Automatic segmentation of corneal dystrophy on photographic images based on texture analysis.

PURPOSE: To develop an automatic algorithm to analyze dystrophic lesions on photographic images of corneal dystrophy. METHODS: The dataset included 32 images of corneal dystrophy. The dystrophic area was manually segmented twice. Manually labeled dystrophy areas were compared with automatically segmented images. First, we manually removed the light reflex from the image of the cornea. Using an automatic approach, we extracted the brown color of the iris. Then, the program detected the circular region of the pupil and the corneal surface. A whitish dystrophy area was defined based on the image intensity on the iris and the pupil. The sliding square kernel was applied to clearly define the dystrophic region. RESULTS: For the manual analysis and the twice automatic approach, the Dice similarity was 0.804 and 0.801, respectively. The Pearson correlation coefficient was 0.807 and 0.806, respectively. The total number of distinct dystrophic areas showed no significant difference between the manual and automatic approaches according to the Wilcoxon signed-rank test (p < 0.0001, both). CONCLUSIONS: We proposed an automatic algorithm for detecting the dystrophy areas on photographic images with an accuracy of approximately 0.80. This system can be applied to detect and predict the progression of corneal dystrophy.

Clinical characteristics and ophthalmologic findings of pituitary adenoma in Korean patients.

PURPOSE: To investigate the clinical characteristics of and ophthalmic findings in Korean patients diagnosed with a pituitary adenoma. METHODS: The medical records of 534 patients diagnosed with a pituitary adenoma at Kyung Hee University Hospital between January 2007 and December 2016 were retrospectively reviewed. RESULTS: Mean patient age was 47.9 ± 16.2 years. The most common symptoms at the time of presentation were headache (26.2%) and visual disturbance (12.4%). The referral rate to the ophthalmology department was 18.44% and patients most often presented to the neurosurgery department. Optic chiasm compression was identified in 23.4% of patients (54.4% of patients referred to ophthalmology, 15.0% of patients not referred to ophthalmology). Normal visual field (57%) was the most common visual field feature followed by bitemporal hemianopsia (17.8%). Optic chiasmal compression without visual field defects was found in 36.1% of patients. Tumor volume was positively correlated with visual field pattern standard deviation (PSD, p = 0.020) and best-corrected logMAR visual acuity (p = 0.000) and negatively associated with tumor volume and visual field mean deviation (MD, p = 0.000). Best-corrected visual acuity (p = 0.000), MD (p = 0.001), and PSD (p = 0.028) significantly improved after surgery. CONCLUSIONS: Pituitary adenoma patients do not always have ocular symptoms at their first presentation, even when optic chiasm compression and visual field deficits are present. Therefore, collaboration with an ophthalmologist is important when evaluating pituitary adenoma patients.

Instrument-Free Synthesizable Fabrication of Label-Free Optical Biosensing Paper Strips for the Early Detection of Infectious Keratoconjunctivitides.

We introduce a surface-enhanced Raman scattering (SERS)-functionalized, gold nanoparticle (GNP)-deposited paper strip capable of label-free biofluid sensing for the early detection of infectious eye diseases. The GNP biosensing paper strip was fabricated by the direct synthesis and deposition of GNPs on wax-divided hydrophilic areas of a permeable porous substrate through a facile, power-free synthesizable, and highly reproducible successive ionic layer absorption and reaction (SILAR) technique. To maximize localized surface plasmon resonance-generated SERS activity, the concentration of the reactive solution and number of SILAR cycles were optimized by controlling the size and gap distance of GNPs and verified by computational modeling with geometrical hypotheses of Gaussian-estimated metallic nanoparticles. The responses of our SERS-functionalized GNP paper strip to Raman intensities exhibited an enhancement factor of 7.8 × 10(8), high reproducibility (relative standard deviation of 7.5%), and 1 pM 2-naphthalenethiol highly sensitive detection limit with a correlation coefficient of 0.99, achieved by optimized SILAR conditions including a 10/10 mM/mM HAuCl4/NaBH4 concentration and six SILAR cycles. The SERS-functionalized GNP paper is supported by a multivariate statistics-preprocessed machine learning-judged bioclassification system to provide excellent label-free chemical structure sensitivity for identifying infectious keratoconjunctivitis. The power-free synthesizable fabrication, label-free, rapid analysis, and high sensitivity feature of the SILAR-fabricated SERS-functionalized GNP biosensing paper strip makes it an excellent alternative in point-of-care applications for the early detection of various infectious diseases.

