Comparison of Arclight Loupe vs Traditional Direct Ophthalmoscope in evaluation of Corneal Epithelial Defects by General Practitioners: a proposal synopsis

Abstract

BACKGROUND

Corneal blindness is the 5^th, 4^th and 3^rd leading cause of blindness globally, in Sub-Saharan Africa and Nigeria, respectively.^1-3 Globally, corneal epithelial defects (CEDs), particularly corneal ulcers, constitute the major cause of corneal blindness.⁴ Regrettably, under-resourced areas and low- and middle-income countries (LMICs) with the least capacity to manage corneal lesions bear the greatest burden.⁴ Therefore, in order to encourage timely diagnosis of CEDs, the use of the +10 dioptre lens of the traditional direct ophthalmoscope (TDO) along with fluorescein dye has been advocated for use by non-ophthalmologists in the evaluation of suspected corneal lesions.⁵

Unfortunately, TDO use by non-ophthalmologists, including the general practitioners (GPs), the first-line physicians, is grossly limited. TDO skills deficiency, its bulk, relatively high cost, and sophistication are largely implicated.⁶ Arclight Loupe (AL), a portable, relatively low-cost and less sophisticated multipurpose diagnostic tool consisting of an anterior segment loupe, ophthalmoscope and otoscope, offers a reliable alternative to TDO.⁷ However, its utility in CEDs by GPs has not been assessed.

OBJECTIVE

To compare the utility of AL vs TDO in the clinical examination of corneal epithelial defects by GPs.

METHODS

A comparative cross-sectional study shall be undertaken. The study shall adhere to the tenets of the Declaration of Helsinki, and ethical approval shall be obtained from the Institutional Review Board of the University of Calabar Teaching Hospital, Calabar. Ten (10) TDO-exposed GPs will be recruited, trained and subsequently randomly assigned into two groups of 5 GPs each (group 1 & group 2). A cross-over design will be utilised in which group 1 uses the Arclight (Figures 1 and 2) first and subsequently the TDO, while group 2 will use the instruments in the reverse order.

Study subjects (CED+ve vs CED-ve) shall be consecutively recruited and independently examined by the GPs. Three experienced Ophthalmologists (SL1-3) shall work together examining each consecutive subject with the Slit Lamp to establish the CED parameters (presence/location/shape/size/depth) as the “reference standard”.

This study will compare the Arclight loupe to the Welch Allyn 11720-VC ophthalmoscope in terms of four measures: (1) accuracy of CED parameters (compared against the “reference standard”), (2) ease of examination (EOE) for the examiners (GPs) using a score of 1–8, (3) ease of use (EOU) for the examiners (GPs) using a score of 1–5, (4) ocular comfort level (OCL) as determine by the level of glare experienced by the subject using a score of 1–4, and (5) length of examination (LOE) as determined by the subject’s perceived duration of the assessment using a score of 1–4.

RESULTS

Data obtained shall be entered and appropriately analysed with STATA/IC version 15.0.

CONCLUSION

The prospective utility in the diagnosis of corneal epithelial defects using AL compared to TDO among GPs in our environment shall be objectively ascertained.