minimum angle of resolution (logMAR) to 0.46 ± 0.25 logMAR at 10 years after conventional corneal crosslinking (p = 0.027). The Kmax and Kmean decreased from 65.90 ± 9.43 D and 52.82 ± 5.16 D to 62.83 ± 8.16 D and 51.52 ± 5.18 D, respectively (p = 0.021, p = 0.028, respectively). Corneal astigmatism decreased from 6.97 ± 2.21 D to 5.53 ± 1.64 D (p = 0.008). The thinnest corneal thickness decreased from 435.11 ± 53.37 μm to 369.22 ± 64.00 μm 1 month after the procedure (p = 0.008), and gradually improved over time. At 10 years, the thinnest corneal thickness increased to 410.11 ± 61.32 μm (p = 0.097). In the untreated eyes, the mean keratometry significantly increased after 4 years of follow-up, but other factors did not change significantly. Although corneal opacity persisted for up to 10 years in 3 eyes of the treatment group, there was no significant difference of BCVA compared to the treated eyes without corneal opacity (p = 0.714). @*Conclusions@#In patients with progressive keratoconus, conventional corneal crosslinking is a safe and effective procedure that suppresses long-term progression.

Analyses of Corneal Morphology of Patients with Obstructive Sleep Apnea

Purpose@#To analyze the relationship between corneal morphological factors and polysomnographic factors in patients with obstructive sleep apnea (OSA). @*Methods@#In all, 22 eyes of 22 patients with OSA were analyzed retrospectively under specular microscopy. The central corneal thickness (CCT), endothelial cell density (ECD), hexagonal cell percentage, and cell variation coefficient were measured using specular microscopy, and polysomnographic factors including the apnea-hypopnea index (AHI), respiratory disturbance index (RDI), oxygen desaturation index, and lowest O2 saturation were compared and analyzed between the OSA group and a control group consisting of 32 subjects. Additionally, we examined the statistical correlation between retinal nerve fiber layer (RNFL) thickness and the polysomnographic factors for the 12 OSA patients in which the RNFL thickness was measured. @*Results@#The mean CCT and mean ECD were significantly lower in the OSA group than in controls (p = 0.033, p = 0.021, respectively). As the severity of OSA worsened, a significant negative correlation developed, such that the CCT decreased as the AHI and RDI increased (r = -0.519, p = 0.013 and r = -0.542, p = 0.009, respectively); in addition, the ECD decreased as the RDI increased (r = -0.454, p = 0.034). As OSA progressed, the nasal RNFL thickness decreased with the lowest O2 saturation (r = 0.703, p = 0.011). @*Conclusions@#CCT and ECD were significantly lower in OSA patients than in controls and there was a significant correlation between corneal morphological factors and polysomnographic factors. Due to the possibility of hypoxia and various ophthalmic clinical diseases associated with OSA, close observation of ophthalmic abnormalities in OSA patients is required.

Analyses of Corneal Morphology of Patients with Obstructive Sleep Apnea

Purpose@#To analyze the relationship between corneal morphological factors and polysomnographic factors in patients with obstructive sleep apnea (OSA). @*Methods@#In all, 22 eyes of 22 patients with OSA were analyzed retrospectively under specular microscopy. The central corneal thickness (CCT), endothelial cell density (ECD), hexagonal cell percentage, and cell variation coefficient were measured using specular microscopy, and polysomnographic factors including the apnea-hypopnea index (AHI), respiratory disturbance index (RDI), oxygen desaturation index, and lowest O2 saturation were compared and analyzed between the OSA group and a control group consisting of 32 subjects. Additionally, we examined the statistical correlation between retinal nerve fiber layer (RNFL) thickness and the polysomnographic factors for the 12 OSA patients in which the RNFL thickness was measured. @*Results@#The mean CCT and mean ECD were significantly lower in the OSA group than in controls (p = 0.033, p = 0.021, respectively). As the severity of OSA worsened, a significant negative correlation developed, such that the CCT decreased as the AHI and RDI increased (r = -0.519, p = 0.013 and r = -0.542, p = 0.009, respectively); in addition, the ECD decreased as the RDI increased (r = -0.454, p = 0.034). As OSA progressed, the nasal RNFL thickness decreased with the lowest O2 saturation (r = 0.703, p = 0.011). @*Conclusions@#CCT and ECD were significantly lower in OSA patients than in controls and there was a significant correlation between corneal morphological factors and polysomnographic factors. Due to the possibility of hypoxia and various ophthalmic clinical diseases associated with OSA, close observation of ophthalmic abnormalities in OSA patients is required.

