Rupture of Radial Keratotomy Incisions by Blunt Trauma 6 Years After Combined Photorefractive Keratectomy/Radial Keratotomy

[Photorefractive Keratectomy (PRK) as a Procedure for Correction of Residual Refractive Errors after Radial Keratotomy]

BACKGROUND

A large number of myopic patients were treated by radial keratotomy (RK) in recent years. Despite being effective in many cases, the refractive results of this surgical intervention proved to be of limited predictability, and it frequently resulted in over- or under-correction in the long term. In this study, we discuss the intermediate and long-term results of a topography-guided photorefractive keratotomy (PRK) in a consecutive series of patients who were previously treated for myopia by radial keratotomy.

MATERIALS AND METHODS

In this retrospective case series, we examined the refraction and visual acuity in a consecutive series of patients-16 eyes-who were treated by PRK for residual refractive errors after radial keratotomy in the past. Mean follow up was 41 months (min. 9, max. 96).

RESULTS

All treated eyes showed an improvement in uncorrected visual acuity, and 56% had an improvement in corrected visual acuity. No serious or sight-threatening complications were recorded. Refraction was stable throughout the study period in all patients.

CONCLUSIONS

In this case series, photorefractive keratotomy was shown to be an effective treatment method for secondary ametropia after radial keratotomy. Apart from the correct planning and execution of the PRK, it is of critical importance to inform the patients about the limitations and the anticipated refractive result of the procedure.

Descemet membrane endothelial keratoplasty and refractive surgery

PURPOSE OF REVIEW

Descemet membrane endothelial keratoplasty (DMEK) has become a first-line treatment in corneal endothelial diseases because of its exceptional clinical outcomes and low complication rates. Because of its improved refractive predictability, DMEK is now also considered for managing cases with endothelial decompensation following previous refractive procedures, or in combination with those. This article reviews the clinical outcomes in these cases and discusses the possibility of refractive interventions following DMEK.

RECENT FINDINGS

DMEK has been successfully performed in eyes after laser in-situ keratomileusis, eyes after anterior chamber intraocular lens (IOL) implantation and aphakic eyes. Often, DMEK is combined with cataract surgery (triple-DMEK). Initial reports on reducing the refractive cylinder by toric IOL implantation are available. Although there are some reports on phacoemulsification and IOL implantation after phakic DMEK, reports on laser refractive procedures following DMEK are lacking.

SUMMARY

In contrast to earlier keratoplasty techniques, DMEK induces on average only mild refractive shifts owing to the 'natural' restoration of the cornea. As such, DMEK may be ideal in managing corneal decompensation in refractive patients. However, further studies are required to assess the safety and efficacy of DMEK after refractive treatment and of refractive procedures following DMEK.

Ruptured globe 20 years after radial and transverse keratotomy

To report a case of corneal rupture due to blunt trauma occurring 20 years after radial keratotomy (RK) and transverse keratotomy. A 57-year-old woman sustained direct blunt trauma to her right eye. Ocular examination revealed a ruptured globe involving two of the eight RK incisions connected together across the visual axis with iris incarceration in the wound. The transverse keratotomy scars remained intact. The patient underwent primary corneal wound repair and iris repositioning. The postoperative period was uneventful. The patient had a visual acuity of counting fingers at 1 m and is awaiting penetrating keratoplasty. Traumatic rupture of RK incisions can still occur after 20 years. Patients having undergone RK many years before should be warned of a possible life-long risk of traumatic rupture. RK scars appear to be more vulnerable to rupture than astigmatic keratotomy scars.

Traumatic ocular hypotonia encountered during reduction of multiple facial fractures

There are many different potential causes of globe hypotonia after ocular surgery. To the best of our knowledge, this is the first report of traumatic intraoperative hypotonia during orbital floor exploration and repair. We present a case involving a patient with a history of cataract surgery who developed intraoperative hypotonia when undergoing ocular manipulation during the exploration of multiple facial fractures.

Wavefront-guided photorefractive keratectomy in eyes with prior radial keratotomy: a multicenter study

PURPOSE

To investigate the outcomes of wavefront-guided photorefractive keratectomy (WG PRK) using prophylactic mitomycin C (MMC) in eyes that had previously undergone radial keratotomy (RK).

DESIGN

Retrospective, observational, consecutive case series.

PARTICIPANTS

Thirty-two eyes of 27 patients with previous RK that underwent WG PRK with MMC.

METHODS

The records were reviewed of consecutive RK patients whose eyes underwent WG PRK with MMC in 4 centers with postoperative follow-up of 6 months or longer (range, 6-21 months). Eyes were divided into myopic WG PRK and hyperopic WG PRK groups based on their preoperative spherical equivalent (SE). Preoperative best spectacle-corrected visual acuity (BSCVA) was compared with postoperative uncorrected visual acuity (UCVA) and BSCVA to ascertain efficacy and safety. Change in SE and attempted versus achieved SE were evaluated. Incidences of haze and other complications were recorded.

MAIN OUTCOME MEASURES

Uncorrected visual acuity, BSCVA, SE, corneal haze, and other complications.

RESULTS

In the myopic WG PRK group (n = 9), UCVA improved by 3 lines on average (P = 0.015) with UCVA of > or =20/20 in 56% and > or =20/40 in 100% of eyes; 55% were within 0.5 diopter (D), and 100% were within 1 D of attempted refraction. In the hyperopic WG PRK group (n = 23), UCVA improved for 3 lines on average (P<0.001), with UCVA of > or =20/20 in 48% and > or =20/40 in 100% of eyes; 57% were within 0.5 D and 74% were within 1 D of attempted refraction. One eye lost 2 lines of BSCVA as a result of the development of mild to moderate haze, but recovered in 4 months. No eyes lost more than 2 lines of BSCVA. Six eyes (19%; 6/32) experienced the development of haze in the postoperative course, with mild to moderate haze in 1 eye and trace haze in the other 5 eyes. No other complications were noted.

CONCLUSIONS

Wavefront-guided PRK with MMC in eyes with prior RK improved the UCVA significantly and was safe over the short follow-up of this series. Although haze occurred, no eye suffered persistent visual loss of 2 or more lines.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Traumatic wound dehiscence after penetrating keratoplasty-a cause for concern

AIM

We report the incidence, causes, characteristics, and the outcome of traumatic corneal graft ruptures in a tertiary referral centre in the UK.

METHOD

A retrospective analysis of all graft ruptures secondary to trauma that were treated at our centre between 1999 and 2005 was undertaken. Statistical analysis of possible prognostic factors was undertaken using the Fisher's test.

RESULTS

Nineteen eyes in 18 patients sustained eye trauma resulting in graft rupture (median age of 53 years; range 27-82; 15 men and four women). Seventeen cases were accidental and two were from violence. The median time interval between grafting and rupture was 8.3 months (range 3 days to 15 years). The 6-year incidence was 3.8%. All graft ruptures occurred at the host-graft junction and ranged from 45 to 270 degrees . Iris prolapse/loss was noticed in 89% and lens loss in 53%. The most common posterior segment complication was vitreous loss (74%), followed by vitreous haemorrhage (32%) and retinal detachment (21%). Grafts with 180 degrees or more of dehiscence were more likely to fail (P<0.001), had more extensive posterior segment damage, and a poorer visual outcome. Grafts without sutures had a more extensive dehiscence (P<0.01). Final visual acuity was worse than 6/60 in 58%.

CONCLUSIONS

The risk of traumatic corneal graft rupture is significant and is associated with a poor visual outcome. This fact needs to be clearly emphasised during preoperative counselling and protective measures encouraged.