Presence of crystalline lens as a protective factor for the late development of open angle glaucoma after vitrectomy

PURPOSE

To evaluate the late development of open angle glaucoma (OAG) after vitrectomy and to compare the rate of postvitrectomy OAG development in phakic and pseudophakic eyes.

METHODS

Retrospective case series of 101 eyes of 101 patients who had vitrectomy for idiopathic epiretinal membrane or idiopathic macular hole with a follow-up duration of more than 6 months. Eligible patients were assessed for new development of OAG during the follow-up period. Patients were separated into two groups based on the lens status at the end of the vitrectomy for statistical analysis using Kaplan-Meier survival analysis with log-rank test and Cox regression analysis.

RESULTS

The mean follow-up duration was 51 months (range, 6-80 months). Of the 101 eyes, 8 (7.9%) eyes developed OAG during the follow-up period. Phakic eyes were less likely to develop OAG after vitrectomy compared with pseudophakic eyes, with 2% and 13%, respectively (log-rank test, P = 0.025). The result remained statistically significant after adjustment for age, refractive error and the use of gas tamponade (adjusted odds ratio = 0.09, P = 0.038).

CONCLUSION

The presence of the crystalline lens may be protective against the late development of OAG after vitrectomy.

Intravitreal bevacizumab (Avastin) for myopic choroidal neovascularisation: 1-year results of a prospective pilot study

AIM

The aim of the study was to examine the 1-year results of intravitreal bevacizumab for myopic choroidal neovascularisation (CNV).

METHODS

Twenty-nine eyes of 29 patients with myopic CNV were prospectively recruited to receive three initial monthly intravitreal bevacizumab injections. Three additional monthly injections were performed in eyes with persistent or recurrent CNV after 3 months.

RESULTS

The mean spherical equivalent refractive error was -10.0 D. Sixteen eyes had previous photodynamic therapy (PDT) and 13 eyes had no prior PDT. All patients completed follow-up at 1 year. Following the initial three bevacizumab injections, 27 (93.1%) eyes had angiographic closure and two (6.9%) required further treatment. Two additional patients required re-treatment for CNV recurrence between 6 and 9 months. The mean baseline logarithm of the minimum angle of resolution (logMAR best-corrected visual acuity) was 0.62 (20/83), which improved to 0.38 (20/48) at 12 months (p<0.001). The mean visual improvement was 2.4 lines and 21 (72.4%) eyes had improvement of > or =2 lines. Optical coherence tomography showed significant reduction in central foveal thickness following treatment. Eyes without previous PDT were more likely to gain > or =2 lines after treatment than eyes that had previous PDT (p = 0.010).

CONCLUSIONS

The 1-year outcomes confirmed the results of previous short-term studies that intravitreal bevacizumab is effective for myopic CNV, with a high proportion of patients sustaining visual gain after treatment.

Intravitreal bevacizumab in inflammatory ocular neovascularization

PURPOSE

To assess the role of bevacizumab in inflammatory ocular neovascularization.

DESIGN

Retrospective, multicenter, consecutive case series of inflammatory ocular neovascularization.

METHODS

Patients with inflammatory ocular neovascularization of varying causes for whom standard therapy failed were treated with intravitreal injection of bevacizumab. Main outcome measures included improvement of best-corrected visual acuity (BCVA) expressed in logarithm of minimum angle of resolution units, response of inflammatory ocular neovascularization by funduscopy and angiography, and decrease in central foveal thickness as measured by optical coherence tomography at the three-month follow-up.

RESULTS

At the three-month follow-up, 84 eyes of 79 patients had been treated with a mean of 1.3 injections (range, one to three). Thirty-four eyes showed juxtafoveal choroidal neovascularization (CNV), 34 eyes showed subfoveal CNV, eight eyes showed peripapillary CNV, and 11 eyes showed neovascularization of the disc (NVD) or neovascularization elsewhere (NVE). BCVA improved 2.4 lines from 0.68 (6/28 or 20/94) to 0.44 (6/17 or 20/55) (P < .001). BCVA improved by one to three lines in 34.5% of the eyes, by four to six lines in 16.7% of the eyes, and by more than six lines in 14.2% of the eyes. Function was unchanged in 23.8% of the eyes. BCVA worsened in 10.7% (zero to three lines in 7.1%, more than four lines in 3.6%). Central foveal thickness decreased from baseline 346 to 252 microm (P < .001). For CNV, 32 eyes (43.2%) had complete regression after the injection, 27 (36.5%) had partial regression, five (6.8%) had no response, and 10 eyes (13.5%) were not evaluated by the contributors. For NVD or NVE, seven eyes (63.6%) had complete regression of new vessels and four eyes (36.4%) had partial regression after the injection.

CONCLUSIONS

Intravitreal bevacizumab led to short-term significant visual improvement and regression of inflammatory ocular neovascularization in a wide variety of inflammatory ocular diseases.

Half-dose verteporfin photodynamic therapy for acute central serous chorioretinopathy: one-year results of a randomized controlled trial

OBJECTIVE

To evaluate the efficacy of photodynamic therapy (PDT) with half-dose verteporfin for treating acute central serous chorioretinopathy (CSC).

DESIGN

Prospective, double-masked, placebo-controlled, randomized clinical trial.

PARTICIPANTS AND CONTROLS

Sixty-three eyes of 63 patients with acute symptomatic CSC of 3 months' duration or less were recruited. Forty-three eyes were randomized to indocyanine green angiography (ICGA)-guided PDT with half-dose (3 mg/m(2)) verteporfin and 21 eyes were randomized to placebo.

INTERVENTION

Patients in the verteporfin group received an infusion of half-dose verteporfin over 8 minutes, followed by ICGA-guided PDT 10 minutes from the start of infusion. Laser was applied for 83 seconds covering the choroidal abnormalities observed in ICGA, with a maximum laser spot size of 4500 mum.

MAIN OUTCOME MEASURES

The primary outcome measure was the proportion of eyes with absence of subretinal fluid at the macula at 12 months. Secondary outcome measures included changes in mean logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA), subjective symptoms, optical coherence tomography (OCT) results, central foveal thickness (CFT), and angiographic findings during the 12-month study period.

RESULTS

Thirty-nine patients in the verteporfin group and 19 patients in the placebo group completed 12 months of follow-up. Thirty-seven (94.9%) eyes in the verteporfin group compared with 11 (57.9%) eyes in the placebo group showed absence of subretinal fluid at the macula at 12 months (P = 0.001). The mean logMAR BCVA at 12 months was significantly better in the verteporfin group compared with the placebo group: -0.05 and 0.05, respectively (P = 0.008). All 39 (100%) verteporfin-treated eyes had stable or improved vision, compared with 15 (78.9%) eyes in the placebo group (P = 0.009). The mean OCT CFT for the verteporfin group also was significantly lower compared with the placebo group at 12 months (P = 0.001). No ocular or systemic adverse event was encountered in the study.

CONCLUSIONS

Photodynamic therapy with half-dose verteporfin is effective in treating acute symptomatic CSC, resulting in a higher proportion of patients with absence of exudative macular detachment and better visual acuity compared with placebo.

Effects of the duration of initial oral corticosteroid treatment on the recurrence of inflammation in Vogt-Koyanagi-Harada disease

PURPOSE

To evaluate the effects of the duration of oral corticosteroid treatment on the recurrence of inflammation in Vogt-Koyanagi-Harada (VKH) disease.

METHODS

Retrospective analysis of 35 VKH patients who received oral corticosteroid during the first attack of VKH with a minimum follow-up of 6 months. Patients were divided into two groups on the basis of the oral corticosteroid treatment duration of less than 6 months or 6 months or more. Kaplan-Meier survival and Cox-regression analyses were carried out to compare the recurrence rates of inflammation in the two groups.

