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ABSTRACT: To study the efficacy and safety of triple therapy (sub-Tenon triamcinolone [∼70 mg], intravitreal bevacizumab [1.25 mg], and focal/grid laser) for refractory diabetic macular edema.
Twenty-nine eyes of 29 patients who received triple therapy were monitored for central foveal thickness, best-corrected visual acuity (BCVA), and side effects over a 1-year period. Their results were compared with a focal/grid laser historical control group of 18 eyes (18 patients).
In the triple therapy group, mean central foveal thickness significantly reduced from baseline value of 441 μm to 298 μm at Month 12 (P < 0.001), but there was no significant change of BCVA. In the control group, there were no sustained significant changes of central foveal thickness or BCVA. A subgroup analysis of 7 eyes in the triple therapy group with baseline BCVA of ≤20/100 showed significant BCVA improvements from 4 weeks to 9 months. The maximum improvement was achieved at 6 months, when the mean BCVA improved by 9.5 Early Treatment Diabetic Retinopathy Study letters from baseline. Intraocular pressure rise (31.0%), partial ptosis (17.2%), and significant cataractogenesis (8.7%) were encountered in the triple therapy group but not in the control group.
Sustained reduction of central foveal thickness was achieved with triple therapy over the 1-year study period. Significant visual improvement was seen only in patients with worse baseline BCVA, but not in the triple therapy group as a whole. Significant side effects of intraocular pressure rise, ptosis, and cataractogenesis were encountered in the triple therapy group.
Retina (Philadelphia, Pa.) 02/2012; 32(4):672-8. · 2.93 Impact Factor
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ABSTRACT: To identify factors associated with variability in anatomical and functional response of diabetic macular oedema (DMO) after 4 mg of intravitreal triamcinolone acetonide (ivTA), and for recurrence of macular oedema. Design: Pooled analysis of individual data from two randomized controlled trials.
This was a multicentre study involving 107 eyes with DMO administered 4 mg ivTA. Predictive factors for response to treatment were evaluated with linear regression analysis. Factors associated with time to recurrence of oedema were studied with Cox proportional hazards modelling. Main outcome measures were maximum improvement in optical coherence tomography (OCT)-measured central foveal thickness (CFT) and best-corrected visual acuity (BCVA), final CFT and BCVA at 12 months and time to oedema recurrence.
Greater reduction of retinal thickening occurred in eyes with worse baseline thickening (P < 0.001). There was also greater improvement of visual acuity in eyes with poorer preoperative BCVA levels (P < 0.001). Age, duration of oedema and previous macular laser treatment had no significant effect on maximal BCVA or CFT improvement. Eyes given 4 mg triamcinolone alone were more likely to develop recurrence of oedema at 12 months than those given a combination of 4 mg triamcinolone plus sequential laser (hazard ratio 2.60 [95% confidence interval: 1.45-4.67]).
Baseline OCT-measured retinal thickening and BCVA are important predictors of maximal anatomical and functional response of DMO to ivTA, respectively. Combination treatment strategy using sequential laser therapy may have a role in delaying recurrence of oedema after triamcinolone.
Clinical and Experimental Ophthalmology 08/2009; 37(6):602-8. · 1.98 Impact Factor
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ABSTRACT: To evaluate the efficacy of intravitreal injections of two different dosages of bevacizumab (Avastin) for treating diffuse diabetic macular edema.
Fifty-two eyes of 52 patients with diabetic macular edema were randomized to receive three monthly intravitreal injections of 1.25 mg or 2.5 mg bevacizumab. Patients were observed for 6 months and optical coherence tomography central foveal thickness, logMAR best-corrected visual acuity (BCVA), and adverse events were assessed.
Forty-eight eyes of 48 patients completed the 6-month follow-up and were analyzed. Significant mean central foveal thickness reductions were observed in both groups at all follow-up visits (P < 0.013). Significant improvements between baseline and 6-month mean logMAR BCVAs were seen, with the mean logMAR BCVA improved from 0.63 to 0.52 in the 1.25 mg group and 0.60 to 0.47 in the 2.5 mg group. No significant difference in BCVA was observed between the two groups at any time point (P > 0.56). Subgroup analysis showed that intravitreal bevacizumab seemed to be more effective in eyes without any previous diabetic macular edema treatment.
