Accutome PachPen handheld ultrasonic pachymeter: intraobserver repeatability and interobserver reproducibility by personnel of different training grades.

To assess the intra-observer repeatability and inter-observer reproducibility of central corneal thickness (CCT) measurements of PachPen (Accutome, Inc., Pennsylvania, USA), a hand-held, portable ultrasonic pachymeter when used by an ophthalmic nurse compared to an ophthalmologist. Ophthalmology Clinic, University of Malaya Medical Center In this prospective study, CCT was measured in 184 eyes of 92 healthy subjects, first by a corneal surgeon experienced in ultrasound pachymetry (Observer 1) followed by an ophthalmic nurse new to the procedure (Observer 2). Nine measurements were obtained from each eye by each observer, independently. Measurements were compared between the observers. Coefficients of repeatability and reproducibility were calculated. The Bland-Altman plot was used to assess agreement between observers. Mean age of the study population was 54.3 ± 15.2 years old and consisted of 43.5% male. Mean CCT as measured by Observers 1 and 2 were 528.3 ± 32.9 and 530.7 ± 33.3 µm, respectively. Observer 1 showed higher repeatability of measurements compared to that of Observer 2 (coefficient of repeatability 3.46 vs. 5.55%). The measurements by both observers showed high correlation (0.96) and good agreement (mean difference -2.4 µm; 95% limits of agreement -21.4, 16.7 µm). Coefficient of reproducibility of measurements between observers was 5.08%. Accutome PachPen hand-held ultrasound pachymeters gives excellent intra-observer repeatability and inter-observer reproducibility by personnel of different training grades.

Spectral-domain optical coherence tomography evaluation of postoperative cystoid macular oedema following phacoemulsification with intraoperative complication.

BACKGROUND: To report the rate of cystoid macular oedema (CMO) as detected by spectral-domain optical coherence tomography (SD-OCT) after intraoperative complication during phacoemulsification. The secondary objectives include comparing mean macular thickness and best-corrected visual acuity (BCVA) between those who developed postoperative CMO against those who did not. METHODS: This is a prospective cohort study conducted in a tertiary hospital between July 2009 and June 2010. Serial SD-OCT and BCVA were performed at baseline, 1 week, 6 weeks and 16 weeks postoperatively. RESULTS: Single eyes from 47 subjects were analyzed; of these 16 (34%) eyes developed CMO. In the CMO group, mean macular thickness (±SD) increased sharply by 56 µm from 273 ± 24 µm at baseline to 329 ± 31 µm at 16 weeks; whereas in the non-CMO group, macular thickness showed a slight increase of 14 µm from 259 ± 21 µm to 272 ± 20 µm. In the CMO group, mean BCVA (in logarithm of minimum angle of resolution) improved modestly from 0.92 ± 0.66 to 0.66 ± 0.41 at week 16; while in the non-CMO group, mean BCVA improved markedly from 0.98 ± 0.59 to 0.21 ± 0.13. The two groups differed significantly in mean macular thickness (p < 0.001) and mean BCVA (p < 0.001) at 16 weeks. CONCLUSION: As detection rate of CMO is high, postoperative OCT monitoring for patients with intraoperative complications allows earlier diagnosis and treatment.

Intravitreal bevacizumab for radiation-induced cystoid macular oedema in patients with nasopharyngeal carcinoma: a clinical series.

AIMS: To evaluate the outcome of intravitreal bevacizumab in the treatment of radiation-induced cystoid macular oedema among patients who underwent external beam radiotherapy for nasopharyngeal carcinoma. METHODS: Five patients were recruited. The length of time from the last external beam radiation therapy to presentation ranged from 12 months to 15 years. Intravitreal bevacizumab (1.25 mg/0.05 ml) was given and repeated monthly injections were administered until best corrected visual acuity (BCVA) improved to 6/9 or until 3 further injections did not show further improvement in BCVA. BCVA was measured and fundus photography, optical coherence tomography (OCT) and fluorescein angiography were performed at baseline. BCVA and OCT were recorded at each monthly visit. The duration of follow-up ranged from 6 months to 2 years. RESULTS: Five patients (7 eyes) were recruited. At the final visit, 3 eyes (71.4%) showed reduction in the central subfield thickness (CST; mean reduction of 17.6%, range 9-149 µm) with improvement in BCVA, whilst 2 eyes worsened in terms of CST and final BCVA. Another 2 eyes remained altered in BCVA despite slight improvement in CST. CONCLUSION: The use of intravitreal bevacizumab in this group of patients showed variable response in terms of CST and BCVA outcome but remains a viable option to treat this challenging condition.

