Clinical Significance of Tear Film Osmolarity in Patients with Mild Dry Eye Syndrome

Purpose@#To seek Pearson correlations of tear film osmolarity measured by the I-PEN® (I-MED Pharma Inc., Dollard-des-Ormeaux, Canada) with Schirmer test result, tear break-up time, and Ocular Surface Disease Index score in patients with mild dry eye syndrome. @*Methods@#Patients with mild dry eye syndrome were divided into two groups according to Ocular Staining Score: group 1 (50 patients; 67 eyes) and group 2 (59 patients; 91 eyes), 90 patients and 158 eyes in total. The above mentioned correlations were derived. @*Results@#No significant correlations were observed between tear film osmolarity and Schirmer test result (r < -0.01, p = 0.97), tear break-up time (r = 0.05, p = 0.54), or Ocular Surface Disease Index score (r = 0.03, p = 0.76). When the two groups were compared, the Ocular Surface Disease Index score significantly differed between groups (p < 0.01), whereas the Schirmer test result (p = 0.31), tear break-up time (p = 0.11), and tear film osmolarity (p = 0.12) did not. @*Conclusions@#No significant correlations were found between tear film osmolarity and other dry eye indicators in patients with mild dry eye syndrome. The diagnostic utility of tear film osmolarity in patients with moderate dry eye syndrome is should be evaluated.

Clinical Significance of Tear Film Osmolarity in Patients with Mild Dry Eye Syndrome

Purpose@#To seek Pearson correlations of tear film osmolarity measured by the I-PEN® (I-MED Pharma Inc., Dollard-des-Ormeaux, Canada) with Schirmer test result, tear break-up time, and Ocular Surface Disease Index score in patients with mild dry eye syndrome. @*Methods@#Patients with mild dry eye syndrome were divided into two groups according to Ocular Staining Score: group 1 (50 patients; 67 eyes) and group 2 (59 patients; 91 eyes), 90 patients and 158 eyes in total. The above mentioned correlations were derived. @*Results@#No significant correlations were observed between tear film osmolarity and Schirmer test result (r < -0.01, p = 0.97), tear break-up time (r = 0.05, p = 0.54), or Ocular Surface Disease Index score (r = 0.03, p = 0.76). When the two groups were compared, the Ocular Surface Disease Index score significantly differed between groups (p < 0.01), whereas the Schirmer test result (p = 0.31), tear break-up time (p = 0.11), and tear film osmolarity (p = 0.12) did not. @*Conclusions@#No significant correlations were found between tear film osmolarity and other dry eye indicators in patients with mild dry eye syndrome. The diagnostic utility of tear film osmolarity in patients with moderate dry eye syndrome is should be evaluated.

Intraocular Lens Power Calculation Using Shammas-PL Formula after Laser In-situ Keratomileusis

Purpose@#To calculate the intraocular lens (IOL) power using the Shammas-PL formula after laser in-situ keratomileusis (LASIK). @*Methods@#Forty-one eyes of 29 patients that had undergone cataract surgery from September 2018 to September 2019 after LASIK were enrolled in this study. A preoperative AL-Scan® (Nidek Co., Gamagori, Japan) was used to measure the axial length, anterior chamber depth, and corneal curvature. An IOL power calculation was performed using the Shammas-PL (post LASIK) formula. Mean absolute error (MAE) and mean arithmetic error (MARE) were calculated using preoperative manifest refraction and postoperative manifest refraction. @*Results@#Of the 41 eyes, 15 eyes (36.6%) were relatively hyperopic-shifted after surgery compared to the predicted refractive error before surgery, 25 eyes (61%) showed a relative myopic shift, and one eye (2.4%) showed no change with respect to the previous refractive predicted error. Refractive errors before cataract surgery were not related to myopic, emmetropic, or hyperopic shifting after surgery (p > 0.05). @*Conclusions@#When cataract surgery using the Shammas-PL formula was performed after LASIK, myopic shifting was more common than hyperopic shifting. The MAE was greater in myopic-shifted cases than that of hyperopic-shifted cases. Thus, it is better to determine IOL power toward the hyperopic side than the target refractive prediction.

