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1.
Indian J Ophthalmol ; 72(4): 526-532, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38454845

RESUMEN

PURPOSE: This study sought to identify the sources of differential performance and misclassification error among local (Indian) and external (non-Indian) corneal specialists in identifying bacterial and fungal keratitis based on corneal photography. METHODS: This study is a secondary analysis of survey data assessing the ability of corneal specialists to identify acute bacterial versus fungal keratitis by using corneal photography. One-hundred images of 100 eyes from 100 patients with acute bacterial or fungal keratitis in South India were previously presented to an international cohort of cornea specialists for interpretation over the span of April to July 2021. Each expert provided a predicted probability that the ulcer was either bacterial or fungal. Using these data, we performed multivariable linear regression to identify factors predictive of expert performance, accounting for primary practice location and surrogate measures to infer local fungal ulcer prevalence, including locality, latitude, and dew point. In addition, Brier score decomposition was used to determine experts' reliability ("calibration") and resolution ("boldness") and were compared between local (Indian) and external (non-Indian) experts. RESULTS: Sixty-six experts from 16 countries participated. Indian practice location was the only independently significant predictor of performance in multivariable linear regression. Resolution among Indian experts was significantly better (0.08) than among non-Indian experts (0.01; P < 0.001), indicating greater confidence in their predictions. There was no significant difference in reliability between the two groups ( P = 0.40). CONCLUSION: Local cornea experts outperformed their international counterparts independent of regional variability in tropical risk factors for fungal keratitis. This may be explained by regional characteristics of infectious ulcers with which local corneal specialists are familiar.


Asunto(s)
Úlcera de la Córnea , Infecciones Bacterianas del Ojo , Infecciones Fúngicas del Ojo , Humanos , Úlcera de la Córnea/diagnóstico , Úlcera de la Córnea/epidemiología , Úlcera de la Córnea/complicaciones , Úlcera , Reproducibilidad de los Resultados , Infecciones Bacterianas del Ojo/diagnóstico , Infecciones Bacterianas del Ojo/epidemiología , Infecciones Bacterianas del Ojo/etiología , Bacterias , Infecciones Fúngicas del Ojo/diagnóstico , Infecciones Fúngicas del Ojo/epidemiología , Infecciones Fúngicas del Ojo/etiología , India/epidemiología
2.
Eye (Lond) ; 38(5): 945-950, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37949975

RESUMEN

BACKGROUND: South Asia is experiencing rapid urbanization, which may be changing the risk factor profile for ocular trauma. The objective of this study was to compare risk factors for traumatic corneal abrasions in rural versus urban Nepal, and to assess if any risk factors were associated with a poor outcome. METHODS: In a prospective, cross-sectional, community-based study performed as part of a cluster-randomized trial, community health workers from Nepal were trained to diagnose and treat traumatic corneal abrasions. Participants with an abrasion were invited to complete a risk factor survey. The main exposure variable was the object of eye injury, stratified by rural-urban residence. The main outcome measure was a lack of corneal healing after a three-day course of antimicrobials. RESULTS: Of 3657 participants diagnosed with a corneal abrasion, 2265 completed a survey. Eye trauma occurred most frequently during agricultural activities. The most common object of injury was vegetative matter, accounting for approximately 40% of injuries in rural, peri-urban, and urban communities. Wood injuries were more common in rural communities (24%) compared with urban or peri-urban communities (13%). Eye injury from an animal was more likely to result in a non-healing corneal abrasion after 3 days of treatment compared with other types of trauma (prevalence ratio 2.59, 95%CI 1.16-5.76). CONCLUSIONS: Health promotion activities for prevention of corneal ulcers in Nepal should focus on agricultural trauma in both rural and urban areas. Community members experiencing eye trauma from an animal may benefit from early referral to an eye clinic.


