Although cataract remains the leading cause of avoidable blindness in Nepal, completion of referral from peripheral Eye Care Centers (ECCs) to Bharatpur Eye Hospital (BEH) for cataract surgery remains very low, with only about 3% of referred patients attending the hospital. Poor referral completion is influenced by barriers such as long travel distances, transportation costs, inadequate counselling, fear of surgery, and limited communication between peripheral eye care providers and ophthalmologists.

This study aims to evaluate whether an enhanced tele-ophthalmology model improves cataract referral completion compared with the existing referral system. A stratified matched-cluster quasi-experimental study will be conducted in 12 satellite ECCs of Bharatpur Eye Hospital, comprising six intervention ECCs and six matched control ECCs. Adults aged 40 years or older diagnosed with visually significant cataract or other conditions requiring ophthalmological consultation will be enrolled.

Participants in intervention ECCs will receive real-time tele-ophthalmology consultation using slit lamp-mounted anterior segment cameras, allowing ophthalmologists to remotely examine patients, confirm the diagnosis, provide counselling, and support referral planning. Control ECCs will continue the existing standard referral process without real-time ophthalmologist-patient interaction.

The primary outcome is referral completion, defined as attendance at Bharatpur Eye Hospital or a designated secondary hospital within 12 weeks of referral. Secondary outcomes include patient-reported barriers to referral completion, time to hospital attendance, acceptance of tele-ophthalmology, and diagnostic confidence among ECC staff. A total of 396 participants (198 per group) will be enrolled. Referral completion rates between groups will be compared to determine whether enhanced tele-ophthalmology improves access to cataract surgical services and strengthens referral systems in rural Nepal.

Background Cataract is the leading cause of avoidable blindness worldwide, particularly in low- and middle-income countries where there is limited access to eye care. According to the World Health Organization, millions of people are visual impaired. In Nepal, cataract accounts for the majority of blindness and severe visual impairment, making timely identification, referral, and surgical treatment essential components of blindness prevention programs. Although Nepal has established an extensive network of community eye care services, many patients diagnosed with operable cataract fail to reach surgical centers after referral, resulting in preventable visual disability and reduced quality of life.

Bharatpur Eye Hospital delivers services through an integrated eye care network consisting of the base hospital, secondary hospitals, city clinics, and twenty satellite Eye Care Centers (ECCs). These peripheral ECCs serve as the first point of contact for rural populations by providing comprehensive eye examinations, refraction, and diagnosis of common ocular diseases, emergency management, and referral of patients requiring specialist ophthalmic care. Cataract patients diagnosed at ECCs are routinely referred to Bharatpur Eye Hospital or designated secondary hospitals for surgical evaluation and management.

Despite the existence of this structured referral pathway, hospital records demonstrate that referral completion among cataract patients remains extremely poor. Analysis of routine service data showed that only about three percent of patients referred from ECCs subsequently attended Bharatpur Eye Hospital for surgical assessment. This substantial loss to follow-up represents one of the major barriers to cataract blindness prevention within the existing eye care delivery system.

Several patient-related and health-system factors contribute to poor referral completion. Patients living in rural communities often experience long travelling distances, transportation difficulties, indirect costs associated with travel, loss of daily wages, fear of cataract surgery, limited awareness regarding disease progression, inadequate counselling, and uncertainty regarding the need for surgery. From the health system perspective, traditional referral mechanisms rely primarily on paper referral slips and verbal counselling without direct interaction between patients and ophthalmologists. Communication between peripheral eye care providers and specialists is often limited, reducing opportunities to reinforce diagnosis, answer patients' concerns, and strengthen confidence in recommended treatment. Consequently, many patients either postpone or completely abandon referral despite being diagnosed with operable cataract.

Tele-ophthalmology has emerged as an effective strategy for extending specialist ophthalmic services to underserved populations through the use of digital communication technologies. Tele-ophthalmology enables transmission of clinical findings, ocular images, and patient information from peripheral eye care facilities to ophthalmologists located at tertiary hospitals. Depending on available infrastructure, consultations may be conducted through asynchronous image transfer or synchronous real-time video communication. Previous studies have demonstrated that tele-ophthalmology improves diagnostic accuracy, facilitates early detection of ocular disease, strengthens communication between primary and specialist eye care providers, and enhances patient satisfaction. Evidence from India has also suggested that patients referred following tele-ophthalmology consultation are more likely to complete referral compared with those managed through conventional referral systems.

