Rigid Gas-Permeable Contact Lens for Visual Rehabilitation in Children Younger Than 12 Years With Penetrative Ocular Trauma

Abstract

Objectives:

To observe the clinical outcomes of visual rehabilitation using rigid gas-permeable contact lenses (RGPCLs) after penetrative ocular trauma in children younger than 12 years in China.

Methods:

Patients younger than 12 years with penetrative ocular trauma fitted with an RGPCL for visual rehabilitation from 2017 to 2021 were included. In the case cohort, the best-corrected visual acuity (BCVA) with spectacles was measured when the RGPCL was fitted, and the initial BCVA with RGPCL, and the BCVA at the last visit were compared.

Results:

Fifteen patients, aged 4 to 12 (mean 8.0±2.7) years, who wore an RGPCL for 7 to 53 (mean 20.3±15.7) months, were included. The BCVA was log of minimal angle of resolution 0.4 (0.2–0.7) with spectacles and 0.1 (0.1–0.2) for RGPCL at the initial visit, and 0.0 (0.0–0.1) for BCVA at the last visit, with a statistically significant difference between the three comparisons (P<0.001). Six of the 15 (40%) children abandoned wearing RGPCL because of discomfort and lens rejection (n=3, 50%), lens loss and inability to replace broken lens because of travel distances and epidemics (n=2, 33%), and cost (n=1, 17%).

Conclusions:

Although application is complicated and initial wearing comfort is poor, an RGPCL is still a beneficial, safe tool for postoperative visual rehabilitation in children with open ocular trauma.

Children are more likely to develop amblyopia after ocular trauma than adults; thus, timely visual rehabilitation after ocular trauma in children is especially important.¹ Most open-globe injuries are accompanied by corneal laceration, and the corneal opacity and corneal irregular astigmatism caused by corneal scarring are important factors that affect vision.² In the past few decades, visual rehabilitation of corneal scarring after corneal laceration has been treated by procedures such as corneal transplantation and contact lens correction.^3–5 Because of the good correction effects, rigid gas-permeable contact lenses (RGPCLs) are increasingly used for refractive correction after corneal trauma.⁶

However, few studies have reported the use of RGPCLs for refractive correction after corneal laceration in children younger than 12 years. The hypothesis is that wearing RGPCL after corneal trauma in children has better visual outcomes than spectacles. In this study, we evaluated the postoperative visual rehabilitation results for children younger than 12 years with open ocular trauma accompanied by corneal laceration who wore RGPCLs.

METHODS

This retrospective case series study included 15 children younger than 12 years who wore an RGPCL for visual rehabilitation after ocular trauma treated at the First Affiliated Hospital of Zhengzhou University from January 2017 to December 2021. Based on medical records and telephone follow-ups, data were collected on sex, age at the time of lens wearing, cause of ocular trauma, grading, surgical procedure, postoperative lens status, length of lens wearing, abandonment or not, corrected visual acuity before wear, corrected visual acuity with an RGPCL, corrected visual acuity at the last follow-up, corneal topography, and amblyopia treatment. This study was approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University and was conducted in accordance with the tenets of the Declaration of Helsinki. Consent was obtained from the parents or guardians of the participants for this study.

All children were referred to the optometry department through the outpatient ophthalmology clinic, evaluated and fitted with an RGPCL, which was customized to meet the requirements of proper mobility, pupillary area coverage, relative center positioning, and ideal distribution of fluorescein under the lens. The parents/guardians and children were taught by professional technicians about lens cleaning, care, wearing, and removal until they were able to perform the application independently. Regular reviews at 1 week, 1 month, and every 3 months thereafter, were required and adjustments to the correction method and amblyopia treatment plan were made on a case-by-case basis. The RGPCLs used in all children were aspherical lenses (Menicon Z material, Menicon, Nagoya, Japan). Corneal morphometry was performed with a Sirius (CSO, Scandicci, Italy) corneal topographer before fitting the RGPCLs, and the corneal topography was reviewed according to follow-up. Visual acuity was converted from decimal values to log of minimal angle of resolution (logMAR). Ocular trauma grading was assessed according to the ocular trauma score.⁷

Statistical analyses were conducted using SPSS version 27.0 (IBM Corp., Armonk, NY). Because none of the data conformed to a normal distribution, the Friedman test was used for comparisons between best-corrected visual acuity (BCVA) with spectacles, initial BCVA with RGPCL, and BCVA with RGPCL at the last visit. The values are expressed as median (first quartile, third quartile) [M(Q_1,Q₃)]. The comparisons between corneal astigmatism at the first visit and corneal astigmatism after 1 year of RGPCL wearing, and the comparison between the root mean square per area (RMS/A) on the anterior surface of the cornea at the first visit and the RMS/A at 1 year after RGPCL wearing were performed using the Wilcoxon signed-rank test. The difference was considered statistically significant at P<0.05.