Asunto(s)
Lesiones de la Cornea , Humanos , Estudios Transversales , Nepal , Estudios Prospectivos , Factores de Riesgo
3.
Cornea ; 43(2): 166-171, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-37335849

RESUMEN

PURPOSE: The aim of this study was to validate the C-DU(KE) calculator as a predictor of treatment outcomes on a data set derived from patients with culture-positive ulcers. METHODS: C-DU(KE) criteria were compiled from a data set consisting of 1063 cases of infectious keratitis from the Steroids for Corneal Ulcer Trial (SCUT) and Mycotic Ulcer Treatment Trial (MUTT) studies. These criteria include corticosteroid use after symptoms, visual acuity, ulcer area, fungal etiology, and elapsed time to organism-sensitive therapy. Univariate analysis was performed followed by multivariable logistic regressions on culture-exclusive and culture-inclusive models to assess for associations between the variables and outcome. The predictive probability of treatment failure, defined as the need for surgical intervention, was calculated for each study participant. Discrimination was assessed using the area under the curve for each model. RESULTS: Overall, 17.9% of SCUT/MUTT participants required surgical intervention. Univariate analysis showed that decreased visual acuity, larger ulcer area, and fungal etiology had a significant association with failed medical management. The other 2 criteria did not. In the culture-exclusive model, 2 of 3 criteria, decreased vision [odds ratio (OR) = 3.13, P < 0.001] and increased ulcer area (OR = 1.03, P < 0.001), affected outcomes. In the culture-inclusive model, 3 of 5 criteria, decreased vision (OR = 4.9, P < 0.001), ulcer area (OR = 1.02, P < 0.001), and fungal etiology (OR = 9.8, P < 0.001), affected results. The area under the curves were 0.784 for the culture-exclusive model and 0.846 for the culture-inclusive model which were comparable to the original study. CONCLUSIONS: The C-DU(KE) calculator is generalizable to a study population from large international studies primarily taking place in India. These results support its use as a risk stratification tool assisting ophthalmologists in patient management.


Asunto(s)
Úlcera de la Córnea , Infecciones Fúngicas del Ojo , Micosis , Humanos , Antifúngicos/uso terapéutico , Úlcera de la Córnea/diagnóstico , Úlcera de la Córnea/tratamiento farmacológico , Úlcera de la Córnea/microbiología , Infecciones Fúngicas del Ojo/diagnóstico , Infecciones Fúngicas del Ojo/tratamiento farmacológico , Infecciones Fúngicas del Ojo/microbiología , Micosis/microbiología , Esteroides , Úlcera/tratamiento farmacológico , Ensayos Clínicos como Asunto
4.
Cornea Open ; 2(3)2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38076595

RESUMEN

Purpose: To evaluate the diagnostic accuracy of smartphone corneal photography in detecting corneal opacities in a community-based setting. Methods: A case-control, diagnostic accuracy study was nested in a cluster-randomized trial of a corneal ulcer prevention intervention in Nepal. Smartphone corneal photography was performed annually on community members self-reporting a potential risk factor for a corneal infection. Corneal photographs were graded for the presence or absence of an opacity. All cases with an opacity on smartphone photography and an equal number of controls were invited for a comprehensive eye examination with a slit lamp biomicroscope at an eye hospital. A mobile team visited participants unable to come to the hospital, conducting a limited examination with a penlight. Results: Of 1332 study participants (666 cases and 666 controls), 1097 had a penlight examination (535 cases and 562 controls) and 191 had a slit lamp examination (120 cases and 71 controls). When penlight examination was considered the reference standard, smartphone diagnosis of a corneal opacity had a positive predictive value (PPV) of 47% (95% confidence interval 43-52%) and negative predictive value (NPV) of 95% (93-97%). When slit lamp examination was considered the reference standard, the overall PPV and NPV were 71% (62-78%) and 80% (70-88%), respectively. The NPV was greater for detection of opacities > 1mm, estimated at 95% (90-98%). Conclusions: Corneal photography performed in a resource-limited community-based setting using a smartphone coupled to an external attachment had acceptable diagnostic accuracy for detection of corneal opacities large enough to be clinically meaningful.

