Applications of Different Types of Gas-Permeable Contact Lenses in Keratoconus and Their Visual Results

Kazanci, Burak; Özek, Dilay; Anayol, Alparslan; Balıkçı, Ayşe Tüfekçi; Ileri, Dilek; Yılmazbaş, Pelin

doi:10.5301/ejo.5000449

Cited by 9 publications

(9 citation statements)

References 11 publications

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“…In this study, aspherical-curve HCLs were used for stages 3 and 4. Kazanci et al reported poorer BCVA outcomes than those in our study [ 17 ]. Our aspherical-curve HCLs may have achieved better BCVA than those in previous studies because of the larger eccentricity (E) values in the peripheral-zone curve design, resulting in a good HCL fit ( Table 7 ).…”

Section: Discussioncontrasting

confidence: 81%

“…In previous studies on multi-curve HCLs, the HCLs were not designed to have a flat peripheral zone curve; however, the BCVA, duration of HCL wear, and HCL wearing success rates were better than those obtained in this study [ 17 – 19 ]. The reason for the poor result of multi-curve HCLs in our study may be that most multi-curve HCLs were used for stage 4 cases.…”

Section: Discussioncontrasting

confidence: 70%

“…Previous studies on aspherical-curve HCLs have been reported by Yanai et al [ 16 ] and Kazanci et al [ 17 ]. In the report by Yanai et al, the E value of the peripheral-zone curve design was small, and HCLs were not used for severe cases [ 16 ].…”

Section: Discussionmentioning

confidence: 99%

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Clinical evaluation of flat peripheral curve design with aspherical-curve and multi-curve hard contact lenses for keratoconus

et al. 2022

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Aspherical- and multi-curve rigid gas-permeable hard contact lenses (HCLs) have a flattened curve in the peripheral zone and are mostly used for patients with keratoconus who cannot wear glasses, soft contact lenses, or spherical HCLs. In this retrospective study, a total of 95 eyes of 77 patients who used aspherical- or multi-curve HCLs (mean age: 40.0 ± 11.0 years) were evaluated. This study examined the types of aspherical- and multi-curve HCLs, best-corrected visual acuity (BCVA) values before and after wearing HCLs, the association with the Amsler-Krumeich classification, duration of wear, corneal/conjunctival disorder, and the frequency of changing HCLs. There were 78 eyes that used aspherical-curve HCLs and 17 that used multi-curve HCLs. BCVA significantly improved from 0.42 logMAR to 0.06 logMAR after wearing either form of HCL. The Amsler-Krumeich classification showed that aspherical-curve HCLs were commonly used for patients with stage 2 keratoconus, and multi-curve HCLs were commonly used for stage 4 patients. The BCVA values were worse when the disease stage was more severe (stages 3 and 4) regardless of HCL type. The mean base curve of the lenses was steeper in multi-curve HCLs than in aspherical-curve HCLs. The more severe the disease stage, the steeper the base curve in both aspherical- and multi-curve HCLs. The duration of wear significantly improved from 2.1 h to 10.2 h, and corneal/conjunctival disorder similarly improved. The mean frequency of changing HCL types was 1.1 times. This study suggests that a flat peripheral curve design with aspherical- and multi-curve HCLs is useful for patients with keratoconus.

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Section: Discussioncontrasting

confidence: 81%

Section: Discussioncontrasting

confidence: 70%

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Clinical evaluation of flat peripheral curve design with aspherical-curve and multi-curve hard contact lenses for keratoconus

et al. 2022

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“…Contact lens are the primary form of visual correction for patients with keratoconus [16]. In a large lens trial for keratoconus, it was observed that aspheric RGP was preferred by patients wearing lenses 4-8 hours/day, but Rose K was reported to have wearing time more than 8 hours a day [17]. In our patient, his wearing habit of keratoconus RGP contact lens was 8 to 9 hours in a day.…”

