Use Of Rigid Gas Permeable Contact Lenses Research Articles

Compliance with rigid gas-permeable contact lens use in children younger than 6 years in China: a 6-year retrospective study.

To explore the abandonment rate and factors influencing the use of rigid gas-permeable contact lenses (RGPCL) among children aged < 6 years. This retrospective case series study included 70 children aged < 6 years who were fitted with RGPCL for visual rehabilitation between January 2016 and December 2021. We collected data on indications, discontinuation rates, and reasons for discontinuation from medical records and via telephone calls and investigated the factors influencing contact lens abandonment. The median age of the 70 participants was 5.0 (interquartile range: 4.0-5.9) years. Further, 36 (51.4%) children stopped wearing contact lenses; among them, 17 (47.2%) stopped within 3 months, and the median duration of lens wearing was 4.0 (interquartile range: 1.0-11.5) months. Additionally, there was a correlation between the duration of lens wearing and lens abandonment (r = -0.698, P < 0.001). A high parental education level (hazard ratio [HR] = 0.425; 95% confidence interval [CI] 0.198, 0.913; P = 0.028) was a protective factor against lens abandonment, while parental assessment indicating harder than expected practicality (HR = 4.062; 95% CI 1.204, 13.707; P = 0.024) was a risk factor for abandonment. Children aged < 6 years are susceptible to early discontinuation of RGPCL use. Since parents perform daily lens manipulation, they are crucial to the continuity of lens use in these children. To improve RGPCL use continuity, communication and supervision should be strengthened before and after RGPCL fittings.

The Challenge of Contact Lens Visual Rehabilitation for Open Globe Injuries in Children Under 5 Years of Age.

To investigate the clinical course of children younger than 5 years old who underwent rigid gas-permeable (RGP) contact lens (CL) wearing as visual rehabilitation of open globe injuries (OGIs) in Japan. This retrospective case series involved six eyes of six children (four boys and two girls) with OGIs. The mean patient age at injury was 4.0±0.83 SD (range: 2.5-5 years), and the mean follow-up period was 42.9 months (range: 31.6-52.8 months). In each child, data regarding injury type, ocular surgery performed, outcomes of amblyopia management (including best-corrected visual acuity [BCVA] with RGP CL or spectacles), the RGP CL-wear training period, and rate of continuous RGP CL-wear were analyzed. Trauma type was penetrating injury (four eyes) and globe rupture (two eyes). All six cases showed lens penetration, and underwent corneal suture, lensectomy, and pars plana vitrectomy under general anesthesia. The mean RGP CL-wear training period was 3.5 months, and only one of the six cases discontinued RGP CL use. The mean BCVA with spectacles and with RGP CL was LogMAR: 1.52±0.41 (range 1.00-2.00) and 0.73±0.41 (range: 0.30-1.15), respectively. In all patients, except in one case in which strabismus developed, BCVA improved with RGP CL wear more than 0.2 logMAR compared with that with spectacles. Although the training period for RGP CL-wear is long in pediatric patients with OGIs, the treatment can be effective for refractive problems and for preventing the development of strabismus.

Effect of Rigid Gas Permeable Contact Lenses on Nystagmus and Visual Function in Hyperopic Patients with Infantile Nystagmus Syndrome

ABSTRACTPurpose: To determine the effect of rigid gas permeable contact lenses (RGPCL) on involuntary eye movements and visual function in hyperopic patients with infantile nystagmus syndrome. Methods: This prospective interventional case series was conducted on 16 patients with infantile nystagmus and hyperopia equal or more than +0.5 D and astigmatism more than -1 D over a 2-year period. A complete ophthalmological examination including determination of best corrected visual acuity (BCVA), contrast sensitivity, and videonystagmography was performed for all patients before and after at least 3 months of RGPCL use, and the outcomes were compared. Results: Thirty-two eyes of 16 patients with mean age of 18.6±4.9 years were enrolled. Mean spherical equivalent refractive error was +1.5±2.35 (range +1 to +6.25) diopters (D); corresponding values were +2.45±2.44 D (range +0.5 to +7.5) for spherical error and +1.90±0.83 D (range +1 to +4) for astigmatism. Monocular BCVA improved from 0.56±0.23 to 0.51±0.23 Log MAR (P=0.007), and binocular BCVA improved from 0.54±0.25 to 0.48±0.24 Log MAR (P=0.01) after fitting RGPCL. Following the use of RGPCL, contrast sensitivity was significantly improved at low (P=0.02) and intermediate (P< 0.001) frequencies but not at high frequencies (P=0.6). The frequency, amplitude, and intensity of nystagmus were decreased significantly after RGPCL use (P<0.001). Conclusion: RGPCL improved monocular and binocular BCVA and contrast sensitivity in hyperopic patients with infantile nystagmus syndrome. Motor indices of nystagmus (frequency, amplitude, and intensity) were also significantly improved after RGPCL use.