5.
Indian J Ophthalmol ; 71(9): 3132-3141, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37602599

RESUMEN

Corneal blindness ranks third among the causes of blindness worldwide, after cataract and glaucoma. Corneal transplantation offers us a means to address this, and is currently the most commonly performed transplantation procedure worldwide - restoring the gift of sight to many an eye. Eye banks play a very important role in these procedures. India was quick to develop its own eye bank in 1945 soon after the launch of world's first eye bank in 1944. The evolution over the past six decades has been tremendous, placing India on the top, with one of the largest eye-banking system in the world. As of 2023, around 740 members are registered under the Eye Bank Association of India. The highest-ever collection of 71,700 donor eyes was achieved in 2017-2018. The overall tissue utilisation rate ranged between 22 - 28 % for voluntary donations and 50% for hospital-based corneal retrieval programs. Though India has an excellent infrastructure and readiness for corneal transplantation surgery, the need of the hour is to create a strong and independent nodal system. It shall take care of the logistics and factor in technological advances - surgical and otherwise. Public awareness, a national corneal grid, and reducing the red-tape barriers, shall improve availability of grafts nationwide. This review aims to detail the evolution of eye banking in India, to provide a comprehensive understanding, and help the stakeholders focus on the road ahead to attain our targets faster.


Asunto(s)
Trasplante de Córnea , Bancos de Ojos , Humanos , India/epidemiología , Córnea , Ceguera
6.
Br J Ophthalmol ; 107(12): 1771-1775, 2023 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-36202599

RESUMEN

BACKGROUND/AIMS: We aimed to examine risk factors for corneal ulcer in a rural and peri-urban setting in Nepal. METHODS: This population-based matched case-control study was nested in a cluster randomised trial in 24 village development committees in Nepal. Incidence density sampling was used to match incident corneal opacity cases to controls, matching on time of opacity, age, sex and location. Cases and controls were invited to participate in a survey of risk factors for corneal ulcer. Risk factors were evaluated using conditional logistic regression to account for matching. RESULTS: Of the 540 participants with incident opacities identified in the trial, 433 were willing to participate in this substudy and matched to a control. Compared with controls, cases had lower odds of having any education vs no education (adjusted OR, aOR 0.60, 95% CI 0.39 to 0.94), working in non-manual labour occupations vs manual labour occupations (aOR 0.64, 95% CI 0.42 to 0.95) and preferring medical shops for ocular trauma versus eye care system centres (aOR 0.58, 95% CI 0.37 to 0.92). Cases had higher odds of protective goggle use versus no protection (aOR 3.8, 95% CI 1.3 to 11.0) and having an ocular injury vs none (aOR 7.7, 95% CI 4.3 to 13.6) compared with controls. CONCLUSION: We found ocular injury, manual labour and lower education to be strongly associated with the development of corneal ulcer. Given the persistent burden of corneal blindness in this area, prevention efforts could target efforts to increase access to care in areas where these factors are common.


Asunto(s)
Úlcera de la Córnea , Humanos , Úlcera de la Córnea/epidemiología , Estudios de Casos y Controles , Nepal/epidemiología , Córnea , Factores de Riesgo
7.
Ophthalmol Sci ; 2(2): 100119, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36249698

RESUMEN

Purpose: Develop computer vision models for image-based differentiation of bacterial and fungal corneal ulcers and compare their performance against human experts. Design: Cross-sectional comparison of diagnostic performance. Participants: Patients with acute, culture-proven bacterial or fungal keratitis from 4 centers in South India. Methods: Five convolutional neural networks (CNNs) were trained using images from handheld cameras collected from patients with culture-proven corneal ulcers in South India recruited as part of clinical trials conducted between 2006 and 2015. Their performance was evaluated on 2 hold-out test sets (1 single center and 1 multicenter) from South India. Twelve local expert cornea specialists performed remote interpretation of the images in the multicenter test set to enable direct comparison against CNN performance. Main Outcome Measures: Area under the receiver operating characteristic curve (AUC) individually and for each group collectively (i.e., CNN ensemble and human ensemble). Results: The best-performing CNN architecture was MobileNet, which attained an AUC of 0.86 on the single-center test set (other CNNs range, 0.68-0.84) and 0.83 on the multicenter test set (other CNNs range, 0.75-0.83). Expert human AUCs on the multicenter test set ranged from 0.42 to 0.79. The CNN ensemble achieved a statistically significantly higher AUC (0.84) than the human ensemble (0.76; P < 0.01). CNNs showed relatively higher accuracy for fungal (81%) versus bacterial (75%) ulcers, whereas humans showed relatively higher accuracy for bacterial (88%) versus fungal (56%) ulcers. An ensemble of the best-performing CNN and best-performing human achieved the highest AUC of 0.87, although this was not statistically significantly higher than the best CNN (0.83; P = 0.17) or best human (0.79; P = 0.09). Conclusions: Computer vision models achieved superhuman performance in identifying the underlying infectious cause of corneal ulcers compared with cornea specialists. The best-performing model, MobileNet, attained an AUC of 0.83 to 0.86 without any additional clinical or historical information. These findings suggest the potential for future implementation of these models to enable earlier directed antimicrobial therapy in the management of infectious keratitis, which may improve visual outcomes. Additional studies are ongoing to incorporate clinical history and expert opinion into predictive models.

