|Year : 2014 | Volume
| Issue : 1 | Page : 50-55
Rose-K versus soper contact lens in keratoconus: A randomized comparative trial
Raghav Gupta, Rajesh Sinha, Pooja Singh, Namrata Sharma, Radhika Tandon, Jeewan S Titiyal
Department of Ophthalmology, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
|Date of Web Publication||1-Jan-2014|
S-7, Department of Ophthalmology, Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Purpose: To perform a comparative evaluation of the efficacy and acceptability of Rose-K and Soper contact lenses in Keratoconus.
Setting: Dr. Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi.
Materials and Methods: A randomized comparative clinical trial was performed in keratoconic eyes fitted with Rose-K (Rose-K group) and Soper (Soper group) contact lenses. Patients data were evaluated for best spectacle corrected visual acuity, best contact lens corrected visual acuity (BCLCVA), corneal topography, glare acuity, contrast sensitivity, tear function tests and specular microscopy. Patients were also asked to complete a self-reported comfort questionnaire at each visit.
Results: Sixty eyes were randomized to the Rose-K and Soper groups. The two groups were comparable in all the baseline parameters. There was a statistically significant improvement in BCLCVA in both groups at 3 months (P < 0.01, both groups). The difference between in BCLCVA in both groups was not statistically significant. In both groups, there was a significant improvement in the comfort score at 3 months compared to baseline (P < 0.05, both group). The Rose-K group had statistically significantly better scores at 1 and 3 months compared with the Soper group (P = 0.006 and P < 0.001 respectively). Both groups were associated with a significant (P < 0.01), but comparable improvement in glare acuity at 3 months. There was a significant improvement in contrast sensitivity at 3 months in both groups (P < 0.01); the Rose-K group was significantly better than the Soper group at 1 and 3 months (P = 0.001 and 0.002 respectively). The mean number of trial lenses required for fitting Rose-K lens (2.00 ± 0.59) was significantly lower than the Soper lens (3.43 ± 0.82; P < 0.001).
Conclusion: Both the contact lens designs provide an equal improvement in visual acuity in patients with Keratoconus. However, Rose-K contact lens provides greater comfort, better quality of vision and requires less chair time compared with the Soper lens and hence may possibly have a greater acceptability.
Keywords: Keratoconus, Rose-K Contact Lens, Soper Contact Lens
|How to cite this article:|
Gupta R, Sinha R, Singh P, Sharma N, Tandon R, Titiyal JS. Rose-K versus soper contact lens in keratoconus: A randomized comparative trial. Middle East Afr J Ophthalmol 2014;21:50-5
|How to cite this URL:|
Gupta R, Sinha R, Singh P, Sharma N, Tandon R, Titiyal JS. Rose-K versus soper contact lens in keratoconus: A randomized comparative trial. Middle East Afr J Ophthalmol [serial online] 2014 [cited 2019 Dec 11];21:50-5. Available from: http://www.meajo.org/text.asp?2014/21/1/50/124095
| Introduction|| |
Keratoconus is a non-inflammatory ocular entity characterized by progressive ectasia and thinning of the cornea, which results in irregular astigmatism and visual deterioration.  It is usually bilateral, although it may be asymmetric or unilateral at initial presentation. , Forme fruste Keratoconus patients are patients who are classified as Keratoconus suspects on the basis of corneal topography alone with normal slit lamp findings.
Contact lenses are the mainstay therapy for Keratoconus and are the treatment modality of choice in 90% of patients due to the corneal surface irregularity. ,, Popular options in contact lenses for Keratoconus include Rigid Gas Permeable (RGP) lenses, hybrid contact lenses, piggyback lenses and scleral contact lenses. Two commonly used RGP lens designs include the Soper contact lens and the Rose-K contact lens. The Soper lens system includes bicurve lenses based on sagittal depth. The smaller lenses are used for smaller, centrally located cones. The large diameters are used for oval cones. The Rose-K lens for Keratoconus is a proprietary design. It is a multi-spherical posterior design with aberration control aspheric optics across the back and front optic zone diameters.
