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 Table of Contents  
Year : 2023  |  Volume : 3  |  Issue : 2  |  Page : 597-598

Defect at the multiples of 3

1 Bausch and Lomb Contact Lens Centre, LV Prasad Eye Institute Kode Venkatadri Chowdary Campus, Vijayawada, Andhra Pradesh, India
2 Brien Holden Institute of Optometry and Vision Sciences, L V Prasad Eye Institute, Road No. 2; Prof. Brien Holden Eye Research Centre, Hyderabad Eye Research Foundation, L V Prasad Eye Institute, Banjara Hills, Hyderabad, Telangana, India

Date of Submission19-Aug-2022
Date of Acceptance07-Dec-2022
Date of Web Publication28-Apr-2023

Correspondence Address:
Manikanda Prabhu
Department of Cornea and Anterior Segment, LV Prasad Eye Institute Kode Venkatadri Chowdary Campus, Vijayawada, Andhra Pradesh
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijo.IJO_2038_22

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Keywords: Epithelial defect, RGP, three-point touch

How to cite this article:
Prabhu M, Bhalerao S, Durai VR. Defect at the multiples of 3. Indian J Ophthalmol Case Rep 2023;3:597-8

How to cite this URL:
Prabhu M, Bhalerao S, Durai VR. Defect at the multiples of 3. Indian J Ophthalmol Case Rep [serial online] 2023 [cited 2023 Jun 3];3:597-8. Available from: https://www.ijoreports.in/text.asp?2023/3/2/597/374926

Various contact lenses are used to rehabilitate optically the patients diagnosed with keratoconus. Among them, corneal rigid gas permeable (RGP) contact lenses are the first choice for patients with keratoconus and are widely used to rehabilitate them. Spherical RGP on irregular cornea will always result in slight disagreement between the contact lens and cornea, which results in 3 and 9 o' clock staining, lens ejection, or rejection from the eye. The problem of 3 and 9 o' clock staining has been difficult to manage by the clinician since the early days of corneal lenses. This case enlightens the clinician to educate the patients about new care and regimen techniques during the pandemic, for example, the hand sanitizer should not be used before inserting the contact lens, and also the importance of symmetric edge clearance in fitting keratoconus.

A 26-year-old female presented to the clinic with the chief complaints of red eye, foreign body sensation, photophobia, and burning sensation after inserting RGP contact lens in the left eye. She was a known case of keratoconus for 2 years and had been optically rehabilitated with contact lenses since then. Due to the ongoing pandemic, patient started sanitizing her hands using 75% ethyl alcohol. She also reported that she did not dry her hand after the use. She reported that she used the sanitizer and touched the contact lens with the same hand and inserted it in her eye. Copious preservative-free topical lubricating eye drops and antibiotic eye drops resulted in complete resolution of the clinical sign within a week.

  Discussion Top

RGP lenses are known for their best correction for keratoconus by creating a uniform optical surface. The most commonly used RGP lenses are spherical corneal lenses with a tricurve or quadracurve design. The central aspherical area of cornea can be fitted with a spherical back optic zone contact lens. Asymmetric edge clearance is one of most common signs noted while fitting spherical RGP lens on an irregular cornea. Three broadly discussed RGP-fitting philosophies are apical clearance, apical bearing, and divided support.[1] In [Figure 1], the static fitting lenses show the central feathery touch with midperipheral pooling with asymmetric peripheral clearance. Slit-lamp image was taken in the first visit. Insufficient edge clearance causes corneal superficial damage as there is no adequate gap between the lens edge and cornea. In this case, the patient was using lens with asymmetric edge clearance without any discomfort previously and on slit-lamp examination, there was no peripheral staining. On examination, the epithelial defect was noted precisely at 3 and 9 o' clock position. This illustrates that the excessive edge clearance has more tear exchange between the lens and cornea than the insufficient edge clearance of the lenses.[2] A previous study reported that chemical residue in bi-prism contributed to epithelial disruption.[3] In the present case, the chemical residue present in the lens edge caused epithelial defect exactly at 3 and 9 o' clock position [Figure 2], whereas in other areas, there was no epithelial defect due to excessive edge clearance. Insufficient edge clearance does not flush away the chemical residue during blinking. But in the vertical zone, the edge profile is excessive, so the chemical residue may have flushed away during blinking.
Figure 1: Fluorescein pattern of rigid gas permeable contact lens on irregular cornea. The oval dotted marker points to the thin edge clearance at the 3 and 9 o' clock position

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Figure 2: (a) The RGP lens with fluorescein staining. The oval dotted marker indicates epithelial defect at 3 and 9 o' clock position. (b) Complete resolution of epithelial defect after use of copious lubricants and antibiotic medications along with cessation of contact lens use

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Albeit the best practice during pandemic is to keep our hands clean, practitioners should educate the patients about the new guidelines of inserting the lenses. This also drives home the importance of symmetric edge clearance in fitting keratoconus.

Declaration of 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 initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Leung KK. RGP fitting philosophies for keratoconus. Clin Exp Optom 1999;82:230-5.  Back to cited text no. 1
Edrington TB, Gundel RE, Libassi DP, Wagner H, Pierce GE, Walline JJ, et al. Variables affecting rigid contact lens comfort in the collaborative longitudinal evaluation of keratoconus (CLEK) study. Optom Vis Sci 2004;81:182-8.  Back to cited text no. 2
Durai R, Singh P, Ramappa M. Target sign: An applanation epitheliopathy. Indian J Ophthalmol 2019;67:1694-5.  Back to cited text no. 3
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