Xeroderma Pigmentosum in a Pediatric Patient with a Progressive Pterygium-like Lesion

Purpose@#We report a case of xeroderma pigmentosum in a pediatric patient with a progressive pterygium-like lesion.Case summary: A 2-year-old girl with photophobia and localized, scattered, small, round brownish macules on skin areas exposed to the sun visited hospital. During follow-up, at the age of 7, she was diagnosed with xeroderma pigmentosum in Japan, and pigmented freckles on the upper and lower eyelids of both eyes were observed. At the age of 11, a possible medial limbal pingueculum and lower lid telangiectasis of the right eye were observed via slit-lamp examination, and one year later, a pterygium-like lesion and gradual fibrovascular tissue growth were found in the same location of the right eye. At the last visit, the progressive pterygium-like lesion and, lower lid telangiectasis of the right eye, and lid pigmentations of both eyes (xeroderma pigmentosum) were observed. The size of pterygium-like lesion continues to increase, but the patient remains under observation because the lesion was too small to remove. @*Conclusions@#We report the first case of xeroderma pigmentosum in a pediatric patient with a progressive pterygium-like lesion that showed age-related degeneration. We suggest that the pterygium-like lesion may reflect the photosensitivity to ultraviolet radiation characteristic of xeroderma pigmentosum.

Two Cases of Oculopharyngeal Muscular Dystrophy in Brothers with Ptosis and Eye Movement Disorder

Purpose@#To report two cases of early onset oculopharyngeal muscular dystrophy, which were suspected to be chronic progressive external ophthalmoplegia.Case summary: Case 1, a 15-year-old male and Case 2, a 13-year-old male brother, visited the clinic with persistent diplopia 6 years prior. The older brother’s best-corrected visual acuity was 0.6 in both eyes and showed an exodeviation of 25 prism diopters. Bilateral ptosis was observed with ocular muscle movement limitations in all directions, and bilateral macular edema was found on fundus examinations. The younger brother had a best-corrected visual acuity of 1.0 in both eyes and showed exodeviation of 45 prism diopters. Bilateral ptosis and ocular muscle movement limitations were also observed. Both patients were suspected to have chronic progressive external ophthalmoplegia and were referred to a neurologist for a neurological examination and muscle biopsy. The muscle biopsies showed that both patients were diagnosed with oculopharyngeal muscular dystrophy. @*Conclusions@#It is important, initially, to report a case of early onset oculopharyngeal muscular dystrophy that has eyelid and eye movement symptoms, but no other typical symptoms.

Visual Prognosis and Satisfaction of Advanced Cataract Patients Unable to be Evaluated by Fundus Imaging

PURPOSE: We evaluated the surgical prognoses of patients with advanced cataract who were unable to be evaluated by fundus imaging and their satisfaction with daily life.METHODS: We retrospectively reviewed 748 eyes of 480 patients who underwent cataract surgery from January 2015 to December 2017. Preoperative factors, surgical technique, degree of cataract, and the best-corrected visual acuity for 1 and 6 months after surgery were analyzed. Among 91 eyes of 78 patients with advanced cataract who were unable to be evaluated by fundus imaging, the degree of discomfort before surgery and postoperative satisfaction were evaluated.RESULTS: Hypertension was positively correlated with visual acuity after cataract surgery (p = 0.004). Low corneal endothelial cell count, primary open-angle glaucoma, a history of trabeculectomy due to glaucoma, corneal dystrophy or corneal opacity, advanced cataract unable to be evaluated by fundus imaging, hypermature cataract, extracapsular cataract extraction, and intracapsular cataract extraction and visual acuity <0.5 after 1 month showed negative correlations with the visual outcomes after 6 months (p = 0.019, p = 0.002, p = 0.037, p = 0.001, p = 0.004, p = 0.012, p = 0.00, and p = 0.00, respectively). The risk of a final visual acuity <0.5 after cataract surgery was 3.18-fold higher in cases of advanced cataract, unable to be evaluated by fundus imaging (p = 0.003). Ten patients with 10 eyes postponed surgery due to poor prognoses, which was expected, and six patients (60%) had a best-corrected visual acuity <0.5 after 6 months. Six patients (60%), expected to have a poor prognosis were satisfied after surgery and the postoperative satisfaction was high when compared with a poor visual outcome.CONCLUSIONS: Poor surgical prognoses were expected in advanced cataract patients unable to be evaluated by fundus imaging. However, advanced cataract patients, who postponed surgery due to an unfavorable visual prognosis, showed a higher subjective satisfaction when compared with the postoperative visual acuity.

