Klebsiella pneumoniae Endophthalmitis with Subretinal Abscess: A Case Series and Review of the Literature.

This study assessed prognostic factors and the role of vitrectomy in patients with subretinal abscesses secondary to K. pneumoniae endophthalmitis. We reviewed published studies, including three cases from our cohort. Among 50 eyes, 26 had poor visual outcomes (final visual acuity <20/800, eyeball removal, or phthisis bulbi). Poor outcomes correlated with delayed ocular symptom-to-diagnosis time, initial visual acuity <20/800, severe vitritis, and macular involvement of abscesses (p < 0.001, p = 0.008, p < 0.001, and p = 0.033, respectively). Vitrectomy had a trend towards reducing eyeball removal and phthisis bulbi rates compared with non-vitrectomy (10.8% vs 30.8%, p = 0.181). However, the final visual acuity was not different and the rate of retinal detachment tended to be higher in vitrectomized eyes (45.9% vs 15.4%, p = 0.095). The study suggested that vitrectomy and drainage of K. pneumoniae subretinal abscesses could be avoided in patients with a mild degree of vitritis.

Subretinal gnathostomiasis: A successful focal laser photocoagulation for a living parasite.

PURPOSE: To report a case of subretinal gnathostomiasis presenting with progressive subretinal tracts of a living parasite and successfully treated with focal laser photocoagulation. METHOD: Observational case report. PATIENT: A 29-year-old Thai male complained of blurred vision and floaters in his left eye for two weeks. An ocular examination showed multiple, whitish, subretinal tracks at the superotemporal retina. After 5 days of oral albendazole, a moving parasite was confirmed by multimodal retinal imaging. An immunoblotting analysis was positive for Gnathostoma species. RESULT: The patient was treated by laser photocoagulation with frequency-doubled Nd:YAG laser around and over the parasite. Oral albendozole was continued and naproxen was prescribed for four weeks. His vision improved to 20/20 and the inflammation subsided completely within three months. The patient has been followed for five years without local and systemic complications. CONCLUSIONS: Focal laser photocoagulation without systemic steroids could be a successful treatment for active subretinal gnathostomiasis with a satisfactory safety profile in a long-term follow-up.

In-Person Verification of Deep Learning Algorithm for Diabetic Retinopathy Screening Using Different Techniques Across Fundus Image Devices.

Purpose: To evaluate the clinical performance of an automated diabetic retinopathy (DR) screening model to detect referable cases at Siriraj Hospital, Bangkok, Thailand. Methods: A retrospective review of two sets of fundus photographs (Eidon and Nidek) was undertaken. The images were classified by DR staging prior to the development of a DR screening model. In a prospective cross-sectional enrollment of patients with diabetes, automated detection of referable DR was compared with the results of the gold standard, a dilated fundus examination. Results: The study analyzed 2533 Nidek fundus images and 1989 Eidon images. The sensitivities calculated for the Nidek and Eidon images were 0.93 and 0.88 and the specificities were 0.91 and 0.85, respectively. In a clinical verification phase using 982 Nidek and 674 Eidon photographs, the calculated sensitivities and specificities were 0.86 and 0.92 for Nidek along with 0.92 and 0.84 for Eidon, respectively. The 60°-field images from the Eidon yielded a more desirable performance in differentiating referable DR than did the corresponding images from the Nidek. Conclusions: A conventional fundus examination requires intense healthcare resources. It is time consuming and possibly leads to unavoidable human errors. The deep learning algorithm for the detection of referable DR exhibited a favorable performance and is a promising alternative for DR screening. However, variations in the color and pixels of photographs can cause differences in sensitivity and specificity. The image angle and poor quality of fundus photographs were the main limitations of the automated method. Translational Relevance: The deep learning algorithm, developed from basic research of image processing, was applied to detect referable DR in a real-word clinical care setting.

Extralesional microvascular and structural macular abnormalities in cytomegalovirus retinitis.