Bharatpur Eye Hospital has gradually established tele-ophthalmology services across its satellite network during the past several years. All participating ECCs currently have access to routine teleconsultation through mobile-based communication platforms for selected ophthalmic conditions. In addition, several centers have advanced tele-ophthalmology facilities incorporating slit lamp-mounted anterior segment cameras that allow ophthalmologists at the base hospital to perform real-time remote examinations while communicating directly with patients.

Objectives/hypothesis This study aims to determine whether an enhanced tele-ophthalmology referral model improves referral completion among patients with cataract compared with the existing referral practice within the Bharatpur Eye Hospital network. The primary hypothesis is that real-time tele-ophthalmology consultation involving direct interaction between ophthalmologists and patients will significantly increase the proportion of referred cataract patients attending Bharatpur Eye Hospital or designated secondary hospitals for surgical evaluation.

Study design and Methodology The study will employ a stratified matched-cluster quasi-experimental design. The sampling frame consists of all twenty satellite Eye Care Centres (ECCs) operating under Bharatpur Eye Hospital. To ensure representation of different geographical and service delivery contexts, ECCs will first be stratified into six categories based on ecological region and accessibility: hilly region, Terai region, highway corridor, rural village, town outside the highway, and emerging highway town. One intervention ECC will be purposively selected from each stratum based on operational feasibility, availability of advanced tele-ophthalmology infrastructure, staffing, and geographical representation. A corresponding control ECC will then be selected using matched-cluster sampling based on similarity in distance from the base hospital, catchment population, accessibility, transportation, and baseline referral volume. This approach is intended to reduce confounding arising from differences between centres while maintaining the feasibility of implementing the intervention under routine service conditions.

The study will be conducted at Bharatpur Eye Hospital and twelve participating satellite ECCs, comprising six intervention centres and six matched control centres. These facilities provide comprehensive primary eye care services to rural and semi-urban populations and represent the first point of contact for most patients seeking ophthalmic care. Each ECC is staffed by trained optometrists or ophthalmic assistants responsible for vision assessment, refraction, slit-lamp examination, identification of ocular diseases, referral of patients requiring specialist management, and maintenance of electronic medical records.

Eligible participants will include adults aged 40 years or older diagnosed with visually significant cataract requiring referral for surgical evaluation. Patients with additional ocular conditions requiring ophthalmologist consultation may also undergo teleconsultation according to routine clinical practice; however, referral completion among cataract patients constitutes the primary outcome of the study. Patients requiring emergency ophthalmic referral, those already receiving follow-up care at Bharatpur Eye Hospital, and individuals unable to participate in teleconsultation without an accompanying caregiver when required will be excluded.

Intervention- Participants attending intervention ECCs will receive enhanced tele-ophthalmology consultation using slit lamp-mounted anterior segment cameras connected through a secure broadband network. Live, high-resolution ocular images will be transmitted to an ophthalmologist located at Bharatpur Eye Hospital. During the consultation, the ophthalmologist will remotely examine the patient, review clinical findings, request additional examinations if necessary, confirm the diagnosis, assess surgical suitability, and communicate directly with the patient through real-time video. The consultation will provide an opportunity for patients and accompanying family members to discuss symptoms, expected visual outcomes, risks and benefits of cataract surgery, postoperative care requirements, available financial subsidies, and referral procedures. Following the consultation, the ophthalmologist will recommend appropriate management, while the ECC staff will prepare the referral documentation, record the consultation within the hospital information system, and provide individualized counselling regarding hospital attendance.

Participants attending control ECCs will continue to receive the standard referral pathway currently practiced within the network. Clinical assessment will be performed by the ECC optometrist or ophthalmic assistant, and referrals will be issued according to existing clinical protocols. Although routine teleconsultation through mobile communication platforms may occasionally be used for selected ophthalmic conditions, cataract patients in the control centers will not receive the enhanced real-time tele-ophthalmology consultation involving direct ophthalmologist-patient interaction. Consequently, counselling regarding cataract surgery will be provided only by the ECC staff following routine practice.