Clinical Course and Prognostic Factors of Acquired Third, Fourth, and Sixth Cranial Nerve Palsy in Korean Patients

PURPOSE: This study aimed to evaluate the clinical course and prognostic factors of acquired third, fourth, and sixth cranial nerve (CN) palsy grouped according to etiology. METHODS: This study involved a retrospective review of the medical records of 153 patients who were diagnosed with acquired paralytic strabismus from January 2004 to July 2015. Outcomes, recovery rates, and time to recovery were investigated according to the affected CN: CN3, CN4, and CN6 palsies. The patients were classified into four groups based on etiology: idiopathic, traumatic, neoplastic, and vascular. RESULTS: The mean age of the patients was 59.8 ± 14.5 years and the mean follow-up period was 10.8 months. Out of the 153 patients, 63 (41.2%) had CN3 palsy, 35 (22.9%) had CN4 palsy, and 55 (35.9%) had CN6 palsy. The most common causes were vascular related (54.9%), followed by idiopathic (28.1%), trauma (8.5%), and neoplasm (5.88%). About 50% of the patients recovered within six months. Among the four etiologic groups, the idiopathic group showed the best prognosis because about 50% of the patients in this group recovered within three months. This was followed by the vascular, traumatic, and neoplastic groups. Cox proportional hazard analysis revealed a significant association between the baseline prism diopter and recovery rate. CONCLUSIONS: The prognosis and natural history of paralytic strabismus vary depending on its cause. The vascular group had the best recovery rate and shortest recovery time, whereas the neoplastic group required the longest time to recover.

The Long-term Clinical Outcome after Corneal Collagen Cross-linking in Korean Patients with Progressive Keratoconus

PURPOSE: To evaluate the long-term clinical effectiveness and safety of corneal collagen cross-linking (CXL) in progressive keratoconus compared with untreated contralateral eyes. METHODS: In this retrospective study, nine eyes of nine patients with progressive keratoconus who received CXL (treatment group) and nine untreated contralateral eyes with keratoconus (control group) were included. All patients were followed for at least 5 years and assessed with best-corrected visual acuity, maximum keratometry, mean keratometry, corneal astigmatism, and corneal thickness. Clinical data were collected preoperatively and at 1, 3, 6, 12, 24, 36, 48, and 60 months, postoperatively. RESULTS: Mean best-corrected visual acuity improved significantly from 0.58 ± 0.37 logarithm of minimum angle of resolution preoperatively to 0.39 ± 0.29 logarithm of minimum angle of resolution at 5 years after corneal CXL (p = 0.012). There was significant flattening of the maximum keratometry and mean keratometry from preoperative values of 63.39 ± 10.89 and 50.87 ± 6.27 diopter (D) to postoperative values of 60.89 ± 11.29 and 49.54 ± 7.23 D, respectively (p = 0.038, 0.021). Corneal astigmatism decreased significantly from 7.20 ± 1.83 D preoperatively to 5.41 ± 1.79 D postoperatively (p = 0.021). The thinnest corneal thickness decreased from 434.00 ± 54.13 to 365.78 ± 71.58 µm during 1 month after treatment, then increased to 402.67 ± 52.55 µm at 5 years, which showed a statistically significant decrease compared to the baseline (p = 0.020). In the untreated contralateral eyes, mean keratometry increased significantly at 2 years compared with the baseline (p = 0.043). CONCLUSIONS: CXL seems to be an effective and safe treatment for halting the progression of keratoconus over a long-term follow-up period of up to 5 years in progressive keratoconus.