8.
Am J Ophthalmol ; 243: 66-76, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35817091

RESUMEN

PURPOSE: To determine whether exposure to unclean cooking fuels was associated with subsequent cataract progression as reported in previous cross-sectional studies. DESIGN: Prospective cohort study. METHODS: This is a secondary observational analysis of the community-based Antioxidants in Prevention of Cataracts trial (ClinicalTrials.gov ID NCT01664819). The exposure of interest was cooking fuel type, measured at baseline. Main outcome measures were baseline cataract severity and self-reported cataract surgery at a 15-year visit. RESULTS: Baseline and 15-year follow-up data were available for 798 and 579 participants, respectively. Wood or kerosene was used by 711 of 798 (89.1%) baseline participants, including 539 of 579 (93.1%) participants with complete follow-up. Cooking fuel type was not associated with cataract severity at baseline (P = .443). Of 8334 person-years of follow-up, 90 cataract surgeries were observed over 15 years (1.08 surgeries per 100 person-years; 95% CI = 0.87-1.32). Use of wood or kerosene was not associated with 15-year incidence of cataract surgery relative to use of propane (adjusted P = .154). Cataract surgery was more common in older individuals (HR = 1.1 per year, 95% CI = 1.1-1.2, P < .001), those with baseline myopia (HR = 2.1, 95% CI = 1.2-3.5, P = .009), and women (HR = 3.5, 95% CI = 1.2-10.1, P = .019). CONCLUSIONS: This study found no association between unclean cooking fuels and cataract progression over a 15-year period. No other modifiable risk factors were associated with incident self-reported cataract surgery.


Asunto(s)
Extracción de Catarata , Catarata , Humanos , Femenino , Anciano , Estudios Prospectivos , Propano , Catarata/epidemiología , Catarata/etiología , Culinaria , Extracción de Catarata/efectos adversos , Factores de Riesgo
9.
Lancet Glob Health ; 10(4): e501-e509, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35303460

RESUMEN

BACKGROUND: Corneal ulcers are a common cause of blindness in low-income and middle-income countries, usually resulting from traumatic corneal abrasions during agricultural work. Antimicrobial prophylaxis of corneal abrasions can help prevent corneal ulcers, but delays in the initiation of therapy are frequent. We aimed to assess whether a community-based programme for corneal ulcer prevention would reduce the incidence of corneal ulceration. METHODS: A cluster-randomised trial was performed in village development committees (VDCs) in Nepal. VDCs in the catchment area of Bharatpur Eye Hospital, Nepal with less than 15 000 people were eligible for inclusion. We randomly assigned (1:1) VDCs to either an intervention group or a control group. In the intervention VDCs, existing female community health volunteers (FCHVs) were trained to diagnose corneal abrasions and provide a 3-day course of ophthalmic antimicrobials to their patients. In the control VDCs, FCHVs did not provide this intervention. Participants were not masked given the nature of the intervention. Both groups were followed up for 3 years for photographic evidence of corneal ulceration. The primary outcome was the incidence of corneal ulceration, determined by masked assessment of corneal photographs. The analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, NCT01969786. FINDINGS: We assessed 112 VDCs, of which 24 were enrolled. The study was performed between Feb 4, 2014, and Oct 20, 2017. 12 VDCs were randomly assigned to the intervention group and 12 to the control group. 252 539 individuals were included in the study (130 579 in the intervention group and 121 960 in the control group). FCHVs diagnosed and provided antimicrobials for 4777 corneal abrasions. The census identified 289 corneal ulcers among 246 893 person-years in the intervention group (incidence 1·21 cases [95% CI 0·85-1·74] per 1000 person-years) and 262 corneal ulcers among 239 170 person-years in the control group (incidence 1·18 cases [0·82-1·70] per 1000 person-years; incidence rate ratio 1·03 [95% CI 0·63-1·67]; p=0·93). Medication allergy was self-reported in 0·2% of participants. INTERPRETATION: We did not detect a reduction in the incidence of corneal ulceration during the first 3 years of a community-based corneal ulcer prevention programme. Further study might be warranted in more rural areas where basic eye care facilities are not available. FUNDING: National Eye Institute.