A Case of Orbital Metastasis of Uterine Leiomyosarcoma With Intracranial Extension Presenting With Proptosis.

A 57-year-old woman presented with protrusion of the OS 2 months in duration and decreased vision 1 month in duration. The patient was diagnosed with uterine leiomyosarcoma approximately 3 years before presentation. Lung and liver metastases were diagnosed by biopsy 1 year prior to this visit. CT revealed a solid mass with central necrosis in the left lateral orbit that resulted in orbital shifting, bony destruction, and intracranial extension. The diagnosis was left orbital metastatic leiomyosarcoma, and the patient died 2 months after receiving the diagnosis.

Label-free biochemical analytic method for the early detection of adenoviral conjunctivitis using human tear biofluids.

Cell culture and polymerase chain reaction are currently regarded as the gold standard for adenoviral conjunctivitis diagnosis. They maximize sensitivity and specificity but require several days to 3 weeks to get the results. The aim of this study is to determine the potential of Raman spectroscopy as a stand-alone analytical tool for clinical diagnosis of adenoviral conjunctivitis using human tear fluids. A drop-coating deposition surface enhanced Raman scattering (DCD-SERS) method was identified as the most effective method of proteomic analysis in tear biofluids. The proposed DCD-SERS method (using a 2-µL sample) led to Raman spectra with high reproducibility, noise-independence, and uniformity. Additionally, the spectra were independent of the volume of biofluids used and detection zones, including the ring, middle, and central zone, with the exception of the outer layer of the ring zone. Assessments with an intensity ratio of 1242-1342 cm(-1) achieved 100% sensitivity and 100% specificity in the central zone. Principal component analysis assessments achieved 0.9453 in the area under the receiver operating characteristic curve (AUC) as well as 93.3% sensitivity and 94.5% specificity in the central zone. Multi-Gaussian peak assessments showed that the differences between these two groups resulted from the reduction of the amide III α-helix structures of the proteins. The presence of adenovirus in tear fluids could be detected more accurately in the center of the sample than in the periphery. The DCD-SERS technique allowed for high chemical structure sensitivity without additional tagging or chemical modification, making it a good alternative for early clinical diagnosis of adenoviral conjunctivitis. Therefore, we are hopeful that the DCD-SERS method will be approved for use in ophthalmological clinics in the near future.

Structural and biomechanical effects of photooxidative collagen cross-linking with photosensitizer riboflavin and 370 nm UVA light on human corneoscleral tissues.

This study quantitatively investigated the immediate effects of a photooxidative collagen cross-linking treatment with photosensitizer riboflavin (RF) and 370 nm UVA light in in vitro human corneoscleral collagen fibrils using histology, thickness, scanning electron microscopy, and atomic force microscopy analyses. Twenty 8 x 2 mm corneoscleral strips were dissected sagittally from donor tissue using a scalpel. Four parameters were investigated, including the density, thickness, adhesion force, and stiffness of corneoscleral tissues before and after the collagen cross-linking treatment. The RFUVA-catalyzed collagen cross-linking treatment led to an increase in the density of both corneal (8%) and scleral (23%) stromal collagens. However, there was no difference in corneoscleral thickness. Furthermore, RFUVA-catalyzed collagen cross-linking treatment led to an increased biomechanical response of corneosclera: 25 and 8% increases in corneoscleral stiffness, and 24 and 22% increases in corneoscleral adhesion force. The collagen cross-linking treatment through RF-sensitized photoreaction may cause structural and biomechanical changes in the collagen fibril network of the cornea and the sclera. This is due to narrowing of the interfibrillar spacing and the stromal edema.

Short-term response of mitomycin C on the human rectus muscle following strabismus surgery: histological, ultrastructural, and biomechanical evaluation.