Central corneal thickness measurements with different imaging devices and ultrasound pachymetry.

PURPOSE: The aim of this study was to compare 4 methods of central corneal thickness (CCT) measurements in terms of their agreement, repeatability, and measurement time. METHODS: CCT was measured in 184 eyes of 92 healthy subjects by the same examiner. The methods used were as follows: noncontact specular microscopy (SM; Topcon SP-3000P; Topcon Corporation, Tokyo, Japan), Pentacam rotating Scheimpflug photography system (Oculus Inc, Wetzlar, Germany), optical low-coherence reflectometry (OLCR; LenStar LS900; Haag-Streit AG, Koeniz, Switzerland), and ultrasound pachymetry (UP; PachPen; Accutome Inc, Malvern, PA). The duration for each examination was measured by an independent observer. RESULTS: The mean age (±SD) of the subjects was 54.3 (± 15.3) years. The mean CCTs (± SD) for SM, Pentacam, OLCR, and UP were 507.8 (± 30.2), 538.4 (± 31.7), 531.8 (± 31.4), and 528.3 (± 32.9) µm, respectively. The Bland-Altman plots showed closest agreement for OLCR-UP, followed by OLCR-Pentacam and Pentacam-UP. SM had the poorest agreement with the other methods. CCTs measured by SM were on average 20 to 30 µm thinner than those of the other methods. The coefficient of repeatability for SM, Pentacam, OLCR, and UP were 3.14%, 4.23%, 1.51%, and 3.46%, respectively. The mean measurement times (± SD) were 13.5 (± 5.7), 45.7 (± 12.3), 18.5 (± 7.1), and 5.6 (± 1.0) seconds, respectively. CONCLUSIONS: CCT measurements between OLCR-UP and OLCR-Pentacam are comparable and can be used interchangeably in clinical practice. However, SM underestimates CCT compared with the other methods, whereas Pentacam was found to be the least repeatable and took the longest time.

Plasma, aqueous and vitreous homocysteine levels in proliferative diabetic retinopathy.

BACKGROUND/AIMS: To compare homocysteine (Hcy) concentration in the blood plasma, vitreous and aqueous of eyes with proliferative diabetic retinopathy (PDR) against control, and to investigate associations between Hcy concentration in blood plasma with that of aqueous and vitreous in these two groups. METHODS: Blood plasma, aqueous and vitreous samples were collected during combined cataract and pars plana vitrectomy from 20 eyes with PDR and 21 eyes of patients without diabetes mellitus. Hcy concentration in the samples was determined by chemiluminescent microparticle immunoassay. RESULTS: The mean Hcy concentration (± standard deviation) of blood plasma, vitreous and aqueous were 13.7± 2.2 µmol/l, 3.4±0.7 µmol/l and 1.6±0.3 µmol/l respectively in the PDR group; in the control group, they were 10.4±1.1 µmol/l, 2.6±0.9 µmol/l and 1.2±0.2 µmol/l, respectively. The estimated geometric mean of Hcy concentration of all three variables in the PDR group was about 30% higher than control. In the PDR group, Hcy concentration between the blood plasma and vitreous was significantly associated (ρ=0.71; p-value < 0.001), as was that between the blood plasma and aqueous (ρ=0.68; p-value < 0.001). In the control group, only Hcy concentration in the blood plasma and vitreous was significantly associated (ρ=0.66; p-value = 0.001). CONCLUSION: The geometric mean of Hcy concentration in the blood plasma, vitreous and aqueous of the PDR group was significantly higher than control. The Hcy levels in the blood plasma and vitreous were also significantly associated in both groups. However, the blood plasma and aqueous were significantly associated only in the PDR group.

Endogenous Cushing syndrome from an ectopic adrenocorticotropic hormone production as a rare cause of ocular hypertension.

Ocular hypertension caused by endogenous Cushing syndrome from an ectopic adrenocorticotropic hormone-producing tumor is rare. We report an 11-year-old boy who presented with intraocular pressures (IOPs) of 50 mm Hg in both eyes. Surgical resection of the tumor was performed with subsequent normalization of serum cortisol and IOP levels.