We performed a randomized comparative trial evaluating the efficacy and acceptability of Rose-K Contact Lens and Soper Contact Lens in Keratoconus. To the best of our knowledge, no such randomized study has been performed and reported to date.
| Materials and Methods|| |
A randomized comparative clinical trial was performed between July 1, 2009 and March 31, 2011 to evaluate the efficacy of Rose-K and Soper contact lenses in Keratoconus at a tertiary care center. All patients were enrolled after an informed consent and approval of Institutional Ethics and Review Committee was taken. Sixty eyes were enrolled in the study from the Contact Lens Services of our center. The enrolled subjects were new cases of primary Keratoconus aged between 15 year and 40 years with keratometric values ranging between 48 and 60 diopters (D). Patients suffering from vernal keratoconjunctivitis, hydrops, giant papillary conjunctivitis, dry eye, ocular surface disorder, corneal scarring or any other corneal pathology as well as patients who had undergone some surgical intervention for Keratoconus in the past were excluded from the study. Patients were randomized into two groups based on the type of contact lens fitted: Rose-K group (n = 30 eyes) and; Soper Group (n = 30 eyes). Patients in each group were further subdivided into one of the 3 subgroups according to keratometric value, subgroup 1: 48-52 D (Rose-K group = 12 eyes; Soper = 12 eyes), subgroup 2: 52-56 D (Rose-K = 10 eyes; Soper = 9 eyes), subgroup 3: >56 D (Rose-K = 8 eyes; Soper = 9 eyes). The distribution of patients into different subgroups was comparable P = 0.95 (Chi-square test).
The enrolled patients were evaluated based on the evaluation parameters and a patient comfort questionnaire at baseline (time of fitting), 1 month and 3 month visits [Table 1]. Evaluation parameters included uncorrected visual acuity, best spectacle corrected visual acuity (BSCVA), best contact lens corrected visual acuity (BCLCVA), corneal topography (Videokeratography: Carl Zeiss Meditec Atlas More Details Version A 12.2, Jena, Germany and Orbscan II [Bausch and Lomb, Orbtek Inc., Rochester, NY, USA]), glare acuity (Allergan Humphrey 570 autorefractor), contrast sensitivity [Pelli-Robson chart], Schirmer test and tear break-up time and endothelial cell count (Topcon SP 3000P; Topcon America Corporation, Paramus, NJ, USA). Patients were also asked to fill out a self-reported comfort questionnaire at each visit [Table 1].
All the data were recorded on a pre-designed data collection sheet and managed with an excel spread sheet. Stata-11 software (StataCorp LP, College Station, TX, USA) was used for statistical analysis. The arithmetic means and standard deviations were calculated for all the descriptive parameters. The Chi-square test was used to determine the significance of the association between categorical variables. For variables measured on an interval scale, comparisons were performed with Student's t-test. If there was a large range and variation the data were compared using the non-parametric tests such Mann-Whitney test. P <0.05 was considered to be statistically significant.
| Results|| |
The mean age between groups was comparable (Rose-K group: 21.9 ± 5.57 years, Soper group: 19.7 ± 4.29 years; P = 0.1). There were not differences in gender distribution between groups (Rose-K group: 18 males, 12 females; Soper group: 16 males, 14 females; P = 0.79).
The mean spherical refractive power in the Rose-K group was −6.93 ± 4.73 D and −5.52 ± 4.88 D in the Soper group (P = 0.29). The mean cylinder in the Rose-K group was −3.06 ± 2.88 D and −2.97 ± 1.25 in the Soper group (P = 0.89).
The two groups were comparable in terms of BSCVA (P = 0.19), and BCLCVA at baseline (P = 0.86) and at 3 months (P = 0.23) [Table 2]. There was a statistically significant improvement both groups in BCLCVA at 3 months over the BSCVA (P < 0.01). This difference between groups was not statistically significant (P > 0.05) [Table 2].
The comfort score at baseline was not significantly different between groups (P = 0.84). In both groups, it improved statistically significantly at 3 months with the Rose-K group showing statistically significantly better scores at 1 and 3 months (P = 0.006 and P < 0.001 respectively). The Rose-K group was significantly better than the Soper group in subgroups 2 and 3 [Table 3], [Table 4], [Table 5] and [Table 6].
