Yosanan Yospaiboon

Infectious endophthalmitis: review of 420 cases

Background To characterize the causative pathogens and the visual outcomes among patients with endophthalmitis at a large referral center in northeastern Thailand. Methods All cases of infectious endophthalmitis treated between 1983 and 2007 were reviewed retrospectively. The patient data – including age, sex, history of ocular injuries, previous treatment and duration of the symptoms – were recorded. The ocular examination included affected side, anterior chamber reaction, vitreous haze, and presence of intraocular foreign bodies. Smears and cultures were prepared from anterior chamber paracentesis and/or vitreous tapping. Intraocular antibiotics were administered at the time of anterior chamber paracentesis and/or vitreous tapping. Vitrectomy and/or lensectomy were performed when indicated. Initial visual acuity before treatment and the final best-corrected vision were compared. Results A total of 420 cases of endophthalmitis were reviewed: 181 cases (43.1%) had ocular trauma before the infection; 135 (32.2%) developed endophthalmitis after intraocular surgery; and, 122 (29.1%) had a positive culture. Bacteria were isolated in 114 cases (93.4%) and fungi were noted in eight (6.6%). The common causative bacterium was Staphylococcus epidermidis. Combined vitrectomy and intraocular antibiotics were performed in 189 cases (45.0%), whereas 69 cases (16.4%) were treated with intraocular antibiotics alone. Conclusion Most of the reviewed cases were associated with trauma and intraocular surgery. The most frequently encountered bacterium causing infectious endophthalmitis was S. epidermidis. Most cases were treated with combined vitrectomy and intraocular antibiotics. The final visual outcomes seem to vary according to the type of endophthalmitis.

Air vs Perfluoropropane Gas in Pneumatic Retinopexy: A Randomized Noninferiority Trial

OBJECTIVE To evaluate whether air is as effective as perfluoropropane gas in treating rhegmatogenous retinal detachment by pneumatic retinopexy. METHODS In a double-blind, randomized, clinically controlled noninferiority trial, eligible patients were randomized into 2 treatment groups by using block randomization and treated by pneumatic retinopexy using filtered air or perfluoropropane gas. MAIN OUTCOME MEASURES Retinal reattachment rate and final visual recovery. RESULTS One hundred twenty-six patients were recruited. Half (63 patients) were assigned to receive filtered air during pneumatic retinopexy and half received perfluoropropane gas. The single-procedure reattachment rate was higher for the perfluoropropane gas group (73.0%[46 patients]) than for the air group (60.3% [38]), but the difference was not statistically significant (risk difference, -12.7%; 95% confidence interval, -29.0% to 3.6%). The final reattachment rate after additional pneumatic retinopexy and/or surgical procedures was 92.1% (58) in the air group and 96.8% (61) in the perfluoropropane gas group. This result showed an equivalent effect on the final reattachment rate (risk difference, -4.7%; 95% confidence interval, -12.7% to 3.2%). Final visual acuity did not differ significantly between groups. CONCLUSION Pneumatic retinopexy using filtered air is associated with a nonsignificantly lower initial reattachment rate than using perfluoropropane gas but results in an equivalent final reattachment rate and final visual recovery. APPLICATION TO CLINICAL PRACTICE Air is an acceptable alternative to perfluoropropane gas when treating rhegmatogenous retinal detachment by pneumatic retinopexy. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00120445.

The Impact of Preprinted Prescription Forms on Medication Prescribing Errors in an Ophthalmology Clinic in Northeast Thailand: A Non-Randomised Interventional Study

Objectives To understand the incidence and types of medication prescribing errors in a low resource setting ophthalmology clinic and to determine the impact of a preprinted prescription based on the hospital formulary (FormularyScript) on medication prescribing errors. Design Non-randomised interventional study. Setting Ophthalmology clinic in a teaching hospital in northeast Thailand. Participants 4349 handwritten prescriptions collected from October 2009 to December 2009, and 4146 FormularyScripts collected from February 2010 to May 2010. Primary and secondary outcome measures All prescriptions from the handwritten and FormularyScript groups were analysed for medication error rates by types (legibility, ambiguous, incomplete, abbreviation and accuracy) and subtypes (drug name, strength, which eye, route and dispensed amount). Results Comparison of error rates in the two groups showed a 10-fold reduction in the overall error rate using FormularyScript (32.9%–3.5%, p<0.001). FormularyScripts were associated with statistically significant (p<0.001) decreases in the following error types: legibility (16.1%–0.1%), incomplete (16.1%–0.1%) and abbreviation (3.1%–0.3%). There was no statistically significant change in accuracy errors (0.8%–0.6%, p=0.21). Ambiguous errors increased with FormularyScripts (0.6%–2.5%, p<0.001), likely due to the introduction of new ways to make errors. Decreases were seen in all legibility, abbreviation and accuracy error subtypes, and four out of six incomplete error subtypes. There were statistically significant increases in both ambiguous error subtypes: which eye (0.3%–2.5%, p<0.001) and drug name (0.3%–0.6%, p=0.03). Conclusions In our study population, outpatient medication prescribing errors were common and primarily due to legibility and incomplete error types. A preprinted prescription form has the potential to decrease medication prescribing errors related to legibility, incomplete prescribing information and use of unacceptable abbreviations without changing the overall rate of accuracy errors. However, new error types can occur.

