Optometry (2009) 80, 193-196

A comparison of multipurpose and conventional 2-steprigid gas-permeable solutions with Paragon cornealrefractive therapy lenses

Marjorie J. Rah, O.D., Ph.D.,a Li Deng, Ph.D.,a Lynette Johns, O.D.,b

and Jacob Lang, O.D.c

aNew England College of Optometry, Boston, Massachusetts; bBoston Foundation for Sight, Boston, Massachusetts;and cAssociated Eye Care, Stillwater, Minnesota.

KEYWORDSOrthokeratology;Contact lens care

system;Visual acuity;Contact lens comfort

AbstractPURPOSE: This investigation compared 2 commonly used care systems, Boston Advance� care systemand Boston Simplus� (Bausch & Lomb, Rochester, New York) multipurpose solution, and the effectsof these solutions on unaided daytime vision, care, and handling and comfort with Paragon corneal re-fractive therapy (CRT)� (Paragon Vision Sciences, Mesa, Arizona) lenses.METHODS: Eighteen subjects wearing CRT lenses were recruited. Three evaluations were conductedover 2 months. Subjects were randomly assigned a solution and returned for a follow-up visit after1 month. At the conclusion of the 1-month visit, each patient was reassigned the other solution forthe second month. The final visit included an additional questionnaire regarding which solution wasdeemed the best and worst for unaided daytime vision, comfort, care, and handling.RESULTS: From the responses of the 18 patients, a trend is evident that patients favor Boston Simplusover Boston Advance for comfort, unaided daytime vision, and care and handling. However, the samplesize is small in this study; therefore, most of the differences are not significant at the 0.05 level exceptthe preference for care and handling (P 5 0.03).CONCLUSIONS: Patients preferred Boston Simplus to Boston Advance with corneal reshaping lens wearwhen evaluated for comfort, unaided daytime vision, and care and handling. The preference of BostonSimplus to Boston Advance for care and handling is very strong and statistically significant, whereasother such advantages of Boston Simplus were not found to be statistically significant in this study. Fur-ther confirmation of these results as well as a better understanding of other visual and ocular interactionsof Boston Simplus versus conventional solutions, will require using a larger sample in further studies.Optometry 2009;80:193-196

With new advances in gas-permeable (GP) lens design andhigh oxygen transmissible materials, overnight orthokera-tology has become a safe and viable option for the correction

Corresponding author: Marjorie J. Rah, O.D., Ph.D., Massachusetts

Eye and Ear Infirmary, Contact Lens Service, 243 Charles Street, Boston,

Massachusetts 02114.

E-mail: marjorie_rah@meei.harvard.edu

1529-1839/09/$ -see front matter � 2009 American Optometric Association.

doi:10.1016/j.optm.2008.07.020

of myopia.1-8 Paralleling these advances in lens design areadvances in GP cleaning and disinfecting solutions. Theseadvances have led to the creation of multipurpose GP solu-tions with the goal of making lens care easier for patients.9

It has been shown that patient comfort is influenced by thewettability, viscosity, and substantivity of the soaking solu-tions used for rigid GP (RGP) contact lenses.10 Solutionswith higher viscosity have been found to result in greater

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194 Optometry, Vol 80, No 4, April 2009

patient comfort10 and a slowed rate of decentering of rigidcontact lenses.11 In addition to viscosity, the length of timethe solution remains on the lens during normal blinking canalso affect comfort.12 Overnight orthokeratology presents anew frontier for RGP solutions because these lenses areworn overnight while the patients’ eyes are closed. Thelenses are much less mobile compared with conventionalRGP lens wear.

This investigation compared 2 commonly used caresystems, Boston Advance� care system (which includes theBoston Advance Cleaner� and Boston Advance� ComfortFormula conditioning solution), and Boston Simplus�multipurpose solution (Bausch & Lomb, Rochester, NewYork), and the effects of these solutions on unaided daytimevision, comfort, and care and handling with regard to Par-agon corneal refractive therapy (CRT)� (Paragon VisionSciences, Mesa, Arizona) lenses.

Methods

The tenets of the Declaration of Helsinki were followedthroughout the study. The Institutional Review Board at theNew England College of Optometry approved the protocol,and informed consent was obtained from all subjects afterthe protocol had been explained.

Each subject was required to have had a complete eyeexamination, including dilated fundus examination, at theNew England Eye Institute within 10 months beforeenrollment in the study. Three visits were conducted over2 months and were performed by masked investigators. Abaseline examination was conducted to determine eligibil-ity. At the initial visit, eligible patients completed aquestionnaire regarding their current contact lens solutionand care methods. The care system to be used for the firstmonth was selected randomly and dispensed by a researchassistant. The investigators were masked to the type ofsolution being used. The assistant educated the patientregarding lens care and proper use of solution (as indicatedon the package inserts and manufacturer’s instructions.) Atthe conclusion of month 1, a progress evaluation wasperformed, a questionnaire was completed with regard tothe first solution, and the second solution was dispensed tothe patient. Once again, the patient was educated on theproper use of this solution. The patient was asked to use thesecond solution for 1 month. Any questions the patients hadregarding solutions and cleaning were directed to theresearch assistant. After month 2, the final progress eval-uation included an additional questionnaire regardingwhich solutions were deemed the best and worst forunaided daytime vision, comfort, and care and handling.