A Case of Posterior Reversible Encephalopathy Syndrome with Bilateral Visual Impairment

PURPOSE: To report a case of recovery of bilateral cortical blindness in a patient with posterior reversible encephalopathy syndrome. CASE SUMMARY: A 46-year-old female visited the ophthalmology department due to abrupt visual acuity decrease. Ten days earlier, she had received conservative management due to anemia caused by menorrhagia and uterine prolapse. She underwent a gynecological operation to remove a uterine myoma two days previously, and was given a blood transfusion postoperatively because of excessive bleeding. After the transfusion, she complained of acute blurred vision. Her best corrected visual acuity (BCVA) was hand motion 10 cm in both eyes. There were no abnormal specific findings except retinal dot hemorrhage at the temporal side in the left eye on fundus examination. Her pupillary light reflex was normal and optical coherence tomography examination was unremarkable in both eyes. However, flash visual evoked potential findings showed reduced P100 amplitude in both eyes and she was diagnosed with posterior reversible encephalopathy syndrome based on brain magnetic resonance imaging. After close observation without any treatment, the symptoms gradually improved. Finally, her BCVA recovered to 1.0 and P1 and P100 amplitudes were restored to normal range in both eyes at 16 weeks from the first diagnosis. CONCLUSIONS: A patient complained of bilateral visual loss without other neurological symptoms after chronic blood loss and blood transfusion. She recovered visual acuity completely with prompt diagnosis of posterior reversible encephalopathy syndrome and close observation only.

A Case of Conjunctival Lithiasis with Clinical Manifestations of Superior Limbic Keratoconjunctivitis

PURPOSE: To report a case of conjunctival lithiasis with clinical manifestations of superior limbic keratoconjunctivitis. CASE SUMMARY: A 40-year-old male complained of pain, foreign body sensation and injection in the left eye lasting 1 month. The slit-lamp examination revealed injection of the superior bulbar conjunctiva, linear corneal band opacity, fine punctate staining and epithelial defect in the superior cornea area. After eversion of the left upper eyelid, there were many various-sized conjunctional concretions and inflammation in the superior tarsal conjunctiva. Therefore, we considered conjunctival lithiasis-induced clinical manifestations of superior limbic keratoconjunctivitis and then removed the conjunctival concretions using a 30-gauge needle. After the procedures, artificial tears, antibiotic eye drops, steroid eye drops and a therapeutic contact lens were applied. After 1 week, all symptoms and signs improved and there was no recurrence for 4 months. CONCLUSIONS: Mechanical stimulation by severe conjunctival lithiasis can induce clinical manifestations of superior limbic keratoconjunctivitis. Therefore, in patients with clinical manifestations of superior limbic keratoconjunctivitis, conjunctival lithiasis should be considered by observing the superior tarsal conjunctiva more closely.

Analysis of Retinal Vascular Calibers with Cardiovascular Risk Factors

PURPOSE: To analyze the association between retinal vascular caliber and cardiovascular risk factors including smoking, blood pressure, diabetes and age. METHODS: This study included 60 Korean male participants 40-69 years of age. The retinal vessel caliber was measured using computer-assisted fundus photography. Four vessels coursing through the area of one half disc diameter from the optic disc margin were measured. Additionally, we analyzed the association between the retinal vessel caliber and risk factors including smoking, diabetes, hypertension and age. RESULTS: Smoking was not significantly associated with retinal vessel calibers. The diabetes group showed larger average retinal vessel calibers than normal group, but veins were significantly wider (p < 0.05). The average retinal vessel caliber was wider and inferior vein and artery were significantly larger in the hypertension group (p < 0.05). Although the retinal vessel caliber increased with age, significance was observed only in the superior artery (p < 0.05). CONCLUSIONS: In our study, retinal vessel caliber was easily measured using a semi-automatic computer program. This method should prove useful in further studies examining the correlation among retinal vessel caliber variations in many localized ophthalmologic disorder.

Comparison of Ganglion Cell-Inner Plexiform Layer and Retinal Nerve Fiber Layer after Cataract Surgery

PURPOSE: To observe the change in the measured thickness of ganglion cell-inner plexiform layer (GCIPL) and retinal nerve fiber layer (RNFL) thickness before and after cataract surgery. METHODS: Forty-six eyes of 32 patients, scheduled to have cataract surgery, were imaged with spectral-domain optical coherence tomography (OCT) (Cirrus HD OCT) before and 5 weeks after the surgery to measure GCIPL and RNFL thickness repeatly. RESULTS: All GCIPL and RNFL thickness parameters were significantly higher postoperatively compared with preoperative measurements (p < 0.001). RNFL thickness changed more than GCIPL; the increased amount of mean RNFL thickness (14.16%) was higher than GCIPL thickness (7.36%; p < 0.001). GCIPL and RNFL thicknesses and, GCIPL signal strength changes were significantly increased in all types of cataracts (p < 0.05). RNFL signal strength change was significantly increased in posterior subcapsular cataracts (p < 0.05). CONCLUSIONS: Cataracts may affect GCIPL and RNFL thicknesses. After cataract surgery, GCIPL thickness, similar to the RNFL thickness, was increased significantly. As GCIPL thickness may be less affected by cataracts than RNFL thickness, GCIPL thickness may be a more meaningful indicator for the diagnosis of glaucoma with cataract.

