Clinical Correlation of Retinal Fluid Fluctuation Represented by Fluctuation Index in Wet Age-Related Macular Degeneration: TOWER Study Report 2.

Purpose: To explore outcomes and biomarkers associated with retinal fluid instability represented by a new parameter in neovascular age-related macular degeneration (nAMD). Methods: Patients with treatment-naïve nAMD receiving anti-vascular endothelial growth factor (VEGF) injections for a duration of 1 to 3 years were consecutively reviewed. Fluctuation Index (FI) of each eye, calculated by averaging the sum of differences in 1-mm central subfield thickness between each follow-up from months 3 to 24, was arranged into ascending order from the lowest to the highest and split equally into low, moderate, and high fluctuation groups. Outcomes were analyzed at 24 months. Results: Of 558 eyes, FI values showed a negative correlation with a degree-response gradient with 24-month visual improvement. After controlling for baseline best-corrected visual acuity and potential confounders, eyes with low fluctuation gained more Early Treatment Diabetic Retinopathy Study letters than those in the moderate and high fluctuation group (Δ, 10.1 and 14.0 letters, respectively). Significant best-corrected visual acuity improvement from baseline to month 24 (11.8 letters) was observed exclusively in the low fluctuation group despite the indifference in the number of injections and types of anti-VEGF drug used among groups. Patients presenting with central subfield thickness of ≥405 µm or intraretinal fluid coinciding with subretinal fluid showed a significant association with foveal thickness instability during the maintenance phase. Conclusions: Apart from the central subfield thickness values, unstable macular thickening represented by the FI was associated with some baseline features and may contribute to substandard visual outcomes. Translational Relevance: FI may be a valuable tool for assessing therapeutic adequacy in the treatment of nAMD.

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.

Treatment Outcome of Wet Age-Related Macular Degeneration Management in Thailand: A Retrospective Real-World Study (TOWER Study).

INTRODUCTION: To present real-world outcomes of neovascular age-related macular degeneration (nAMD) management in Thailand. METHODS: This multicenter retrospective study reviewed medical records of naive nAMD patients diagnosed from 1 January 2016 until 31 December 2018. The patients received at least one intravitreal anti-vascular endothelial growth factor (VEGF) treatment and had captured visual acuity (VA) at baseline and at month 12. Treatment outcomes were assessed at month 12, 24, and 36. The primary outcome was a mean change in VA from baseline to month 12. RESULTS: Five hundred seventy-two (572) eyes were included in this study and of these eyes, 222 and 96 had 2- and 3-year follow-up periods, respectively. At month 12, the mean improvement of VA (ETDRS letter) was six letters (P < 0.0001), and central retinal thickness (CRT) decreased on average by 104 microns (P < 0.0001). However, visual improvement by 0.1 letters at month 36 did not show statistical significance. The presence of fluid was found in approximately half of patients throughout the study period (45.98%, 48.85%, and 50.91% at month 12, 24, and 36, respectively). Mean number of injections (SD) was 6.06 (3.00), 3.44 (2.94), and 2.71 (3.07) for years 1, 2, and 3, respectively. The mean number of visits (SD) in year 1 was 9.01 (2.60) and declined to 5.67 (2.69) in year 2 and 4.93 (2.49) in year 3. Patients who had an average injection interval of ≤ 8 weeks were 74.46% in year 1, 51.28% in year 2, and 45.24 in year 3; 35.31% of patients were lost to follow-up. CONCLUSIONS: This analysis reflects real-world nAMD management with significant improvement of outcomes. At the same time, the study reveals unmet needs in anti-VEGF therapy in nAMD including persistent disease activities, inadequacy of available treatment, and lack of treatment adherence leading to visual deterioration in the long-term.

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.

Unusual non-nanophthalmic uveal effusion syndrome with histologically normal scleral architecture: a case report.