Aberration changes of the corneal anterior surface following discontinued use of rigid gas permeable contact lenses.

To record aberrations with a corneal topographic device on the anterior surface of the cornea at different time-points prior to wearing and following discontinued use of rigid gas permeable (RGP) contact lenses. The effect of wearing RGP on the anterior surface of the cornea was discussed to provide guidance for clinical refractive error correction. The study objects were 24 eyes from 24 patients. All patients underwent identical examination procedures prior to lens use, as well as afterwards, including slit-lamp examination, non-contact tonometer measurement, computer optometry and corneal curvature measurement, subjective refraction test, and corneal topography analysis. The patients wore contact lenses everyday for 1 month and then discontinued. Corneal topographies were recorded at certain time points of 30 minutes, 1 day, 3, 7 and 14 days following use. Total corneal aberration at each time point following discontinued use of RGP contact lenses was less than the time point prior to use. Detailed results were as follows: root mean square (RMS) (pre)=(1.438±0.328)µm, RMS (30 minutes)=(1.076±0.355)µm, RMS (1 day)=(1.362±0.402)µm, RMS (3 days)=(1.373±0.398)µm, RMS (7 days)=(1.387±0.415)µm, and RMS (14 days)=(1.430±0.423)µm. Results showed that at 30 minutes after discontinued use of RGP contact lenses, almost all 2(nd)- and 3(rd)-order aberrations change. Quadrafoil Z10 and spherical Z12 of the 4(th)-order were also changed. Alterations to Z5, Z6, and Z12 at 1 day after discontinued use were significant differences compared with the time period prior to RGP use: Z5 and Z6 decreased, and Z12 increased slightly. Z5 and Z6 remained decreased at 3 days after discontinued use, but Z9 and Z10 continued to increase and Z12 returned to levels prior to RGP use. At 14 days after discontinued use, all aberrations were not significantly different from the values prior to use. The use RGP contact lenses greatly reduced total aberration of the anterior surface of the cornea. Changes to 2(nd)- and 3(rd)-order aberrations (including Z3, Z4, Z5, Z6, Z7, and Z8) were more significant. Following discontinued use of RGP contact lenses, the majority of lower order aberrations returned to original levels in a short period of time. During this process, a transient higher order aberration appeared, but all changes disappeared within 14 days after discontinued use of RGP contact lenses.

Analysis of aberration changes of the corneal anterior surface following discontinued use of rigid gas permeable contact lenses

The present study used a corneal topographic device to record aberrations on the anterior surface of the cornea at different time-points prior to wearing and following discontinued use of rigid gas permeable (RGP) contact lenses. The effect of wearing RGPCL on the anterior surface of the cornea was discussed to provide guidance for clinical refractive error correction. The study objects were 60 eyes from 30 patients. All patients underwent identical examination procedures prior to lens use, as well as afterwards, including slit-lamp examination, non-contact tonometer measurement, computer optometry & corneal curvature measurement, subjective refraction test, and corneal topography analysis. The patients wore contact lenses every day for 1 month and then discontinued. Corneal topographies were recorded at certain time points of 30 min, 1 day, 3 days, 1 week, and 2 weeks following use. Total corneal aberration at each time point following discontinued use of RGP contact lenses was less than the time point prior to use. Detailed results are as follows; root mean square (RMS) (pre) = (1.438 ± 0.328), RMS (30 min) = (1.076 ± 0.355), RMS (1 day) = (1.362 ± 0.402), RMS (3 day) = (1.373 ± 0.398), RMS (7 day) = (1.387 ± 0.415), and RMS (14 day) = (1.448 ± 0.423). Results showed that at 30 minutes after discontinued use of RGP contact lenses, almost all 2(nd)- and 3(rd)-order aberrations were altered. Quadrafoil Z10 and spherical Z12 of the 4(th)-order were also changed. Alterations to Z5, Z6, and Z12 at 1 day after discontinued use were significant compared with the time period prior to RGP use: Z5 and Z6 decreased, and Z12 increased slightly (F = 2.869 ∼ 5.549, P = 0.001 ∼ 0.042). Z5 and Z6 remained decreased at 3 days after discontinued use, but Z9 and Z10 continued to increase and Z12 returned to levels prior to RGP use (P > 0.05). At 2 weeks after discontinued use, all aberrations were not significantly different from the values prior to use (P > 0.05). The use RGP contact lenses greatly reduced total aberration of the anterior surface of the cornea. Changes to 2(nd)- and 3(rd)-order aberrations (including Z3, Z4, Z5, Z6, Z7, and Z8) were more significant. Following discontinued use of RGP contact lenses, the majority of lower order aberrations returned to original levels in a short period of time. During this process, a transient higher order aberration appeared, but all changes disappeared within 2 weeks after discontinued use of RGP contact lenses.