RESULTS

The mean age of onset was 42.5 years and the mean follow-up duration was 3.6 years. During the follow-up period, 10 (58.8%) of the 17 patients who received oral corticosteroid for less than 6 months compared with 2 (11.1%) of the 18 patients who had treatment for 6 months or more developed recurrence of inflammation (P=0.003). Cox-regression analysis showed that the duration of oral corticosteroid treatment for less than 6 months was the only significant risk factor for recurrence of VKH after adjustment for age, gender, and the initial dosage of oral corticosteroid treatment (adjusted odds ratio=8.8, P=0.008). Patients who received oral corticosteroid treatment for less than 6 months were also more likely to have one eye with visual acuity of 20/200 or worse (P=0.016).

CONCLUSIONS

Early withdrawal of oral corticosteroid is associated with increased risk of recurrence of VKH and worse visual prognosis. Oral corticosteroid should be tapered off slowly and maintained for at least 6 months for the treatment of acute VKH.

Quality of reporting of key methodological items of randomized controlled trials in clinical ophthalmic journals

PURPOSE

To evaluate the reporting quality of key methodological items in randomized controlled trials (RCTs) in four general clinical ophthalmology journals.

METHODS

The reporting of 11 key methodological items in RCTs published in American Journal of Ophthalmology, Archives of Ophthalmology, British Journal of Ophthalmology and Ophthalmology in the year 2005 was assessed.

RESULTS

Sixty-seven eligible RCTs were assessed and the mean number of items reported was 6.3 per RCT. No significant difference in the mean number of items reported was found between the four journals (P=0.20). The most frequently reported item was ethics approval and informed consent (97.0%), followed by masking status (85.1%), description of withdrawals (76.1%), adverse events (73.1%), and intention-to-treat analysis (71.6%). Details on sequence generation, randomization restriction, allocation concealment, allocation implementation, patient flow diagrams, and sample size calculation were reported in <50% of the RCTs assessed. Both sample size and page length of the RCTs correlated with the number of methodological items reported (P=0.024 and P=0.008, respectively).

CONCLUSIONS

Similar to other specialties, rooms for improvement exist in the reporting of key methodological items of RCTs in clinical ophthalmic journals. Stricter adoption of the CONSORT statement might enhance the reporting quality of RCTs in ophthalmic journals.

Genotype phenotype analysis of Bietti's crystalline dystrophy in patients with CYP4V2 mutations

PURPOSE

To evaluate the genotypic and phenotypic correlations of Bietti's crystalline dystrophy (BCD) in patients with the CYP4V2 gene by mutation screening and clinical and electrophysiological assessment.

METHODS

Eighteen Chinese patients in 13 families with BCD were recruited for full ophthalmic examinations, optical coherence tomography (OCT), and visual electrophysiological tests, including electrooculography (EOG), full-field electroretinography (ERG), and multifocal electroretinography (mfERG). Peripheral venous blood was obtained from all index patients and their family members for genomic DNA extraction and CYP4V2 sequence screening by direct sequencing.

RESULTS

All 18 patients with BCD had mutations in the CYP4V2 gene: five were novel (Y219H, W244X, D324V, P396L, and R400C) and four had been reported. A common mutation occurred at the splice site IVS6-8del17bp/insGC of 12 patients, four being homozygous. OCT showed the presence of intraretinal crystals in all patients. Patients with more severe thinning of the retina had worse visual acuity, and there was moderate correlation between the OCT central foveal thickness and visual acuity (Spearman rho = 0.46, P = 0.005). Patients with splice site mutations (i.e., homozygous IVS6-8del17bp/insGC or compound heterozygous IVS6-8del17bp/insGC and IVS8-2A>G) had lower EOG Arden index (P = 0.014) and were more likely to have a nonrecordable scotopic full-field ERG (P = 0.003) and nonrecordable 30-Hz flicker ERG (P = 0.043).

CONCLUSIONS

BCD patients with homozygous IVS6-8del17bp/insGC or compound heterozygous IVS6-8del17bp/insGC and IVS8-2A>G mutations appeared to have more severe disease phenotype based on electrophysiological testing. The level of visual loss in BCD is related to the severity of retinal thinning.

Intravitreal Bevacizumab (Avastin) for Myopic Choroidal Neovascularization

PURPOSE

To evaluate the safety and efficacy of intravitreal bevacizumab in the treatment of choroidal neovascularization (CNV) secondary to pathologic myopia (PM).

DESIGN

Prospective, consecutive, nonrandomized, interventional case series.

PARTICIPANTS

Twenty-two eyes of 22 patients with CNV secondary to PM.

METHODS

Consecutive patients with subfoveal or juxtafoveal CNV secondary to PM were recruited prospectively to receive an initial course of 3 monthly intravitreal injections of bevacizumab. Three additional monthly injections were performed in eyes with persistent CNV leakage after 3 months. Patients were followed up for 6 months, and the best-corrected visual acuity (BCVA), changes in fluorescein angiography, and optical coherence tomography (OCT) results were assessed.

MAIN OUTCOME MEASURES

Changes in BCVA, angiographic closure, and OCT central foveal thickness (CFT) at the 6-month follow-up.

RESULTS

The mean+/-standard deviation (SD) spherical equivalent refractive error of the 22 eyes was -10.3+/-3.7 D (range, -6.0D to -18.0D). All patients completed follow-up at 6 months. Twenty (90.9%) eyes had angiographic closure after 3 monthly injections of intravitreal bevacizumab, and 2 (9.1%) eyes required further treatment up to 6 months. The mean+/-SD logarithm of the minimum angle of resolution (logMAR) BCVA at baseline was 0.60+/-0.18 (Snellen equivalent, 20/80). At 1 and 6 months, the mean+/-SD logMAR BCVA improved significantly to 0.43 (Snellen equivalent, 20/53; P = 0.003) and 0.35 (Snellen equivalent, 20/45; P<0.001), respectively. The mean lines of improvements at 1 and 6 month compared with baseline were 1.7 and 2.6 lines, respectively. Fifteen (68.2%) eyes had an improvement of 2 or more lines at 6 months. The OCT results also showed significant reduction in CFT after treatment. No ocular or systemic complications were noted after intravitreal injections.

CONCLUSIONS

The 6-month outcomes suggest intravitreal bevacizumab to be a promising treatment method for CNV secondary to PM, resulting in both visual and anatomic improvements. Treatment resulted in complete absence of angiographic leakage in 90.9% of eyes at 3 months. Further studies to evaluate the safety, efficacy, and optimal treatment regimen are justified.

Ranibizumab for retinal angiomatous proliferation in neovascular age-related macular degeneration

BACKGROUND

To report the efficacy of intravitreal injection of ranibizumab (Lucentis) in the treatment of retinal angiomatous proliferation (RAP) in neovascular age-related macular degeneration (AMD).

METHODS

Case review of four consecutive patients who received 3 injections at monthly intervals of intravitreal ranibizumab injections for RAP. The serial changes in best-corrected visual acuity (BCVA), optical coherence tomography (OCT), fluorescein angiography (FA), and indocyanine green angiography (ICGA) are presented.

RESULTS

The baseline mean logMAR BCVA was 0.89 (Snellen equivalent of 20/155). After three injections of ranibizumab, all four patients had visual improvement and the mean logMAR BCVA improved to 0.59 (Snellen equivalent of 20/78). The mean visual improvement was 3.0 lines. All patients also had complete resolution of subretinal fluid after treatment, and the mean OCT central foveal thickness reduced from 438 microm at baseline to 169 microm at 3 months. Follow-up FA and ICGA at 3 months showed absence of leakage in three patients with minimal leakage in the remaining patient. One patient had recurrence of RAP at 8 months after commencement of treatment, and repeat ranibizumab injection resulted in resolution of the subretinal fluid and pigment epithelial detachment and visual improvement.