Subretinal angiostrongyliasis-induced optic neuritis.

A 27-year-old Thai male presented with progressive visual loss and a membrane-like floater in the right eye that had persisted for 1 month. He had a history of eating raw foods, including snails. His initial visual acuity was counting fingers at 1 ft and he had a relative afferent pupillary defect. A movable larva with subretinal tracks was found in the subretinal space near a normal optic disc. Visually evoked potentials showed delayed latency, which indicated secondary retrobulbar optic neuritis. A diode laser was directly applied to the motile worm. The patient was subsequently prescribed oral prednisolone and albendazole. After treatment, his visual acuity was slightly improved at 2/60. Ocular manifestation is a very rare event resulting from parasitic infection. In only 1.1% of angiostrongyliasis cases is an Angiostrongylus cantonensis larva identified in the eye. Ocular angiostrongyliasis with optic neuritis may be secondary to mechanical injury and/or inflammatory reactions. Steroid treatment is recommended, although most patients have only slight visual improvement after treatment.

Blood culture bottles are superior to conventional media for vitreous culture.

To compare blood culture bottles and conventional media for the vitreous culture in patients with clinically suspected infectious endophthalmitis.

Comparing smartphone camera adapters in imaging post-operative cataract patients.

Introduction The goal of this study is to compare image quality and clinical confidence for managing post-operative cataract patients based on anterior segment smartphone images obtained in real-world settings using four types of adapters: (a) macro lens (ML), (b) ML with augmented light-emitting diode (LED) illumination (ML-LED), (c) no adapter (NA) and (d) slit lamp (SL) adapter. Methods Anterior segment images were obtained from 190 eyes after cataract surgery using an eight-megapixel iPhone 6 smartphone camera with four adapters: ML, ML-LED, NA, and SL. Smartphone images were subjectively rated by ophthalmologists as acceptable or not acceptable for: (a) image quality for evaluating the anterior segment structures and (b) reader confidence in clinically managing post-operative patients based on smartphone images. Results NA, ML-LED, and SL had the highest scores for image quality with 100%, 93.7%, and 86.3% judged as acceptable, respectively. NA, SL, and ML-LED were also rated highest in clinical confidence with 100%, 98%, and 93.2% having acceptable levels, respectively. ML was judged lowest in both image quality (61.1% acceptable) and clinical confidence (37.4% acceptable). Discussion This study represents the first effort to compare different smartphone camera adapters’ ability to image the anterior segment of the eye in a real-world setting. Our study shows that ML-LED, NA, and SL adapters were acceptable for visualizing anterior segment structures to physician readers in 86–100% of cases. When coupled with visual acuity, intro-ocular pressure and history, these images can result in acceptable clinical confidence in 93–100% of cases.

Laser-Induced Choroidal Neovascularizations: Clinical Study of 3 Cases

Background: We report 3 patients with laser-induced choroidal neovascularization (CNV). Method: Retrospective, observational case series. Medical charts and photographs were reviewed. Results: Two patients with central serous chorioretinopathy who developed iatrogenic CNV after focal laser photocoagulation were treated with intravitreal ranibizumab injections. One patient with CNV secondary to thermal laser photocoagulation for diabetic macular edema was treated with photodynamic therapy (PDT). Visual improvement has been demonstrated in the patients treated with intravitreal ranibizumab injections, and their successful visual outcome was stable for more than 2 years. Stable visual acuity was also observed in the patient treated with PDT, no visual improvement was observed possibly due to the macular scar and macular ischemia. No systemic or ocular complications were detected among the 3 cases. Conclusion: To prevent a laser-induced CNV, it is critical to avoid heavy small-spot laser burns and repeated application. Patients should be monitored carefully for CNV after laser treatment. In our cases, PDT and intravitreal ranibizumab injections were effective for the treatment of laser-induced CNV.