Central Toxic Keratopathy after Femtosecond Laser in-situ Keratomileusis

Purpose@#To report a case of central toxic keratopathy after femtosecond laser in-situ keratomileusis (LASIK).Case summary: A 26-year-old male developed diffuse lamellar keratitis bilaterally on day 2 after femtosecond LASIK. He was applying topical steroid frequently, while also using topical antibiotics. On day 6 after LASIK, slit-lamp biomicroscopy showed a thick central corneal opacity on the right eye so a flap irrigation was performed. He was then treated with systemic methylprednisolone. A corneal epithelial crack and stromal striae were noted by slit-lamp biomicroscopy on postoperative day 10. Four weeks after LASIK, the refractive error was +4.25 Dsph = -1.25 Dcyl Axis 80°. He was treated with topical steroid, topical antibiotics, and oral doxycycline until eight weeks after LASIK. Eight weeks after LASIK, the patient was observed without treatment. The central corneal thickness recovered from 488 μm at eight weeks to 540 μm, and the refractive error was +1.25 Dsph = -0.75 Dcyl Axis 85° at postoperative 72 weeks. The central corneal opacity also recovered. @*Conclusions@#Because femtosecond LASIK may result in a combination of diffuse lamellar keratitis and central toxic keratopathy, the clinical characteristics and natural course of both diseases should be understood and timely treatment should be available.

Comparison of Perioperative Contrast Sensitivity between Laser in situ Keratomileusis and Small-incision Lenticule Extraction

Purpose@#To compare contrast sensitivity before and after surgery in patients who underwent laser in situ keratomileusis (LASIK)and small-incision lenticule extraction (SMILE). @*Methods@#From February 2019 to April 2019, 20 patients who underwent LASIK, and 21 who underwent SMILE, were comparedbefore, one day, one week, and one month after surgery. @*Results@#On postoperative day (POD) 1, contrast sensitivity was better in the LASIK group than in the SMILE group under all conditionsfor 1.6, 1, and 0.64 cycles per degree (cpd). One week after surgery, the contrast sensitivity of the LASIK group was betterthan that of the SMILE group under photopic conditions with glare for 1.6, 1, and 0.64 cpd, under photopic conditions withoutglare for 1 and 0.64 cpd, and under all scotopic conditions for 2.5, 1.6, and 0.64 cpd (p< 0.05). There was no significant differencebetween the two groups, except under the scotopic conditions without glare for 0.64 cpd at one month after surgery. In theLASIK group, the contrast sensitivity was best at one week after surgery. The SMILE group showed the poorest contrast sensitivityon POD 1, but this gradually improved. @*Conclusions@#The LASIK group had better contrast sensitivity on one day and one week after surgery than the SMILE group, butthere was no significant difference at one month after surgery. In the LASIK group, the contrast sensitivity was best at one weekafter surgery. In the SMILE group, the contrast sensitivity was worst on POD 1.

Refractive Power Outcomes with an Intraocular Lens with 0.25-diopter Intervals

Purpose@#The Eyelike K-flex Aspheric® (Koryoeyetech, Seoul, Korea) is manufactured in 0.25-diopter (D) intervals, which allows the target refractive error after surgery to be achieved. We here evaluate the refractive power outcomes. @*Methods@#We retrospectively studied 95 eyes of 72 patients who underwent cataract surgery with implantation of the Eyelike K-flex Aspheric®. Refractive error was measured at 1 and 2 months postoperatively (33 eyes of 27 patients) and compared to that of patients fitted with 0.50-D-interval lenses (62 eyes of 49 patients). @*Results@#At 1 month postoperatively, the mean absolute error between the spherical equivalent and planned value was 0.33 ± 0.28 and 0.41 ± 0.39 D in the 0.25- and 0.50 D-interval lens groups, respectively (p = 0.318). At 2 months postoperatively, the respective values were 0.21 ± 0.15 and 0.34 ± 0.29 D (p = 0.009). @*Conclusions@#The Eyelike K-flex Aspheric® shows excellent refractive predictability; use of 0.25-D-interval intraocular lenses close to the target refractive power allows the desired spherical equivalent to be achieved.