CONCLUSIONS

Intravitreal ranibizumab injections appeared to be an effective treatment for RAP, resulting in visual gain and reduction in macular thickness. Further long-term studies to evaluate the efficacy of intravitreal ranibizumab in RAP are warranted.

First and second-order kernel multifocal electroretinography abnormalities in acute central serous chorioretinopathy

PURPOSE

To evaluate the first and second-order kernel multifocal electroretinogram (mfERG) response abnormalities in patients with acute central serous chorioretinopathy (CSC).

METHODS

This was a cross-sectional observational study in which 45 eyes of 45 patients with acute CSC underwent mfERG recordings. Peak amplitudes and implicit times of the first and second-order kernel responses were analyzed and compared with 20 age-matched normal controls. Correlation analyses were performed between the patients' visual acuity and the first and second-order amplitudes and implicit times.

RESULTS

The first-order N1 and P1 mfERG amplitudes in the central three concentric rings were reduced in eyes with acute CSC compared with controls (P < 0.05). The first-order P1 implicit times of the central four rings were also delayed (P < 0.05). For the second-order mfERG response, there were significant reductions in the second-order P1 and N1 amplitudes in rings 3-5 compared with controls (P < 0.05). No significant difference between the second-order P1 and N1 implicit times was found compared with controls (P > 0.05). Correlation analyses showed significant correlations between visual acuity and the first-order N1 response amplitudes of rings 1 and 2, and for the first-order N1 and P1 implicit times of rings 1-4 (P < 0.05).

CONCLUSION

Both first and second-order mfERG response abnormalities occur in eyes with acute CSC. These results suggest that in acute CSC, while outer retinal dysfunction is mostly localized to the central macula, there might be more widespread impairment in adaptive mechanisms of the inner retina or outer plexiform layer dysfunction in the more peripheral macula.

Intravitreal bevacizumab (avastin) for choroidal neovascularization secondary to central serous chorioretinopathy, secondary to punctate inner choroidopathy, or of idiopathic origin

PURPOSE

To evaluate the safety and efficacy of intravitreal bevacizumab in the treatment of idiopathic choroidal neovascularization (CNV) and CNV secondary to central serous chorioretinopathy (CSC) or punctate inner choroidopathy (PIC).

DESIGN

Prospective, nonrandomized, interventional case series.

METHODS

In an institutional clinical practice, 15 patients were recruited; nine had idiopathic CNV, two had CNV secondary to CSC, and four had CNV attributable to PIC. Patients received three monthly 1.25-mg intravitreal bevacizumab injections for three months. Patients were followed for six months, and the best-corrected visual acuity (BCVA), fluorescein angiography (FA) findings, and optical coherence tomography (OCT) central foveal thickness (CFT) were assessed.

RESULTS

At baseline, the mean logMAR BCVA was 0.48 (Snellen equivalent = 20/60). The mean logMAR BCVA improved significantly to 0.25 (Snellen equivalent = 20/36) and 0.17 (Snellen equivalent = 20/30) at one and six months, respectively (both P = .001). The mean OCT CFT reduced from 306 microm at baseline to 201 microm at six months (P < .001). All eyes (100%) had visual improvement of 1 line or more at six months, and 11 (73.3%) improved by 2 or more lines. FA showed absence of CNV leakage, the angiographic end point, at three months, and no recurrence was observed at six months in all eyes. No systemic or ocular adverse events were encountered.

CONCLUSIONS

Intravitreal bevacizumab injections resulted in visual and anatomic improvements in eyes with idiopathic CNV and CNV attributable to CSC or PIC. Further studies are warranted to assess the long-term safety and the regimen for optimal efficacy of intravitreal bevacizumab.

Intravitreal triamcinolone plus sequential grid laser versus triamcinolone or laser alone for treating diabetic macular edema: six-month outcomes

OBJECTIVE

To evaluate the efficacy of sequential intravitreal triamcinolone acetonide (TA) injection followed by grid laser photocoagulation for treating diabetic macular edema (DME).

DESIGN

Prospective, 3-armed, randomized clinical trial.

PARTICIPANTS

One hundred eleven eyes of 111 patients with DME involving the fovea.

INTERVENTION

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).

MAIN OUTCOME MEASURES

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.

RESULTS

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.

CONCLUSIONS

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.

The clinical applications of multifocal electroretinography: a systematic review

Multifocal electroretinography (mfERG) is an investigation that can simultaneously measure multiple electroretinographic responses at different retinal locations by cross-correlation techniques. mfERG therefore allows topographic mapping of retinal function in the central 40-50 degrees of the retina. The strength of mfERG lies in its ability to provide objective assessment of the central retinal function at different retinal areas within a short duration of time. Since the introduction of mfERG in 1992, mfERG has been applied in a large variety of clinical settings. This article reviews the clinical applications of mfERG based on the currently available evidence. mfERG has been found to be useful in the assessment of localized retinal dysfunction caused by various acquired or hereditary retinal disorders. The use of mfERG also enabled clinicians to objectively monitor the treatment outcomes as the changes in visual functions might not be reflected by subjective methods of assessment. By changing the stimulus, recording, and analysis parameters, investigation of specific retinal electrophysiological components can be performed topographically. Further developments and consolidations of these parameters will likely broaden the use of mfERG in the clinical setting.

Retinal pigment epithelial tear following intravitreal ranibizumab injections for neovascular age-related macular degeneration

BACKGROUND

To report the development of retinal pigment epithelial (RPE) tear after intravitreal injection of ranibizumab (Lucentis, Novartis, Basel, Switzerland).

METHODS

Case report with presentation of the fundus photography, fluorescein angiography (FA) and optical coherence tomography (OCT) findings.

RESULTS

A 70-year-old man received intravitreal injections of ranibizumab for the treatment of occult choroidal neovascularisation (CNV) with fibrovascular pigment epithelial detachment due to age-related macular degeneration. One day after the third intravitreal ranibizumab injection, fundus examination showed a RPE defect at the foveal region. FA and OCT confirmed the presence of RPE tear sparing the fovea. No further progression of the RPE tear was observed after withholding subsequent ranibizumab injection and his right eye visual acuity remained at 20/100 at 3 months from the last injection.

CONCLUSIONS

As with other anti-vascular endothelial growth factor treatment for CNV, RPE tear might occur after intravitreal ranibizumab injection even after previous uneventful intravitreal injections.

Combined photodynamic therapy and intravitreal triamcinolone injection for the treatment of choroidal neovascularisation secondary to pathological myopia: a pilot study

BACKGROUND

To assess the efficacy and safety of combined intravitreal triamcinolone (IVTA) and photodynamic therapy (PDT) with verteporfin in the treatment of choroidal neovascularisation (CNV) secondary to pathological myopia.

METHODS

22 eyes of 22 patients with subfoveal or juxtafoveal CNV due to pathological myopia were prospectively recruited for combined PDT with IVTA. The treatment outcomes at 1 year were compared with those in a control group of 22 eyes that received PDT monotherapy.