Macular sensitivity after half-dose verteporfin photodynamic therapy in central serous chorioretinopathy

Objective To study the macular sensitivity after half-dose verteporfin photodynamic therapy in patients with resolved central serous chorioretinopathy using the automated static perimeter. Methods Prospective consecutive case study of 24 patients with resolved central serous chorioretinopathy was performed. The macular sensitivity was measured using a conventional automated static perimeter with the Swedish interactive threshold algorithm 10-2 and foveal threshold. Best corrected visual acuity, intraocular pressure, fundus examination, macular thickness, and volume were also examined. The mean macular sensitivities of the affected eyes and their normal fellow eyes were calculated and compared. P<0.05 was considered statistically significant. Results The mean macular sensitivities of the affected eyes were lower than the normal fellow eyes with a statistically significant difference in all areas of the study (P<0.05). Best corrected visual acuity improved significantly from pretreatment (0.26±0.3 logMAR) to posttreatment (0.075±0.15 logMAR, P<0.05). Macular thicknesses in affected eyes were 230.66±67.34 μm and in the normal eyes were 238.33±92.26 μm (P=0.68). Macular volumes in affected eyes were 8.77±0.49 and in the normal eyes were 8.70±0.50 (P=0.60). These findings were not statistically significant. Conclusion Eyes with resolved central serous chorioretinopathy after half-dose verteporfin photodynamic therapy had lower macular sensitivity than normal fellow eyes. These findings agreed well with the previous microperimetric studies. The conventional automated static perimeter can also be used when a microperimeter is not available.

Lower conjunctival fornix packing for mydriasis in premature infants: a randomized trial.

Objective To compare the mydriatic effect of lower conjunctival fornix packing to conventional instillation of eyedrops containing 2.5% phenylephrine and 1% tropicamide in premature infants undergoing examination for retinopathy of prematurity. Methods The patients were randomized to receive either conventional instillation of mydriatic drops or lower conjunctival fornix packing in one eye and the alternate method in the fellow eye. For the eyes receiving lower conjunctival fornix packing (study group), one small piece of the cotton wool soaked with one drop of 2.5% phenylephrine and one drop of 1% tropicamide was packed in the lower conjunctival fornix for 15 minutes. For the eyes receiving the conventional instillation (control group), 2.5% phenylephrine and 1% tropicamide were alternately instilled every 5 minutes for two doses each. Horizontal pupil diameter was measured with a ruler in millimeters 40 minutes later. Results The mean dilated pupil diameter in study group and control group were 5.76 ± 1.01 mm and 4.50 ± 1.08 mm, respectively. This difference was statistically significant (P < 0.05). Conclusion The dilated pupil diameter after receiving the lower conjunctival fornix packing was larger than conventional instillation with a statistically significant difference. We recommended the packing method to dilate the preterm infant pupil, especially if the pupil is difficult to dilate.

Predictive factors in the treatment of streptococcal endophthalmitis

Objective To evaluate visual outcomes and possible predictive factors in the treatment of infectious endophthalmitis caused by Streptococcus species during 2012–2016 at a large referral eye center in northeastern Thailand. Methods A retrospective medical record chart review of patients with culture-positive endophthalmitis caused by Streptococcus species was conducted. Demographic data including age, gender, occupation, duration of symptoms, time to surgery, surgical procedures, initial visual acuity at presentation, and final visual acuity after treatment were collected and analyzed. Possible predictive factors associated with improved visual outcomes were also studied. Results Forty-five eyes of 45 patients were recruited for the study. The 3 most common types of endophthalmitis were postoperative (35.56%), posttraumatic (20%), and endogenous (15.56%). At presentation, most patients (95.56%) had visual acuity of hand motion (55.56%), light perception (28.89%), or no light perception (11.11%). The 3 most common isolates were Streptococcus pneumoniae (44.44%), Group B β-hemolytic Streptococcus (26.68%), and Streptococcus viridans (20%). Most patients (62.22%) were treated with surgical interventions, either pars plana vitrectomy with intravitreal antibiotics or pars plana vitrectomy with intravitreal antibiotics and silicone oil tamponade. After treatment, improved visual outcome was noted in only 9 patients (20%), and no visual improvement was seen in 36 patients (80%). Evisceration and enucleation were performed in 15 patients (33.33%). The only possible predictive factor associated with improved visual outcomes was early vitrectomy, performed within 3 days. Conclusion Streptococcal endophthalmitis is often associated with poor visual prognosis. Only 9 patients (20%) had improved vision after treatment. The only possible predictive factor associated with improved visual outcomes was vitrectomy within 3 days. Early diagnosis and early vitrectomy are therefore recommended.