|Year : 2023 | Volume
| Issue : 1 | Page : 86-88
Managing visual symptoms in cone-rod dystrophy with prosthetic soft contact lens: A case report
Manju Balakrishnan, Asif Iqbal
Department of Contact Lens, Sankara Nethralaya, Unit of Medical Research Foundation, Chennai, Tamil Nadu, India
|Date of Submission||16-May-2022|
|Date of Acceptance||05-Sep-2022|
|Date of Web Publication||20-Jan-2023|
Department of Contact Lens, Sankara Nethralaya, Medical Research Foundation, No. 18, College Road, Nungambakkam, Chennai - 600 006, Tamil Nadu
Source of Support: None, Conflict of Interest: None
This case demonstrates the utilization of a prosthetic type C contact lens to manage visual symptoms such as photophobia and glare in patients with cone-rod dystrophy. A 20-year-old female patient reported to our clinic with complaints of photophobia, glare, and impaired vision and was evaluated with different contact lens trials to improve her ability to use her remaining vision effectively. The patient was fitted with ACUVUE OASYS transitions, X-chrome red-tinted contact lenses, and tinted type C contact lenses. All the trials manifest optimal fitting and better comfort but only the tinted type C contact lens resulted in pronounced improvement in photophobia, glare, and vision both indoors and outdoors. Finally, a tinted type C contact lens is effective in relieving photophobia and glare and making a remarkable changeover in the quality of life. Thus, all contact lens practitioners should use these lenses to treat victims with glare and photophobia caused by cone-rod dystrophy.
Keywords: Cone-rod dystrophy, glare, photochromatic contact lens, photophobia, prosthetic contact lens
|How to cite this article:|
Balakrishnan M, Iqbal A. Managing visual symptoms in cone-rod dystrophy with prosthetic soft contact lens: A case report. Indian J Ophthalmol Case Rep 2023;3:86-8
|How to cite this URL:|
Balakrishnan M, Iqbal A. Managing visual symptoms in cone-rod dystrophy with prosthetic soft contact lens: A case report. Indian J Ophthalmol Case Rep [serial online] 2023 [cited 2023 Feb 1];3:86-8. Available from: https://www.ijoreports.in/text.asp?2023/3/1/86/368128
Cone-rod dystrophy describes a group of associated eye disorder that affects both cone and rod cells of the retina and causes central and peripheral vision loss, impaired color vision, photophobia, and glare. Patients have reported a significant amount of photophobia in daylight and also in artificial bright light, which can be overcome with tinted optical filters and contact lenses. Tinted contact lenses have been clinically proven as an effective option to reduce photophobia and glare to a significant amount and also reported improved visual acuity, contrast sensitivity, and color vision. Previously reported studies have used a different range of tints such as red, brown, amber, and gray., These lenses come under the category of prosthetic type B lenses, with no pupil and tinted iris portions. Along with the enhanced appearance of disfigured eyes, prosthetic lenses are also proven beneficial to reduce visual symptoms in sighted eyes, especially type B and type C lenses. Type C prosthetic contact lenses are with a clear pupil with a tinted iris of different diameters and are chiefly used to improve visual function by reducing glare and photophobia in eyes with dilated or irregular pupils, aniridia, and albinism. This case report will illustrate the utilization of type C lenses to reduce visual symptoms and improve visual performance in a case of cone-rod dystrophy.
| Case Report|| |
A 20- year-old female patient presented to our clinic with complaints of difficulty in viewing slides on a microscope in bright illumination, poor contrast, and photophobia. Past ocular history revealed cone-rod dystrophy, and the corrected visual acuity in the right eye was −3.50 DS/−0.50 DC × 180 (20/200, [email protected] and in the left eye was −3.50 DS (20/200, [email protected]). Slit-lamp examination revealed normal adnexa, and fundus showed blunted foveal reflex. Optical coherence tomography (OCT) showed a missing foveal inner-outer segment photoreceptor junction. Full-field electroretinogram showed reduced scotopic and non-recordable photopic responses. Mesopic pupil size was 5.0 mm in both eyes. She was able to appreciate only the demo plate in both eyes with Ishihara plates, and the use of a red filter did not show any significant improvement (1/21 in both eyes).