Three monthly intravitreal bevacizumab injections resulted in significant reduction in central foveal thickness and improvements in BCVA in diabetic macular edema patients. Both 1.25 mg and 2.5 mg seemed to have similar treatment efficacy.
Retina (Philadelphia, Pa.) 04/2009; 29(3):292-9. · 2.93 Impact Factor
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ABSTRACT: To determine the repeatability and reproducibility of central and peripheral corneal pachymetry mapping with anterior segment-optical coherence tomography (AS-OCT).
An observational cross-sectional study involving two groups: 27 healthy eyes and 20 eyes with keratoconus. Each subject underwent scanning sessions with AS-OCT to determine intraobserver repeatability, interobserver reproducibility, and additionally for healthy eyes, intersession reproducibility for different regions of the cornea up to a 10-mm diameter. Main outcome measures were reproducibility and repeatability coefficients, intraclass correlation coefficients, and coefficients of variation of the average central (0-2 mm), pericentral (2-5 mm), transitional (5-7 mm), and peripheral (7-10 mm) corneal thicknesses generated by the Visante AS-OCT (Carl Zeiss Meditec, Inc., Dublin, CA) pachymetric mapping protocol.
The coefficients of repeatability were less than 2% in healthy subjects and less than 3% in patients with keratoconus. The reproducibility coefficients were less than 2% and 4% in healthy subjects and patients with keratoconus, respectively. There was no significant difference between scans obtained by different observers or during different visits. The intraclass correlation coefficients were greater than 0.99 and 0.97 in healthy subjects and patients with keratoconus, respectively.
With the pachymetric mapping protocol of Visante AS-OCT, these results suggest that central and peripheral corneal thickness measurements in healthy subjects and in eyes with keratoconus are repeatable and reproducible.
Investigative Ophthalmology & Visual Science 01/2008; 48(12):5499-504. · 3.60 Impact Factor
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ABSTRACT: To evaluate the efficacy of sequential intravitreal triamcinolone acetonide (TA) injection followed by grid laser photocoagulation for treating diabetic macular edema (DME).
Prospective, 3-armed, randomized clinical trial.
One hundred eleven eyes of 111 patients with DME involving the fovea.
Patients were randomized to grid laser photocoagulation (37 eyes), 4 mg of intravitreal TA (38 eyes), or 4 mg of intravitreal TA combined with sequential grid laser about 1 month later (36 eyes).
Central foveal thickness (CFT) as measured by optical coherence tomography, logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA), and side effect profiles. The 6-month results are reported.
All patients completed 6 months' follow-up. Baseline mean (+/- standard deviation) CFTs were 385+/-100 microm, 396+/-91 microm, and 424+/-108 microm for the laser, intravitreal TA, and combined groups, respectively (P = 0.24). After treatment, significant CFT reductions were noted in both the intravitreal TA and combined groups at all follow-up visits (P<0.01) but not in the laser group. Mean CFT improved significantly to minimums of 267+/-75 microm and 256+/-73 microm for the intravitreal TA and combined groups, respectively, but the difference between the 3 groups was not significant at 6 months. The standardized change in macular thickening at 17 weeks was significantly greater in the combined group versus the intravitreal TA group (P = 0.007), suggesting that combined treatment might prolong the effects of intravitreal TA. Mean baseline logMAR BCVAs were 0.64+/-0.37, 0.72+/-0.34, and 0.69+/-0.34 in the laser, intravitreal TA, and combined groups, respectively (P = 0.67). Best-corrected visual acuity improved significantly at 4 and 9 weeks for the intravitreal TA group but did not change significantly in the other 2 groups. No significant difference in BCVA was observed between the 3 groups at any time point.