Asunto(s)
Enfermedades de los Trabajadores Agrícolas/prevención & control , Agentes Comunitarios de Salud , Lesiones de la Cornea/complicaciones , Úlcera de la Córnea/prevención & control , Enfermedades de los Trabajadores Agrícolas/epidemiología , Análisis por Conglomerados , Agentes Comunitarios de Salud/educación , Úlcera de la Córnea/epidemiología , Femenino , Humanos , Nepal/epidemiología , Voluntarios/educación
10.
PLoS One ; 17(2): e0264021, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35171970

RESUMEN

BACKGROUND: Acanthamoeba keratitis is challenging to treat and thought to result in poor outcomes, but very few comparative studies exist to assess whether ulcers caused by Acanthamoeba are worse than those caused by bacteria or fungus. METHODS: In a retrospective cohort study, all cases of smear- or culture-proven Acanthamoeba keratitis diagnosed from January 2006 to June 2011 at an eye hospital in South India were identified from the microbiology database. Random samples of the same number of cases of bacterial and fungal keratitis, matched by year, were identified from the same database in order to compare outcomes between the three types of organism. The main outcomes were the time until the following events: re-epithelialization, discontinuation of antimicrobials, perforation/keratoplasty, elevated intraocular pressure, and new cataract. RESULTS: The median time until re-epithelialization was 113 days for Acanthamoeba keratitis, 30 days for fungal keratitis, and 25 days for bacterial keratitis, and the median time until discontinuation of antimicrobial therapy was 100 days for Acanthamoeba keratitis, 49 days for fungal keratitis, and 40 days for bacterial keratitis. Compared to the other two organisms, Acanthamoeba ulcers took significantly longer to re-epithelialize (adjusted HR 0.4, 95% CI 0.3 to 0.6 relative to bacterial ulcers and HR 0.3, 95% CI 0.2 to 0.5 relative to fungal ulcers; overall p<0.001) and had significantly longer courses of antimicrobials (adjusted HR 0.3, 95% CI 0.2 to 0.6 relative to bacterial ulcers and HR 0.5, 95%CI 0.3 to 0.8 relative to fungal ulcers; overall p<0.001). No statistically significant difference was observed between the three organisms for the other time-to-event outcomes. CONCLUSIONS: Acanthamoeba keratitis was more difficult to treat and had worse clinical outcomes than bacterial or fungal ulcers, highlighting the lack of adequate treatment regimens for this infection.


Asunto(s)
Queratitis por Acanthamoeba/patología , Antiinfecciosos/uso terapéutico , Infecciones Bacterianas del Ojo/patología , Infecciones Fúngicas del Ojo/patología , Repitelización , Acanthamoeba/aislamiento & purificación , Queratitis por Acanthamoeba/tratamiento farmacológico , Queratitis por Acanthamoeba/parasitología , Adulto , Bacterias/aislamiento & purificación , Infecciones Bacterianas del Ojo/tratamiento farmacológico , Infecciones Bacterianas del Ojo/microbiología , Infecciones Fúngicas del Ojo/tratamiento farmacológico , Infecciones Fúngicas del Ojo/microbiología , Femenino , Hongos/aislamiento & purificación , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Factores de Riesgo
11.
JAMA Ophthalmol ; 140(2): 179-184, 2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-35024776