The endothelial cell count in the Rose-K group decreased from 2850.4 ± 408.7 cells/mm 2 to 2750.5 ± 372.6 cells/mm 2 (P = 0.33). Similarly in the Soper group, the endothelial cell count decreased from 2886.4 ± 461.6 cells/mm 2 to 2788.7 ± 461.3 cells/mm 2 (P = 0.41). There was no statistically significant difference in the decrease in endothelial cell count between groups (P > 0.05).
In both the contact lens groups the simulated Keratometry (Sim K) did not change significantly for the duration of the study. In the Rose-K group, the Sim K maximum (max) changed from 56.72 ± 4.54 D to 56.27 ± 4.29 D (P = 0.43 D) and Sim K minimum (min) changed from 50.77 ± 3.21 to 50.78 ± 3.19 D (P = 0.99). In the Soper group, the Sim K (max) changed from 55.5 ± 3.88 D to 55.8 ± 4.62 D (P = 0.99) and Sim K (min) from 50.48 ± 2.71 D to 50.7 ± 3.45 D (P = 0.99).
The value of Schirmer test in the Rose-K group changed from 13.77 ± 1.76 mm to 13.12 ± 1.58 mm at 3 months (P = 0.14). In the Soper group, the value of Schirmer changed from 13.47 ± 1.46 mm to 13.02 ± 2.11 mm (P = 0.3). The mean tear break up times at baseline in Rose-K and Soper group were 12.46 ± 1.06 s and 12.47 ± 1.04 s respectively (P = 0.97). At 3 months the same were 12.2 ± 0.76 s and 12.12 ± 0.52 s respectively (P = 0.63).
Both contact lens groups were associated with a significant improvement in the glare acuity at 3 months (P < 0.01) and the two groups were comparable [Table 7].
There was a significant improvement in the contrast sensitivity at 3 months in both groups (P < 0.01). When the two groups were compared, the Rose-K group was significantly better than the Soper group at 1 and 3 months (P = 0.001 and P = 0.002, respectively) [Table 8].
The mean number of trial lenses required for fitting Rose-K lens was 2.00 ± 0.59 and 3.43 ± 0.82 for the Soper lens (P < 0.001). In the Rose-K group, the edge modification was used in 6 (20%) of 30 patients. Edge modification was not possible in Soper contact lens.
In subgroup analysis Rose-K lens was significantly better than the Soper contact lens in terms of glare acuity and contrast sensitivity in subgroup 1, only in comfort score in subgroup 2 and both in contrast sensitivity and comfort score in subgroup 3 (P < 0.05, all comparisons) [Table 4], [Table 5] and [Table 6].
A definitive correlation between Base Curve (BC) and 3 mm K (p3mm) and 5 mm K (p5mm) on Orbscan II topography was observed with both Rose-K and Soper lens [Pearson correlation values in [Figure 1], [Figure 2], [Figure 3] and [Figure 4].
|Figure 1: Rose-K: Correlation of base curve in diopters with 3 mm Keratometry on Orbscan. r = 0.84; P < 0.001; BC = 17.16 + 0.63 × p3mm (r = Pearson correlation coefficient)|
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|Figure 2: Rose K: Correlation of base curve in diopters with 5 mm Keratometry on Orbscan. r = 0.76; P < 0.001; BC = -25.39 + 1.57 × p5mm|
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|Figure 3: Soper: Correlation of Base Curve in diopters with 3 mm Keratometry on Orbscan. r = 0.87; P < 0.001; BC = 17.6 + 0.64 × p3mm|
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|Figure 4: Soper: Correlation of Base Curve in diopters with 5 mm Keratometry on Orbscan. r = 0.77; P < 0.001; BC = 20.71 + 0.61 × p5mm|
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| Discussion|| |
RGP contact lens is the best available management option for the visual rehabilitation in Keratoconus.  Improvement in contact lens design has decreased the number of patients who require penetrating keratoplasty.  However due to irregular corneal topography the fitting of RGP lenses in these eyes is difficult and requires more chair time.  For the same reason, it is also important to make an appropriate choice of contact lens design. ,,,,
A retrospective study that assessed the demographic profile of patients with Keratoconus reported the median age of presentation of the patients was 24 years (15-36 years).  In our study, the average age of the patients was lower in both groups.