RESULTS

At 1 year, the logMAR best-corrected visual acuity (BCVA) for the combined PDT with IVTA group changed from 0.62 to 0.61 (p = 0.74), whereas that for the monotherapy group changed from 0.61 to 0.67 (p = 0.33). The mean logMAR BCVA and proportions of patients without losing > or =3 lines at 1 year were similar between the two groups (p = 0.68 and 0.74, respectively). Subgroup analyses showed that eyes with baseline logMAR BCVA worse than 0.6 (Snellen equivalent 20/80) or CNV with greatest linear dimension > or =750 microm which received combined therapy had better mean logMAR BCVA at 1 year (p = 0.023 and 0.041, respectively), with a higher proportion of eyes gaining > or =2 lines of BCVA (p = 0.027 and 0.017, respectively) compared with PDT monotherapy.

CONCLUSIONS

Combined PDT with IVTA did not seem to result in significantly better visual outcome compared with PDT monotherapy. However, combined therapy might result in better visual outcome in selected patients with worse initial visual acuity or larger myopic CNV. Further studies are warranted to investigate the role of combined PDT with IVTA in the treatment of myopic CNV, especially in patients with worse prognostic factors.

Results of high-density silicone oil as a tamponade agent in macular hole retinal detachment in patients with high myopia

BACKGROUND

To evaluate the use of high-density silicone oil (HDSO) as a tamponade agent for retinal detachment secondary to myopic macular hole.

METHODS

12 eyes of 12 patients with macular hole retinal detachment underwent pars plana vitrectomy, internal limiting membrane peeling and HDSO tamponade. No posturing was required postoperatively and HDSO was removed 3-4 months later. Outcome measures included macular hole closure and retinal attachment rates, best-corrected visual acuity (BCVA), and intraoperative and postoperative complications.

RESULTS

The mean age of the patients was 67.8 years and the mean spherical equivalent refractive error was -13.4 diopters. After the removal of HDSO, 10 (83%) eyes had macular hole closure with retinal reattachment without any tamponade. One eye had retinal reattachment after re-operation and the other refused further surgery. At the last follow-up, the median BCVA improved from 20/800 to 20/600 (p = 0.046). A transient increase in intraocular pressure was observed in 5 (42%) eyes and one eye each developed mild oil emulsification and transient peripheral choroidal detachment. None of the eyes was found to have severe intraocular inflammation postoperatively.

CONCLUSIONS

HDSO seemed to be an effective tamponade agent for myopic macular hole retinal detachment. Further prospective controlled studies seem warranted.

Safety and Efficacy of Micro-Incisional Cataract Surgery with Bimanual Phacoemulsification for White Mature Cataract

BACKGROUND

To evaluate the safety and efficacy of micro-incisional cataract surgery (MICS) with bimanual phacoemulsification for the management of white mature cataract.

METHODS

Twenty-five eyes in 25 patients with mature cataract were prospectively recruited to undergo MICS with bimanual phacoemulsification. Serial changes in best-corrected visual acuity (BCVA), central corneal thickness (CCT) and endothelial cell density (ECD) were compared using the Wilcoxon signed-rank test.

RESULTS

MICS was successfully performed in 24 (96%) of the 25 eyes, with 1 eye requiring conversion to extracapsular cataract extraction due to radial tear during continuous curvilinear capsulorhexis. The median preoperative BCVA was hand movement. On day 1 postoperatively, the median BCVA improved to 0.6 (p < 0.001 compared with baseline). All patients had BCVA of 0.6 or better at 3 months after surgery (p < 0.001 compared with baseline). The mean increase in CCT at day 1 and week 1 postoperatively was 11.5 and 7.1%, respectively. The change in mean CCT was no longer significant at month 3 postoperatively (p = 0.82). The mean reduction in ECD at 3 months postoperatively was 7.8% (p = 0.037). None of the patients developed any postoperative complications.

CONCLUSIONS

MICS with bimanual phacoemulsification appeared to be a promising alterative for the management of white mature cataract.

A prospective randomised trial of different doses of intravitreal triamcinolone for diabetic macular oedema

OBJECTIVE

To compare the safety and efficacy of different doses of intravitreal triamcinolone (ivTA) in treating clinically significant diabetic macular oedema (CSMO).

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Peripheral and posterior pole retinal lesions in association with high myopia: a cross-sectional community-based study in Hong Kong

PURPOSE

To evaluate the prevalence and factors associated with posterior pole and peripheral retinal lesions in Chinese subjects with high myopia.

METHODS

Three hundred and thirty-seven asymptomatic adults with high myopia of refractive error <or=-6 D were examined in a cross-sectional community-based study. All subjects underwent cycloplegic refraction, ultrasound biometry and dilated fundal examination. Statistical analysis was performed to assess factors associated with the presence of posterior pole and peripheral retinal lesions.

RESULTS

The mean age of the 337 subjects was 36.0 years and the mean spherical equivalent refractive error was -10.2 D. Thirty-eight eyes (11.3%, 95% CI=8.1-15.2%) were found to have one or more posterior pole lesions and subjects with posterior pole lesion had significantly older age, longer axial length and higher degree of myopia (all P<0.001) compared with subjects without posterior pole lesion. After controlling for axial length, both the severity of refractive error and older age were significantly associated with the presence of posterior pole lesion (both P<0.001). For peripheral retinal lesions, 189 eyes (56.1%, 95% CI=50.6-61.5%) were found to have one or more peripheral retinal lesions. The presence of peripheral retinal lesion was associated with younger age and higher degree of refractive error (P=0.046 and 0.002, respectively).

CONCLUSION

Posterior pole and peripheral retinal degenerative lesions were found in a considerable proportion of subjects with high myopia. As some of these retinal lesions might predispose to visual impairment, highly myopic individuals should be educated on the symptoms of various eye conditions and seek care immediately if symptoms arise.

Safety enhanced photodynamic therapy with half dose verteporfin for chronic central serous chorioretinopathy: a short term pilot study

AIM

To evaluate short term safety of an enhanced photodynamic therapy (PDT) protocol with half dose verteporfin for treating chronic central serous chorioretinopathy (CSC).

METHODS

20 eyes of 18 patients with symptomatic chronic CSC underwent PDT using 3 mg/m2 verteporfin. Verteporfin was infused over 8 minutes followed by indocyanine green angiography guided laser application 2 minutes later. Serial optical coherence tomography (OCT) and multifocal electroretinography (mfERG) recordings were performed before PDT, at 4 days, 2 weeks, and 1 month after PDT. The best corrected visual acuity (BCVA), OCT central retinal thickness, and mean mfERG response amplitudes and peak latencies were compared longitudinally. Subgroup analysis was further performed for eyes with or without pigment epithelial detachment (PED).

RESULTS

At 1 month after PDT, the median BCVA improved from 20/40 to 20/30 (p = 0.001). The mean central retinal thickness also reduced from 276 microm to 158 microm (p < 0.001) and 17 (85%) eyes had complete resolution of serous retinal detachment and/or PED. MfERG showed no significant changes in the mean N1 and P1 response amplitude and latency for all eyes. Subgroup analysis demonstrated that eyes without PED had a significant increase in the mean central mfERG P1 response amplitude with reduction in P1 peak latency at 1 month post-PDT. For eyes with PED, transient reduction in the mean central P1 response amplitude was observed at 4 days post-PDT.

CONCLUSIONS

The modified safety enhanced PDT protocol with half dose verteporfin appeared to be a beneficial treatment option for patients with chronic CSC, especially in eyes without serous PED. Further controlled study is warranted to demonstrate the long term safety and efficacy of this treatment option.

Visual Field and Multifocal Electroretinography and their Correlations in Patients on Hydroxychloroquine Therapy

PURPOSE

To evaluate the effects of hydroxychloroquine on visual field and multifocal electroretinography (mfERG) and their correlations in patients taking hydroxychloroquine.