Accuracy of Intraocular Lens Power Calculations Based on Total and Standard Keratometry

Purpose@#To compare the accuracy of standard and total keratometry data obtained using the Barrett Universal II and Barrett Toric Calculator. @*Methods@#In total, 111 eyes of 111 patients who visited our hospital for cataract surgery from February 2019 to September 2019 were included in this study. Total keratometry and standard keratometry data were obtained using the Barrett Universal II and the Barrett Toric Calculator; mean absolute errors were derived by using preoperative IOL Master 700® (Carl Zeiss Meditech AG, Jena, Germany) data and 2-month postoperative manifest refraction data. The mean absolute errors of the two methods were compared in terms of a posterior corneal astigmatism greater than 0.3 diopter (D) in patients fitted with Toric intraocular lenses. @*Results@#Using the Barrett Universal II formula, the mean absolute error spherical equivalent difference between total keratometry and standard keratometry was 0.021 ± 0.102 D (p = 0.65) when the Barrett Toric Calculator was used. The mean absolute error differences between the two methods were 0.015 ± 0.121 D for the spherical equivalent (p = 0.80) and 0.005 ± 0.870 D for the cylinder measurement (p = 0.94). In terms of a posterior corneal astigmatism greater than 0.3 D, the mean absolute error spherical equivalent and cylinder measurement differences were -0.020 ± 0.107 D (p = 0.70) and -0.023 ± 0.055 D (p = 0.50) in patients fitted with Toric intraocular lenses. @*Conclusions@#The total keratometry method, which directly measures posterior corneal curvature, yields data comparable to those of the standard keratometry method. When the posterior corneal astigmatism was greater than 0.3 D, we found no significant difference between the total keratometry and standard keratometry data of patients fitted with Toric intraocular lenses.

Refractive Power Outcomes with an Intraocular Lens with 0.25-diopter Intervals

Purpose@#The Eyelike K-flex Aspheric® (Koryoeyetech, Seoul, Korea) is manufactured in 0.25-diopter (D) intervals, which allows the target refractive error after surgery to be achieved. We here evaluate the refractive power outcomes. @*Methods@#We retrospectively studied 95 eyes of 72 patients who underwent cataract surgery with implantation of the Eyelike K-flex Aspheric®. Refractive error was measured at 1 and 2 months postoperatively (33 eyes of 27 patients) and compared to that of patients fitted with 0.50-D-interval lenses (62 eyes of 49 patients). @*Results@#At 1 month postoperatively, the mean absolute error between the spherical equivalent and planned value was 0.33 ± 0.28 and 0.41 ± 0.39 D in the 0.25- and 0.50 D-interval lens groups, respectively (p = 0.318). At 2 months postoperatively, the respective values were 0.21 ± 0.15 and 0.34 ± 0.29 D (p = 0.009). @*Conclusions@#The Eyelike K-flex Aspheric® shows excellent refractive predictability; use of 0.25-D-interval intraocular lenses close to the target refractive power allows the desired spherical equivalent to be achieved.

