Visvaraja Subrayan

Agreement analysis of LENSTAR with other techniques of biometry

PurposeTo assess the agreement of the optical low-coherence reflectometry (OLCR) device LENSTAR LS900 with partial coherence interferometry (PCI) device IOLMaster and applanation and immersion ultrasound biometry.MethodsWe conducted the study at the Ophthalmology Clinic, University of Malaya Medical Center, Malaysia. Phakic eyes of 76 consecutive cataract patients were measured using four different methods: IOLMaster, LENSTAR and A-scan applanation and immersion ultrasound biometry. We assessed the method agreement in the LENSTAR-IOLMaster, LENSTAR-applanation, and LENSTAR-immersion comparisons for axial length (AL) and intraocular lens (IOL) power using Bland–Altman plots. For average K, we compared LENSTAR with IOLMaster and the TOPCON KR-8100 autorefractor-keratometer. SRK/T formula was used to compute IOL power, with emmetropia as the target refractive outcome.ResultsFor all the variables studied, LENSTAR agreement with IOLMaster is strongest, followed by those with immersion and applanation. For the LENSTAR-IOLMaster comparison, the estimated proportion of differences falling within 0.33 mm from zero AL and within 1D from zero IOL power is 100%. The estimated proportion of differences falling within 0.5 D from zero average K is almost 100% in the LENSTAR-IOLMaster comparison but 88% in the LENSTAR-TOPCON comparison. The proportion of differences falling within 0.10 mm (AL) and within 1D (IOL power) in the LENSTAR-IOLMaster comparison has practically significant discrepancy with that of LENSTAR-applanation and LENSTAR-immersion comparisons.ConclusionsIn phakic eyes of cataract patients, measurements of AL, average K, and IOL power calculated using the SRK/T formula from LENSTAR are biometrically equivalent to those from IOLMaster, but not with those from applanation and immersion ultrasound biometry.

Changes in anterior chamber depth and intraocular pressure after phacoemulsification in eyes with occludable angles.

PURPOSE: To evaluate changes in anterior chamber depth (ACD) and intraocular pressure (IOP) after phacoemulsification in eyes with occludable angles and compare the results with those in eyes with normal open angles. SETTING: Eye Clinic, Ipoh General Hospital, Ipoh, Perak, Malaysia. METHODS: Patients with nonglaucomatous eyes with open angles or with occludable angles were recruited. Ocular biometric measurements (ACD, axial length [AL], lens thickness and position) and IOP (tonometry) were performed preoperatively and 1 day and 1, 4, 9, and 12 weeks postoperatively. RESULTS: The open‐angle group and occludable‐angle group each comprised 35 patients. The occludable‐angle group had a shallower ACD, shorter AL, thicker and relatively anterior lens position, and higher IOP preoperatively; postoperatively, there was a significant increase in ACD and a significant reduction in IOP (P<.01). Anterior chamber deepening was inversely related to preoperative ACD in the occludable‐angle group (P<.01). The mean preoperative IOP was higher in the occludable‐angle group (15.77 mm Hg ± 2.20 [SD]) than in the open‐angle group (14.52 ± 2.65 mm Hg) (P<.05). The IOP dropped progressively and significantly over 12 weeks postoperatively; the mean decrease was 2.31 ± 0.99 mm Hg in the occludable‐angle group and 0.77 ± 1.17 mm Hg in the open‐angle group. The IOP decrease in the occludable‐angle group was inversely related to the preoperative IOP (P<.01). CONCLUSION: Phacoemulsification led to anterior chamber deepening and lower IOP in eyes with occludable angles, which suggests it is an option for preventing acute angle–closure attacks in eyes with occludable angles and cataract. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Retinal nerve fiber layer structure abnormalities in schizophrenia and its relationship to disease state: evidence from optical coherence tomography.