Contrary to the results of a recent study, combined treatment of intravitreal TA plus grid laser did not yield better CFT reduction or BCVA improvement at 6 months than intravitreal TA alone. Grid laser alone was significantly worse than the 2 other treatment modalities.
Ophthalmology 12/2007; 114(12):2162-7. · 5.45 Impact Factor
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ABSTRACT: To assess the agreement of central and paracentral corneal thickness measurements between ultrasound pachymetry (USP), Orbscan II, and Visante anterior segment optical coherence tomography (ASOCT).
Observational cross-sectional study.
Seventy eyes of 70 subjects.
Each subject underwent Orbscan II (using an acoustic equivalent correction factor of 0.89), ASOCT, and USP examination. Bland-Altman plots were used to evaluate agreement between instruments.
Central and paracentral corneal thickness measurements by the 3 methods and agreement, as evaluated by 95% limits of agreement (LOA).
The mean measurements of average central corneal thickness by USP, Orbscan II, and ASOCT were 553.5+/-30.26 microm, 553.22+/-25.47 microm, and 538.79+/-26.22 microm, respectively. There was high correlation between instruments: USP with ASOCT (r = 0.936, P<0.001), USP with Orbscan II (r = 0.900, P<0.001) for central corneal thickness measurements, and Orbscan II with ASOCT for average paracentral 2- to 5-mm measurements (r = 0.947, P<0.001). The mean differences (and upper/lower LOA) for central corneal thickness measurements were 0.31+/-13.34 microm (26.44/-25.83) between USP and Orbscan II, 14.74+/-10.84 microm (36.0/-6.51) between USP and ASOCT, and 14.44+/-9.14 microm (32.36/-3.48) between Orbscan II and ASOCT. The average mean difference (and upper/lower LOA) between Orbscan II and ASOCT for paracentral 2- to 5-mm corneal thickness measurements was 10.35+/-8.67 microm (27.35/-6.65).
Anterior segment optical coherence tomography underestimated corneal thickness compared with that measured with USP. Anterior segment optical coherence tomography had better agreement with the gold standard USP, as compared with Orbscan II. However, important discrepancies among instruments exist. Clinicians should be aware that corneal thickness measurements are influenced by the method of measurement and that, although highly correlated, these instruments should not be used interchangeably for the assessment of corneal thickness.
Ophthalmology 10/2007; 114(10):1842-7. · 5.45 Impact Factor
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British Journal of Ophthalmology 09/2007; 91(8):1084-5. · 2.90 Impact Factor
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Christopher Kai-Shun Leung,
Arthur Chak Kwan Cheng,
Kelvin Kam Lung Chong,
King Sai Leung, Shaheeda Mohamed,
Charles Sing Lok Lau,
Carol Yim Lui Cheung,
Geoffrey Chin-Hung Chu,
Ricky Yiu Kwong Lai,
Calvin Chi Pui Pang,
Dennis Shun Chiu Lam
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ABSTRACT: To evaluate the relationships between optic disc measurements, obtained by an optical coherence tomograph and a confocal scanning laser ophthalmoscope, and myopia.
One hundred thirty-three eyes from 133 healthy subjects with mean spherical equivalent -6.0 +/- 4.2 D (range, -13.13 to +3.25 D) were analyzed. Optic disc measurements including disc area, rim area, cup area, cup-to-disc area, and vertical and horizontal ratios were obtained with an optical coherence tomograph (StratusOCT; Carl Zeiss Meditec Inc., Dublin, CA) and a confocal scanning laser ophthalmoscope (Heidelberg Retina Tomograph, HRT 3; Heidelberg Engineering, GmbH, Dossenheim, Germany). The modified axial length method derived from prior published work was used to correct the OCT measurements for ocular magnification. Bland-Altman plots were used to evaluate the agreement for each optic disc parameter. Associations between optic disc area and axial length/spherical equivalent were evaluated by linear regression analysis.