To evaluate extralesional microvascular and structural changes of the macula using optical coherence tomography angiography (OCTA) and structural OCT in cytomegalovirus retinitis (CMVR). An observational study of CMVR patients were performed. Complete ophthalmic examination, serial color fundus photography, structural OCT and OCTA were performed at baseline and follow-up visits for up to 12 months. The structural OCT was analyzed to evaluate macular areas within, bordering and beyond the CMVR lesions. Extralesional retinal capillary plexus of the macula were evaluated by OCT angiography and compared with the unaffected fellow eyes. Thirteen eyes from 13 patients were enrolled. At baseline, macular areas without CMVR lesions showed decreased vessel density (VD) of both the superficial (P = 0.0002) and deep (P < 0.0001) retinal capillary plexus in eyes with CMVR as compared with the corresponding macular areas of the unaffected fellow eyes. The decrease of VD persisted through the follow-up period for up to 12 months after adjusting for degree of vitreous haze. Structural macular OCT characteristics at the borders and beyond the lesions included intraretinal hyperreflective dots, cystoid macular edema, subretinal fluid and selective ellipsoid zone (EZ) loss. The selective EZ loss found in 6 of 12 eyes showed recovery in 4 eyes after receiving anti-viral treatment. In CMVR eyes, there were microvascular and microstructural abnormalities in the macular area without clinically visible CMVR lesions. Our results provided interesting insights into CMV infection of the retina.

Enhanced depth imaging spectral-domain optical coherence tomography of the choroid in Thai population.

OBJECTIVE: To examine subfoveal choroidal thickness (SFCT) in Thai population using enhanced depth imaging spectral- domain optical coherence tomography (EDI-OCT) and to study its correlation with foveal retinal pigment epithelium thickness (FRPE), central neurosensory retinal thickness (CNRT), age, and refraction. MATERIAL AND METHOD: Four hundred eighty eyes from 240 subjects without glaucoma, retinal, or choroidal diseases underwent scanning of the retina and choroid using EDI-OCT SFCT FRPE, and CNRT measurements were based on the 1:1 micron images and wereperformed by two independent observers. The reliability ofmeasurements between the observers was evaluated by intraclass correlation coefficient (ICC). The correlations of SFCT with FRPE, CNRT, age, and refractive error were analyzed RESULTS: The mean age of the subjects was 36.22 years (range 20-81years). The means (95% reference intervals) of SFCT, CNRT andFRPE were 294.02 µm (137.14-450.90 µm), 174.22 µm (141.82-206.62 µm), and 41.94 µm (34.65-49.23 µm), respectively. SFCT and CNRThad excellent reliability between the two observers [ICC = 0.947 (95% CI, 0.918-0.963) and 0.929 (95% CI, 0.906-0.945), respectively], while FRPE showed good reliability [ICC = 0. 729 (95% CI, 0.637-0.793)]. SFCT had a low positive correlation with FRPE (r = 0.179, p<0. 0001) but not with CNRT (p = 0.317). SFCT showed a positive correlation with refraction (r = 0.338, p<0.0001) and a negative correlation with age (r = -0.166, p<0.0001). Regression analysis suggested that the SFCT decreased by 12.23 pm per one decade oflife and by 11.42 pm per one diopter of myopia. CONCLUSION: Normal values of SFCT in Thai population were obtained SFCT significantly decreased with older age and higher myopia. SFCT was associated with FRPE, reflecting the same vascular supply of the choroid and retinal pigment epithelium. When measured with our technique based on the 1:1 micron images, the reliability ofSFCT measurement was very high despite highly morphologic inter-individual variations.

Visual outcome and prognostic factors in posterior segment intraocular foreign bodies.

OBJECTIVE: To identify the prognostic factors that predict visual outcome in eyes with penetrating ocular injuries with retained intraocular foreign bodies (IOFBs). DESIGN: Retrospective cases series MATERIAL AND METHOD: The authors reviewed the records of 228 patients who had penetrating eye injuries with retained posterior segment IOFBs managed at Siriraj Hospital between June 1995 and February 2008. One hundred and forty-one patients (61.8%) were included in the present study. Associations between final visual outcome and various pre-operative and post operative variables were statistically analyzed. RESULTS: After a mean follow-up of 10.4 +/- 7.7 months, 68 eyes (48.2%) achieved visual acuity of 6/18 or better The final visual acuity ranged between 6/24 and 6/60 in 22 eyes (15.6%) and 51 eyes (36.2%) had visual acuity less than 6/60. Final visual acuity significantly depended on initial visual acuity (p = 0.002), size of entry wound (p = 0.020), size of foreign body (p = 0.018), presence of vitreous hemorrhage (p = 0.014), retinal detachment (p = 0.026) and endophthalmitis (p < 0.0001). CONCLUSION: Visual outcome in penetrating ocular injuries with retained IOFBs was affected by initial visual acuity, size of entry wound, size of foreign body, vitreous hemorrhage, retinal detachment and endophthalmitis. These factors may be helpful for pre-operative counseling and predicting the final visual outcome.