BACKGROUND: To report an unusual case of non-nanophthalmic uveal effusion syndrome (UES) with histologically normal sclera but responsive to scleral resection. CASE PRESENTATION: A73-year-old man presented with a bullous retinal detachment without ciliochoroidal detachment on funduscopic examination of the right eye. The axial length of both eyes was normal. Extensive investigations for possible causes of exudative retinal detachment were performed with unremarkable results except for choroidal hyperpermeability on indocyanine green angiography (ICGA). Ultrasound biomicroscopy (UBM) revealed scleral thickening with peripheral choroidal elevation leading to the diagnosis of UES. Partial thickness sclerectomy and sclerotomy was performed resulting in complete retinal reattachment, reduction of choroidal hyperpermeability on ICGA and improvement of visual acuity. However, histological studies of the excised sclera revealed no scleral architectural changes or abnormal deposits. CONCLUSIONS: The diagnosis of UES in non-nanophthalmic eyes is challenging. Thorough systemic and ocular investigations are critical to rule out other etiologies. UBM can be helpful to evaluate scleral thickness and anterior choroid in equivocal cases. Our case was unique in that, although the sclera was thick, no abnormal microscopic scleral architecture could be identified. Misdiagnosis may lead to different surgical procedures such as vitrectomy resulting in unfavorable outcomes.

A real-world study of effectiveness of intravitreal bevacizumab and ranibizumab injection for treating retinal diseases in Thailand.

BACKGROUND: To evaluate the effectiveness of intravitreal bevacizumab (IVB) and intravitreal ranibizumab (IVR) in actual practice for treating patients with retinal diseases in Thailand. METHODS: A prospective, multi-centre, observational study was conducted among eight hospitals in their ophthalmology outpatient departments. Participants consisted of patients who had previously not received any IVB or IVR treatment between 2013 and 2014. The primary outcome measurement was the change in best-corrected visual acuity (BCVA) at the end of the follow-up period compared to baseline. RESULTS: There were 1629 treatment-naïve patients for the pro re nata (PRN) treatment pattern and 226 treatment-naive patients for the three-injections (3Inj) treatment pattern. BCVA improvements were found in 35% of the PRN group and 47% of the 3Inj group; however, it was not clinically meaningful between the IVB and IVR groups (P-value = 0.568 for PRN, P-value = 0.103 for 3Inj). A multivariable logistic regression (using the propensity score) showed that positive factors associated with vision improvement for the PRN pattern were the number of drug injections, having retinal vein occlusion, and under 60 years of age, while good BCVA at baseline was a negative predictive factor. For the 3Inj pattern, under 60 years of age and baseline BCVA were statistically significant predictors. Nonetheless, diabetes mellitus (DM) without other comorbidities was a statistically significant predictor of low response to vision improvement compared to DM with other comorbidities. CONCLUSIONS: This study was the first observational, prospective study to evaluate the real-life effectiveness of IVB and IVR in Thailand. The majority of participants who used IVB or IVR showed improvements in BCVA after treatment. Further evaluation such as long-term follow-ups and subsequent comparison of effectiveness between IVB and IVR should be investigated due to the limited sample of IVR patients. TRIAL REGISTRATION: Thai Clinical Trial Registry TCTR20141002001 . Registered 02 October 2014 (retrospectively registered).

Idiopathic polypoidal choroidal vasculopathy in Thai patients with clinical and angiographic choroidal neovascularization.

OBJECTIVE: This study aimed to study the prevalence and characteristics of idiopathic polypoidal choroidal vasculopathy (IPCV) in Thai patients with clinical and angiographic choroidal neovascularization (CNV). PATIENTS AND METHODS: A consecutive case study of 140 patients presenting with CNV was conducted in nine large referral eye centers throughout Thailand. The demographic data, fundus photographs, fundus fluorescein angiography and indocyanine green angiography of the patients were analyzed. RESULTS: Of 129 patients with clinical and angiographic CNV, IPCV was diagnosed in 100 patients (77.52%), idiopathic CNVs in 16 patients (12.40%) and age-related macular degeneration (AMD) in 12 patients (9.30%). Of the 107 eyes with IPCV, 90 eyes (84.11%) had both branching venous networks (BVNs) and polypoidal lesions. Most IPCV patients (93%) had unilateral involvement and were at a younger age than AMD patients. In all, 79 eyes (73.83%) had lesions found in the macular area, 14 eyes (13.08%) in the temporal to vascular arcades, ten eyes (9.35%) in the peripapillary area and four eyes (3.74%) in both macular and peripapillary areas. The clinical manifestations of IPCV at presentation were categorized into two patterns. There were 95 eyes (88.79%) of a hemorrhagic pattern and 12 eyes (11.21%) of an exudative pattern. CONCLUSION: IPCV is the most common macular disease in Thai patients with CNV. Most IPCVs have both BVNs and polypoidal lesions located in the macular area and present with a hemorrhagic pattern.