Disc area increased with the axial length/negative spherical equivalent in the HRT and the corrected OCT measurements although opposite directions of associations were found when the OCT measurements were not corrected for magnification. The difference of the corrected OCT and HRT disc area (corrected OCT disc area minus HRT disc area) was correlated with the axial length (r = 0.195, P = 0.025). When the ametropia was limited to -8.0 to +4.0 D, the correlations became insignificant in the HRT. Using the corrected OCT measurements, disc area, rim area, and cup area, cup-to-disc area, and cup-to-disc horizontal and vertical ratios were significantly larger than those measured by the HRT, with a span of 95% limits of agreement at 1.99, 1.33, and 1.86 mm(2) for the areas, 0.34, 0.53, and 0.58 for the ratios, respectively.
While optic disc area generally increased with the axial length and myopic refraction, the HRT measurements demonstrated that optic disc size was largely independent of axial length and refractive error between -8 and +4 D. OCT may overestimate optic disc size in myopic eyes and results in poor agreement between the two instruments.
Investigative Ophthalmology & Visual Science 08/2007; 48(7):3178-83. · 3.60 Impact Factor
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ABSTRACT: To describe the use of anterior segment optical coherence tomography (OCT) in imaging intrableb morphology after trabeculectomy.
14 post-trabeculectomy eyes from 11 primary open angle glaucoma and 3 primary angle closure glaucoma subjects were studied. The blebs were classified with reference to slit lamp morphology and bleb function. They included diffuse filtering (n = 7), cystic (n = 2), encapsulated (n = 2) and flattened (n = 3) bleb types. One eye in each patient was imaged with the Visante anterior segment OCT. A vertical scan line of 10 mm consisting of 512 A-scans was positioned at the centre of the bleb. The images were then analysed by built-in software. Intrableb morphologies and structures, including bleb wall thickness, subconjunctival fluid collections, suprascleral fluid space, scleral flap thickness, intrableb intensity (low, medium or high) and the route under the scleral flap were characterised and measured.
Diffuse filtering blebs were found by subconjunctival fluid collections. Suprascleral fluid space and the route under the scleral flap were identified in four of the seven cases. Cystic blebs were composed of a large hyporeflective space with multiloculated fluid collections covered by a thin layer of conjunctiva. Encapsulated blebs had a thick bleb wall with high reflectivity and an enclosed fluid filled space. Flattened blebs demonstrated high scleral reflectivity and no bleb elevation.
Visante anterior segment OCT can be used for bleb imaging. The different patterns of intrableb morphology identified by OCT were related to slit lamp appearance and bleb function. This information may be useful to study the different surgical outcomes and the process of wound healing in trabeculectomised eyes.
British Journal of Ophthalmology 04/2007; 91(3):340-4. · 2.90 Impact Factor
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ABSTRACT: To compare the safety and efficacy of different doses of intravitreal triamcinolone (ivTA) in treating clinically significant diabetic macular oedema (CSMO).
63 eyes of 63 patients with CSMO and central foveal thickness (CFT) of > or =250 microm on optical coherence tomography were randomised to receive 4 mg (n = 23), 6 mg (n = 20) or 8 mg (n = 20) ivTA. Patients were followed up for 6 months, and changes in best-corrected visual acuity (BCVA), optical coherence tomography CFT, standardised change in macular thickness (SCMT), and side effects such as intraocular pressure and cataractogenesis were compared between the three groups.
After ivTA injection, improvements of BCVA and CFT occurred in all groups. The mean BCVA improvement at 6 months was significantly higher for the 8 mg group compared with the 4 mg group, with 9.9 and 3.1 improvement in letters on the Early Treatment of Diabetic Retinopathy Study chart, respectively (p = 0.047). The mean SCMT at 6 months for the 4, 6 and 8 mg groups was 28.7%, 42.3% and 60.5%, respectively (p = 0.06). The proportion of eyes with SCMT > or =75% at 6 months was higher in the 8 mg group, but the difference failed to reach significance (p = 0.06). Ocular hypertensive responses (>21 mm Hg) occurred in 39%, 30% and 55% of eyes in the 4, 6, and 8 mg groups, respectively (p = 0.27).