Changes in wave-front aberrations after rigid gas permeable contact lens fitting in post—laser in situ keratomileusis patients with visual complaints

Objective: To evaluate the effect of rigid gas permeable (RGP) contact lenses in reducing wave-front aberrations in post-laser in situ keratomileusis (LASIK) myopic patients. Design: Cross-sectional study. Participants: Thirty patients with visual complaints after conventional LASIK procedure for correcting myopia. Methods: The 30 patients were fitted with RGP contact lenses. Wave-front measurements were taken before and after RGP contact lens wearing. Results: Compared with bare eye examinations, root mean-square values of higher-order aberrations (HOAs) significantly decreased with RGP contact lens use. Amongthese, spherical aberration decreased from 0.507 (SD 0.304) μm to 0.164 (SD 0.121) μm( t = 7.186, p < 0.001); coma decreased from 0.470 (SD 0.312) μm to 0.165 (SD 0.090) μm ( t = 5.566, p < 0.001); secondary coma decreased from 0.079 (SD 0.050) μm to 0.044 (SD 0.027) μm ( t = 4.118, p < 0.001); and total HOAs decreased from 0.782 (SD 0.449) μm to 0.307 (SD 0.140) μm ( t = 6.710, p < 0.001). Conclusions: Fitting RGP contact lenses effectively decreased HOAs induced by conventional myopic LASIK surgery. Possible reasons may be the elimination of irregularity and dissymmetry on the corneal anteriorsurface, relief of the aspherical extent of the central corneal surface, and enlargement of the effective optical zone.

Effects of Multicurve RGP Contact Lens Use on Topographic Changes in Keratoconus

PurposeTo evaluate the effects of wearing rigid gas permeable (RGP) contact lenses on the topographic changes in keratoconus.MethodsSeventy-seven keratoconic eyes that wore multicurve RGP contact lenses and 30 keratoconic eyes that wore no contact lenses were retrospectively analyzed. The mean follow-ups were 22.6 and 20.5 months in the lens-wearing and control groups, respectively. Visual acuity, comfort, daily wearing time, and corneal staining were evaluated for both groups. The changes in topographic indices were compared between the lens-wearing and control groups.ResultsMulticurve RGP lens corrected logarithm of the minimum angle of resolution visual acuity of the lens-wearing group significantly improved from -0.016±0.065 to -0.032±0.10 at follow-up (p=0.05). In the lens-wearing group with advanced keratoconus, the Sim Kmax, Sim Kmin, apical power, astigmatic index, and anterior elevation significantly decreased from 57.68±4.26 diopter (D), 50.50±2.32 D, 62.79±5.11 D, 7.20±0.55 D and 67.36±16.30 µm to 55.51±4.28 D, 49.62±3.26 D, 60.31±5.41 D, 5.90±0.51 D and 60.61±16.09 µm, respectively (paired t-test, p<0.05). The irregularity index of 3 mm did not significantly change. Meanwhile, in the control group, the apical power and irregularity index increased from 55.56±7.25 D and 3.06±1.68 D to 57.11±7.75 D and 3.25±1.71 D, respectively (paired t-test, p=0.008, p=0.01).ConclusionsProperly fitted multicurve RGP contact lenses are not likely to contribute to the progression of keratoconus.

Why do Patients with Improved Visual Acuity Drop out of RGP Contact Lens use? Ten-Year Follow-Up Results in Patients with Scarred Corneas

To evaluate the long-term results of rigid gas permeable (RGP) contact lenses and to investigate the reasons for patient dissatisfaction with this therapy. Records of 17 patients (20 eyes) who started using RGP contact lenses for correction of irregular astigmatism due to scarred corneas between 1995 and 1996 were evaluated retrospectively. Best-corrected visual acuities with or without RGP contact lenses were noted. The mean duration of contact lens use, reasons for discontinuation of therapy, and treatment methods preferred over contact lens use were evaluated. The irregular astigmatisms were induced by herpetic keratitis (3 eyes), corneal trauma (5 eyes), and previous corneal infections (12 eyes). All of the patients had increase in visual acuity with RGP contact lenses (p=0.000). At the end of the follow-up it was found that only one patient was still using RGP contact lenses (5%). The mean duration for contact lens use was 21.42+/-4.53 SE months (2-72 months). The reasons for dropping out contact lenses were intervening surgical procedures (57.8%), loss of patient motivation (26.3%), recurrent punctate epitheliopathy (10.5%), and herpes simplex keratitis reactivation (5.2%). RGP contact lens use is a successful method of increasing visual acuity in scarred corneas. However, patients with good visual acuity in the fellow eye find it hard to remain motivated for RGP contact lens use in the unhealthy eye. Furthermore, patients prefer permanent treatment methods even though these methods would result in decreased visual acuity.