In our study, there was a significant improvement in visual acuity with contact lens in comparison to spectacle correction at 1 and 3 months in both groups (P < 0.05, all comparisons). The results of this study are comparable to the earlier reported success of the RGP contact lens in visual rehabilitation of patients of Keratoconus. ,, When the two types of contact lenses were compared in our study, visual acuity gained was not significantly different at 1 and 3 months (P = 0.86 and P = 0.23 respectively). In a similar study, Betts et al.  also concluded that there was no difference in the improvement in visual acuity with the Rose-K lenses compared with the patients' habitual lenses.
In the present study, both groups experienced a significant improvement in the comfort score at 3 rd month follow-up visit (P < 0.001) compared with the baseline visit. Although the difference between the two groups was not statistically significant at the baseline (P = 0.84), Rose-K group was significantly better than the Soper group at 1 month (P = 0.006) and 3 month follow-up (P < 0.001). We believe that the increased comfort with Rose-K lens is due to the improved multicurve design of Rose-K and also due to the ability of the edge design to be further modified. Similar self-reported comfort has also been demonstrated with the use of Rose-K contact lens by other studies. ,
Both groups provided a statistically significant improvement in the glare acuity. Furthermore, at the 3 month follow-up, the glare acuity with Rose-K lens was significantly better than Soper lens in subgroup 1. This suggests that in mild Keratoconus, Rose-K provides better glare acuity than the Soper contact lens.
Both the contact lens showed a significant improvement in contrast sensitivity at 3 month follow-up. However, Rose-K lens was significantly better than the Soper Lens at 1 month (P = 0.001) and 3 months (P = 0.002) follow-up. Similarly, in the subgroup 1 and 3, Rose-K lens was significantly better than the Soper lens group. Betts et al.  did not find any significant change in high- or low-contrast visual acuity with the Rose K lenses over the patients' habitual lenses.
The number of trial lenses required to finalize Rose-K lens parameters was significantly lower than the Soper lens group. Thus, less chair time was required in fitting the Rose-K CL when compared with the Soper CL. Rose-K lenses were initially claimed to have an 80-90% first-fit success rate. , However, further clinical studies did not show this high first fit success rate. ,
With both contact lens types, the 3 mm and 5 mm average K value on Orbscan II topography had a significant correlation with the BC of the lens. In a retrospective study, it was found that 5 mm average K reading on axial map was the best predictor of final BC of Rose K lens in Keratoconus.  However in our study in both groups, 3 mm average K had a stronger correlation than the 5 mm average K. We could also derive an equation to judge the BC of the lens from the average keratometric value at 3 and 5 mm in both groups. This can reduce the time required in finalizing the contact lens fitting.
There are some limitations of this study. We did not look into the socio-economic aspects and education levels of the patients. This is more applicable in developing countries like India where the Soper design is desired by many patients due to its low cost in comparison to Rose K lens. Further, a study with a longer follow-up may be more helpful as it may determine the drop outs and the reasons amongst the contact lens users as well as the need for replacement of any type of contact lens. A long-term study will also be useful to determine the changes in the corneal and ocular surface caused by the two lenses.
Bourne et al.  evaluated the effect of rigid contact lens on the endothelium of corneal transplants for Keratoconus. They  found that compared with normal controls the changes in the endothelium were more severe in the abnormal cornea. Though there was no significant change in the endothelial density, the contact lens group developed polymegethism. In our study, we found that though there was a decrease in the endothelial count in both groups, the change was not significant. However, a long-term study on the endothelial changes may provide better information.
The study concludes that both the contact lenses provide comparable improvement in visual acuity in cases of Keratoconus. However, Rose-K lens provides better comfort, quality of vision and requires less chair time in comparison to the Soper lens. It may be attributed to improved multicurve design and the option of edge modification with Rose-K lens.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8]