METHODS

This was a cross-sectional study in which patients on hydroxychloroquine therapy underwent automated 10-2 threshold static visual field examination and mfERG recordings. Non-parametric unadjusted and age-adjusted Spearman correlation coefficients rho were calculated between the cumulative dose of hydroxychloroquine and the visual field mean deviation (MD) and pattern standard deviation (PSD) values; and the mfERG response amplitudes and peak latencies. Correlation analysis was also performed between the visual field MD and PSD values and the mfERG response amplitudes and peak latencies.

RESULTS

A total of 26 eyes in 13 patients were analyzed. The mean duration of hydroxychloroquine therapy was 4.9 years and the mean cumulative dose was 574 g. No significant correlation was found between the cumulative dose of hydroxychloroquine and the visual field MD and PSD values. There were significant correlations between the cumulative dose of hydroxychloroquine and mfERG N1 and P1 response amplitudes for the central rings (ring 1-3). The correlations between the dose of hydroxychloroquine and mfERG N1 and P1 response amplitudes were strongest for the paracentral ring 2 (rho =-0.63 and rho =-0.62, respectively, P = 0.001). Significant correlations were also found between the visual field MD values and mfERG response amplitudes of various ring eccentricities.

CONCLUSIONS

In patients on hydroxychloroquine, mfERG response amplitude correlated with both the 10-2 visual field MD values and with the cumulative dose of hydroxychloroquine used. The use of mfERG can provide objective measurement of retinal function in patients on hydroxychloroquine and may provide supplementary quantitative information to visual field findings.

Decreasing efficacy of repeated intravitreal triamcinolone injections in diabetic macular oedema

BACKGROUND/AIM

Intravitreal triamcinolone (IVTA) results in transient improvements in diabetic macular oedema (DMO), necessitating repeated injections. The authors report a case series of 10 eyes of 10 patients with DMO, who received a repeat injection of 4 mg IVTA, at least 26 weeks after the first injection of the same dose.

METHOD

Pre-injection and at 2, 4, 9, and 17 weeks post-injection, best corrected visual acuity (BCVA) and central foveal thickness (CFT) on optical coherence tomography, after the first and repeat injections, were compared using paired t test. Side effects were monitored.

RESULTS

BCVA, CFT, intraocular pressure (IOP), and cataract scores were not significantly different before initial and repeat injections (given at 32.5 (SD 3.5) weeks after the first injection). Transient improvements of BCVA and CFT were achieved after both injections. However, after the repeat injection, the BCVA was significantly worse at all time points (p<0.05) and so were the best achieved CFT and the CFT at 4 weeks post-injection (p = 0.034 and 0.011 respectively), compared with the initial injection. Post-injection maximum IOPs and increase in cataract scores were not significantly different between the two injections.

CONCLUSION

A repeat injection of 4 mg of IVTA may not be as effective as an initial injection for the treatment of DMO.

Assessment of macular function by multifocal electroretinography following epiretinal membrane surgery with indocyanine green-assisted internal limiting membrane peeling

PURPOSE

To evaluate the changes in macular function and potential retinal toxicity in epiretinal membrane (ERM) surgery with indocyanine green (ICG)-assisted internal limiting membrane (ILM) peeling using multifocal electroretinography (mfERG).

METHODS

Thirteen eyes of 13 patients were randomly assigned to have ERM surgery with ILM peeling using 0.5 mg/ml or 1.25 mg/ml ICG staining. Patients were examined at baseline and at 3 and 6 months postoperatively. The postoperative mfERG N1 and P1 response amplitudes and peak latencies of various ring eccentricities were assessed and compared with baseline to determine any serial changes.

RESULTS

After surgery, the median best-corrected visual acuity improved from 20/70 at baseline to 20/30 at 6 months postoperatively (Wilcoxon signed-ranks test, P=0.004). At 3 months postoperatively, the 0.5 mg/ml group showed no significant changes in N1 and P1 response amplitudes and peak latencies, whereas the 1.25 mg/ml ICG group showed significant reductions in N1 and P1 response amplitudes compared with baseline. No significant changes in mfERG responses were observed in either group at 6 months after surgery.

CONCLUSIONS

Our mfERG findings suggested that the use of a higher concentration of ICG for ILM staining might result in transient retinal functional impairment postoperatively. The lowest possible concentration of ICG should be used intraoperatively to minimize potential retinal toxicity.

How Evidence-Based Are Publications in Clinical Ophthalmic Journals?

PURPOSE

To evaluate the methodological quality and level of evidence of publications in four leading general clinical ophthalmology journals.

METHODS

All 1919 articles published in the American Journal of Ophthalmology, Archives of Ophthalmology, British Journal of Ophthalmology, and Ophthalmology in 2004 were reviewed. The methodological rigor and the level of evidence in the articles were rated according to the McMaster Hedges Project criteria and the Oxford Centre for Evidence-Based Medicine levels of evidence.

RESULTS

Overall, 196 (24.4%) of the 804 publications that were included for assessment met the Hedges criteria. Articles on economics evaluation and those on prognosis achieved the highest passing rate, with 80.0% and 74.4% of articles, respectively, meeting the Hedges criteria. Publications on etiology, diagnosis, and treatment fared less well, with respective passing rates of 28.3%, 20.2%, and 14.7%. Published systematic reviews and randomized controlled trials were uncommon in the ophthalmic literature, at least in these four journals during 2004. According to the Oxford criteria, 57.6% of the articles were classified as level 4 evidence compared with 18.1% classified as level 1. Articles on prognosis had the highest proportion (43.0%) rated as level 1 evidence. Generally, articles that reached the Hedges threshold were rated higher on the level-of-evidence scale (Spermans rho = 0.73; P < 0.001).

CONCLUSIONS

The methodological quality of publications in the clinical ophthalmic literature was comparable to that in the literature of other specialties. There was substantial heterogeneity in quality between different types of articles. Future methodological improvements should focus on the areas identified as having the largest deficiencies.

Photodynamic Therapy in Macular Diseases of Asian Populations: When East Meets West

PURPOSE

We reviewed the indications, safety, and efficacy of photodynamic therapy with verteporfin in various macular diseases and vasculopathies, which are common in Asian populations, and compared the outcomes of photodynamic therapy in Asian patients with the outcomes in Caucasian patients.

METHODS

Relevant clinical and laboratory original articles, case reports, and review articles that have been published in the literature between January 1999 and October 2004 were searched in Medline. The potential differences in the response to photodynamic therapy between Asian and Caucasian patients were evaluated. Articles in foreign languages with English abstracts were included.

RESULTS

Macular diseases commonly seen in Asian populations, including choroidal neovascularization (CNV) of age-related macular degeneration, secondary to pathologic myopia or from an idiopathic cause, and choroidal vasculopathies such as central serous chorioretinopathy and polypoidal choroidal vasculopathy were included in the review. The results were tabulated and the differences with Caucasian populations were compared and highlighted.

CONCLUSION

Photodynamic therapy has been found to be an effective and noninvasive treatment for various subfoveal CNV and choroidal vasculopathies of the macula. Diverse behavior in different ethnic groups is observed.

Combined photodynamic therapy and intravitreal triamcinolone injection for the treatment of subfoveal choroidal neovascularisation in age related macular degeneration: a comparative study

AIM

To evaluate the outcomes of combined intravitreal triamcinolone (IVTA) and photodynamic therapy (PDT) with verteporfin in the treatment of subfoveal choroidal neovascularisation (CNV) caused by age related macular degeneration (AMD).

METHODS

48 eyes from 48 patients with subfoveal CNV caused by AMD were prospective recruited, with 24 eyes treated with combined PDT with IVTA and compared with a control group of 24 eyes which received PDT monotherapy. In the combined treatment group, IVTA was performed immediately after PDT as an outpatient procedure. The mean number of treatments, mean logMAR best corrected visual acuity (BCVA), mean line of visual acuity changes, and proportion of patients without moderate visual loss at 1 year were compared between the combined and monotherapy groups.