This study investigated the inflammatory effect of intraoperative mitomycin C (MMC) on adhesion reformation in human rectus muscles. Ten consecutive patients who underwent medial rectus resection had their postoperative rectus muscles divided into two groups: control group (n = 10) and MMC group (n = 10). In the MMC group, the muscle was soaked for 2 min with MMC, prepared as a 0.2 mg/mL (0.02%) solution. The 0.02% MMC reactions were examined using histological analysis with hematoxylin-eosin (inflammatory response) and Masson's trichrome (collagen fibrils), immunoreactivities of cyclooxygenase-II (inflammatory response), and collagen type I and III, scanning electron microscopy analysis to quantify the diameter and D-periodicity of collagen fibrils, and atomic force microscopy analysis to quantify the diameter, D-periodicity, and adhesion force of collagen fibrils. The rectus muscles treated with 0.02% MMC showed a significantly increased inflammatory response (p < 0.05), increased collagen density (p < 0.0001), increased fibril diameter (p < 0.001 or p < 0.05), and decreased fibril adhesion force (p < 0.005) compared to the rectus muscles in the control group. MMC simultaneously caused an inflammatory response as well as nanostructural and biomechanical property changes in the collagen fibril network.

Structural response of human corneal and scleral tissues to collagen cross-linking treatment with riboflavin and ultraviolet A light.

High success rates in clinical trials on keratoconic corneas suggest the possibility of efficient treatment against myopic progression. This study quantitatively investigated the in vitro ultrastructural effects of a photooxidative collagen cross-linking treatment with photosensitizer riboflavin and UVA light in human corneo-scleral collagen fibrils. A total of 30.8 × 2 mm corneo-scleral strips from donor tissue were sagittally dissected using a scalpel. The five analytic parameters namely fibril density, fibril area, corneo-scleral thickness, fibril diameter, and fibril arrangement were investigated before and after riboflavin-UVA-catalyzed collagen cross-linking treatment. Collagen cross-linking effects were measured at the corneo-scleral stroma and were based on clinical corneal cross-linking procedures. The structural response levels were assessed by histology, digital mechanical caliper measurement, scanning electron microscopy, and atomic force microscopy. Riboflavin-UVA-catalyzed collagen cross-linking treatment led to an increase in the area, density, and diameters of both corneal (110, 112, and 103 %) and scleral (133, 133, and 127 %) stromal collagens. It also led to increases in corneal (107 %) and scleral (105 %) thickness. Collagen cross-linking treatment through riboflavin-sensitized photoreaction may cause structural property changes in the collagen fibril network of the cornea and sclera due to stromal edema and interfibrillar spacing narrowing. These changes were particularly prominent in the sclera. This technique can be used to treat progressive keratoconus in the cornea as well as progressive myopia in the sclera. Long-term collagen cross-linking treatment of keratoconic and myopic progression dramatically improves weakened corneo-scleral tissues.

Effect of fibrin glue as an adjuvant to hang-back surgery.

BACKGROUND: The hang-back surgery is a useful technique in the field of strabismus surgery. The aim of this study is to determine the stabilizing effects of fibrin glue as an adjuvant to hang-back surgery. MATERIALS AND METHODS: Four (4)-mm hang-back recessions of the superior rectus muscle was performed in 32 eyes of 16 rabbits. Only in the left eye of the 16 rabbits, fibrin glue was applied between the recessed muscle bed and the sclera at the end of hang-back surgery (fibrin glue group). After 6 weeks, we compared the stability of the recessed rectus muscle between the fibrin glue group and the control group by evaluating the displacement of the muscle. RESULTS: The frequency of stable insertion of the recessed muscle at the intended site was greater in the fibrin glue group (9 eyes) compared to the control group (3 eyes) (p=0.028). In the control group, 5 eyes showed anterior displacement and 8 eyes showed posterior displacement and in the fibrin glue group, 1 eye showed anterior displacement, and 6 eyes showed posterior displacement. Anterior displacement was more common in the control group (6.3% Vs 31.3%). The control group and the fibrin glue group showed similar histological findings on microscopic examination. CONCLUSIONS: Fibrin glue is effective in stabilizing the new rectus muscle insertion and decreasing the displacement in the hang-back surgery.

Short-term nanostructural effects of high radiofrequency treatment on the skin tissues of rabbits.