RESULTS

There were 15 patients in this case series (10 males, five females), aged 4 to 12 (mean 8.0±2.7) years, with an interval of 3 to 52 (mean 21.1±17.6) months between injury and RGPCL wear, and a continuous lens wear time of 7 to 53 (mean 20.3±15.7) months. Eleven patients were pseudophakic and four patients were aphakic. Twelve patients wore RGPCL after the removal of corneal sutures, and one patient wore RGPCL without the removal of sutures, 4 months after corneal suturing (case 10). Two patients wore corneal bandage lenses to assist in wound healing after corneal trauma was treated without sutures, and wore RGPCL after corneal healing (cases 3, 7). Patient characteristics are presented in Table 1.

TABLE 1.

Patient Demographic Details and Clinical Features

No.	Sex	Eye	Cause of Injury	Status of Lens	Grade of injury (OTS)	Posterior Segment injury	Age at Wearing RGPCL	Time Between Injury and Wearing RGPCL (months)	Wearing RGPCL Duration (months)	RGPCL-wear
1	F	OD	Pencil	IOL	1	N	12	42	53	Continuous wear
2	F	OS	Pencil	Phakic	2	N	10	52	45	Continuous wear
3	M	OS	Pencil	Phakic	1	N	5	3	45	Continuous wear
4	F	OS	Scissors	IOL	1	N	5	37	35	Continuous wear
5	M	OD	Branch	IOL	1	N	11	44	15	Drop out
6	M	OD	Pencil	Phakic	1	N	5	19	17	Drop out
7	M	OS	Pencil	IOL	2	N	7	4	13	Drop out
8	M	OS	Pencil	IOL	1	Retinal detachment with hole	6	12	7	Drop out
9	F	OD	Pencil	IOL	1	N	10	38	10	Drop out
10	M	OS	Slingshot	IOL	1	N	4	4	13	Continuous wear
11	M	OS	Bamboo sticks	IOL	1	Retinal detachment with hole	10	9	12	Continuous wear
12	F	OS	Trolley frame	Phakic	1	N	6	5	11	Continuous wear
13	M	OS	Book	IOL	1	N	10	10	10	Continuous wear
14	M	OD	Slingshot	IOL	1	N	10	16	10	Continuous wear
15	M	OD	Umbrella	IOL	1	N	9	24	6	Drop out

F, female; IOL, intraocular lens; M, male; N, no injuries; OD, oculus dexter (right eye); OTS, Ocular Trauma Score; OS, oculus sinister (left eye); RGPCL, rigid gas-permeable contact lens.

In all cases, an RGPCL was the main correction method, because the intraocular lens (IOL) eye has no accommodation power and spectacles are used to compensate for accommodation loss; spectacles are used for near or distance vision depending on the refraction of the healthy eye. For example, one patient (case 11) showed −2.50 DS refractive error in the healthy eye, and the traumatic eye was fitted with an RGPCL to achieve the BCVA for near vision; the patient wore frames with lenses for both eyes for distance vision. The RGPCL could not completely correct the irregular astigmatism; however, there was a relatively stable residual small degree of astigmatism (spectacles prescription: +0.50–1.50×145), and spectacles improved the visual acuity from 0.1 to 0 (case 10).

Data from all 15 patients were included in statistical analysis. The BCVA was 0.4 (0.2–0.7) for spectacles and 0.1 (0.1–0.2) for RGPCL at the initial visit, and 0.0 (0.0–0.1) for BCVA at the last visit, and the difference between the three comparisons was statistically significant (P<0.001); all children wore an RGPCL, and six children wore it in combination with spectacles (Table 2). Fourteen of the 15 (93.3%) children showed a BCVA equal to or better than 0.1 logMAR with RGPCL at the last visit. All BCVA data are shown in Figure 1. Except for two patients (cases 1, 2), the remaining 13 patients underwent amblyopia treatment and used part-time occlusion with RGPCLs; the duration of coverage was adjusted according to the visual acuity at follow-up.

TABLE 2.

Analysis of Variability for the Three BCVA Measurements [M(Q_1,Q₃)]

	(1) First Visit with Spectacles (n=15)	(2) First Visit with RGPCL (n=15)	(3) Last Visit with RGPCL (n=15)	P
				Overall	(1) vs. (2)	(1) vs. (3)	(2) vs. (3)
BCVA	0.4 (0.2–0.7)	0.1 (0.1–0.2)	0.0 (0.0–0.1)	<0.001	0.004	<0.001	0.204

P-values were derived with the Friedman test.

BCVA, best-corrected visual acuity; RGPCL, rigid gas-permeable contact lens; versus, vs..