Statistical methods

The exact binomial tests were conducted to assess thesignificance of patients’ preference of one solution to

another regarding comfort, unaided daytime vision, andcare and handling because the sample size is small and thenormal approximation is not suitable. All patients wereasked which they favored most and which they favoredleast for comfort, unaided daytime vision, and care andhandling among the 3 care system options (Simplus, BostonAdvance, and the baseline system used before entering thestudy). For each test area, a preference score was created asfollows: 11 for a brand if it is the most favored; 21 if it isthe least favored; and zero for neither most favored norleast favored brand or brand with both most and leastfavored responses from the same patient. The difference inpreference scores yielded directly a patient’s preferencebetween 2 brands. If patients like the 2 brands equally, thenthe chance that one is more favored is 50%. A 2-sidedbinomial test is applied to test equal preferences (P 5 0.5)between Boston Simplus and Boston Advance.

Results

Eighteen subjects wearing CRT lenses were recruited. Eightpatients used the Boston Advance as the first care system,whereas 10 patients used Boston Simplus first. A list of thesolutions being used before the study can be found in Table1. From the responses of the 18 patients, a trend was evi-dent that patients favor Boston Simplus over Boston Ad-vance care system when evaluated with regard tocomfort, unaided daytime vision, and easy care and han-dling with corneal reshaping lenses (see Figures 1-3). How-ever, because the sample size is small in this study, most ofthe differences were not significant at the 0.05 level withthe exception of the preference for Simplus with regardto care and handling (P 5 0.03; see Table 2).

Discussion

Satisfaction and comfort with GP contact lenses can dependon the care system utilized by the patient. A preference forBoston Simplus over Boston Advance with regard to care andhandling was detected in this study. Similar trends were notedfor patient-reported comfort and unaided daytime vision.

Table 1 Baseline solutions used by patients beforeinitiation of study protocol

Solution No. of Patients

Unique pH 7Boston Simplicity 3Boston Original 3Boston Simplus 2ClearCare* 1Renu† 1B & L Rigid Gas Permeable Care System 1

* CIBA Vision, Duluth, Georgia.† Bausch & Lomb, Rochester, New York.

Rah et al Clinical Research 195

Previous research has shown that the viscosity of acontact lens solution can affect the comfort of a GP contactlens, the patient’s satisfaction with vision, and the posi-tioning of the contact lens on the eye.10-12 Although somereports hypothesize that the higher viscosity of artificial tearsor contact lens solutions increases patient comfort,10,13

others have found that patient comfort is actually greaterwith solutions of lower viscosity.12,14 The studies that havemeasured viscosity have done so in vitro and did not takeinto account the effect of tear chemistry on solution viscosity.Tear chemistry appears to be an important variable becausewhen contact lens solutions come into contact with tears,the properties of the solution change.

Other factors such as pH, wettability, and tonicity play arole in comfort, satisfaction, and vision as well.14 Smallerwetting angles indicate greater wettability, which theoreti-cally improves comfort.10 For example, Boston AdvanceConditioning solution has been shown to have low viscosityand a smaller wetting angle10,12,14 and has been shown tohave high patient satisfaction with regard to comfort, han-dling and vision.14 Although little is available in the currentliterature regarding the viscosity, wettability, and other fac-tors associated with Boston Simplus, it is our hypothesisthat these factors play a key role in our results.

0

2

4

6

8

10

12

14

Baseline BostonAdvance

Baseline BostonAdvance

BostonSimplus

BostonSimplus

Figure 2 Numbers of patients who prefer one brand of solution when it

is compared with a second type for comfort.

0

2

4

6

8

10

12

14

16

Baseline BostonAdvance

Baseline BostonSimplus

BostonSimplus

BostonAdvance

Figure 1 Numbers of patients who prefer one brand of solution when it

is compared with a second type for ease of care and handling.

Conclusion

The preference of Boston Simplus to Boston Advance forcare and handling is very strong and statistically significant,

0

2

4

6

8

10

12

14

16

Baseline BostonAdvance

Baseline BostonAdvance

BostonSimplus

BostonSimplus

Figure 3 Numbers of patients who prefer one brand of solution when it

is compared with a second type for unaided daytime vision.

Table 2 Test results for preference of one brand of solutionto another for comfort, unaided daytime vision, and care andhandling, respectively

Boston Advance versus baseline solution

Binomial test

No. of subjects favoringBoston Advance P-value

Favor for careand handling

4/18 0.0309

Favor for comfort 5/18 0.0963Favor for unaided

daytime vision6/18 0.2379

Boston Simplus versus baseline solution

Binomial test

No. of subjects favoringBoston Simplus P-value

Favor for careand handling

13/18 0.0963

Favor for comfort 12/18 0.2379Favor for unaided

daytime vision11/18 0.4807

Boston Simplus versus Boston Advance

Binomial test

No. of subjects favoringBoston Simplus P-value

Favor for care andhandling

14/18 0.0309

Favor for comfort 13/18 0.0963Favor for unaided

daytime vision12/18 0.2379

196 Optometry, Vol 80, No 4, April 2009

whereas other such advantages of Boston Simplus are notstatistically significant in this preliminary investigation.Further confirmation of these results and declaration ofsignificance of superior performance of Boston Simplusrequires the use of a larger population sample.

Acknowledgment

This study was supported by National Institutes of HealthGrant R24 EY014817.

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