Nonmydriatic digital retinal images for determining diabetic retinopathy.

OBJECTIVE: To evaluate the efficacy of nonmydriatic digital retinal images for determining diabetic retinopathy. MATERIAL AND METHOD: Single field 45-degree digital retinal images of 225 eyes from 142 diabetic patients were obtained with a nonmydriatic camera. The images were diagnosed and graded by a general ophthalmologist. These results were compared with clinical diagnosis obtained by retinal specialists, after examination by using biomicroscope with plus lens and indirect ophthalmoscope of the patients. International clinical diabetic retinopathy disease severity scale was used for grading diabetic retinopathy in all cases. RESULTS: Presence of diabetic retinopathy was detected in 70 eyes (31.1%). The sensitivity and specificity for determining diabetic retinopathy was 68.57% (95%CI 57.00-78.20) and 92.25% (95%CI 87.00-95.50), respectively. The positive predictive value and negative predictive value was 80.00% (95%CI 68.20-88.20) and 86.67% (95%CI 80.60-91.00). Overall accuracy was 84.89%. CONCLUSION: Single field 45-degree nonmydriatic digital retinal images were limited by fair sensitivity for determining diabetic retinopathy although overall accuracy from the present study was relatively high. Upcountry, this tool might facilitate increased access of diabetic patients for eye evaluation but cannot replace standard eye examination.

Effect of subthreshold infrared laser treatment for drusen regression on macular autofluorescence in patients with age-related macular degeneration.

BACKGROUND: Subthreshold laser therapy has been shown to cause drusen reduction. Using this method, visible laser burns are not created in the retina; presumably, the energy is absorbed by the retinal pigment epithelium (RPE) and stimulates reabsorption of drusen material, sparing photoreceptors from destruction. We hypothesized that autofluorescence (AF) changes would be visible after such treatment and might be sensitive to quantify RPE changes. METHODS: Twenty eyes of 13 patients with non-exudative age-related macular degeneration were studied. Forty-eight subthreshold infrared diode laser spots were applied as treatment to cause drusen regression. Before, immediately after, and 3 months after treatment, color fundus photography, fluorescein angiography (FA), and autofluorescence (AF) imaging were performed. Treated lesions were identified on overlay images of all three imaging methods. RESULTS: : The averaged sensitivity of AF imaging compared with FA was 29.6+/-28.7% versus 10.2+/-12.2% (P=0.008) at the immediate posttreatment time point and 43.5+/-28.7% versus 33.8+/-26.5% (P=0.043) at the 3-month posttreatment time point, respectively. Reduction of drusen at 3 months correlated with the detection sensitivity of AF imaging at the immediate posttreatment time point (P=0.022). CONCLUSION: Immediately after subthreshold laser treatment, AF imaging was more sensitive to detect RPE changes than FA. This suggests that noninvasive AF imaging may allow prediction of the effect of subthreshold laser treatment and might be used to titrate treatment dose.

Sheathotomy without separation of venule overlying arteriole at occlusion site in uncommon branch retinal vein occlusion.

Two cases of uncommon branch retinal vein occlusion (BRVO) with vein overlying artery at occlusion site that can be found in less than 1% who underwent retinal venule sheathotomy without separation of retinal vessel for decompression of BRVO were reported. Both patients had macular hemorrhage, edema, and area of macular capillary nonperfusion. Visual acuity (VA) worsened to 6/60 in both cases. The retinal venules were dissected around the crossing site without separation of retinal vessels. Intraoperative dilation, pulsation and restoration of downstream blood flow of the involved venules were observed. In the first patient, at 1 day, 2 weeks, and 6 weeks postoperatively, VA improved to 6/36, 6/9, and 6/6, respectively, and remained unchanged at 12 months postoperatively. In the second patient, VA improved to 6/24 on the first day postoperatively and improved to 6/18 at 1 week follow up and continuously improved to nearly normal at 2 months postoperatively then patient lost contact. Postoperative fundus fluorescein angiogram showed dilated and improved perfusion with decreased macular edema in both cases. Optical coherent tomography confirmed remarkable reduction of retinal thickness (from 874 microns preoperatively to 420 microns at 1 week postoperatively) in the second patient. Retinal venule sheathotomy without separation of retinal vessel for decompression of BRVO with venule overlying arteriole at occlusion site could be effective for improving VA and decreased macular edema.