FIG. 1.

Best-corrected visual acuity of the 15 children with ocular trauma who wore an RGPCL.

Except for those who abandoned the RGPCL without regular follow-up and those who wore an RGPCL for less than 12 months, the rest who wore an RGPCL continuously for more than 12 months were regularly followed up (6 patients; cases 1, 2, 3, 4, 10, 11) and had their corneal topography reviewed at 12 months of RGPCL wear. There was no statistically significant difference between corneal astigmatism and RMS/A at 6 mm on the anterior surface of the cornea at 12 months of continuous RGPCL wear compared with that at the initial visit. However, changes were clearly observed in the topography of cases 10 and 11, as shown in Figs. 2,3.

FIG. 2.

Representative patients wearing an RGPCL after ocular trauma (case 10). (A) Slitlamp microscopic photograph of left eye after wearing an RGPCL, which shows the white spot of the left inferior temporal cornea with the suture in place. (B) Distribution of tear fluid under the RGPCL after fluorescent staining. (C) Corneal topography before the first RGPCL wear. (D) Corneal topography after 1 year of RGPCL wear. RGPCL, rigid gas-permeable contact lens.

FIG. 3.

Representative patients wearing an RGPCL after ocular trauma (case 11). (A) Slitlamp microscopic photograph after RGPCL wear in the left eye, which shows the central transverse scar of the left cornea spanning the pupillary region. (B) Distribution of tear fluid under the RGPCL after fluorescent staining. (C) Topography of the cornea before wearing the RGPCL. (D) Topography of the cornea after RGPCL wear for 1 year. RGPCL, rigid gas-permeable contact lens.

Four patients had one or two incidents of grade I spotting of the corneal epithelium during follow-up, which recovered after medication. Other patients showed no adverse reactions during RGPCL wear. In addition, one patient (case 7) was found to have decreased visual acuity because of posterior capsular opacification at the 6-month follow-up for RGPCL wear, and visual acuity gradually improved after timely neodymium-doped yttrium aluminum garnet laser posterior capsulotomy.

The RGPCLs were worn and removed during one to 4 (mean 1.9±0.9) days; parents/guardians applied the lenses for 11 patients and four children were able to apply the lens (cases 1, 2, 5, 9). Six of the 15 (40%) patients abandoned wearing the RGPCL. The reasons for abandonment included discomfort and lens rejection (n=3, 50%), lens loss and inability to replace a broken lens because of travel distances and epidemics (n=2, 33%), and cost (n=1, 17%).

DISCUSSION

The latest reported prevalence of ocular trauma in children in China is 14.6% and is consistent with many other studies in that the prevalence is higher in boys than in girls, as it was in our study.^8,9 Unlike adults, children are more likely to acquire poor final vision because of amblyopia after ocular trauma.¹ Moreover, some studies have shown that factors such as young age and heavy injury are important risk factors for poorer final BCVA after ocular trauma in children.^1,10,11 Therefore, visual rehabilitation needs to be more timely and complete to avoid amblyopia and to maximize the final BCVA in children with ocular trauma.

Suturing of corneal ruptures can lead to corneal scarring, irregular astigmatism, and higher order aberrations on the anterior surface of the cornea, which can affect vision to varying degrees.¹² A study on traumatic open-globe injuries in American children showed that the average final visual acuity was 1.401 logMAR.¹³ Shah et al.¹⁴ reported that only 38.4% of children who underwent traumatic cataract surgery after open-globe injury showed visual acuity better than or equal to 0.3 logMAR. In our study, 14 of the 15 (93.3%) children with penetrative ocular trauma who wore RGPCL for visual rehabilitation demonstrated a final BCVA equal to or better than 0.1 logMAR. For post-traumatic corneal injury patients, wearing an RGPCL with posterior tear filling to compensate for the irregular anterior surface of the cornea can improve vision.¹⁵ RGPCL wear can reduce the root mean square and aberrations to some extent, especially in those with high corneal aberrations.¹⁶ This is one of the reasons why an RGPCL can help improve corrected visual acuity in patients after corneal trauma. Itoi et al.¹⁷ previously reported that BCVA improved with RGPCL wear more than 0.2 logMAR compared with spectacles in 5 (83%) pediatric patients. In our study, the BCVA of these 15 patients with RGPCL at their first and last visits is better than their BCVA with spectacles at their first visit. In 10 of the 15 (67%) patients, BCVA improved with RGPCL at the last visit was more than 0.2 logMAR compared with spectacles at the first visit, and BCVA improved was equal to 0.2 logMAR in three patients (20%).