RESUMEN

IMPORTANCE: Antifungal resistance has been shown to impact treatment success, but research analyzing antifungal resistance is scarce. OBJECTIVE: To evaluate changes in antifungal resistance over time. DESIGN, SETTING, AND PARTICIPANTS: Ad hoc analysis of 3 randomized clinical trials including consecutive patients 18 years and older presenting with smear-positive fungal ulcers to Aravind Eye Hospitals in Madurai, Coimbatore, Pondicherry, and Tirunelveli in South India who participated in 1 of 3 clinical trials: the Mycotic Ulcer Treatment Trials (MUTT) I (2010 to 2011) or II (2010 to 2015) or the Cross-Linking Assisted Infection Reduction (CLAIR) trial (2016 to 2018). This post hoc analysis was designed in March 2021 and data were analyzed in May and November 2021. INTERVENTIONS: Minimum inhibitory concentration (MIC) of natamycin and voriconazole was determined from corneal cultures obtained using standardized methods outlined in the Clinical and Laboratory Standards Institute. MAIN OUTCOMES AND MEASURES: The primary outcome of this post hoc analysis was MIC of natamycin and voriconazole. RESULTS: A total of 890 fungal isolates were obtained from 651 patients (mean [SD] age, 49.6 [13.0]; 191 [43.3%] female) from 2010 to 2018. MICs were available for 522 samples in 446 patients. Fungal isolates overall demonstrated a 1.02-fold increase per year in voriconazole resistance as measured by MICs (95% CI, 1.00-1.04; P = .06). In subgroup analyses, Fusarium species demonstrated a 1.04-fold increase in voriconazole resistance per year (95% CI, 1.00-1.06; P = .01). Fungal isolates showed a 1.06-fold increase in natamycin resistance per year overall (95% CI, 1.03-1.09; P < .001). Fusarium species had a 1.06-fold increase in natamycin resistance (95% CI, 1.05-1.08; P < .001), Aspergillus had a 1.09-fold increase in resistance (95% CI, 1.05-1.15; P < .001), and other filamentous fungi had a 1.07-fold increase in resistance to natamycin per year (95% CI, 1.04-1.10; P < .001). CONCLUSIONS AND RELEVANCE: This post hoc analysis suggests that susceptibility to both natamycin and voriconazole may be decreasing over the last decade in South India. While a trend of increasing resistance could impact treatment of mycoses in general and infectious fungal keratitis in particular, further study is needed to confirm these findings and determine their generalizability to other regions of the world. TRIAL REGISTRATION: ClinicalTrials.gov Identifiers: NCT00996736 and NCT02570321.


Asunto(s)
Úlcera de la Córnea , Infecciones Fúngicas del Ojo , Fusarium , Queratitis , Micosis , Adulto , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Úlcera de la Córnea/tratamiento farmacológico , Úlcera de la Córnea/epidemiología , Úlcera de la Córnea/microbiología , Infecciones Fúngicas del Ojo/tratamiento farmacológico , Infecciones Fúngicas del Ojo/epidemiología , Infecciones Fúngicas del Ojo/microbiología , Femenino , Humanos , India/epidemiología , Queratitis/tratamiento farmacológico , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Micosis/tratamiento farmacológico , Micosis/epidemiología , Micosis/microbiología , Natamicina/farmacología , Natamicina/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como Asunto , Voriconazol/farmacología , Voriconazol/uso terapéutico
13.
Ophthalmic Epidemiol ; 29(5): 491-498, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-34607500