Preventive versus treatment effect of AG3340, a potent matrix metalloproteinase inhibitor in a rat model of choroidal neovascularization.

PURPOSE: AG3340 (prinomastat) is a nonpeptidic, small-molecular-weight, synthetic matrix metalloproteinase inhibitor (MMPI) with selective inhibitory action of MMP-2, MMP-9, MMP-3, and MT-MMP1. We evaluated AG3340 injected intravitreally to treat choroidal neovascularization in a laser induced rat CNV model. METHODS: In the pretreatment group, the drug was injected the same day after induction of choroidal neovascularization by diode laser. In the treatment group, the drug was injected 2 weeks after induction of choroidal neovascularization (CNV). Fluorescein and indocyanine green angiography were performed to evaluate CNV. ERG recordings and histology were performed to assess toxicity and the CNV lesions. RESULTS: When used at the time of CNV induction, 62.8% of lesions in control versus 22.8% of the laser lesions in treated eyes developed CNV (p < 0.0001). The invading fibrovascular complex was thicker in the control eyes than that in the treated eyes. No signs of toxicity were detected. When used to treat established CNV, the percentage of leakage in treated and control eyes were 54.1% and 58.9% respectively (p > 0.05). Prinomastat was effective when given at the time of induction of CNV in the rat model. Administration of prinomastat 2 weeks after laser induction did not show efficacy. CONCLUSION: Prinomastat was active in the earliest stages of experimental CNV. It might be best used in combination with photodynamic therapy to inhibit recurrence of CNV from temporarily closed new vessels.

Valganciclovir therapy for immune recovery uveitis complicated by macular edema.

PURPOSE: To determine whether treatment with valganciclovir will improve visual acuity in eyes with immune recovery uveitis complicated by macular edema. DESIGN: Prospective open label controlled Phase II drug study. METHODS: Five patients with chronic macular edema as a result of immune recovery uveitis were studied. Baseline fluorescein angiograms, best-corrected ETDRS visions, and cytomegalovirus (CMV) lymphoproliferative T-cell function assays were obtained and repeated after three months of valganciclovir therapy (900 mg daily) and again three months after withdrawal of therapy. RESULTS: Vision improved by a mean of 11 letters in the treatment phase (P =.05). Graded angiograms showed three patients had treatment reduction of macular edema. One patient had rebound increase in macular edema after the withdrawal phase. The CMV lymphoproliferative response was not affected by the valganciclovir. CONCLUSION: Results suggest valganciclovir treatment may benefit visual acuity in patients with macular edema from immune recovery uveitis.

Volumetric analysis of macular edema by scanning laser tomography in immune recovery uveitis.

OBJECTIVES: To evaluate the macular volume in eyes with immune recovery uveitis (IRU) and to describe a new method to quantify macular edema with the use of confocal scanning laser tomography (cSLT). METHODS: A prospective study was performed to assess the macular volume with cSLT in patients with and without IRU. None of the patients enrolled had cytomegalovirus retinitis within 3000 micro m of the fovea. Eight eyes had healed cytomegalovirus retinitis with IRU and cystoid macular edema (group A); 4 eyes had healed cytomegalovirus retinitis with IRU and clinically normal maculas (group B); 18 eyes had no IRU (group C); and 3 eyes underwent pars plana vitrectomy and epiretinal membrane peeling for epiretinal membranes associated with cystoid macular edema and IRU (group D). Patients with IRU underwent standard clinical examinations and cSLT. On cSLT, volume above the reference plane was calculated within a fovea-centered circle of 3 mm in diameter. We devised a novel system for defining the reference plane. Measurements were performed 3 times in masked fashion and the mean was used for analyses. RESULTS: The mean macular volume was highest in group A (1.97 mm3). This was significantly higher (P<.001) than that in groups B (1.15 mm3), C (1.02 mm3), and D (0.86 mm3). CONCLUSIONS: Macular edema in patients with IRU can be consistently and objectively quantitated by cSLT. The method of defining the reference plane used in our study is novel and can be used in other disorders causing macular edema.

Ganciclovir release rates in vitreous from different formulations of 1-O-hexadecylpropanediol-3-phospho-ganciclovir.