Accuracy of Intraocular Lens Power Calculations Based on Total and Standard Keratometry

Purpose@#To compare the accuracy of standard and total keratometry data obtained using the Barrett Universal II and Barrett Toric Calculator. @*Methods@#In total, 111 eyes of 111 patients who visited our hospital for cataract surgery from February 2019 to September 2019 were included in this study. Total keratometry and standard keratometry data were obtained using the Barrett Universal II and the Barrett Toric Calculator; mean absolute errors were derived by using preoperative IOL Master 700® (Carl Zeiss Meditech AG, Jena, Germany) data and 2-month postoperative manifest refraction data. The mean absolute errors of the two methods were compared in terms of a posterior corneal astigmatism greater than 0.3 diopter (D) in patients fitted with Toric intraocular lenses. @*Results@#Using the Barrett Universal II formula, the mean absolute error spherical equivalent difference between total keratometry and standard keratometry was 0.021 ± 0.102 D (p = 0.65) when the Barrett Toric Calculator was used. The mean absolute error differences between the two methods were 0.015 ± 0.121 D for the spherical equivalent (p = 0.80) and 0.005 ± 0.870 D for the cylinder measurement (p = 0.94). In terms of a posterior corneal astigmatism greater than 0.3 D, the mean absolute error spherical equivalent and cylinder measurement differences were -0.020 ± 0.107 D (p = 0.70) and -0.023 ± 0.055 D (p = 0.50) in patients fitted with Toric intraocular lenses. @*Conclusions@#The total keratometry method, which directly measures posterior corneal curvature, yields data comparable to those of the standard keratometry method. When the posterior corneal astigmatism was greater than 0.3 D, we found no significant difference between the total keratometry and standard keratometry data of patients fitted with Toric intraocular lenses.

A Case of Clozapine-induced Corneal and Lenticular Pigmentation

PURPOSE: To report a case of corneal and lenticular pigmentation after prolonged clozapine therapy. CASE SUMMARY: A 56-year-old male visited our hospital with a progressive decline in vision that affected both eyes. He had a history of schizophrenia. He was being treated with 200 mg clozapine and 1 mg lorazepam daily, and had been treated with clozapine for 5 years. At the first visit, his best-corrected-visual acuity was 20/32 in both eyes. Slit lamp examination of the corneas showed bright, fine, grayish-brown deposits on the endothelium, and on dilation, bilateral central stellate opacity of the anterior portion of the lens capsule was revealed. CONCLUSIONS: Clozapine may induce corneal and lenticular pigmentation and thus may lead to a decline in vision. Patients on long-term clozapine therapy should be considered for regular ophthalmic review.

The Optical Coherence Tomography Findings of Optic Tract Syndrome

PURPOSE: To report a case of optic tract syndrome in which optical coherence tomography (OCT) demonstrated the specific findings of the retinal nerve fiber layer (RNFL). CASE SUMMARY: A 32-year-old male patient visited the hospital with right side visual field defect in both eyes that occurred immediately after a traffic accident 8 months prior. The visual acuity of both eyes was normal, and a relative afferent papillary defect was evident in the right eye. In addition, suspicious band atrophy of the right optic disc and thinning of the superior and inferior arcuate bundle were observed in the left eye. On visual field examination, homonymous hemianopia was present. Optic tract syndrome was suspected, although there was no abnormality of the visual tract on MRI. On fast RNFL thickness 3.4 scan, a thinning of RNFL in the nasal and temporal segments in the right eye and superior and inferior segments in the left eye were observed. Based on the findings, optic tract syndrome was diagnosed in the left eye. CONCLUSIONS: We report specific OCT findings which can be useful when making a diagnosis of optic tract syndrome.