Open-globe injuries in children are often associated with lens damage, and these children may have aphakic or IOL eyes, in short, eyes in an unadjusted state. In this study, we had to choose the appropriate correction and give the best and most complete refractive correction possible, including bifocal correction at distance and near vision.^18,19 In our study, six children with IOL eyes still needed to wear near or distance spectacles after wearing an RGPCL to ensure maximum clear vision in distance and near viewing, especially those children who needed masking and amblyopia training. In addition, the prescription for spectacles worn by case 11 helped maximize the balance of retinal imaging in both eyes, while avoiding refractive aberrations.

Navon²⁰ concluded that corneal morphology is largely stable 14 weeks after suture removal for corneal trauma and spontaneous corneal morphologic changes are difficult. Elseht and Nagy²¹ showed that in pediatric ocular trauma patients who wore an RGPCL after a mean time of 4.1 months after suture removal, there was a reduction in corneal astigmatism and corneal aberration after 6 months of continuous wear. However, in our study, there was no statistically significant difference in the corneal topography before and after 1 year of wearing an RGPCL in six patients; however, as shown in Figure 2, we could clearly observe that the anterior surface curvature of the cornea became more regular in cases 10 and 11. We considered this was because some of the children included in the statistics were fitted with an RGPCL too long after the time of injury (42 months for case 1, 52 months for case 2, 37 months for case 4), the corneal scar had stabilized and it was indeed difficult to change the morphology, such that the statistical results showed no difference. In our opinion, to avoid amblyopia in younger children and restore visual acuity as soon as possible and improve anterior surface morphology of the cornea, an RGPCL can be tried in eyes with corneal sutures with intact corneal epithelium after a comprehensive evaluation. In eyes with removed corneal sutures, an RGPCL can be worn as soon as possible after the corneal epithelium has fully recovered. The RGPCL may “shape” the anterior surface of the cornea, promoting regularization of the “fresh” corneal scar. Corneal morphology changes fastest in early post-traumatic corneal injury and has the greatest variability.¹ However, the effect of an RGPCL on corneal morphology after corneal laceration requires further investigation. In our study, two children with unsutured corneas showed lens parameter changes within 2 months after lens prescription, and the basal arcs changed significantly, tightening 0.4 and relaxing 0.6, which is also related to the unstable corneal morphology of these two patients after injury; their prescriptions for lenses were changed in a short period of time.

Unlike the results of Itoi et al.'s¹⁷ study, the parents/guardians or slightly older children in this case series had a short time to learn lens removal and were able to wear them in an average of 1.87 days, and the children were cooperative in the process of receiving examinations, which we consider was because of the enhanced adaptation of these children who had received multiple and prolonged ophthalmic examinations and treatments after ocular trauma. However, learning to apply lenses quickly does not indicate that children will be able to adhere to wearing lenses day after day. Different studies have come to different conclusions regarding the duration of continuous RGPCL wear. Pradhan et al.²² reported that for children with ocular trauma who wore an RGPCL, 91% continued to use an RGPCL during a mean follow-up of 15 months. In Itoi et al.‘s¹⁷ study, RGPCL wear was discontinued in only one of six children during a mean follow-up of 42.9 months. Our study differs in that the abandonment rate reached 40%, which we consider was most closely related to the economic conditions of the children's parents/guardians and whether they could insist on helping or supervising their children to wear an RGPCL. Concurrently, because of the coronavirus disease 2019 pandemic and the impact of disease control and prevention policies implemented thereafter, patients in remote areas could not check or replace lenses in time or reorder broken lenses, which contributed to the drop-out rate.

This study has some limitations. The small sample size, short follow-up time because of abandonment of RGPCL wear in some patients, and incomplete medical record data because of irregular follow-ups affected the statistical power of this study. However, these are the characteristics of a retrospective study; thus, these limitations are inherent to the study design. The effect of an RGPCL on corneal morphology after open eye trauma in children, and its role in visual rehabilitation, requires further reasonable and comprehensive prospective studies with large samples and long-term follow-ups.

Studies have shown that a variety of contact lenses can be used effectively for visual rehabilitation after ocular trauma.⁵ However, in China, most doctors and parents will not choose soft contact lenses for children, and scleral lenses are not approved for clinical use. Rigid gas-permeable keratocontact lenses are approved for clinical use in pediatric patients for the control of axial myopia, refractive correction of aphakic eyes after congenital cataract surgery, or other reasons.^23–25 Rigid gas-permeable keratocontact lenses have also been shown to be effective in the treatment of a variety of clinical conditions.²⁶ Nevertheless, many parents and even doctors are hesitant to use them because of concerns about the safety, cost, and the complexity of rigid keratocontact lenses. Our study of children with ocular trauma has shown that an RGPCL was a powerful tool for visual rehabilitation after ocular trauma in children younger than 12 years.

ACKNOWLEDGMENTS

The authors would like to thank Editage (www.editage.com) for English language editing.