Safety and efficacy of Intacs in Indian eyes with keratoconus: An initial report

Abstract

ContextIn contact lens-intolerant keratoconus patients, intrastromal placement of Intacs is becoming a promising new modality of treatment.AimsTo study the safety and efficacy of implantation of microthin corneal inserts (Intacs) in Asian-Indian keratoconus patients.Settings and DesignRetrospective interventional case series, in the cornea and refractive surgery service, at a tertiary care eye hospital in South India, between May 2006 and July 2007.Materials and MethodsIntacs (Addition Technology, USA) were successfully implanted by mechanically creating tunnels, in 12 eyes of 12 keratoconus patients, who were contact lens-intolerant. The patients (mean age 25.58 years, nine male and three female) had a minimum follow-up of six months. Five patients had severe keratoconus (mean K > 53 D) and nine had central cones.ResultsAll patients improved or retained visual acuity. The uncorrected visual acuity (UCVA) improved from a mean value of 0.06, (SD ± 0.08) to 0.19 postoperatively (SD± 0.15) (P= 0.01). The change in mean best corrected visual acuity (BCVA) was from 0.51, (SD ± 0.24), to 0.69, (SD ±0.00) (P = 0.01) postoperatively. The average central keratometry reading was 52.55 D. The change in mean K from 52.84 to 49.16 and 49.15 at one and six months respectively, was statistically significant. We did not have any major intra- or early postoperative complications. Eight of 12 eyes became contact lens-tolerant post-surgery.ConclusionThe procedure of Intacs implantation appears to be safe and effective in a small group of Indian population at an intermediate follow-up.

Review

“…In contrast, India, with a likely higher keratoconus prevalence, has a lower graft percentage (6%-11% compared with approximately 20%). 127 This is because of graft shortage because cornea donor and banking programs are limited, and only 10% of cornea demand is met in India. 128 The contribution of keratoconus to a country's total graft burden is influenced by ethnic differences in true incidence, severity, surgeon threshold for keratoplasty, patient access to grafts, success of preoperative treatment to slow keratoconus progression, and prevalence of other graft-competing corneal diseases.…”

Efficacy of Different Procedures of Intra-Corneal Ring Segment Implantation in Keratoconus: a Systematic Review and Meta-Analysis

“…When the optical zone was 6 mm,14,63,71,82,87 the inner diameter varied from 6.014,63,82 to 6.6 mm,87 and the outer diameter varied from 7.08 to 7.5 mm 87. Finally, when the optical zone was 7 mm,83,102,108,109 the inner diameter was 7 mm and the outer diameter was 8.2 mm. One or two rings were inserted depending on the keratoconus grade in 44 studies ( references 8, 14, 26–30, 32, 41, 49–51, 53–55, 59–61, 67, 68, 75–77, 80, 82, 84, 85, 87–89, 92–94, 96, 97, 102, 103, 107, 109, 110, 112, 116 ).…”

“…Topical anesthesia was used for all procedures. Surgery was performed by one ( references 14–16, 27–37, 39–46, 48, 50–53, 55–57, 59, 60, 62, 63, 65, 66, 70–78, 81–84, 86, 88–94, 98–102, 104–110, 112–116 ), two ( references …”

“…The reference point was a Sinskey hook marking the center of the pupil. Channel depth varied between 70% ( references 14–16, 33, 35, 37, 48-54, 63, 65, 66, 70, 80, 82, 83, 87, 88, 90, 92, 95, 98, 99, 102, 103, 105, 108, 109, 111, 113, 114 ), 75% ( references 26, 27, 34, 39, 41, 42, 45, 58, 60, 64, 71, 79, 110 ), or 80% ( references 8, 29, 30, 32, 33, 43, 47, 54–56, 59, 62, 67–69, 72–…”

“…The degree of the channel was determined using nomograms of specific ICRS used or was a 360-degree15,16,26,32,34,36,39,96 tunnel for inserting the segments. Five ICRS were used: Keraring (Mediphacos, Belo Horizonte, Brazil) ( references 8, 16, 27, 28, 31, 32, 36, 41, 42, 47, 54, 55, 58–61, 64, 66, 67, 69, 70, 77, 80, 88, 92, 93, 97–99, 102, 103, 107, 110, 112, 116 ), Ferrara ring (Ferrara Ophthalmics, Belo Horizonte, Brazil) ( references 14, 30, 35, 43, 62, 63, 76, 78, 81, 82, 84, 85, 89, 91, 94, 101, 104 ), Intacs (Addition Technology, Inc., Des Plaines, IL) ( references 16, 26, 33, 37, 39, 40,…”