Higher-order aberrations in young refractive surgery candidates in India: Establishment of normal values and comparison with white and Chinese Asian populations

To establish normal values of higher-order aberrations (HOAs) in young candidates in an Indian population and compare them with results in white and Asian (Chinese) populations. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India. This prospective trial comprised 206 consecutive candidates (412 eyes) for customized laser in situ keratomileusis. Exclusion criteria were previous ocular surgery, corneal ectasia, rigid gas-permeable contact lens use, corneal scar, or cataract. Higher-order aberrations were analyzed on a Zywave workstation (Bausch & Lomb Surgical). The mean age was 23.63 years +/- 1.99 (SD); the mean refractive error, -2.97 +/- 4.0 diopters (D) sphere and -1.73 +/- 3.6 D cylinder; and the mean 6.0 mm HOA root mean square (RMS), 0.36 +/- 0.26 microm. The most predominant HOAs were 3rd order (coma, trefoil). The summated RMS of the 3rd order was the most predominant (mean 0.23 +/- 0.15 microm), followed by the 4th and 5th orders (P<.0001). The ratio between summated RMS means was 1:0.7:0.3, similar to that in white populations (1:0.7:0.3) and different than in Asian (Chinese) populations (1: ~ 0.8:0.002). Third- and 4th-order aberrations were between 60% and 70% higher in Asian (Chinese) eyes. The difference between data in this study and those in others was less than 10% in 3rd and 4th order. The normative data for HOA in Indian eyes closely matched that in white populations but was different from that in Asian (Chinese) populations, which may provide help in nomogram modifications.

The Effect of Contact Lens Wear on the Excitability of Blink Reflex Circuit: A Prospective Controlled Study

This study determined whether the use of contact lenses constitutes a model for adaptive alterations. We included 8 volunteers using contact lenses and 11 volunteers as control group. The blink reflex (BR) recovery was measured using the paired-pulse technique. No differences were observed between groups in initial R2 recovery at 200, 400, 800 and 1000 ms intervals. The 600 ms measurements were lower in the contact lens group (P = 0.037). There was a decrease at 600 ms in the 1st week, which reached the value of the control group in the 1st month (P = 0.049). It was concluded that rigid gas-permeable contact lens use does not cause an increase in the excitability of the interneurons that affect the BR cycle.

Use of a run-in period to decrease loss to follow-up in the contact lens and myopia progression (CLAMP) study

Rigid gas permeable (RGP) contact lenses are initially less comfortable to wear than spectacles. In previous studies evaluating the use of RGP contact lenses to control myopia, more subjects randomly assigned to wear RGP contact lenses have been lost to follow-up than spectacle wearers. Previous rigid contact lens myopia control studies have lost 44% and 47% of the rigid contact lens wearers. This unequal loss to follow-up may compromise the results of the study, so we conducted a run-in period prior to randomized treatment-group assignment to ensure that all participants could adapt to RGP contact lens wear. We enrolled 147 children ages 8–11 years with myopia in the run-in period. Of the 147 subjects, 116 (78.9%) were able to wear RGP contact lenses for at least 40 hours per week and reported that they were “usually comfortable” or “always comfortable.” After 3 years, no subjects were lost to follow-up. The run-in period greatly reduced the loss to follow-up suffered by previous RGP contact lens myopia progression studies and may help provide more definitive answers regarding myopia control with RGP contact lenses.

Contact lens care in keratoconus

Purpose: To quantify the complexity involved in fitting contact lenses on the eyes of patients with keratoconus. Methods: The contact lens care of one randomly selected eye each of 38 keratoconus patients was retrospectively analyzed and compared to that of 38 gender and age matched controls. We evaluated the number of diagnostic contact lenses used to establish the initial contact lens order, number of ordered rigid gas permeable (RGP) contact lenses needed to complete the fit, number of office visits during the initial 4 months of care, best spectacle and RGP contact lenses corrected Log MAR visual acuities, complications encountered, and whether or not the patient was successful in contact lens wear. Results: Keratoconic eyes statistically used more diagnostic lenses, more ordered lenses, and more office visits than did normal eyes. Visual acuities improved from an average of 20/40 with spectacles to an average of 20/20 by use of RGP contact lenses in keratoconic eyes. Visions were corrected to 20/20 with both spectacles and contact lenses in control eyes. Sixty nine percent (69%) of keratoconic eyes and 95% of controls were successful in contact lens wear. Conclusions: Contact lens care of keratoconic eyes is more challenging than care of normal eyes because of the need for more diagnostic and ordered contact lenses and the use of more professional time. Keratoconic eyes may suffer more complications than normals during contact lens care, but this does not affect the success rates, and such patients benefit from enhanced visual acuity with RGP contact lenses compared to that achieved with spectacles.