RESULTS

At 1 year the logMAR BCVA for the PDT with IVTA group changed from 0.88 to 0.95 (p = 0.32 compared with baseline), whereas the logMAR BCVA for the monotherapy group reduced from 0.74 to 1.09 (p<0.001 compared with baseline). A significantly higher proportion of patients who had PDT with IVTA did not develop moderate visual loss at 1 year compared with the monotherapy group (70.8% and 33.3% respectively, p = 0.009). Eyes which had combined treatment had significantly fewer lines lost compared with monotherapy alone (0.7 and 3.5 lines respectively, p = 0.015). Subgroup analysis showed that PDT with IVTA is effective in preventing visual loss in both predominately classic and occult CNV groups. The mean number of treatments for the combined and monotherapy groups was 1.5 and 1.96 respectively (p = 0.076).

CONCLUSIONS

Combined PDT with IVTA appeared more effective statistically at 12 months for stabilisation of vision (<3 logMAR lines change) compared with PDT monotherapy. Further randomised control trials might be justified to conclude the efficacy of PDT with IVTA.

Extensive submacular haemorrhage in polypoidal choroidal vasculopathy managed by sequential gas displacement and photodynamic therapy: a pilot study of one-year follow up

BACKGROUND

Polypoidal choroidal vasculopathy (PCV) with peculiar vascular lesions presents frequently as recurrent submacular haemorrhage. The best treatment is still not certain. It is the authors' objective to evaluate the 1-year safety and efficacy of photodynamic therapy (PDT) using verteporfin for persistent macular PCV after pneumatic displacement of the massive submacular haemorrhage with intravitreal perfluoropropane (C(3)F(8)).

METHODS

A prospective, non-comparative, interventional case series on patients with extensive and thick submacular haemorrhage secondary to PCV, which was displaced pneumatically with intravitreal pure 0.4 ml C(3)F(8). Fluorescein angiography and indocyanine green angiography were repeated 1-2 weeks later to delineate any persistent active leaking polypoidal lesions, which were then treated with PDT. Retreatment might be considered in each follow up at every 3 months.

RESULTS

Six eyes of six patients with the mean age of 53.6 years had been recruited and completed 1-year follow up. The mean baseline Snellen equivalent best-corrected visual acuity (BCVA) was 6/92 and the mean final BCVA at 1 year was 6/17. The mean improvement in logMAR BCVA after the sequential treatments was seven lines (range +3 to +19 lines) (Wilcoxon signed-ranks test, P = 0.03). All patients had at least moderate visual gains. No patient suffered serious complications from PDT.

CONCLUSIONS

This first report on combined treatment with intravitreal gas injection and sequential PDT on PCV seems to be a well-tolerated option. Further comparative studies with larger sample size and longer follow up are warranted.

Aqueous humor levels of vascular endothelial growth factor and pigment epithelium-derived factor in polypoidal choroidal vasculopathy and choroidal neovascularization

PURPOSE

To determine the aqueous levels of vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) in patients with active polypoidal choroidal vasculopathy (PCV) and choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) and pathologic myopia.

DESIGN

Prospective, comparative control study.

METHODS

Aqueous humors were collected from 32 eyes of 32 patients for either active PCV or CNV. Among them, 11 eyes had active and symptomatic PCV, 12 eyes had active CNV secondary to AMD, and nine eyes had active CNV of pathologic myopia. Levels of VEGF and PEDF were determined by commercially available enzyme-linked immunosorbent assay kits. A group of 10 aqueous samples from 10 patients who underwent cataract surgery without other ocular or systemic diseases comprised the controls.

RESULTS

VEGF concentrations in aqueous humor were markedly increased in patients with PCV, CNV of AMD, and CNV of myopia when compared with the controls (analysis of variance [ANOVA], P < .001). VEGF levels in eyes with PCV were, however, significantly lower than those of exudative AMD (P = .045). The PEDF levels were also significantly different among the groups (ANOVA, P = .001), and we observed increased levels in PCV, CNV of AMD, and CNV of myopia.

CONCLUSIONS

VEGF and PEDF factors were coexpressed and increased with positive correlation in aqueous humor of eyes with active PCV. The different levels of both factors in eyes of PCV and AMD might suggest distinct clinical entities or different angiogenesis courses between PCV and AMD.

Effect of application duration of 2% lidocaine jelly on aqueous lidocaine concentration for topical anesthesia in cataract surgery

BACKGROUND

To evaluate the intraocular penetration of lidocaine 2% gel after different duration of application and to assess their effects on intraoperative pain.

METHODS

Samples of aqueous humor were obtained in 41 eyes that had phacoemulsification under topical anesthesia with 2% lidocaine gel. The duration between lidocaine gel application and paracentesis was recorded. The aqueous concentration of lidocaine was measured using high performance liquid chromatography (HPLC). Patients were also asked to report the severity of intraoperative pain using a verbal analogue scale. Correlation analysis was performed to analyze the relationship between duration of lidocaine gel application, aqueous lidocaine concentration and intraoperative pain score.

RESULTS

The mean duration of lidocaine gel application was 20.3+/-6.1 min and the mean aqueous lidocaine level was 14.2+/-8.5 micro g/ml. Longer duration of lidocaine gel application was significantly associated with higher aqueous concentration of lidocaine (Spearman's rho=0.58, P<0.001). Eyes in which lidocaine gel was applied for 20 minutes or more had significantly higher aqueous lidocaine level (two-tailed t-test, P=0.001) However, the duration of lidocaine gel application and the aqueous concentration of lidocaine showed no correlation with the patent's perceived pain score (P=0.20 and P=0.79, respectively).

CONCLUSIONS

Increase in duration of lidocaine gel application resulted in higher aqueous concentration of lidocaine. Patients' level of perceived pain during phacoemulsification under lidocaine gel anesthesia was not related to the intraocular lidocaine absorption level after 10 min of gel application.

Retinal ganglion cells toxicity caused by photosensitising effects of intravitreal indocyanine green with illumination in rat eyes

AIM

To investigate the effects of indocyanine green (ICG) with or without illumination on rat retinal ganglion cells (RGC) and retinal morphology.

METHODS

Intravitreal injections of 1.0 mg/ml ICG solution were performed in rat eyes with or without subsequent illumination for 5 minutes. Eyes in the control group had intravitreal injections of balanced salt solution with illumination. Retrograde labelling of RGC with 6% Fluoro-Gold was performed 1 month later and RGC densities were compared between the three groups. Light microscopy with measurements of outer nuclear layer (ONL) and inner nuclear layer (INL) thicknesses were also performed and compared.

RESULTS

Eyes with ICG without illumination showed insignificant reduction in RGC density compared with the control group (p = 0.28), whereas a significant decrease in RGC density was found in eyes that had ICG injection with illumination (p = 0.036). A significant increase in ONL thickness was also observed in the ICG with illumination treated eyes compared with the ICG without illumination and the control groups (p<0.001). No significant difference in INL thickness was observed between the three groups.

CONCLUSIONS

Intravitreal injection of 0.1 mg/ml ICG in rat eyes followed by illumination resulted in photosensitising toxicity to RGC. Lower ICG concentration or illumination level should be considered when performing ICG assisted macular surgery.

Phacoemulsification with intravitreal triamcinolone in patients with cataract and coexisting diabetic macular oedema: a 6-month prospective pilot study

AIMS

To assess the safety and efficacy of phacoemulsification with intravitreal triamcinolone (ivTA) injection in diabetics with cataract and clinically significant macular oedema (CSMO).