A Case of Dengue Fever with Macular Involvement

PURPOSE: To report a case of Dengue fever with bilateral macular edema and retinitis. CASE SUMMARY: A 31-year-old female was referred to our clinic with blurred vision. The patient had visited Bali, Indonesia approximately 2 weeks prior. Dengue fever was diagnosed at the Division of Infectious Disease because the patient's serum dengue virus antibodies test was positive for dengue viral IgM antibodies. The patient's best corrected visual acuity was 0.4 in the right eye and 0.6 in the left eye. Slit lamp examination showed inflammatory cells in the vitreous but not in the anterior segment of both eyes. Fundus examination showed thickening of the retina in both eyes as well as a splinter retinal hemorrhage in left eye. Fluorescein angiography revealed hyperfluorescence of the venule in the perifoveal vascular network of the left macula, and indocyanine green angiography showed early diffuse hyperfluorescence in both eyes. Standard automated perimetry showed an overall reduction of the visual field and an increase in scotoma in both eyes. At 1 week after the initial visit, the macular edema had not improved and the patient's vision had deteriorated, especially in left eye. To improve the macular edema and ocular inflammation, a subtenon triamcinolone acetonide injection in the left eye was administered. At 5 weeks after treatment, corrected visual acuity improved to 1.0 in both eyes. Ocular findings, such as macular edema and intraretinal hemorrhage were resolved. The patient did not complain of any remaining discomfort. However, standard automated perimetry revealed that a pericentral scotoma was still present in left eye. CONCLUSIONS: In the present study, the authors report a case of bilateral macular edema and retinitis at the posterior pole after dengue infection. The patient demonstrated a relatively positive response to steroid therapy in the left eye and to conservative treatment in the right eye.

Clinical Usefulness of UBM in the Sitting Position in Anterior Chamber Depth and Angle Measurements

PURPOSE: We compared the measurements of anterior chamber depth (ACD) and anterior chamber angle (ACA) using ultrasound biomicroscopy (UBM) in the sitting position compared with IOL Master(R), Pentacam(R), and Spectralis optical coherence tomography (OCT) to evaluate the clinical usefulness of UBM in the sitting position. METHODS: We evaluated 92 eyes in 47 healthy adults. ACD was measured by IOL Master(R), Pentacam(R), and UBM. ACA was measured using Pentacam(R), UBM, and Spectralis OCT. UBM was performed in the sitting position using bag/balloon technology. Measured values were compared statistically. RESULTS: ACD measured by IOL Master(R), Pentacam(R), and UBM was 3.57 +/- 0.32 microm, 3.64 +/- 0.33 microm and 3.51 +/- 0.32 microm, respectively. UBM measurements of ACD were significantly shallower than with the other methods (p 0.8, p 0.05). There was strong correlation between UBM and Spectralis OCT (r = 0.957) but moderate correlation between Pentacam(R) and UBM and Pentacam(R) and Spectralis OCT (r = 0.557, 0.571, respectively, p < 0.05). Specifically, ACA of the superior quadrant showed a low correlation between Pentacam(R) and UBM and Pentacam(R) and Spectralis OCT (r = 0.257, 0.295, respectively). CONCLUSIONS: ACD measured by UBM in the sitting position was shallower compared to the other methods; however, ACD measured by IOL Master(R), Pentacam(R), and UBM showed significant correlations among the methods. The mean ACA measured by Pentacam(R), UBM, and Spectralis OCT showed no significant differences. Due to the high correlation of ACA measurements between UBM and Spectralis OCT in the present study, UBM is expected to be a good tool for measuring anterior segment parameters.

