Measurement of Vessel Density Using Optical Coherence Tomography-angiography in Normal Subjects: Difference by Analysis Area

PURPOSE: To evaluate the vessel density of macula according to analysis area in health subjects using optical coherence tomography angiography (OCTA). METHODS: We retrospectively analyzed 30 eyes of 20 healthy people who underwent OCTA. We measured vessel density (VD) according to analysis area and foveal avascular zone (FAZ) size of superficial capillary plexus (SCP) and deep capillary plexus (DCP). The analysis areas were classified as 3 × 3 mm scan area (Box), Box area excluding FAZ (Box-FAZ), fovea centered 3 mm circle area (Circle), Circle area excluding FAZ (Circle-FAZ) and area between fovea centered 1 mm circle and 3 mm circle (Ring). RESULTS: The SCP VDs were Box 34.00 ± 3.97, Box-FAZ 35.37 ± 4.09, Circle 31.70 ± 4.56, Circle-FAZ 33.34 ± 4.72, and Ring 35.22 ± 5.09. The DCP VDs were Box 30.04 ± 3.51, Circle 29.49 ± 3.57, Box-FAZ 31.59 ± 3.65, Circle-FAZ 31.46 ± 3.72, and Ring 32.60 ± 4.00. There was a significant difference according to analysis area from both SCP and DCP (p < 0.001 and p < 0.001, respectively). Comparison of the vessel density between SCP and DCP in the same analysis area were different in all areas (p < 0.001, p = 0.001, p < 0.001, p = 0.005, p = 0.001, respectively). CONCLUSIONS: This study shows different results according to analysis area when measuring VD using OCTA. Therefore, when comparing studies related to VD, it is necessary to pay attention to the analysis area in the interpretation of the results.

Short-term Analysis of the Residual Volume of an Eye Drop Following 23-Gauge Microincision Vitrectomy Surgery

PURPOSE: To evaluate the change of residual volume of eye drop after instillation in patients with 23-gauge microincision vitrectomy surgery (MIVS). METHODS: Patient who were treated 23-gauge MIVS from November 2014 to July 2015 were included. The residual volume was defined as the amount of remnant eye drop in patient's eyes after instillation, calculated as the difference between instillation volume and spilled volume of eye drop. Calculation of residual volume of eye drop was performed one day before surgery, and daily from postoperative day 1 to day 5. RESULTS: Forty consecutive patients were included. The residual volume of eye drop decreased from 30.3 ± 1.4 µL at baseline to 13.0 ± 1.5 µL at day 1, 18.3 ± 1.6 µL at day 2, 24.7 ± 1.5 µL at day 3, and 27.9 ± 1.4 µL in day 4, postoperatively (p < 0.001, respectively). The volume at postoperative day 5 was 29.4 ± 1.3 µL, but it was not different from the volume at baseline (p = 0.105). The change of residual volume was significantly correlated with postoperative chemosis (r = 0.672, p < 0.001) and effected by the number of quadrant with postoperative chemosis (p < 0.05). CONCLUSIONS: This study shows that postoperative residual volume of eye drop after instillation decreased until postoperative day 4, and postoperative chemosis affects the change of residual volume. Thus, checking proper use of eye drops and teaching about instillation technique by physician is necessary for patients with 23-gauge MIVS.

Sympathetic Ophthalmia after Ocular Wasp Sting

No abstract available.

Analysis of Factors Associated with Retinal Vascular Caliber in Normal Korean Subjects

PURPOSE: To measure the diameter of the retinal arterial and venous caliber of normal Korean subjects and evaluate the factors affecting these diameters. METHODS: Fundus photography was performed on 152 normal Korean subjects. Central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) were measured with a computer-based program (IVAN), and were used to investigate the relationship between the diameter and factors including age, gender, hypertension, diabetes, and smoking. RESULTS: Among the study subjects, the CRVE was 209.33 +/- 12.40 microm and the CRAE was 149.70 +/- 9.01 microm. The CRVE and CRAE decreased with increasing age in all study subjects (both p 0.05). CONCLUSIONS: In our study group, retinal vascular caliber of normal Korean subjects decreased with aging. Retinal vascular caliber was affected by gender and hypertension, but not by smoking and diabetes.

A Case of Double Descemet's Membrane after Penetrating Keratoplasty Converted from Deep Anterior Lamellar Keratoplasty

PURPOSE: To report a case of double Descemet's membrane in a patient who had penetrating keratoplasty after rupture of Descemet's membrane during deep anterior lamellar keratoplasty (DALK). CASE SUMMARY: A 24-year-old female had keratoconus in her right eye and underwent DALK for treatment. Descemet's membrane was ruptured while separating the corneal stroma from Descemet's membrane with the big bubble technique. The operation method was changed from DALK to penetrating keratoplasty. Detached Descemet's membrane was observed in the anterior chamber after suturing. Sterile air was injected into the anterior chamber to attach the Descemet's membrane. Five days after the surgery, Descemet's membrane was detached and a second air injection was performed. Corneal edema was improved but Descemet's membrane was re-detached. Double Descemet's membrane was observed by anterior segment optical coherence tomography (OCT). The detached Descemet's membrane originated from the recipient's cornea and not from the donor's cornea. Detached Descemet's membrane was removed successfully. Patient's cornea was clear and best corrected visual acuity was 20/25. CONCLUSIONS: When penetrating keratoplasty is performed instead of DALK, the surgeon should completely remove the remnant corneal stroma and Descemet's membrane. Remnant Descemet's membrane can be disregarded as it comes from the donor cornea. Unnecessary anterior chamber air injection causes endothelial damage. Anterior segment OCT is a useful tool to identify anatomical structures of transplanted cornea.

Two Cases of Long-Term Changes in the Retinal Nerve Fiber Layer Thickness after Intravitreal Bevacizumab for Diabetic Papillopathy

PURPOSE: To report long-term changes in the average retinal nerve fiber layer (RNFL) thickness in 2 patients who had intravitreal bevacizumab (IVB) injection for diabetic papillopathy. CASE SUMMARY: A 36-year-old patient with diabetes complained of decreased visual acuity (20/200) in the right eye. The fundus examination showed optic disc swelling in both eyes. The average RNFL thickness based on optical coherence tomography (OCT) increased to 278 microm and Goldmann perimetry showed nasal visual field defect in the right eye. The IVB was injected into the right eye. Three weeks after the IVB injection, RNFL thickness decreased to 135 microm and visual acuity improved to 20/25 in the right eye. However, RNFL thickness increased from 126 to 207 microm and visual acuity decreased to 20/32 in the left eye. Thus, IVB was injected into the left eye. In week 3, RNFL thickness decreased to 147 microm and visual acuity improved to 20/20 in the left eye. At 12 months after IVB injection, RNFL thickness was 87 microm in the right eye and 109 microm in the left eye. A 57-year-old patient with diabetes complained of decreased visual acuity (20/200) and showed optic disc swelling in the right eye. The average RNFL thickness increased to 252 microm and Goldmann perimetry showed an enlarged blind spot in the right eye. IVB was injected into the right eye. After 3 weeks, RNFL thickness decreased to 136 microm and visual acuity improved to 20/70 in the right eye. Six months after IVB injection, RNFL thickness was 83 microm in the right eye. CONCLUSIONS: Visual acuity progressively improved within 3 weeks and RNFL thickness measured by spectral domain OCT showed progressive thickness reduction in 2 cases of diabetic papillopathy patients who had IVB injections.