Outcome measure- The primary outcome of the study is referral completion, defined as the proportion of cataract patients referred from participating Eye Care Centres (ECCs) who attend Bharatpur Eye Hospital or a designated secondary hospital within 12 weeks (±1 week) of referral. Referral completion will be determined by linking the unique referral identification number recorded at the ECC with the hospital information system at the receiving hospital. An interim assessment at four weeks (±1 week) will also be conducted to evaluate early referral attendance. Patients who fail to attend the referral hospital within the predefined follow-up period will be considered as not completing the referral.

Sample size justification- The sample size was calculated to detect an increase in referral completion from approximately 3% under the existing referral system to 15% following implementation of the enhanced tele-ophthalmology intervention, with a two-sided significance level of 5% and a statistical power of 80%. After adjustment for anticipated non-response and clustering of participants within Eye Care Centres using an estimated design effect, the final required sample size was determined to be 396 participants, comprising 198 participants in the intervention arm and 198 participants in the control arm. Participants will be recruited consecutively from the participating ECCs until the required sample size is achieved.

Data collection and follow up- Data will be collected using standardized study instruments, including the ECC cataract screening form, teleconsultation log sheet, referral tracking register, and Bharatpur Eye Hospital surgical attendance records. Information collected will include demographic characteristics, presenting and best-corrected visual acuity, ocular diagnosis, cataract grading, teleconsultation details, referral status, referral completion, and reasons for non-completion. Referral tracking will utilize the existing electronic medical record system together with standardized referral documentation to ensure accurate linkage between peripheral centers and the receiving hospital. Pilot testing of the referral tracking process will be undertaken before commencement of participant recruitment to verify completeness and accuracy of data linkage Statistical analysis- For Objective 1, the cataract referral completion rate will be calculated as the proportion of referred cataract patients who complete their referral to Bharatpur Eye Hospital within 12 weeks of referral. Referral completion rates will be presented as percentages for both the intervention and control groups. The referral completion rates between the two groups will be compared using the Chi-square test.

The Chi-square test is appropriate because both the exposure variable (intervention vs. control group) and the outcome variable (referral completed: Yes/No) are categorical variables.] This test will determine whether there is a statistically significant difference in referral completion rates between the two groups.

The effect of the intervention will be reported as the difference in referral completion rates between the intervention and control groups, along with 95% confidence intervals. A p-value of less than 0.05 will be considered statistically significant.

Results will be presented in tables and graphs showing the proportion of patients completing referral in each study arm.

Training and monitoring- To ensure intervention fidelity, standardized training will be provided to optometrists and ophthalmic assistants before study initiation. Training will include operation of tele-ophthalmology equipment, standardized examination procedures, patient counselling techniques, referral documentation, data entry, and use of the hospital information system. The research team will conduct regular monitoring visits to participating centers to evaluate protocol adherence, assess teleconsultation quality, identify technical problems, and verify data quality.

Ethical consideration Ethical approval will be obtained from the Institutional Review Committee of Nepal Netra Jyoti Sangh before commencement of the study. Written informed consent will be obtained from all participants before teleconsultation and electronic transfer of clinical information or ocular images. Participants unable to provide written consent because of illiteracy or physical limitations will be assisted according to approved ethical procedures, including the involvement of legally acceptable representatives or witnesses where appropriate. Participation will be entirely voluntary, and refusal to participate or withdrawal from the study will not affect access to routine eye care services.

Data security- Confidentiality of participant information will be maintained throughout the study. Clinical information and ocular images will be transmitted using secure communication systems and stored within password-protected hospital information systems accessible only to authorized study personnel. Participant identifiers will be replaced with unique study identification numbers during analysis to preserve confidentiality. All research data will be retained securely according to institutional policy and applicable ethical guidelines.

Expected impact This study is expected to generate high-quality evidence regarding the effectiveness of enhanced tele-ophthalmology in improving cataract referral completion within an established rural eye care network. If successful, the intervention could strengthen communication between primary eye care providers and ophthalmologists, improve patient confidence in cataract surgery, reduce avoidable blindness through earlier surgical treatment, and enhance the efficiency of referral systems.

Inclusion Criteria:

• Patients aged ≥40 years
• Diagnosed with visually significant cataract or other ocular conditions requiring Ophthalmological consultation by ECC staff
• Provided a referral slip to BEH for cataract surgery

Exclusion Criteria:

• Patients requiring urgent referral for other ocular comorbidities
• Patients already under follow-up at BEH
• Patients unable to participate in tele-consultation due to hearing, communication, or cognitive limitations when companion-assisted consultation is not feasible