Javadi 2010.
| Methods | Randomised comparative clinical trial in a single private clinic in Iran. Randomisation based on a random number table | |
| Participants | 81 eyes of 81 participants: 46 undergoing DALK and 35 undergoing penetrating keratoplasty. All 81 had data available with regards to graft failure and presence of rejection episodes. Four DALK recipients were excluded from analyses relating to visual and refractive outcomes as they failed to achieve bared Descemet's membrane, leaving 42 DALK recipients and 77 total recipients in these analyses. Age and gender breakdown are provided only for these 77 recipients. DALK: 29 males, 13 females; mean age = 26.91 ± 7.9 years, range 15‐44; penetrating keratoplasty: 28 males, 7 females; mean age = 30.89 ± 10.3 years, range 17‐50. Study dates not reported, but pre‐2009 | |
| Interventions | DALK was conducted using the big‐bubble technique with the recipient cornea trephined 7.75 mm or 8 mm, depending on the recipients' vertical corneal diameter (greater than or equal to versus less than 10.5 mm). Air was injected into the mid‐stroma to form a big‐bubble extending to the trephination site. The stroma was then removed In penetrating keratoplasty, the recipient trephination size (7.75 mm or 8 mm) was again dependent on the recipients' vertical corneal diameter (greater than or equal to versus less than 10.5mm). Trephenation was conducted with a Hessburg‐Barron suction trephine and the excision was completed using right and left corneal scissors. For these donor corneas, trephination was conducted from the endothelial side In all surgeries, the size of the corneal donor button was dependent on the recipient trephine size and was 0.25 mm or 0.5mm larger depending on vitreous length (greater than or equal to versus less than 16 mm). The donor cornea was sutured to the recipient in one of three different ways, all using 10‐0 nylon sutures: 16 interrupted sutures, one single 16‐ to 18‐bite running suture, or a single 16‐bite running suture plus an 8‐bite interrupted suture. This was based on surgeon preference and the condition of the eye. Suture tension was adjusted via intraoperative keratoscopy. Cefazolin 100 mg and betamethasone 4 mg were injected subconjunctivally. Subjects received topical chloramphenicol every six hours for 30 days and topical betamethasone 0.1% every six hours, tapered over two to three months Follow‐up examinations were performed at 1, 3, 7 and 30 days; 3, 6, 12 and 24 months; and 3‐6 months after complete suture removal |
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| Outcomes | Primary outcomes:
Secondary outcomes:
Specific outcome information regarding number of grafts with rejection episodes, attainment of BCVA/UCVA of 20/40 and mean keratometric astigmatism, was provided at 3‐6 months after complete suture removal. Data for some visual outcomes and refraction were shown at 3, 6, 12 and 24 months as well as post‐suture removal within figures, but not referred to in‐text, with no specific measurements provided |
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| Notes | Some secondary procedures (e.g. resuturing) were carried out in some subjects. Study conducted by the Ophthalmic Research Centre at Shahid Beheshti University. No financial support or conflicts of interest reported |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Randomisation based on a "random number table" |
| Allocation concealment (selection bias) | Unclear risk | Randomisation occurred in the private clinic where the surgery was carried out. It is unclear whether the allocation was concealed from staff recruiting participants to the trial |
| Blinding of participants and personnel (performance bias) All outcomes | High risk | It was impossible to mask the surgeon to which surgery was being conducted. It is unclear whether participants were masked to which surgery they underwent |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | It is unclear who conducted the outcome assessment or whether they were aware of group allocation |
| Incomplete outcome data (attrition bias) All outcomes | High risk | Four eyes were excluded from the DALK group because of failed air injection. The outcomes data for these four eyes were excluded from follow‐up analyses. This may skew the results in favour of DALK as the outcomes for these participants were more likely to be negative. There was great variation in follow‐up length, though all participants (except the four excluded at time of surgery) completed 6 month follow‐up |
| Selective reporting (reporting bias) | Unclear risk | Unclear if outcome measures are what was planned as protocol not available |
| Other bias | Unclear risk | Not mentioned |