RESUMEN

PURPOSE: To determine if smartphone photography could be a useful adjunct to blindness prevalence surveys by providing an accurate diagnosis of corneal opacity. METHODS: A total of 174 patients with infectious keratitis who had undergone corneal culturing over the past 5 years were enrolled in a diagnostic accuracy study at an eye hospital in South India. Both eyes had an ophthalmologist-performed slit lamp examination, followed by anterior segment photography with a handheld digital single lens reflex (SLR) camera and a smartphone camera coupled to an external attachment that provided magnification and illumination. The diagnostic accuracy of photography was assessed relative to slit lamp examination. RESULTS: In total, 90 of 174 enrolled participants had a corneal opacity in the cultured eye and no opacity in the contralateral eye, and did not have a penetrating keratoplasty or missing photographs. Relative to slit lamp examination, the sensitivity of corneal opacity diagnosis was 68% (95%CI 58-77%) using the smartphone's default settings and 59% (95%CI 49-69%) using the SLR, and the specificity was 97% (95%CI 93-100%) for the smartphone and 97% (95%CI 92-100%) for the SLR. The sensitivity of smartphone-based corneal opacity diagnosis was higher for larger scars (81% for opacities 2 mm in diameter or larger), more visually significant scars (100% for eyes with visual acuity worse than 20/400), and more recent scars (85% for eyes cultured in the past 12 months). CONCLUSION: The diagnostic performance of a smartphone coupled to an external attachment, while somewhat variable, demonstrated high specificity and high sensitivity for all but the smallest opacities.


Asunto(s)
Opacidad de la Córnea , Teléfono Inteligente , Ceguera/diagnóstico , Ceguera/epidemiología , Cicatriz , Humanos , Prevalencia
14.
Ophthalmology ; 129(2): 139-146, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34352302

RESUMEN

PURPOSE: To develop and evaluate an automated, portable algorithm to differentiate active corneal ulcers from healed scars using only external photographs. DESIGN: A convolutional neural network was trained and tested using photographs of corneal ulcers and scars. PARTICIPANTS: De-identified photographs of corneal ulcers were obtained from the Steroids for Corneal Ulcers Trial (SCUT), Mycotic Ulcer Treatment Trial (MUTT), and Byers Eye Institute at Stanford University. METHODS: Photographs of corneal ulcers (n = 1313) and scars (n = 1132) from the SCUT and MUTT were used to train a convolutional neural network (CNN). The CNN was tested on 2 different patient populations from eye clinics in India (n = 200) and the Byers Eye Institute at Stanford University (n = 101). Accuracy was evaluated against gold standard clinical classifications. Feature importances for the trained model were visualized using gradient-weighted class activation mapping. MAIN OUTCOME MEASURES: Accuracy of the CNN was assessed via F1 score. The area under the receiver operating characteristic (ROC) curve (AUC) was used to measure the precision-recall trade-off. RESULTS: The CNN correctly classified 115 of 123 active ulcers and 65 of 77 scars in patients with corneal ulcer from India (F1 score, 92.0% [95% confidence interval (CI), 88.2%-95.8%]; sensitivity, 93.5% [95% CI, 89.1%-97.9%]; specificity, 84.42% [95% CI, 79.42%-89.42%]; ROC: AUC, 0.9731). The CNN correctly classified 43 of 55 active ulcers and 42 of 46 scars in patients with corneal ulcers from Northern California (F1 score, 84.3% [95% CI, 77.2%-91.4%]; sensitivity, 78.2% [95% CI, 67.3%-89.1%]; specificity, 91.3% [95% CI, 85.8%-96.8%]; ROC: AUC, 0.9474). The CNN visualizations correlated with clinically relevant features such as corneal infiltrate, hypopyon, and conjunctival injection. CONCLUSIONS: The CNN classified corneal ulcers and scars with high accuracy and generalized to patient populations outside of its training data. The CNN focused on clinically relevant features when it made a diagnosis. The CNN demonstrated potential as an inexpensive diagnostic approach that may aid triage in communities with limited access to eye care.