The aim of this study is to quantitatively investigate the short-term effects of RF tissue-tightening treatment in in vivo rabbit dermal collagen fibrils. These effects were measured at different energy levels and at varying pass procedures on the nanostructural response level using histology and AFM analysis. Each rabbit was divided into one of seven experimental groups, which included the following: control group, and six RF group according to RF energy (20 W and 40 W) and three RF pass procedures. The progressive changes in the diameter and D-periodicity of rabbit dermal collagen fibrils were investigated in detail over a 7-day post-treatment period. The dermal tissues treated with the RF tissue-tightening device showed more prominent inflammatory responses with inflammatory cell ingrowth compared to the control. This effect showed more prominent with the passage of day after treatment. Although an increase in the diameter and D-periodicity of dermal collagen fibrils was identified immediately after the RF treatment, a decrease in the morphology of dermal collagen fibrils continued until post-operative day 7. Furthermore, RF treatment led to the loss of distinct borders. Increases in RF energy with the same pass procedure, as well as an increase in the number of RF passes, increased the occurrence of irreversible collagen fibril injury. A multiple-pass treatment at low energy rather than a single-pass treatment at high energy showed a large amount of collagen fibrils contraction at the nanostructural level.

AFM study for morphological and mechanical properties of human scleral surface.

This study examined the structures and the elastic and viscous properties of human scleral collagen fibrils by atomic force microscopy (AFM). Sample preparation was performed to minimize the sources of artifacts for further imaging. To observe the morphological and property characteristics of human scleral surfaces, AFM was used as a microscopic tool. The AFM topography, phase shift and deflection images of the dehydrated scleral collagen fibrils were obtained. The visco-elasticity of collagen fibrils was determined from the force-distance curves of the AFM. Inspection of the fibril surface in high resolution showed that the D-period spacing along the collagen fibrils was clearly evident. The fibril diameter over a scan size of 5 x 5 microm2 was 145.22 +/- 17.78 nm (n = 178) ranging from 98 to 220 nm, and the D-periodicity was 69.14 +/- 14.15 nm (n = 189), which is similar to the normal 67 nm D-periodicity. Force-distance analysis indicated that human scleral collagen had comparatively high adhesion force and elasticity, to protect the eye from external trauma and to withstand the expansive force made by the intraocular pressure.

Oral-Facial-Digital Syndrome Type IX with Subfoveal Drusenoid Deposit.

We describe a patient with oral-facial-digital syndrome (OFDS) with the following anomalies: cleft lip, cleft palate, micrognathia, hypertelorism, nasal septum deviation, thumb polydactyly in the right hand, and partial agenesis of the corpus callosum. In addition, the patient had optic disc coloboma in the left eye and subfoveal drusenoid deposit in the right eye, features of OFDS type IX. Subfoveal drusenoid deposit has not been previously reported in OFDS type IX. Evaluation of the fundus is necessary for diagnosis of OFDS.

Photochemical Retinopathy induced by blue light emitted from a light-emitting diode Face Mask: A case report and literature review.

RATIONALE: Skin photobiomodulation involves the use of low doses of light of a specific wavelength to reduce skin inflammation and promote tissue repair. Recently, a face mask using a light-emitting diode (LED) to induce photobiomodulation has been widely introduced in the market. However, a short wavelength of high-energy blue light can cause retinal damage. We would like to report a rare case of photochemical retinopathy after using a blue LED face mask. PATIENT CONCERNS: A 37-year-old woman presented with complaints of distorted vision. The patient was exposed to blue light from an LED face mask 1 month before presentation. DIAGNOSIS: Color fundus photography revealed a yellowish chorioretinal lesion and optical coherence tomography revealed retinal pigment epithelium destruction in the parafoveal area. Fluorescein angiography revealed leakage from the lesion at the parafovea. The patient was diagnosed with blue LED-induced photochemical retinopathy. INTERVENTIONS: Intravitreal bevacizumab was injected in the right eye. OUTCOMES: After 4 weeks, dysmorphopsia was improved. LESSONS: This case report demonstrates that retinal damage can occur in humans due to prolonged exposure to blue light. Therefore, it is important to be wary of eye exposure and ensure the eyes are covered during LED face mask use.