PURPOSE: To determine the optimal formulation of lipid prodrug, 1-O-hexadecyloxypropyl-phospho-ganciclovir (HDP-P-GCV), for intravitreal delivery. METHODS: Equal concentrations of crystalline or liposomal HDP-P-GCV were exposed to rabbit whole vitreous, core vitreous, peripheral vitreous, human plasma, and heat inactivated rabbit vitreous, and the samples were incubated at 37 degrees C for one week. Aliquots were taken at day 1, 2, 3, and 7 and subjected to HPLC analysis for conversion to GCV. RESULTS: The resultant concentration of GCV from crystalline HDP-P-GCV in vitreous was 198 +/- 49 microM (n = 3) at day 1 and 1253 +/- 248 microM (n = 3) at day 7. The resultant concentration of GCV from the liposomal formulation of HDP-P-GCV in vitreous was much lower, yielding a concentration of 66 +/- 7 microM (n = 3) at day 1 and 243 +/- 39 microM (n = 3) at day 7 (P < 0.001, t Test). When the crystalline HDP-P-GCV was incubated with heat-inactivated vitreous, the detectable GCV concentrations were low (22 microM) and did not increase over time. The concentration of GCV detected from the crystalline HDP-P-GCV in the core vitreous was 19.69 +/- 3.84 microM (n = 3) at day 1 and 1537.36 +/- 177.14 microM (n = 3) at day 7. The concentration of GCV released from crystalline HDP-P-GCV in peripheral vitreous was 32.86 +/- 5.07 microM (n = 3) at day 1 and 1805.78 +/- 327.94 microM (n = 3) at day 7. Detectable GCV concentration from both core and peripheral vitreous samples increased over time, however, the magnitude of GCV release from peripheral vitreous samples was higher (P < 0.05, t Test). CONCLUSION: In vitreous, HDP-P-GCV as a crystalline formulation was converted to GCV more rapidly than liposomal formulation of HDP-P-GCV. Vitreous cells may play an important role in the metabolism of either formulation of HDP-P-GCV delivered into vitreous.

Predictors of drusen reduction after subthreshold infrared (810 nm) diode laser macular grid photocoagulation for nonexudative age-related macular degeneration.

PURPOSE: To determine the predictors of drusen reduction in eyes with nonexudative age-related macular degeneration (ARMD) treated with subthreshold infrared (810 nm) diode laser macular grid photocoagulation. Additionally, to determine the relationship of laser-induced drusen reduction and best-corrected visual acuity (BCVA) 18 months after laser treatment. DESIGN: Randomized controlled clinical trial. METHODS: Fifty patients (100 eyes) with bilateral nonexudative ARMD were enrolled at two centers. One eye of each patient was randomized to the observation; the other eye was treated with 48 subthreshold (invisible end point) applications of infrared (810 nm) diode laser in a macular grid pattern. The eyes that received subthreshold laser treatment were compared with the eyes that received no treatment. The baseline fundus characteristics (number, size, and distribution of drusen, as well as focal hyperpigmentation) from two macula areas (central 1500 micro diameter, pericentral 1500 micro ring area) on stereo color photographs, the number of laser-induced lesions, and the area of laser induced retinal pigment epithelial (RPE) lesions on fluorescein angiography 3 months after treatment were studied as predictors of major drusen reduction (> or = 50% drusen reduction from baseline) 18 months after laser treatment. BCVA at baseline and 18 months later was compared in observation eyes and in laser-treated eyes. RESULTS: Eighteen months after randomization, 24 (48%) of 50 eyes treated with subthreshold laser had major drusen reduction compared with three (6%) of 50 observation eyes (P =.00001). At 3 months post-treatment in laser-treated eyes with major drusen reduction, the mean number of laser-induced lesions on fluorescein angiography was 30.7 and the mean area of RPE change was 0.81 mm(2) compared with 14.8 laser-induced lesions and 0.35 mm(2) area of RPE change in eyes without major drusen reduction (P =.0001 and P =.0003, respectively). At baseline, fundus characteristics were not significantly different between observation eyes and laser-treated eyes or between the major drusen reduction group and the nonmajor drusen reduction group. At 18 months after treatment, BCVA was not significantly different in laser-treated eyes and in observation eyes. CONCLUSIONS: Subthreshold infrared (810 nm) diode laser macular grid photocoagulation in eyes with nonexudative ARMD significantly reduced drusen 18 months after laser treatment. Both the number of subthreshold laser lesions and the area of RPE changes visible on fluorescein angiography 3 months after treatment appeared to be predictors for major drusen reduction 18 months after treatment. However, it remains to be determined whether laser-induced drusen reduction is beneficial for visual acuity or reduces the incidence of choroidal neovascularization (CNV) in eyes with nonexudative ARMD.