Asunto(s)
Cicatriz/diagnóstico por imagen , Úlcera de la Córnea/diagnóstico por imagen , Aprendizaje Profundo , Infecciones Bacterianas del Ojo/diagnóstico por imagen , Infecciones Fúngicas del Ojo/diagnóstico por imagen , Fotograbar , Cicatrización de Heridas/fisiología , Algoritmos , Área Bajo la Curva , Cicatriz/fisiopatología , Úlcera de la Córnea/clasificación , Úlcera de la Córnea/microbiología , Infecciones Bacterianas del Ojo/clasificación , Infecciones Bacterianas del Ojo/microbiología , Infecciones Fúngicas del Ojo/clasificación , Infecciones Fúngicas del Ojo/microbiología , Reacciones Falso Positivas , Humanos , Valor Predictivo de las Pruebas , Curva ROC , Estudios Retrospectivos , Sensibilidad y Especificidad , Microscopía con Lámpara de Hendidura
15.
Am J Ophthalmol ; 237: 259-266, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34942106

RESUMEN

PURPOSE: To determine whether a community health worker (CHW) program increases referrals to local eye care providers and ultimately reduces the incidence of corneal ulcers. DESIGN: Cluster-randomized trial performed from 2014 to 2017 in rural South India. METHODS: This was a community-based study that included all inhabitants of 42 rural South Indian communities. CHWs were trained to diagnose corneal abrasions and assist participants in seeking care at a local vision center. Given the nature of the intervention, the trial was not masked. The main outcome measure was incident corneal ulcer, defined as an active infiltrate or evidence of a new opacity, as assessed by means of penlight examination during an annual door-to-door census. RESULTS: Twenty-one study clusters were randomized to the CHW intervention and 21 to no intervention. Vision centers diagnosed 195 corneal abrasions from the intervention clusters during the 2-year study (rate, 223 per 100,000 person-years; 95% CI, 28-1743) and 62 from the control clusters (rate, 62 per 100,000 person-years; 95% CI, 8-496; incidence rate ratio, 3.57; 95% CI, 2.01-6.35; P < .001). The estimated incidence of corneal ulceration during the study period was 60 per 100,000 person-years (95% CI, 25-141) in the intervention group and 32 per 100,000 person-years (95% CI, 13-80) in the control group (incidence rate ratio, 1.86; 95% CI, 0.5-6.4; P = .32). CONCLUSIONS: A CHW program resulted in 3.5 times more referrals to local eye care providers for corneal abrasions, but no difference could be detected in the incidence of corneal ulceration. CHW programs provide a mechanism for increasing referrals to eye hospitals. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT02284698.


Asunto(s)
Lesiones de la Cornea , Úlcera de la Córnea , Agentes Comunitarios de Salud , Úlcera de la Córnea/diagnóstico , Úlcera de la Córnea/epidemiología , Úlcera de la Córnea/prevención & control , Humanos , India/epidemiología , Población Rural
16.
Cornea ; 40(7): 921-925, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33591031

RESUMEN

PURPOSE: To report a case of late spontaneous detachment of Descemet membrane (DM) in a donor penetrating keratoplasty (PKP) graft and its successful management using a supra-Descemetic venting incision combined with gas descemetopexy. METHODS: Case report with review of literature. RESULTS: A 56-year-old man who had undergone PKP after acute hydrops in pellucid marginal degeneration 27 years before presentation experienced sudden onset vision loss. Clinical features mimicked acute graft rejection but detailed evaluation and anterior segment optical coherence tomography showed a DM detachment (DMD) of the graft. Ten weeks after the onset of DMD, he underwent descemetopexy with a supra-Descemetic stromal venting incision and sulfur hexafluoride gas tamponade. DM reattached with complete resolution of graft edema. CONCLUSIONS: Late spontaneous DMD of the graft after PKP is very uncommon and must be differentiated from acute graft rejection. Anterior segment optical coherence tomography may help to diagnose this entity that can be managed successfully despite late intervention. The addition of a venting incision that drains fluid from the supra-Descemetic space can increase the chance of success of descemetopexy when compared with descemetopexy with air or gas alone.


Asunto(s)
Lámina Limitante Posterior/cirugía , Queratoplastia Penetrante , Procedimientos Quirúrgicos Oftalmológicos , Dehiscencia de la Herida Operatoria/cirugía , Distrofias Hereditarias de la Córnea/cirugía , Humanos , Masculino , Persona de Mediana Edad , Tomografía de Coherencia Óptica , Agudeza Visual
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