METHODS

A total of 19 eyes of 15 consecutive diabetic patients with cataract and CSMO were prospectively recruited. Patients underwent phacoemulsification and intraocular lens implantation with 4 mg ivTA injection at completion of surgery. Patients were followed up on day 1, then weekly for 1 month, and thereafter monthly until 6 months postoperatively. Best corrected visual acuity (BCVA), central macular thickness (CMT) measured by optical coherence tomography, and adverse events were recorded.

RESULTS

In total, 17 eyes completed 6 months of follow-up. In all, 58.8% showed improvement in BCVA of >or=2 lines, with statistically significant improvement in mean Snellen BCVA of 2.4 lines at 6 months. The peak BCVA was achieved at 4 months. The mean CMT decreased from a baseline of 449 microm to a minimum of 321+/-148 microm (28.5% reduction) achieved at 2 months, with statistically significant reduction at all postoperative time intervals until 6 months. Of 17 eyes, 4 (23.5%) developed transiently elevated intraocular pressure that normalised by 6 months in all but one patient. No injection- or surgery-related complications were encountered.

CONCLUSIONS

Phacoemulsification with concurrent 4 mg ivTA injection appears to be a safe option for managing diabetics with cataract and CSMO. However, large-scaled randomised controlled trials are necessary for delineating the relative contributions of cataract removal and CMT reduction to visual improvement. Moreover, the transient effect on CMT may warrant further studies to determine optimal timing and dosage of further ivTA injections.

Results of trabeculectomy with adjunctive intraoperative mitomycin C in Chinese patients with glaucoma

BACKGROUND AND OBJECTIVE

To report the results of trabeculectomy with adjunctive intraoperative mitomycin C in Chinese patients with glaucoma.

PATIENTS AND METHODS

The medical records of Chinese patients who received trabeculectomy with intraoperative mitomycin C from 1992 to 1998 were retrospectively reviewed. A "successful" trabeculectomy was defined as one after which the intraocular pressure (IOP) could be controlled to between 5 and 21 mm Hg, inclusive, with no more than 3 glaucoma medications.

RESULTS

One hundred fourteen trabeculectomies in 105 eyes of 90 patients were retrospectively reviewed. Mean age +/- standard deviation was 48.1 +/- 21.9 years. Primary open-angle glaucoma (43.0%) and angle-closure glaucoma (27.2%) were the most common diagnoses leading to trabeculectomy. The mean follow-up +/- standard deviation was 29.6 +/- 18.6 months (range, 6 to 92 months). The overall success rate at the last follow-up was 73.7% (84 of 114 trabeculectomies).

CONCLUSIONS

Trabeculectomy with mitomycin C is a safe and effective procedure for the control of IOP in Chinese patients with glaucoma.

Choroidal neovascularisation in pathological myopia: an update in management

Choroidal neovascularisation (CNV) secondary to pathological myopia is an important cause of significant visual impairment in young and middle aged adults globally and is particularly prevalent in Asian populations. In the past few years, there have been rapid advancements in the different treatments for myopic CNV. The purpose of this perspective is to give an overview of the natural history of myopic CNV and the various treatment options including laser photocoagulation, photodynamic therapy, sub-macular surgery, and macular translocation surgery. Future directions in the management of myopic CNV are also discussed.

Multifocal electroretinographic changes in patients receiving hydroxychloroquine therapy

PURPOSE

To evaluate the longitudinal changes in multifocal electroretinography (mfERG) in patients receiving hydroxychloroquine and to assess the effects of cumulative hydroxychloroquine dose on mfERG.

DESIGN

Prospective cohort study.

METHODS

Twenty-four eyes in 12 patients receiving hydroxychloroquine underwent mfERG recordings at baseline and 1 to 2 years later. The first negative (N1) and first positive (P1) response amplitudes and peak latencies were compared with normal controls. Serial changes in the pattern of mfERG abnormalities and in response amplitudes and peak latencies were also compared between eyes in which hydroxychloroquine therapy was continued or stopped. Correlation analyses were performed to assess the effects of a cumulative dose of hydroxychloroquine on mfERG.

RESULTS

At baseline, reductions in N1 and P1 response amplitudes were observed in patients receiving hydroxychloroquine compared with controls. At follow-up, in addition to the reductions in N1 and P1 response amplitudes, increases in P1 peak latencies compared with controls were observed. In patients who stopped hydroxychloroquine therapy, there were significant increases in N1 and P1 response amplitudes at follow-up mfERG.

CONCLUSIONS

Patients receiving hydroxychloroquine showed a longitudinal decline in retinal function; patients who stopped hydroxychloroquine therapy showed improvement. Although these data are insufficient to demonstrate the sensitivity of mfERG for evaluating early hydroxychloroquine toxicity, the results suggest that serial mfERG assessment may help detect early retinal changes associated with hydroxychloroquine therapy. Further studies with long-term results will be useful in clarifying the value of mfERG in evaluating early retinal toxicity due to hydroxychloroquine.

Prioritization of cataract surgery: visual analogue scale versus scoring system

BACKGROUND

The purpose of the present paper was to evaluate the variability of using a visual analogue scale (VAS) and to assess the feasibility of a priority-setting scoring system for prioritizing elective cataract surgery.

METHODS

Consecutive cases listed for cataract surgery were prospectively recruited. Ophthalmologists listed patients to undergo early or normal surgery and were asked to rate the urgency of surgery using a VAS. Patients were then reassessed and a cataract surgery prioritization (CSP) score was calculated based on the New Zealand priority criteria for cataract surgery. Correlation coefficients between VAS and CSP scores were calculated to determine the variability among ophthalmologists in using the VAS in prioritizing surgery. Further analyses were performed to assess the potential impact of implementing the CSP system.

RESULTS

A total of 326 patients were recruited. There was a positive correlation between VAS and CSP scores (Spearman rho= 0.407, P < 0.001). A high degree of variation among ophthalmologists in the use of VAS was found. Patients with poor binocular vision were not listed as early, whereas patients with poor vision in the eye listed for cataract surgery but good vision in the fellow eye were more likely to be prioritized to have early operation. These findings suggest that patients with severe impairment in binocular visual function were not adequately accounted for during cataract surgery listing.

CONCLUSIONS

The use of a VAS for prioritizing cataract surgery may be suboptimal due to high subjectivity. Adoption of an objective criteria-validated priority-setting scoring system may allow better stratification of patients to ensure better service provision.

Vitrectomy and gas tamponade without internal limiting membrane peeling for myopic foveoschisis

AIM

To evaluate the clinical and anatomical outcomes of pars plana vitrectomy and gas tamponade without internal limiting membrane (ILM) peeling in symptomatic patients caused by myopic foveoschisis.

METHODS

Nine eyes in eight highly myopic patients who had myopic foveoschisis with foveal detachment underwent vitrectomy without ILM peeling followed by gas tamponade. Main outcome measures include change in best corrected visual acuity (BCVA) and changes in height of the foveal detachment and resolution of the myopic foveoschisis measured by optical coherence tomography (OCT).

RESULTS

After surgery, BCVA improved in eight eyes with the median BCVA improved from 20/80 to 20/50 (p=0.012). The mean line of visual improvement was 3.6 lines. OCT showed complete resolution of myopic foveoschisis with complete foveal reattachment in seven (77.8%) eyes with partial resolution in two (22.2%) eyes. The mean height of foveal detachment decreased from 505 mum preoperatively to 21 mum postoperatively (p<0.001).