PURPOSE We determined structural retinal nerve fiber layer (RNFL) changes in schizophrenia patients and established if the structural changes were related to the duration of the illness using spectral-domain optical coherence tomography (SD-OCT). METHODS We recruited a total of 30 schizophrenic patients and 30 age-matched controls in the study. The schizophrenic patients were subdivided further to acute (n = 5), chronic (n = 13), and long-term chronic (n = 12) subgroups depending on their duration of illness. Using SD-OCT, the peripapillary RNFL thickness, macula thickness, and macula volume measurements of schizophrenic patients and the control subjects were measured and compared at each location. RESULTS Schizophrenic patients showed a statistically significant reduction in overall peripapillary RNFL thickness (cases, 94.70 ± 9.88 μm; controls, 103.53 ± 6.53 μm; P < 0.001), macula thickness (cases, 269.26 ± 12.59 μm; controls, 284.83 ± 9.76 μm; P < 0.001), and macula volume (cases, 9.61 ± 0.45 mm(3); controls, 10.17 ± 0.35 μm; P < 0.001). Chronic and long-term chronic schizophrenic patients were found to have significant peripapillary RNFL thinning, macula thinning, and reduction of macula volume when compared to controls (P < 0.001). There also was a statistically significant reverse correlation (P < 0.05) of peripapillary RNFL thickness (r = -0.36), macula thickness (r = -0.38), and macula volume reduction (r = -0.36) with the duration of schizophrenic illness. CONCLUSIONS These results indicate that RNFL and macula thickness, as well as macula volume measurements are reduced in schizophrenic patients. The degree of thinning and reduction was more significant in the chronic phase of the disease and correlated with the duration of illness. These findings demonstrate that SD-OCT can be a useful tool for the diagnosis and monitoring the progression of this disease.

Childhood blindness and severe visual impairment in Malaysia: a nationwide study

AimTo determine the causes of childhood blindness and severe visual impairment (BL/SVI) in schools for the blind in Malaysia.MethodsAll children ≤15years attending 24 schools for the blind throughout the country were examined using the WHO Prevention of Blindness Programme (WHO/PBL) eye examination record for children, and visual loss was classified according to the International Classification of Disease (ICD).ResultsIn all, 469 children were examined, of whom 448 (95.6%) had BL/SVI. The major causes of visual loss were retinal disorders (n=148, 33%; mainly retinopathy of prematurity (n=78, 17.4%)), cataract/pseudophakia/aphakia (n=77, 17.2%), and anomalies affecting the whole globe. (n=86, 19.2%). The major underlying etiology was undetermined (n=193, 43.1%), followed by hereditary factors, 21.7% (mainly retinal dystrophies), and perinatal factors, 20.5%. More than 34 (7.6%) cases were considered potentially preventable and 192 (42.9%) potentially treatable.ConclusionDiseases of the retina are the major cause of visual impairment, with retinopathy of prematurity being an important avoidable cause. This reflects expansion of neonatal services in Malaysia, and improved survival of very low birth weight and preterm babies. Lens-related causes of visual impairment reflect the need to further improve pediatric ophthalmology services in Malaysia.

Cladosporium cladosporioides Keratomycosis : A Case Report

Keratomycosis is a frequent cause of ocular morbidity and blindness. Filamentous fungi such as Fusarium and Aspergillus have been reported to be leading causes of keratomycosis in India1 and China.2 Keratomycosis caused by Cladosporium cladosporioides, a pigmented fi lamentous fungus, is very rare. We report a case of Cladosporium cladosporioides keratomycosis identifi ed by polymerase chain reaction (PCR) and DNA typing.

Association of potential salivary biomarkers with diabetic retinopathy and its severity in type-2 diabetes mellitus: a proteomic analysis by mass spectrometry

Aim/hypothesis: The aim of our study was to characterize the human salivary proteome and determine the changes in protein expression in two different stages of diabetic retinopathy with type-2 diabetes mellitus: (1) with non-proliferative diabetic retinopathy (NPDR) and (2) with proliferative diabetic retinopathy (PDR). Type-2 diabetes mellitus without diabetic retinopathy (XDR) was designated as control. Method: In this study, 45 saliva samples were collected (15 samples from XDR control group, 15 samples from NPDR disease group and 15 samples from PDR disease group). Salivary proteins were extracted, reduced, alkylated, trypsin digested and labeled with an isobaric tag for relative and absolute quantitation (iTRAQ) before being analyzed by an Orbitrap fusion tribrid mass spectrometer. Protein annotation, fold change calculation and statistical analysis were interrogated by Proteome Discoverer. Biological pathway analysis was performed by Ingenuity Pathway Analysis. Data are available via ProteomeXchange with identifiers PXD003723–PX003725. Results: A total of 315 proteins were identified from the salivary proteome and 119 proteins were found to be differentially expressed. The differentially expressed proteins from the NPDR disease group and the PDR disease group were assigned to respective canonical pathways indicating increased Liver X receptor/Retinoid X receptor (LXR/RXR) activation, Farnesoid X receptor/Retinoid X receptor (FXR/RXR) activation, acute phase response signaling, sucrose degradation V and regulation of actin-based motility by Rho in the PDR disease group compared to the NPDR disease group. Conclusions/Interpretation: Progression from non-proliferative to proliferative retinopathy in type-2 diabetic patients is a complex multi-mechanism and systemic process. Furthermore, saliva was shown to be a feasible alternative sample source for diabetic retinopathy biomarkers.