Relationship between early structural changes at cornea incision sites and surgical outcomes after phacoemulsification.

AIM: To assess the early structural changes at clear corneal cataract incision sites and surgical outcomes using anterior segment optical coherence tomography (AS-OCT). METHODS: We evaluated 80 eyes of 59 patients who underwent phacoemulsification with a clear corneal incision. All incisions were evaluated 1wk, 1, and 3mo postoperatively using AS-OCT and analyzed regarding angle, length of the incision, maximal corneal thickness at the incision, and if present, corneal endothelial gap length and incision gap area. The patients were divided into two groups according to whether or not an endothelial gap was present at 1wk postoperatively (endothelial gap, group 1; no endothelial gap, group 2). We analyzed the difference in patient and surgical factors between the two groups, and compared the surgical outcome and the refractive outcome. RESULTS: An endothelial gap was observed in 56 (70.0%) of 80 eyes at 1wk postoperatively but not at 3mo postoperatively. The mean patient age was significantly higher in group 1 than in group 2. The longer the length of the corneal incision and the steeper the incision angle, the greater the length and area of the endothelial gap. In group 1, the mean change in mean keratometry of the anterior cornea was significantly greater than in group 2, and the spherical equivalent (SE) and mean numerical error indicated significant myopic changes at 1wk postoperatively. CONCLUSION: The risk of an endothelial gap increases with patient age and a long corneal incision and steep incision angle. The presence of an endothelial gap after surgery may affect the early postoperative corneal curvature and SE.

Effects of scleral collagen crosslinking with different carbohydrate on chemical bond and ultrastructure of rabbit sclera: Future treatment for myopia progression.

BACKGROUND: Myopia is the most common ocular disorder and is mainly caused by axial elongation of the sclera. If the stiffness of sclera increased, it can inhibit myopia progression. The aim of this study is to compare the effect of the collagen crosslinking with different types and concentrations of carbohydrates on chemical bond and ultrastructural change of rabbit sclera. METHODS: Nine New Zealand white rabbits were treated with five, sequential sub-Tenon injections of 0.15 mL solutions of ribose, sucrose, and glycogen of 0.1, 0.2 and 0.4 M concentration at the right eye over 14 days. Ten weeks after the last injection, the rabbits were sacrificed and chemical bond and ultrastructural changes were compared with those of the untreated left sclera using Raman spectroscopy, atomic force microscopy (AFM), and histology. RESULTS: Raman spectroscopy of the control and cross-linked rabbit sclera tissue revealed different types of collagen interactions. Raman shift of 919 cm-1 (C-C stretching and vibration of the proline ring in collagen) was the highest in ribose, followed by sucrose and glycogen. Total energy intensity was also highest in ribose, followed by sucrose and glycogen, and showed a tendency to increase at higher concentrations. AFM revealed interlocking arrangements of collagen fibrils. The collagen fibril diameter was 105.6 ± 21.2 nm, 109.4 ± 28.8 nm, 113.1 ± 30.8 nm and 137.6 ± 25.3 nm for control group, 0.4 M glycogen, sucrose, and ribose, respectively. Histology indicated increased density of the collagen bundle and no increase in inflammatory cell recruitment compared to control at high concentrations of ribose. CONCLUSIONS: Scleral crosslinking using glycation increased the scleral biomechanical rigidity and these results were particularly pronounced in ribose. Scleral crosslinking using glycation may be a promising method for inhibiting high myopia progression.

Successful treatment of conjunctival lymphangiectasia accompanied by corneal dellen using a high-frequency radiowave electrosurgical device.

A 62-year-old man presented with a 1-month history of right eye pain unresponsive to artificial tears and topical steroids. At presentation, bullous yellowish fluid collection was noted in the nasal conjunctiva. Corneal thinning and opacity were observed at the 3 o'clock position of the cornea. High-frequency radiowave ablation and biopsy were performed at the affected area. Conjunctival lymphangiectasia was confirmed by excisional biopsy. An improvement in the degree of corneal dellen and chemosis was evident 1 week after ablation. Use of a high-frequency radiowave electrosurgical device may be a simple and effective treatment option for symptomatic conjunctival lymphangiectasia.

