Accuracy of Intraocular Pressure Measurements of Eyes with Therapeutic Contact Lenses after Vitrectomy

Purpose@#To evaluate the accuracy of intraocular pressure (IOP) measurements obtained by a rebound and non-contact tonometer in eyes with a therapeutic contact lens (CL) after vitrectomy. @*Methods@#In 60 eyes of 60 patients who underwent vitrectomy for vitreoretinal disease, IOP was measured using a rebound tonometer (iCare ic200®; IOPRT) and non-contact computerized air puff tonometer (CT-80, IOPNCT), before and after wearing a CL (Purevision2®, +0.0 diopter). The mean IOP of three consecutive measurements were analyzed, and a comparative analysis with IOP measured by a Goldman applanation tonometer (IOPGAT) was performed. @*Results@#The mean IOPRT without and with the CL was 12.55 ± 5.43 and 13.12 ± 5.13 mmHg, respectively, showing a statistically significant difference (p = 0.02) and strong positive correlation (r = 0.90, p < 0.001). The mean IOPNCT with and without the CL was 12.18 ± 3.24 and 12.17 ± 3.14 mmHg, showing no statistically significant difference (p = 0.17). The consistency with IOPGAT (12.57 ± 5.22 mmHg) was highest in IOPRT without the CL, followed by IOPRT with the CL, IOPNCT without the CL, and IOPNCT with the CL (intraclass correlation coefficients = 0.955, 0.945, 0.856, and 0.850, respectively). In addition, the rebound tonometer successfully measured IOP, regardless of whether the CL was worn; however, the non-contact tonometer failed to measure IOP in seven eyes without the CL and nine with the CL. No difference was observed according to intraocular tamponade type. @*Conclusions@#A rebound tonometer can be used as an alternative IOL measuring method in eyes for which it is difficult to use a Goldman applanation tonometer due to the postoperative presence of a therapeutic CL.

Clinical Features of Ocular Ischemic Syndrome and Risk Factors for Neovascular Glaucoma

PURPOSE: We aimed to examine the clinical features and prognosis of ocular ischemic syndrome and to investigate the risk factors for the development of neovascular glaucoma (NVG). METHODS: The medical records from 25 patients (25 eyes) who were diagnosed with ocular ischemic syndrome were retrospectively analyzed. We recorded the length of time between symptom onset and diagnosis, visual acuity, intraocular pressure, clinical findings of the anterior and posterior segments of the eye, fluorescein angiography, systemic diseases, smoking history, and the extent of any ipsilateral carotid artery stenosis. The risk factors for NVG in patients with ocular ischemic syndrome were investigated. RESULTS: The mean age was 67.9 ± 12.5 years, and 21 men and 4 women were included in this study. At initial examination, the mean logarithm of the minimum angle of resolution (logMAR) was 2.02 ± 1.26, and the mean intraocular pressure was 21.0 ± 10.3 mmHg. Among 25 eyes of the 25 patients, NVG occurred in 17 eyes after a mean period of 12.6 ± 14.0 months. The length of time between symptom onset and diagnosis (p = 0.025) and the extent of ipsilateral carotid artery stenosis (p = 0.032) were identified as significant risk factors for NVG. At the final follow-up, the mean logMAR visual acuity was 3.13 ± 1.24, showing a poor prognosis regardless of whether NVG occurred. CONCLUSIONS: Overall, the prognosis for ocular ischemic syndrome is very poor. The risk of NVG increases with the length of time between symptom onset and diagnosis, as well as with the severity of ipsilateral carotid artery stenosis.

Association of the GSTM1 and GSTT1 Genes with Diabetic Retinopathy in the Korean Population

PURPOSE: To investigate the correlation between Glutathione-S-transferase (GST) genes and diabetic retinopathy (DR) in patients with type 2 diabetes mellitus (DM). METHODS: In this case-control study, 131 patients who were diagnosed with DR, 105 diabetic patients who did not have DR, and 45 nondiabetic controls were examined from January 2013 to November 2015. To analyze deletion of the GSTT1 and GSTM1 genes, polymerase chain reactions of DNA in a buffy coat from peripheral blood were performed via electrophoresis. RESULTS: There were no statistically significant differences in age, sex, or spherical equivalent between the 236 type 2 diabetic patients and the 45 normal controls (p > 0.05). In both univariate and multivariate analyses, the duration of type 2 DR was longer (p = 0.004, p = 0.013), and HbA1c was higher (p = 0.004, p = 0.007) in the DR group than in the non-DR group. Presence of a GSTM1 deletion is associated with a lower frequency of DR (p = 0.017, p = 0.012). CONCLUSIONS: Deletion of the GSTT1 gene is not associated with an increased risk of DR, whereas GSTM1 deletion is associated with a lower risk of DR in patients with type 2 DM in the Korean population. Additional studies with larger sample sizes and different types of GST genes are needed to confirm this study.