Higher doses of ivTA may prolong the duration of visual benefit in diabetic CSMO and seemed to result in more sustained reduction in macular oedema. Further studies are warranted to investigate the optimum dose of ivTA in treating diabetic CSMO.
British Journal of Ophthalmology 03/2007; 91(2):199-203. · 2.90 Impact Factor
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ABSTRACT: To investigate the relationship between myopia and macular thickness, as measured by optical coherence tomography.
A total of 143 normal subjects comprising 80 eyes with high myopia (spherical equivalent [SE] < -6.0 D), 37 eyes with low to moderate myopia (SE between -6.0 and -0.5 D), and 26 nonmyopic eyes (SE > -0.5 D) were analyzed in this cross-sectional study. Total average, foveal, and inner and outer average macular thicknesses measured by the StratusOCT (Carl Zeiss Meditec Inc., Dublin, CA) were compared among the three diagnostic groups. Associations between macular thickness and refractive error/axial length were evaluated by linear regression analysis.
The minimum foveal and average foveal (1-mm ring on the OCT retinal thickness map) thicknesses were significantly greater, and the outer ring macular (3-6-mm) thicknesses significantly lower in the high myopic eyes than in the low to moderate myopic and nonmyopic eyes. No significant difference was found in the inner ring (1-3-mm) macular thickness measurements among the groups. There was a positive correlation between the axial length and the average foveal thickness (r = 0.374, P < 0.001). Negative correlations were found between axial length and the average outer ring macular thickness (r= -0.471, P < 0.001) and total average macular thickness (r= -0.311, P < 0.001).
Retinal thickness is related to refractive error/axial length in normal subjects with regional variations in correlation within the 6-mm macular region. Analysis of macular thickness in the evaluation of macular diseases and glaucoma should be interpreted only in the context of refractive errors and the location of measurement.
Investigative Ophthalmology & Visual Science 02/2007; 48(1):376-82. · 3.60 Impact Factor
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ABSTRACT: Comparison of corneal pachymetry assessment with ultrasound and Orbscan II using acoustic factor and subtraction methods.
Ultrasound and Orbscan pachymetry for all patients with LASIK performed between July 2002 and May 2003 were retrospectively analyzed. Comparison between the 2 preoperative measurements was analyzed.
Using a custom acoustic factor of 0.93, there was no significant difference between the overall ultrasound and Orbscan pachymetry (P = 0.696). However, there was underestimation in thick corneas and overestimation in thin corneas. Using the subtraction method as the correcting technique, the magnitude of over- and underestimation was reduced.
The current correction method by means of acoustic factor may result in error in assessing extremes of corneal thickness. Alternative approaches such as the subtraction method can be considered to achieve more accurate results.
Cornea 01/2007; 25(10):1158-61. · 1.73 Impact Factor
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ABSTRACT: To evaluate the relationship between retinal nerve fiber layer (RNFL) thickness measured by optical coherence tomography (OCT) and the axial length/refractive error of the eye.
A total of 115 eyes of 115 healthy subjects, comprising 75 eyes with high myopia (spherical equivalent [SE] < -6.0 D) and 40 eyes with low to moderate myopia (SE between -6.0 D and -0.5D), were analyzed in this cross-sectional study. Total average and mean clock hour RNFL thicknesses were measured by OCT and compared between the two myopia groups. Associations between RNFL measurements and axial length and spherical equivalent were evaluated by linear regression analysis.
The RNFL measurements were significantly lower in the high myopia group compared with those of the low-to-moderate myopia group at 12, 1, and 7 o'clock (right eye orientation). Apart from the temporal clock hours, significant correlations were evident between RNFL measurements and the axial length and spherical equivalent. The average RNFL thickness decreased with increasing axial length (r = -0.314, P = 0.001) and negative refractive power (r = 0.291, P = 0.002). A significant proportion of myopic eyes were classified as outside normal limits, with reference to the normative database. The most frequently abnormal sector was at 2 o'clock, where 16.5% of myopic eyes were outside normal limits.