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.

Conjunctival Inclusion Cysts in Long-standing Chronic Vernal Keratoconjunctivitis.

PURPOSE: To report a case of conjunctival inclusion cysts on the corneal limbus of a patient with chronic vernal keratoconjunctivitis during 16 months' follow up. METHODS: The patient was a 26 year old male without any specific history of surgery or trauma. Giant papillae, shield ulcers, and Horner-Trantas dots were detected. During the 16 month follow-up, Sodium cromoglycate eye drops and Prednisolone acetate 1% eye drops were given 3 times a day. During this period, conjunctival cysts were detected on the corneal limbus in both eyes. In spite of improvement of the corneal and conjunctival conditions, the conjunctival cysts did not seem to show any specific changes. For relief of foreign body sensation, excision of the conjunctival cysts and giant papillae of the left eye and histopathologic examination of the specimen was performed. RESULTS: On histopathological examination, the conjunctival cysts consisted of nonkeratinizing stratified epithelial cells filled with PAS-positive mucous substance. Inflammatory cells were not found in the vicinity. CONCLUSIONS: Conjunctival inclusion cysts can be seen as an atypical finding of long-standing vernal keratoconjunctivitis. Mechanical friction between the giant papillae and conjunctiva may be a factor in inducing the formation of the conjunctival cysts.

Bilateral peripheral infiltrative keratitis after LASIK.

PURPOSE: To present a case of peripheral infiltrative keratitis mimicking infectious keratitis on the flap margin and limbus, which appeared on the first postoperative day after the laser in situ keratomileusis (LASIK). METHODS: A 36-year-old woman who underwent uneventful bilateral simultaneous LASIK developed multiple round infiltrate along the flap margin reaching to limbus from the 11 o'clock to 6 o'clock area in both eyes. RESULTS: The flap was lifted and irrigation was performed with antibiotics. but infiltration seemed to appear again. The infiltrate was more concentrated at the periphery and was extended to the limbus. Direct smear and culture for bacteria and fungus were negative. Topical prednisolone acetate 1% eye drops was added, infiltrative condition was resolved. CONCLUSIONS: LASIK induced peripheral infiltrative keratitis, in which infectious origin was ruled out, is reported.

The Effects of Distance Between the Corneal Apex and the Inner and Outer Corneal Wound Edges on Corneal Astigmatism After Cataract Surgery.

PURPOSE: To compare the effects of the distance from the inner and outer corneal incision wounds to the corneal apex on the changes in corneal astigmatism after cataract surgery. METHODS: Seventy-two eyes with anterior corneal astigmatism less than 2.50 diopters (D) were evaluated. The distance between the incision wound and the corneal apex was measured using the Pentacam (Oculus Optikgeräte, Wetzlar, Germany) Scheimpflug image and the Image J program (National Institutes of Health, Bethesda, MD). Patients were subgrouped into the inner incision distance close (less than 4,816.44 µm) and far (4,816.44 µm or greater) groups based on the median value of inner incision distance and the outer incision distance close (less than 6,131.77 µm) and far (6,131.77 µm or greater) groups based on the median value of outer incision distance. RESULTS: In the inner incision distance group, the mean change in anterior, posterior, and total corneal astigmatism at 1 week and anterior astigmatism at 1 month were statistically significantly greater in the inner incision close group than in the inner incision far group. In the outer incision distance group, the mean change in anterior corneal astigmatism at 1 week was statistically significantly greater in the close group than in the far group. Surgically induced astigmatism (SIA) of the posterior cornea showed a statistically significant increase in the inner incision close group compared to the inner incision far group 1 month postoperatively, whereas there were no significant differences in the outer incision distance groups. Inner incision distance significantly correlated with the mean change in anterior and posterior corneal astigmatism and posterior SIA at 1 week postoperatively. CONCLUSIONS: Corneal astigmatism was affected more by inner incision distance than outer incision distance, and a larger change in the posterior SIA was noted with decreasing inner incision distance. During cataract surgery, the position of the inner corneal incision should be considered rather than the outer incision. [J Refract Surg. 2017;33(7):460-468.].