Anterior Elevation Changes Following Corneal Crosslinking for Keratoconus

PURPOSE: To report the results according to anterior elevation changes following corneal crosslinking (CXL) treatment for keratoconus. METHODS: The present retrospective study included 14 patients (15 eyes) with progressive keratoconus who underwent CXL with a follow-up of 12 months. Patients were classified into 2 groups according to pre and postoperative anterior elevation difference maps. On the preoperative anterior elevation map, distances from maximum anterior elevation to pupil center were compared between the 2 groups. The outcome of best correct visual acuity (BCVA), maximum keratometry and parameters of corneal topography were compared between the 2 groups before CXL as well as 6 and 12 months after CXL. RESULTS: The anterior elevation changes were classified as group 1 (-7.88 +/- 10.53 micrometer) or group 2 (8.71 +/- 5.99 micrometer) (p = 0.001). The preoperative corneal topography of eyes observed in group 1 (0.19 +/- 0.13 mm) had shorter mean distances from maximum anterior elevation to pupil center than eyes in group 2 (0.47 +/- 0.23 mm) (p = 0.018). BCVA (log MAR) improved from 0.68 +/- 0.78 to 0.57 +/- 0.81 (p = 0.115) 12 months after CXL in group 1 and decreased from 0.51 +/- 0.34 to 0.56 +/- 0.38 (p = 0.109) 12 months after CXL in group 2. The maximum keratometry decreased from 63.01 +/- 19.07D to 58.95 +/- 16.32D (p = 0.017) in group 1 and increased from 60.70 +/- 9.46D to 61.29 +/- 7.51D (p = 0.674) in group 2. CONCLUSIONS: Clinical and optical effects improved postoperatively in group 1, and were stabilized in group 2. The preoperative distance from maximum anterior elevation to pupil center and the anterior elevation changes after CXL were factors in predicting the CXL outcome.

Three Cases of Pupil Abnormality in Herpes Zoster Ophthalmicus

PURPOSE: We report the occurrence of pupil abnormality in 3 patients with herpes zoster ophthalmicus. CASE SUMMARY: Three patients diagnosed with herpes zoster ophthalmicus developed pupil abnormality. (Case 1) A 37-year-old male diagnosed 1 month prior with anterior uveitis secondary to herpes zoster ophthalmicus presented with peripheral corneal erosions, inflammatory cells in the anterior chamber, diffuse iris atrophy, almost fully-dilated pupils, and loss of pupil light reflex in the right eye. (Case 2) A 72-year-old male presented with vesicles on the right side of the face, and dendritic corneal ulcer, and inflammatory cells in the anterior chamber on initial examinations. After 5 days without treatment by his choice, decreased vision, decreased pupil light reflex, and ovoid-shaped pupils developed. (Case 3) A 63-year-old female presented with left ocular pain, vesicles around the left eye, dendritic corneal ulcer, inflammatory cells in the anterior chamber, and isocoric pupils with normal pupil light reflexes. However, in her left eye, the pupillary ruff was partially lost and the pupil was larger than the right pupil after the start of a 3-week treatment regimen. The pupil in Case 2 returned to normal after 1 month, but in cases 1 and 3, no improvements of pupil abnormalities were observed during the follow-up period. CONCLUSIONS: Herein we presented 3 patients that were diagnosed with herpes zoster ophthalmicus and subsequently developed pupil abnormalities. In the cases of pupil abnormalities, checking for a history of herpes zoster ophthalmicus is necessary to make a differential diagnosis.

Effects of Anterior Capsulotomy Extension on Rotational Stability of Intraocular Lens

PURPOSE: To evaluate the effects of anterior capsulotomy extension on the rotational stability of four different types of intraocular lenses (IOLs) and to analyze factors influencing IOL rotation. METHODS: The present single-center prospective study was comprised of 128 cataract patients (151 eyes) who underwent cataract surgery and received AcrySof IQ SN60WF, Tecnis ZA9003, Akreos MI60, or Zeiss XL Stabi ZO from March 2010 to December 2010. Sixty-four eyes received an anterior capsulotomy extension which was unintentionally created or performed using Vannas scissors after capsulorrhexis to prevent anterior capsular contracture. After pupil dilation, a digital retroillumination image of the IOL was taken on the operative day and 7 days postoperatively. RESULTS: There was no statistically significant difference in IOL rotation between the 4 types of IOL (p > 0.05). The anterior capsulotomy extension group (2.72 +/- 2.42degrees) and the non-extension group (3.24 +/- 2.16degrees) did not show statistically significant differences in IOL rotation (p > 0.05). A positive correlation was observed between age and IOL rotation. Axial length, anterior chamber depth, and anterior chamber volume did not affect the degree of rotation. CONCLUSIONS: Among the 4 types of IOLs, there was no significant difference in rotational stability. Anterior capsulotomy extension to prevent anterior capsular contracture is not likely to significantly affect the rotational stability of IOLs; the 4 different types of IOL were stable in the eye and suitable as toric IOLs for correction of astigmatism.