The Predictability of Ocular Trauma Score and Prognostic Factors of Open Globe Injury

PURPOSE: To determine the prognostic factors of visual outcome in open globe injury and to assess the possibility of an ocular trauma score (OTS) model of predictive value in open globe injuries in Koreans. METHODS: The medical records of 242 patients with open globe injury from 2000 to 2010 were retrospectively reviewed. Prognostic factors of visual outcome, positive predictive rate, and negative predictive rate were surveyed. RESULTS: In the multivariate analysis, old age, relative afferent pupillary defect, impaired initial visual acuity and retinal detachment were the worst predictive factors of vision survival. In OTS categories 1 and 2, worse final visual acuity was acquired, and positive predictive rate and negative predictive rate for assessment of final visual acuity less than 0.02 were 70.1% and 89.8%, respectively. CONCLUSIONS: The prognostic factors of open globe injury associated with impaired final visual acuity were old age, relative afferent pupillary defect, worse initial visual acuity, retinal detachment and OTS categories 1 and 2. The OTS may have prognostic value in open globe injuries in Korean patients. However, identified prognostic factors of the present study did not entirely coincide with those of other Koreans or previous studies. Therefore, additional studies on the modified open globe injury as a prognostic model in Korean patients are needed.

Effect of Amniotic Membrane on Epithelial Thickness and Formation of Hemidesmosomes after Corneal Stromal Wound

PURPOSE: To investigate the effects of an amniotic membrane patch on corneal epithelial thickness and formation of hemidesmosomes during corneal stromal wound healing. METHODS: A stromal wound 9 mm in diameter and 130 microm in depth was created on rabbit cornea using a microkeratome. The changes in corneal epithelial thickness and hemidesmosome formations were compared between the amniotic membrane, contact lens, and control groups. Changes in the corneal epithelium were examined using H&E staining and hemidesmosome formation was examined using an electron microscope at 2 and 4 weeks after flap removal. RESULTS: Two weeks after treatment, the corneal epithelial thickness was 95.3 +/- 6.3 microm in the amniotic membrane group being significantly thicker than 76.4 +/- 5.1 microm in the contact lens group and 68.3 +/- 6.1 microm in the control group. Furthermore, more hemidesmosome formations were observed in the amniotic membrane group compared to the other 2 groups. However, there were no significant differences in corneal epithelial thickness or hemidesmosome formation among the 3 groups at week 4. CONCLUSIONS: The amniotic membrane group showed a thicker corneal epithelium and more hemidesmosome formation than the other 2 groups 2 weeks after flap removal. Thus, the use of an amniotic membrane patch appears to be effective in the early stages of corneal stromal wound healing.

The Case of Inferior Oblique Muscle Overaction after Orbital Trauma

PURPOSE: To report a case of inferior oblique muscle overaction after orbital trauma. CASE SUMMARY: A 19-year-old male presented with a blowout fracture of the right inferior orbital wall. The patient had no history of facial asymmetry, head tilt, strabismus or diplopia. The day after the reduction operation, the patient complained of diplopia on the down-gaze. The patient had orhthophoria in the primary position. However, the right eye showed a limitation on infraduction. Six weeks later, the limitation of infraduction resolved, however the diplopia worsened. The right eye showed excessive elevation in adduction and hypertropia in the primary position. The hypertropia increased on left gaze, and decreased on right gaze. Bielschowsky's head test revealed a negative result. The fundus photographs showed a mild excyclotorsion of the right eye. Five months later, the symptoms and signs were stable and surgery was performed. Under general anesthesia, the exaggerated forced duction test and traction with strabismus hook on the right inferior oblique muscle revealed tightness. The inferior oblique muscle was found to be recessed. After the operation, the diplopia, hypertropia and the excessive elevation on adduction of the right eye resolved. CONCLUSIONS: A contracture and resultant overaction of inferior oblique muscle could develop after trauma on the inferior orbital wall. Trauma on the inferior orbital wall should be considered as one of the primary causes of acquired inferior oblique overaction.

