The development of measurement tools for prosthetic eye research

Abstract

Background:The aim was to develop tools to measure the condition of ocular prostheses and the socket's response to prosthetic eyewear. Methods: A novel staining technique for displaying deposits on prosthetic eyes was developed. Equal interval perceptual grading scales for measuring inferior palpebral conjunctival inflammation, and anterior and posterior stained surface deposits on prosthetic eyes were developed from 800 photographs of 43 volunteers. The photographs for each scale were chosen by the authors. A group of four ophthalmologists, three optometrists and three senior students was consulted about selection criteria and asked to position the photographs along a 1.5 m rule to determine equal intervals. Photographs judged not to represent exactly equal perceptual intervals were exchanged with others from the original pool. The final scales (a five-photograph scale for inflammation and two 11 photograph scales for deposits) were assessed for inter-rater reliability and test-retest reliability by groups of senior optometry students. Results: Standard deviations for inter-rater reliability tests were 0.52 scale units for the inflammation scale, 0.99 for the anterior surface deposits scale and 1.03 for the posterior surface deposits scale. The standard deviation of the test-retest differences for inflammation was 0.6 scale units and for both anterior and posterior surface deposits it was 0.71. Conclusions: A novel technique for displaying and measuring the intensity and extent of deposit formation on prosthetic eye surfaces has been described. The two equal interval perceptual grading scales that have been developed to quantify the extent of deposit formation together with the equal interval perceptual scale for grading severity of palpebral conjunctival inflammation will for the first time allow the effects of prosthetic eye wear to be evaluated. Further research to validate the scale for palpebral conjunctival inflammation in a clinical setting is recommended. The technique for staining deposits on prosthetic eyes is recommended for clinical practice.

Deposit buildup on prosthetic eyes and implications for conjunctival inflammation and mucoid discharge

“…An optical quality contact lens standard of finish may also facilitate the lubricating function of tears in the retropalpebral zone when the prosthesis is first inserted into the socket and before the layered coatings, films, or plaques of tear protein deposits become established. The finding that wetting angles decreased (and wettability increased) significantly when deposits were present in the retropalpebral zone may be the reason why surface deposits are associated with less severe conjunctival inflammation in anophthalmic sockets1 and that more frequent cleaning of prosthetic eyes (deposit removal) is associated with more severe discharge 15. By increasing surface wettability, the deposits may improve the ability of socket fluids to lubricate the prosthesis.…”

“…A staining solution was made by dispersing 5 g of plaque disclosing gel (a mix of mainly ethyl alcohol, food red 105, and water; GC Corporation, Tokyo, Japan) in 30 mL of 0.85% saline solution 1. The participants’ prostheses were submerged in the solution at 20°C (68°F) for a period of 2 minutes.…”

“…Photographs of the stained prostheses were coded to deidentify the participant but to allow tracking. Each photograph was copied onto the center of a Microsoft PowerPoint (Microsoft Corporation, Redmond, WA) slide which contained a previously developed 0–10 photographic grading scale by which the extent and intensity of deposit buildup could be measured 1. Separate anterior surface and posterior surface deposit scales allowed assessment of the severity of deposit buildup according to the extent and intensity of the stained deposits.…”

The response of the anophthalmic socket to prosthetic eye wear

“…Bailey and colleagues recommended using finer than four‐point grading scales and Chong, Simpson and Fong showed that scales using reference photographs have better repeatability than verbally descriptive scales. Pine and colleagues developed a novel technique for staining deposits on prosthetic eyes and followed the recommendations of Bailey and colleagues and Chong, Simpson and Fong by creating a photographic grading scale with fine divisions for measuring conjunctival inflammation in anophthalmic sockets. Pine and colleagues also created similar scales for measuring the extent and intensity of stained deposits on prosthetic eye surfaces.…”

Patient Evaluation

“…An equal interval photographic grading scale for measuring conjunctival infl ammation in anophthalmic sockets has been developed (Fig. 4.42 ) [ 18 ]. These scales have been tested for inter-rater and test-retest reliability and may be utilised for clinically measuring the extent of conjunctival infl ammation in the same manner that photographic grading scales are used in other fi elds of optometry and ophthalmology (Fig.…”