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.

Combined Optic Neuropathy and Central Retinal Artery Occlusion in Presumed Ocular Tuberculosis without Detectable Systemic Infection

Purpose: To report a rare case of combined optic neuropathy and central retinal artery occlusion in presumed ocular tuberculosis without systemic infection. Case Report: A young man presented with sudden onset of decreased vision in his left eye with combined optic disc swelling and central retinal artery occlusion in a background of vasculitic changes of the same eye. There were no signs or symptoms of active systemic tuberculosis infection. Chest X-ray and computed tomography thorax findings were normal and sputum cultures for tuberculosis were negative. The Mantoux and QuantiFERON-TB Gold tests were strongly positive. No tuberculosis polymerase chain reaction testing was done. Anti-tuberculosis therapy was initiated, based on the strong clinical evidence. Conclusion: The ocular findings improved remarkably with the anti-tuberculosis treatment, although the left eye vision remained poor. A high index of suspicion is required to diagnose ocular tuberculosis when all other systemic investigations are negative, especially in this part of the world where tuberculosis is endemic.

Assessment of Polymerase Chain Reaction in the Detection of Pseudomonas aeruginosa in Contact Lens-Induced Severe Infectious Keratitis

Purpose: The aim of this study is to evaluate the role of real-time polymerase chain reaction (PCR) and conventional bacterial culture methods in the detection of Pseudomonas aeruginosa in contact lens-induced severe, partially treated corneal ulcers referred to a tertiary center. Methods: The study duration was 6 months. All patients with contact lens-related corneal ulcer, requiring admission during the study period were recruited. Samples from corneal scrapings were simultaneously sent at the time of admission for PCR and culture testing. An in-house real-time PCR was developed to detect the P. aeruginosa lasA gene. The results of PCR and culture were compared using McNemars &khgr;2 test. Results: Ten patients were recruited. The mean age was 33 years (20–45 years). All the patients had contact lens-related keratitis (>4 mm) of which eight (80%) were found positive for P. aeruginosa by PCR or culture. There was no significant difference between PCR and culture in detecting P. aeruginosa (P<0.05). Conclusions: PCR is, at least, as good as conventional cultures in detecting P. aeruginosa. It is a rapid assay as compared with culture, and early detection enables prompt treatment thus reducing the destructive effect of the organism on the cornea.

Association between Ocular Pseudoexfoliation and Sensorineural Hearing Loss

Background. Our study aimed to investigate an association between ocular pseudoexfoliation (PXF) and sensorineural hearing loss (SNHL) and to compare them with age and sex matched controls without pseudoexfoliation. Method. This was a case-control study of 123 patients which included 68 cases with PXF (at least one eye) and 55 controls without pseudoexfoliation. Pure-tone audiometry (PTA) was done for these patients at sound frequencies taken as important for speech comprehension, that is, 250 Hertz (Hz), 500 Hz, 1000 Hz, and 2000 Hz. Results. There were 41 patients with pseudoexfoliation syndrome (PXE) and 27 with pseudoexfoliative glaucoma (PXEG). The majority of patients with hearing loss (60%; n = 51) were PXF patients and the remaining 40% (n = 34) were controls. Below average hearing thresholds were significantly higher in the pseudoexfoliation group compared to the control group (P = 0.01; odds ratio (OR), 3.00; 95% confidence interval (CI), 1.25–7.19). However, there was no significant difference in the mean hearing threshold levels between the three groups (PXE, PXEG, and controls) in either ear (ANOVA, right ear: P = 0.46 and left ear P = 0.36). Conclusion. Our study found an association between PXF and SNHL, confirming that PXF can involve organs in the body other than the eye.