A Case of Fibrotic Obstruction of Scleral Orifice of Ex-PRESS Shunt

PURPOSE: To report a case of fibrotic obstruction of scleral orifice in Ex-PRESS shunt. CASE SUMMARY: A 57-year-old male presented with elevated intraocular pressure in his left eye. In the past, laser photocoagulation was performed at a local clinic due to retinal venous occlusion in his left eye. During observation, he was transferred to our hospital due to uncontrolled intraocular pressure despite antiglaucoma medications. He was diagnosed with neovascular glaucoma in the left eye. Since intravitreal injection of anti-vascular endothelial growth factor with maximal medical therapy did not lower the intraocular pressure, an Ex-PRESS shunt device was implanted. Two weeks postoperatively, the bleb was flat and diffuse with shallow anterior chamber and intraocular pressure was below 5 mm Hg. Therefore, we performed scleral flap revision and intraocular pressure was sustained between 10 and 15 mm Hg. Two months postoperatively, the patient experienced high intraocular pressure and no elevated bleb, thus we performed bleb revision. During the surgery, although we removed fibrotic adhesions between the conjunctiva and episclera using a 30-gauge needle, aqueous outflow was not observed. Therefore, we opened the scleral flap and found the scleral orifice of the Ex-PRESS shunt was obstructed by fibrous scar tissue. After scar tissue removal and achieving aqueous outflow through the scleral opening, intraocular pressure decreased to a satisfactory level. CONCLUSIONS: In patients with elevated intraocular pressure after implantation of the Ex-PRESS shunt, the scleral opening of the Ex-PRESS shunt should be examined for obstruction.

Measurement of Corneal Power and Astigmatism Using Placido-based Videokeratography and Comparison with Other Keratometers

PURPOSE: In the present study, the repeatability and reproducibility of the corneal power and astigmatism measurements using placido-based video keratography were evaluated and the agreement with other keratometers were compared. METHODS: This prospective study included 45 patients (45 eyes) scheduled to undergo cataract surgery between November 2015 and January 2016. Three sets of corneal power and astigmatism were measured using placido-based video keratometer (Keratograph® 5M), automatic keratometer (KR-8900®), manual keratometer (B×L manual keratometer®), Placido-scanning-slit keratometer (ORBscan II®), Scheimpflug keratometer (Pentacam®), and low coherence interferometry (Lenstar LS900®). Reliability of each device was analyzed using the coefficient of variation, standard deviation and intraclass correlation coefficient. Repeated measures analysis of variance was used to analyze the interdevice comparison of mean absolute difference. The agreement between the devices was evaluated with 95% limits of agreement (LoA) and Bland-Altman plots. RESULTS: The mean corneal power, astigmatism and power vector analysis (J₀, J₄₅) were not significantly different among devices (p > 0.05). In the Bland-Altman plot analysis, the 95% LoA of corneal power, J₀, and J45 when comparing Keratograph® 5M with others ranged from -0.78 to 0.55 D, from -0.42 to 0.45 D, and from -0.39 to 0.47 D, respectively. CONCLUSIONS: Keratograph® 5M showed good repeatability and reproducibility of corneal power and astigmatism measurements and was interchangeable with other keratometers.

A Case of Recurrent External Ophthalmomyiasis Caused by Lucilia sericata Meigen in a Healthy Patient

PURPOSE: To report a case of recurrent external ophthalmomyiasis caused by Lucilia sericata Meigen in a healthy patient. CASE SUMMARY: A 72-year-old male, who was diagnosed 7 months earlier with ophthalmomyiasis and obtained permanent relief by surgical treatment, presented with severe tearing, redness, foreign body sensation, pain in both eyes and aural discomfort in the left ear. On presentation, visual acuity in both eyes was hand movement. On slit lamp examination, total corneal epithelial defect with stromal infiltrations was observed. However, there were no motile organisms in his eyes due to previous removal of maggots at a local clinic. On physical examination, eschar change was observed at the inferomedial area of the left lower eyelid. On otorhinolaryngological examination, several motile organisms with tympanic membrane perforation were observed in the left external acoustic meatus. The patient was treated with topical antibiotic eye drops hourly with systemic antibiotics, and 6 larvae were removed from the external acoustic meatus using otoscopy. Microscopic findings of the removed larvae revealed L. sericata in their third stage of development. After 1 month, corneal epithelial defect and stromal infiltration improved. However, visual acuity in both eyes was 0.1 due to remaining stromal opacities. CONCLUSIONS: In a healthy patient without any predisposing factors, recurrent ophthalmomyiasis accompanied with aural myiasis can develop under poor hygiene conditions.