Comparison of Ocular Biometry Measured by Ultrasound and Two Kinds of Partial Coherence Interferometers

PURPOSE: To evaluate the reproducibility and repeatibility of biometry in cataractous eyes, pseudophakic eyes and eyes having undergone refractive surgery. The OcuScan(R)RxP, LENSTAR(R) and IOL Master(R) instruments were compared, as were. The accuracies of the refractive results after cataract surgery. METHODS: The biometries of 45 cataractous eyes, 31 pseudophakic eyes, and 32 eyes having undergone refractive surgery were measured by two practitioners using OcuScan(R)RxP, LENSTAR(R) and IOL Master(R) instruments. The paired t-test was used to compare the reproducibilities in the three groups. RESULTS: There were no differences in axial length among the groups when using any of the instruments. There was no significant difference in the repeatibility regardless of the instrument used, although. In the cataractous eyes, pseudophakic eyes and eyes with refractive surgery, OcuScan(R)RxP showed the highest repeatability. However, we knew that all three instruments were excellent in the repeatability because the difference was less than 1.5%. The Prediction error of the instruments with regard to refractive results could not be determined after cataract surgery. In some patients with severe cataract, measurement was impossible for both the LENSTAR(R) and IOL Master(R) instruments. CONCLUSIONS: In all groups, OcuScan(R)RxP, LENSTAR(R) and IOL Master(R) showed no significant differences with regard to reproducibility or prediction of refractive power after surgery. Among three groups, the repeatability was rather high in the existing ultrasound method than in the partial coherence interferometers. In some patients with severe cataract, measurement was impossible for both the LENSTAR(R) and IOL Master(R) instruments.

Intraocular Lens Power Calculation Using Haigis-L Method After Corneal Refractive Surgery

PURPOSE: To evaluate the Haigis-L method of IOL Master that does not require preoperative data for intraocular lens (IOL) power calculations and compare the results with other methods requiring preoperative data. METHODS: Fifty eyes of 25 patients who had undergone laser-assisted subepithelial keratectomy (LASEK) and were followed for 1 month or longer were selected for this study. IOL power was calculated by four different methods: clinical history method, Feiz-Mannis method, modified Masket method, and Haigis-L method. RESULTS: The mean calculated IOL powers showed the following results: clinical history method; 23.65D, Feiz-Mannis method; 24.45D, modified Masket method; 22.89D, and Haigis-L method; 23.80D. Each IOL power differed statistically from others (p=0.000). The difference between each method was analyzed by the Bonferroni test, with the Feiz-Mannis method showing the highest result and the modified Masket method, the lowest. The clinical history method and Haigis-L method presented similar results. CONCLUSIONS: For patients without data prior to corneal refractive surgery, the Haigis-L method is as accurate as the clinical history method. Therefore, comparatively accurate results can be produced in IOL power calculations using the Haigis-L method after corneal refractive surgery.

Valsalva Maneuver-induced Amaurosis Fugax

PURPOSE: To report the case of a patient with amaurosis fugax that occurred following a Valsalva maneuver. CASE SUMMARY: A 40-year-old man presented with amaurosis fugax of the right eye, which had occurred several times during the previous month. After coughing, the visual acuity of the right eye decreased temporarily during the first episode. Subsequently, any time a Valsalva maneuver, such as coughing, occurred, this symptom reappeared. Initially, this symptom persisted for five to ten minutes and occurred once or twice a day, but it gradually increased in frequency. The physical examination was normal, and his best corrected visual acuity was 20/20 bilaterally. Neither specific findings in the slit lamp examination nor abnormal findings in the fundus examination were detected. On fluorescein fundus angiography, no abnormal finding was observed before the symptom was triggered by a Valsalva maneuver, but after the symptom was triggered by coughing, the choroidal and retinal arterial phases were delayed. Hematological and neurological examinations, including magnetic resonance imaging, magnetic resonance angiography, and cerebral angiography, were all normal. Therefore, he was diagnosed with amaurosis fugax generated by a Valsalva maneuver. CONCLUSIONS: In any patient who complains of amaurosis fugax repeatedly, as seen in this case, one must consider the possibility that it results from a Valsalva maneuver, after eliminating occlusive vascular diseases, such as carotid stenosis or atherosclerotic disease.