Treatment outcomes of reduced-dose intravitreal ganciclovir for cytomegalovirus retinitis.

BACKGROUND: Cytomegalovirus retinitis (CMVR) is one of the most common opportunistic infection in immunocompromised individuals. Intravitreal ganciclovir injection has been used successfully but no standard regimen was established. Risks of drug toxicity, endophthalmitis, and injection-related complications increased with number and frequency of injection. The aim of this study is to evaluate the outcomes of reduced-dose intravitreal ganciclovir (2 mg/0.04 mL) for the treatment of CMVR. METHODS: A prospective observational cohort study involving 67 eyes of 49 patients with CMVR was performed. Induction therapy involved intravenous ganciclovir (10 mg/kg/day) for 2 weeks unless contraindicated or patients refused. Patients were then treated with reduced-dose intravitreal ganciclovir every week for 4 weeks, and then every other week until the lesion healed. The patients' demographic data were recorded, and vision parameters were examined every visit. RESULTS: Twenty eyes (29.9 %) presented with initial visual acuities less than 6/60. The majority of patients were diagnosed with CMVR in zones 1 or 2 (63 eyes, 94 %), and, at least, one quadrant of the retina was involved (56 eyes, 83.6 %). Forty-one eyes (61.2 %) completely resolved after treatment within the 6-month follow-up. There was no significant difference in healing time, whether or not patients received induction treatment with intravenous ganciclovir (111.00 ± 12.96 vs 105.00 ± 28.32 days, p = 0.8). Five eyes (12.2 %) of patients with healed CMVR had visual acuities less than 6/60. CONCLUSIONS: Reduced-dose intravitreal ganciclovir is a safe and effective treatment option. It provides comparable results to other weekly regimens. Induction with intravenous ganciclovir is not crucial in a resolution of retinitis, although it may be necessary to reduce systemic cytomegalovirus loads and mortality rates. TRIAL REGISTRATION: The trial was registered with Thai Clinical Trials Registry (TCTR) on 16 March 2016 - TCTR20160316001 .

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.

Optic atrophy after anti-vascular endothelial growth factor injection in diabetic patients with proliferative diabetic retinopathy.

OBJECTIVE: To study the prevalence of optic atrophy in patients with proliferative diabetic retinopathy (PDR) who underwent intravitreal bevacizumab injection and risk factors associated with optic atrophy. MATERIAL AND METHOD: A retrospective case control study enrolled 269 cases (394 eyes) of patients with PDR, in which 166 cases (219 eyes) received intravitreal bevacizumab injection. Associated factors such as type of DM, hemoglobin A1c level, hypertension, hypercholesterolemia, chronic kidney disease, previous intravitreal surgery retinal detachment, and vitreous hemorrhage were recorded. Criteria for diagnosis of optic atrophy were decreased visual acuity, pale optic disc and decreased nerve fiber layer thickness, which was measured by Stratus optical coherence tomography (OCT). The association between intravitreal bevacizumab injection and optic atrophy was analyzed by multiple logistic regression. RESULTS: Two hundred sixty nine patients with PDR, consisting of 166 patients with intravitreal bevacizumab injection and 103 cases without bevacizumab injection. Optic atrophy was found in 11.4% (25/219 eyes) and 8% (14/175 eyes) respectively. There was no evidence that intravitreal bevacizumab injection and associated systemic diseases were related to optic atrophy. The risk factor that was related to optic atrophy was previous intravitreal surgery (adjusted odds ratio (OR), 2.57 [95% CI, 1.13, 5.84], p = 0.024). CONCLUSION: Anti-VEGF (bevacizumab) does not increase the risk of optic atrophy. The ophthalmologists should be aware of subsequent optic atrophy development in patients with PDR who undergo surgical intervention.