CONCLUSIONS

Vitrectomy without ILM peeling followed by gas tamponade appeared to result in favourable visual and anatomical outcomes for treating myopic foveoschisis in highly myopic eyes. The results are comparable with studies in which ILM removal was performed. Further controlled study will be useful to determine the role of ILM peeling in these patients.

The effects of indocyanine green and endoillumination on rabbit retina: an electroretinographic and histological study

AIM

To evaluate the functional and morphological retinal toxicity associated with intravitreal injection of indocyanine green (ICG) dye in rabbit eyes during vitrectomy with endoillumination.

METHODS

20 eyes of 10 New Zealand pigmented rabbits were used in the study. All eyes underwent pars plana vitrectomy and removal of posterior vitreous cortex under endoillumination. In one eye of each rabbit, intravitreal injection of 0.1 ml of 2.5 mg/ml ICG was applied for 30 seconds followed by 10 minutes of endoillumination. The control eye had endoillumination only without ICG injection. Dark adapted and light adapted electroretinograms (ERGs) were performed before the surgery and 1 week after surgery for serial comparisons. Rabbits were killed 1 week after surgery and eyes were enucleated for histological examination.

RESULTS

Serial ERG comparisons showed significant reduction in the light adapted a-wave amplitude (p = 0.037) and significant delays in the dark adapted and light adapted b-wave latencies (p = 0.020 and p = 0.038, respectively) in the ICG treated eyes. Histological examinations demonstrated loss of photoreceptor outer segments with focal absence of photoreceptors in some areas in the ICG injected eyes.

CONCLUSIONS

Vitrectomy followed by intravitreal injection of 2.5 mg/ml ICG for 30 seconds with endoillumination may result in retinal toxicity causing functional and morphological retinal damages in rabbit eyes. The lowest concentration of ICG should be used if necessary for intraocular use to prevent potential retinal toxicity.

A prospective study on trypan blue capsule staining under air vs under viscoelastic

AIM

To compare the safety and effectiveness of trypan blue capsule staining under air vs under viscoelastic.

METHODS

A total of 52 consecutive patients planned for phacoemulsification of white mature cataract were randomly assigned to trypan blue staining under air or under viscoelastic. Perioperative changes in best-corrected visual acuity (BCVA), central corneal thickness (CCT), and endothelial cell density (ECD) were compared between the two groups. The differences in operating and phacoemulsification times, staining pattern, and complications between the two groups were also recorded.

RESULTS

Phacoemulsification of white mature cataract was performed in 50 (96%) eyes. The median preoperative BCVA was hand movement. No significant differences in the baseline characteristics were found between the two groups. At 3 months after phacoemulsification, the median BCVA improved to 0.8. The mean CCT returned to preoperative level by 1 month postoperatively and the mean ECD loss was 11.9% 3 months postoperatively. No significant differences in median BCVA, mean phacoemulsification and operation times, mean CCT, and mean ECD were found between the two groups.

CONCLUSIONS

Trypan blue staining of the anterior lens capsule under air or under viscoelastic were similarly effective and safe methods for the phacoemulsification of white mature cataract.

Idiopathic macular hole surgery in Chinese patients: a randomised study to compare indocyanine green-assisted internal limiting membrane peeling with no internal limiting membrane peeling

OBJECTIVE

To compare the anatomical and visual outcomes of primary idiopathic macular hole surgery using indocyanine green-assisted internal limiting membrane peeling versus no internal limiting membrane peeling.

DESIGN

Prospective randomised controlled clinical trial.

SETTING

University teaching hospital, Hong Kong.

PATIENTS

Fifty-one eyes of 49 Chinese patients with primary idiopathic macular hole were studied.

INTERVENTIONS

Patients were randomised to undergo pars plana vitrectomy with indocyanine green-assisted internal limiting membrane peeling (26 eyes) or surgery without internal limiting membrane peeling (25 eyes). Perfluorocarbon gas was used in all cases as internal tamponade.

MAIN OUTCOME MEASURES

Primary macular hole closure rate and best-corrected visual acuity.

RESULTS

The mean follow-up duration was 12 months (range, 6-23 months). Respectively to the indocyanine green-assisted internal limiting membrane peeling group and non-internal limiting membrane peeling group, the primary anatomical closure rate was 92.3% and 32.0% (P<0.001), whereas improvement in best-corrected visual acuity was 3.7 and 1.5 lines (P=0.002). More eyes in the first group (84.6%) had improvement of 2 or more lines of best-corrected visual acuity after surgery than in the second group (32.0%) [P<0.001]. Multivariate logistic regression showed indocyanine green-assisted internal limiting membrane peeling was the only significant predictor for primary closure of the macular hole (adjusted odds ratio=30.8).

CONCLUSION

Indocyanine green-assisted internal limiting membrane peeling in idiopathic macular hole surgery results in significantly better anatomical and visual outcomes compared with non-internal limiting membrane peeling in Chinese patients.

Causes of childhood blindness in a school for the visually impaired in Hong Kong

OBJECTIVE

To identify the causes of blindness in children attending a school for the blind in Hong Kong.

DESIGN

Cross-sectional observational study.

SETTING

School for blind children in Hong Kong.

PARTICIPANTS

Eighty-two blind students at the Ebenezer School and Home for the Visually Impaired were examined between December 1998 and August 1999.

MAIN OUTCOME MEASURES

Demographic data were obtained from students and a questionnaire assessment made of their medical and ocular history. Visual acuity was assessed and visual loss classified according to the World Health Organization classification of visual impairment. Complete ophthalmic assessments were performed in all students including slit-lamp examination and dilated binocular indirect ophthalmoscopy.

RESULTS

The mean age of the students was 12.2 years. Ten (12.2%) had a family history of eye disease. Major past medical illnesses were reported in 50% with prematurity and diseases of the central nervous system found in 26.8% and 11.0% of students, respectively. The most common anatomical site for visual impairment was the retina (47.6%), followed by diseases of the optic nerve (14.6%), and diseases of the anterior segment and the lens (14.6%).

CONCLUSIONS

The pattern of childhood blindness in Hong Kong is similar to that seen in other developed countries. Preventable causes of childhood blindness, such as prematurity and birth asphyxia, were responsible for a large proportion of cases. Early diagnosis and treatment of such conditions may reduce the incidence of childhood blindness in Hong Kong.

TIMP-1 production in human retinal pigment epithelial cells after laser exposure

PURPOSE

To investigate changes in the production of tissue inhibitor of metalloproteinase type 1 (TIMP-1) by human retinal pigment epithelial (RPE) cells following argon laser exposure.

METHODS

Human cultured ARPE19 cells were exposed to argon green laser at four different energy levels ranging from 60mW to 360mW. After laser exposure, the culture media were sampled at 0, 24, 72 and 144 hours for TIMP-1 concentration produced by the RPE cells. The levels of TIMP-1 in the cells treated with different laser energy levels were compared with a control group not exposed to laser application. Immunocytochemistry for proliferating cell nuclear antigen (PCNA) was performed to detect any adverse effects on the RPE cells caused by laser exposure.

RESULTS

Immediately after laser exposure, the concentration of TIMP-1 was not detectable. At 24 hours after laser exposure, the concentration of TIMP-1 increased significantly in RPE cells treated with 120mW and 240mW at 24 hours (P=0.006 and P=0.001 respectively) compared with control cells. At 72 hours after treatment, RPE cells treated at 120mW, 240mW and 360mW demonstrated significantly increase in TIMP-1 production compared with control (P=0.003, P < 0.001 and P < 0.001, respectively). No significant reduction in cell viability was observed following laser application as detected by PCNA expression.

CONCLUSIONS

Our results demonstrated that early TIMP-1 production by RPE cells in cell cultures was enhanced following laser exposure.