RNFL measurements vary with the axial length/refractive error of the eye. Analysis of RNFL thickness in the evaluation of glaucoma should always be interpreted with reference to the refractive status. Although the normative database provided by OCT has been helpful in identifying ocular diseases involving the RNFL, it may not be reliable in the analysis of myopic eyes.
Investigative Ophthalmology & Visual Science 12/2006; 47(12):5171-6. · 3.60 Impact Factor
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ABSTRACT: To evaluate the safety and efficacy of the 25-gauge transconjunctival sutureless vitrectomy (TSV) system in the surgical management of posterior capsular opacification (PCO) in pseudophakic children.
Pars plana membranectomy was performed for PCO in 10 pseudophakic eyes of six children (mean age 35.1 +/- 37.8 months; range 6-93 months) using the TSV system. Surgical technique, intraoperative problems and postoperative complications including wound leakage, hypotony and the need for suturing were recorded.
Wound leakage and other intraoperative problems were not noted in any of the eyes. All eyes showed improvement of visual acuity from a mean of 6/67 before to 6/29 after surgery (P = 0.001). Mean postoperative intraocular pressure (IOP) was 7.8 +/- 3.1 mmHg (range: 3-10 mmHg). Four eyes (40%) had hypotony on the first postoperative day (IOP: 3-5 mmHg), which was transient in three eyes. One eye in a patient with uveitis had persistent hypotony, but hypotony was also present preoperatively, and the postoperative IOP returned to preoperative levels. This eye also developed recurrent PCO and a second capsulotomy was performed using the 25-gauge TSV system.
Posterior capsulotomy using the 25-gauge TSV system appears to be a safe and effective approach in the management of PCO in pseudophakic children. Advantages include easier manipulation with the smaller instruments in these small eyes, and it can be considered in appropriate cases.
Clinical and Experimental Ophthalmology 11/2005; 33(5):495-8. · 1.98 Impact Factor
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ABSTRACT: The authors report the formation of a subtenon cyst following subtenon triamcinolone injection for chronic recurrent uveitis in Behçet's disease. The steroid was inadvertently placed superficially in the anterior subtenon space and was encapsulated eventually to present as a subtenon cyst. The episode of uveitis recurrence, which did not regress, required treatment with a repeat posterior subtenon injection 2 months later. The cyst was removed 4.5 months after the initial subtenon injection, when the patient underwent a trabeculectomy for refractory glaucoma. Histological examination of the cyst revealed a fibrous encapsulated cavity filled with small birefringent crystals, consistent with an encapsulated triamcinolone collection. Fibrous encapsulation of triamcinolone crystals can arise after a superficially placed anterior subtenon injection and this may impede the absorption of the corticosteroid and hamper its effectiveness in treating ocular inflammatory diseases.
Clinical and Experimental Ophthalmology 34(4):360-2. · 1.98 Impact Factor
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ABSTRACT: To determine the response and safety profile of intravitreal dexamethasone in treating diabetic macular edema.
In this prospective pilot study, 12 eyes of 12 patients with diabetic macular edema were randomized to receive a single injection of 0.4 mg (n = 6) or 0.8 mg (n = 6) of intravitreal dexamethasone. The outcome measures were changes in best-corrected visual acuity and central foveal thickness on optical coherence tomography. Side effects were monitored.
The 3-month results were reported. In both dosage groups, there were transient improvements in best-corrected visual acuity and central foveal thickness, but the changes were not significant at any time point (best-corrected visual acuity: P > or = 0.14; central foveal thickness: P > or = .08). No significant side effects were observed, except one eye developed a peak intraocular pressure of greater than 21 mm Hg.
A single injection of intravitreal dexamethasone (0.4 or 0.8 mg) did not have significant beneficial effects on diabetic macular edema within 3 months from injection in this small pilot study.
Ophthalmic Surgery Lasers and Imaging 41(1):26-30. · 0.62 Impact Factor