Ocular biocompatibility and structural integrity of micro- and nanostructured poly(caprolactone) films.

The identification of biomaterials that are well tolerated in the eye is important for the development of new ocular drug delivery devices and implants, and the application of micro- and nanoengineered devices to biomedical treatments is predicated on the long-term preservation within the target organ or tissue of the very small functional design elements. This study assesses the ocular tolerance and durability of micro- and nanostructured biopolymer thin films injected or implanted into the rabbit eye. Structured poly(caprolactone) (PCL) thin films were placed in adult rabbit eyes for survival studies, with serial ophthalmic examinations over 6 months. Morphologic abnormalities and device/tissue reactions were evaluated by histologic studies, and scanning electron microscopy (SEM) of films was used to determine the structural integrity. Structured PCL thin films (20- to 40-µm thick) were constructed to design specifications with 50-µm linear microgrooves or arrays of nanopores with ~30-nm diameters. After up to 9 months of ocular residency, SEM on devices retrieved from the eye showed preservation of micro- and nanostructural features. In ocular safety evaluations carried out over 6 months, serial examinations in 18 implanted eyes showed no evidence of chronic inflammation, cataractogenesis, or retinal toxicity. Postoperative ocular inflammation was seen in 67% of eyes for 1 week, and persistent corneal edema occurred in 1 eye. Histology revealed no ocular inflammation or morphologic abnormalities of ocular tissues. Thin-film/tissue responses such as cellular reaction, fibrosis, or surface biodeposits were not seen. Micro- and nanostructured PCL thin films exhibited acceptable ocular tolerance and maintained the structural integrity of design features while residing in the eye. Thin-film micro- and nanostructured PCL appears to be a feasible biomaterial for intraocular therapeutic applications.

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.

Bleb-associated infections after intravitreal injection.

PURPOSE: The purpose of this study was to describe two cases of bleb-associated infections after intravitreal injection. METHODS: Case reports of two patients. Case 1: A 41-year-old man with choroidal neovascular membrane received intravitreal injections of ranibizumab. Case 2: A 56-year-old man with cystoid macular edema after retinal detachment surgery received intravitreal triamcinolone acetonide. RESULTS: In Case 1, the patient developed a culture-negative blebitis 3 days after intravitreal ranibizumab and was treated with intravitreal, subconjunctival, and oral antibiotics. The infection resolved after 3 weeks, with stable 20/100 vision and preservation of bleb function. In Case 2, a bleb-associated endophthalmitis (positive for Streptococcus pneumoniae) occurred 3 weeks after intravitreal triamcinolone acetonide, requiring repeated intravitreal antibiotics and two vitrectomy procedures to control the infection, with final vision of hand motions. CONCLUSION: Bleb-associated infections can be a complication of intravitreal injection. The potentially severe results of bleb-associated endophthalmitis warrant monitoring in patients with previous trabeculectomy who undergo intravitreal injection therapies.

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.

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.

Corneal lattice dystrophy, a concealed ophthalmic problem in Thailand.

One single family of corneal lattice dystrophy was examined and interviewed to elucidate the variety of clinical manifestations, factors associated with visual impairment, and the impact on the patient's quality of life. Forty-three out of 88 family members (48.9%) were affected. The inheritance pattern was autosomal dominant. Corneal haze grading from 1 to 4 was 5.3 per cent, 26.3 per cent, 43.4 per cent, and 25 per cent respectively. Surface irregularity grading from 1 to 4 was 18.4 per cent, 39.5 per cent, 32.9 per cent, and 9.2 per cent respectively. Forty-five per cent of the patients had VA < or = 20/200. Corneal haziness, irregularity, corneal erosion and disease duration were significantly related to visual impairment (p < 0.05). This disturbed the patient's activities such as reading (79.1%), working (62.8%) and daily life (69.8%). Corneal lattice dystrophy within the same family may present with different manifestations depending on the severity and duration of the disease and might be misdiagnosed. Inadequate knowledge among patients was susceptible to the high prevalence of the disease leading to impaired quality of life.