Corneal Crosslinking in Far-Advanced Keratoconus

PURPOSE: To report 2 cases of far-advanced keratoconus with a high value of maximum keratometry and very thin corneas treated with corneal crosslinking (CXL). CASE SUMMARY: The thinnest corneal thickness of an 18-year-old woman with maximum keratometry of 106.5 D (case 1) was 335 microm. The thinnest corneal thickness of a 43-year-old man with maximum keratometry of 120.3 D (case 2) was 345 microm. The two cases underwent a customized topography and pachymetry-guided epithelial debridement technique to preserve the epithelium where the cornea was within 2 mm around the cone and subsequent CXL. Postoperative maximum keratometry was 97.2 D 24 months after CXL in case 1 and 109.3 D 18 months after CXL in case 2. Postoperatively, the thinnest corneal thickness was 343 microm in case 1 and 162 microm in case 2. The corneal thickness in case 1 was stabilized during the follow-up examination. The pupil center and apex of the corneal thickness in case 2 with the higher maximum keratometry was stabilized, but the thinnest corneal thickness was decreased immediately after CXL and did not recover before CXL. CONCLUSIONS: CXL was performed in 2 cases of far-advanced keratoconus. Results showed reduced maximum keratometry but, variable values in corneal thickness during the follow-up examination in the 2 cases. Longer follow-up is necessary, and CXL should be performed cautiously, especially for patients with far-advanced keratoconus.

Factors Associated with Incomplete Cleavage of the Corneal Epithelium in Alcohol-Assisted LASEK

PURPOSE: To evaluate the factors associated with unsuccessful cleavage of corneal epithelium in alcohol-assisted LASEK. METHODS: A total of 274 eyes in 137 patients who had received alcohol-assisted LASEK were enrolled in the present study. Associations of central corneal thickness, refractive error, pre-operative corneal curvature, ablation depth, anterior chamber volume and depth, and history of wearing contact lenses with epithelial cleavage were investigated. RESULTS: Complete epithelial cleavage was achieved in 198 eyes (72.3%) and incomplete epithelial cleavage in 76 eyes (27.7%). A history of wearing contact lenses (p = 0.018), continuous use of contact lenses (p = 0.034), longer use of contact lenses (p = 0.000), anterior chamber volume (p = 0.012) and depth (p = 0.012) were significantly associated with incomplete epithelial cleavage. CONCLUSIONS: Alcohol-assisted LASEK may cause problems in patients who experience continuous use of contact lenses and longer use of contact lenses. Patients with incomplete epithelial cleavage have small anterior chamber volume and shallow anterior chamber depth.

Effects of Mitomycin C on Scleral Collagen Fibrils According to Atomic Force Microscopy

PURPOSE: To investigate the effects of mitomycin C on the scleral collagen surfaces using atomic force microscopy (AFM). METHODS: Two non-contact mode AFM machines were used to observe changes in the morphological characteristics of human scleral surfaces before and after one, three, and five minutes of 0.02% mitomycin C application. Based on AFM topography and deflection images of the collagen fibril, the morphological characteristics of scleral fibrils including the fibril diameter and D-period were measured using the line profile. RESULTS: The sclera collagen fibril treated with 0.02% mitomycin C for one minute did not show any significant increases in mean fibril diameter (155.04 +/- 17.46 nm) or mean D-periodicity (70.02 +/- 3.33 nm), compared to those of the control group. However, the scleral collagen fibrils treated with 0.02% mitomycin C for three and five minutes showed significant increases in mean fibril diameter (182.33 +/- 16.33 nm, 199.20 +/- 12.40 nm, respectively) and mean D-periodicity (70.27 +/- 13.66 nm, 72.75 +/- 19.32 nm, respectively), compared to those of the control group. CONCLUSIONS: The present study examined the structural changes in the scleral collagen fibrils before and after mitomycin C application according to atomic force microscopy. The results indirectly suggest that three or more minutes of 0.02% mitomycin C application affects the morphology of scleral collagen.