The patient was not very keen on the X-chrome lens (Silver Line Laboratories, India) as she was able to appreciate only 1/21, and also the red tint was prominent and noticeable and was affecting the cosmetic appearance [[Table 1] and Trial 1] [Figure 1]a. The second trial was with ACUVUE OASYS with transition lenses based on light intelligent technology (Johnson & Johnson Vision Care, Inc, Jacksonville, Florida) [[Table 1] and Trial 2]. Transition lenses are soft silicone hydrogel photochromatic contact lenses that improve the visual experience under bright and changeable lighting conditions. This special lens consists of a photochromatic additive, which darkens in ultraviolet and/or high-energy visible light and returns to a clear state upon removal of light. In bright sunlight, she was happy with photochromatic lenses in their fully activated [Figure 1]c state but failed in inactivated state [Figure 1]b.
|Figure 1: Both eyes (a) with X-chrome contact lens, (b) appearance with inactivated photo chromatic contact lens, (c) appearance with partially activated photo chromatic contact lens, (d) appearance with type C contact lens|
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Subsequently, the patient was offered a custom-made prosthetic type C (Silver Line Laboratories, India) lens. In the initial trial, a dark brown iris tint [[Table 1] and Trial 3] was tried but it was too bright while capturing photos with the flashlight on and noticeable; hence, she was tried with a medium grayish black tint with a 4.0 mm clear pupil and 11.8 mm iris diameter, which showed better cosmesis [[Table 1] and Trial 4] and optimal fit [Figure 1]d. Vision improved to 20/125 in both eyes. The patient reported a significant reduction in photophobia, glare, and enhanced comfort both in indoor and bright sunlight and was able to view the screen with better contrast. After a proper explanation about insertion removal and care regimen, the lenses were dispensed. She was advised to use photochromatic glasses or sunglasses over contact lenses on bright sunny days.
| Discussion|| |
Fully iris-tinted contact lenses are proven beneficial in different retinal dystrophies by reducing visual symptoms such as glare and photophobia. This is based on the concept of reducing the amount of light entering the eye, which prevents rod photoreceptor saturation and reduces glare and photophobia. The previous reports have shown the effectiveness of centrally tinted contact lenses. Present case have reported the usefulness of an iris-tinted, clear pupil contact lens on cone-rod dystrophy by improving vision and reducing visual symptoms. Severinsky et al. reported the use of a tinted segment of 7.00 mm and 10.50 mm diameter, whereas in this case report an 11.80 mm tinted iris segment was used to cut off the light entering through the peripheral cornea.
Previous studies have reported the efficacy of photochromatic transition lenses in both indoor and outdoor lighting., In its indoor state, though the lens appears clear, a few photo chromatic molecules will be activated, which will enable the lens to filter lights across the visible spectrum and can block 15% of light indoors. In the present cases, the patients did not find any significant difference in indoor lighting in the inactivated state, whereas it was very effective in its fully activated state.
Finally, a type C lens with grayish black tint and a larger tinted iris segment reduced the amount of light entering the eye peripherally and the central clear zone smaller than mesopic pupil size helped in reducing photophobia, glare significantly and improved visual acuity as well. The patients experienced immense positive outcomes, in terms of comfort, cosmesis, and vision enhancement with type C lenses both in bright indoor and outdoor lighting. Besides this, the vision improvement from 20/200 to 20/125 could be another reason for accepting type C lenses over other modalities.
| Conclusion|| |
In conclusion, a type C contact lens with a pupil smaller than mesopic pupil diameter and a larger iris tint can be beneficial in terms of reducing photophobia, glare, and additional reflection issues. Apart from relieving photophobia and glare complaints, it also builds up one's self-confidence and immensely improves the quality of life. By taking the positive outcome of this lens, it should be effectively practiced by eye care professionals for the welfare of people with cone-rod dystrophies with visual symptoms and can make their practice unique.
Declaration of the patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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