Section: Discussionmentioning

confidence: 59%

A case report of visual outcome in keratoconus with retinitis pigmentosa

Hou

Chen

Lin

et al. 2018

Preprint

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Background: It is uncommon to see retinitis pigmentosa in keratoconus patients. The main difficulty of visual rehabilitation for this is restricted visual field. We presented the treatment and gene screen of visual system homeobox 1 (VSX 1) gene in this case. Case presentation: A 24-year-old man with retinitis pigmentosa presented with progressively blurred vision. Slit lamp examination revealed Vogt’s striae over both eyes, and corneal topography indicated bilateral keratoconus. We had tested 5 exons of VSX 1 gene from him and the did not find mutation on direct sequence. To improve visual acuity, we prescribed keratoconus rigid gas permeable (RGP) contact lens for him with good efficacy. However, lens dislocation occurred occasionally. He could not find dislocated lens easily due to visual field restriction, so he asked for more stable visual aids. Therefore, we instead prescribed scleral lens (SL), which were more stable on the ocular surface and led to more stable vision. Visual acuity was also gained with SL, but the tolerance time for SL was shorter compared to that of keratoconus RGP contact lens. To compare the efficacy of these two lenses, we surveyed life quality using the National Eye Institute Visual Functioning Questionnaire – 25 in three situations: baseline, with keratoconus RGP contact lens, and with SL. Conclusion: The patient used the two lens types according to his needs, and benefited from vision rehabilitation with both keratoconus RGP contact lens and SL. Keywords: keratoconus; retinitis pigmentosa; rigid gas permeable contact lenses; scleral lenses.

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“…In addition, they use aspheric surfaces to coincident to the ectatic cornea, with increased lens diameters up to 10.00 or 11.00 mm. The fitting of large diameter lenses is becoming more complicated though, because, it could lead to the areas of increased unwanted pressure on the cornea [ 59 - 60 ].…”

Section: Contact Lenses In Keratoconusmentioning

confidence: 99%

Contact Lenses for Keratoconus- Current Practice

Moschos¹,

Nitoda²,

Georgoudis³

et al. 2017

Open Ophthal. J.

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Background:Keratoconus is a chronic, bilateral, usuallly asymmetrical, non-inflammatory, ectatic disorder, being characterized by progressive steepening, thinning and apical scarring of the cornea. Initially, the patient is asymptomatic, but the visual acuity gradually decreases, resulting in significant vision loss due to the development of irregular astigmatism, myopia, corneal thinning and scarring. The classic treatment of visual rehabilitation in keratoconus is based on spectacles and contact lenses (CLs).Objective:To summarize the types of CLs used in the treatment of keratoconus. This is literature review of several important published articles focusing on the visual rehabilitation in keratoconus with CLs.Method:Gas permeable (GP) CLs have been found to achieve better best corrected visual acuity than spectacles, eliminating 3rd-order coma root-mean-square (RMS) error, 3rd-order RMS, and higher-order RMS. However, they have implicated in reduction of corneal basal epithelial cell and anterior stromal keratocyte densities. Soft CLs seem to provide greater comfort and lower cost, but the low oxygen permeability (if the lens is not a silicone hydrogel), and the inability to mask moderate to severe irregular astigmatism are the main disadvantages of them. On the other hand, scleral CLs ensure stable platforms, which eliminate high-order aberrations and provide good centration and visual acuity. Their main disadvantages include the difficulties in application and removal of these lenses along with corneal flattening and swelling.Result:The modern hybrid CLs are indicated in cases of poor centration, poor stability or intolerance with GP lenses. Finally, piggyback CL systems effectively ameliorate visual acuity, but they have been related to corneal neovascularization and giant papillary conjunctivitis.Conclusion:CLs seem to rehabilitate visual performance, diminishing the power of the cylinder and the high-order aberrations. The final choice of CLs is based on their special features, the subsequent corneal changes and the patient’s needs.

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Applications of Different Types of Gas-Permeable Contact Lenses in Keratoconus and Their Visual Results

Abstract: We detected an increase in VA in patients with rigid contact lenses. In addition, some contact lenses were better tolerated by patients and were used for a longer time during the day.

Cited by 9 publications

References 11 publications

Clinical evaluation of flat peripheral curve design with aspherical-curve and multi-curve hard contact lenses for keratoconus

Clinical evaluation of flat peripheral curve design with aspherical-curve and multi-curve hard contact lenses for keratoconus

A case report of visual outcome in keratoconus with retinitis pigmentosa

Contact Lenses for Keratoconus- Current Practice

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