Retinal Detachment MD: Scientific Literature for MDs

Laser Cerclage

Laser Cerclage
Ora Secunda Cerclage, OSC

This article was previously published in Eye World 1998

Prophylaxis Against Retinal Detachment by
Indirect Ophthalmoscope (IDO) Laser Cerclage

Robert Morris, MD, Terry J. Moore, MD, Suzanne Nelson, RN, C. Douglas Witherspoon, MD Ferenc Kuhn, MD

Rhegmatogenous Retinal Detachment (RRD) is an uncommon disorder among the general population. Large population studies support an incidence of 0.005% to 0.01%. However, certain eyes are at significantly increased risk for retinal detachment. These include fellow eyes in persons previously suffering from retinal detachment, eyes with pathologic or high myopia, and eyes undergoing vitreous surgery for any reason but particularly for macular hole closure. Fellow eyes in retinal detachment patients have been shown to have a five year risk of retinal detachment of between 10-26%. The rate of retinal detachment bilaterality varies with the presence of myopia, aphakia, and degree of lattice degeneration. However, even eyes which are phakic, non-myopic, and without lattice have been shown to have a bilateral RRD rate of 8% in the absence of prophylaxis.

It is generally accepted that fellow eyes should be carefully examined with scleral depression, and retinal lesions such as holes, tears, and significant lattice degeneration should be considered for treatment with laser or cryopexy. Such treatment has been shown to be safe and to reduce the risk of bilaterality from 19.4% down to 7.5%. However, treatment of only identifiable lesions appears to be imperfect since new lesions develop over time. In 57% of fellow eye detachments, the causative retinal tear(s) occur in retina which appeared normal at prior examination (i.e.: was free of lattice and defects).

IDO Laser cerclage prophylaxis
We now introduce a treatment modality we term IDO Laser Cerclage Prophylaxis. From the French word meaning surround or encircle, Laser Cerclage is the treatment of the peripheral retina in a 360 degree band, from the equator or vortex veins, to the ora serrata. A pattern type treatment is applied using the indirect ophthalmoscope laser. Typical laser settings would be 300-400 mW,0.1 sec. The laser spots should be of moderate intensity, and are placed about two spot widths apart, with more confluent focal treatment of obvious pathology within the band. An average cerclage treatment would have between 900 and 1200 applications.

IDO Laser Cerclage creates numerous sites of chorioretinal adhesion in that part of the retina where 95% of causative breaks can be expected to be located. This can provide effective prophylaxis either by preventing new defects or by preventing the subretinal accumulation of fluid around new defects. Laser treatment in this manner probably prevents localized elevation of the retina in the earliest stage of retinal detachment, even in the presence of retinal break(s), avoiding propagation to clinically significant retinal detachment.

Pattern encircling laser treatment using slit lamp delivery has been previously reported to be more effective than focal treatment of localized pathology in preventing retinal detachment (1, 2). With the advent of the Indirect Ophthalmoscope (IDO) laser, combined with dynamic scleral depression, Laser Cerclage can be achieved with greater ease and uniformity. We use a retrobulbar block for this procedure to allow predictably adequate scleral depression.

Fellow Eye Prophylaxis Results
We are currently studying two groups of patients in whom IDO Laser Cerclage could be beneficial. First, fellow eyes in patients with RRD, and second, patients undergoing macular hole surgery. We retrospectively reviewed 78 consecutive patients with primary rhegmatogenous retinal detachment who underwent surgical repair. Five-year follow-up data with respect to the fellow eye were analyzed. The fellow eye had careful examination with scleral depression performed usually under anesthesia at the time of repair of the first eye. Treatment of the fellow eye was limited to focal laser treatment to specific, localized pathology such as tears, atrophic defects, and lattice. Treatment of apparently normal retinal tissue was not given. Periodic repeat examinations were given and treatment was applied to any new lesions found. Nineteen patients (24%) developed a RRD in the fellow eye within five years, despite this focal therapy.

A separate cohort of patients underwent 360 degree laser prophylactic treatment. IDO Laser Cerclage was applied in 17 fellow eyes of patients who developed a RRD within 12 months previously. Two of the seventeen patients had suffered RRD due to a giant retinal tear in the first eye. No patient developed a retinal detachment within five years of follow-up. No significant complications occurred.

Macular Hole Vitrectomy Prophylaxis Results
Macula Hole Surgery is now considered to be highly successful from an anatomic as well as functional standpoint. However, postoperative retinal detachment has been reported to occur in from 1-15% of eyes from peripheral retinal tears. We reviewed 94 consecutive macular hole eyes that underwent pars plana vitrectomy, removal of epiretinal proliferation internal limiting membrane around the hole, macular hole closure and long acting gas tamponade. Intraoperatively, IDO Laser Cerclage was placed as a prophylaxis. No cases of postoperative retinal detachment occurred with a minimum of six months follow-up.

Possible complications of IDO Laser Cerclage include: temporary or permanent mydriasis, decreased accommodation, hemorrhage in the retina or choroid, full thickness retinal defects, epimacular proliferation, and reduced visual field or night vision. We have seen no significant complications to date. We estimate that less than 5% of patients may have temporary mydriasis, which has resolved in all cases after several months.

Conclusion
IDO Laser Cerclage, in our experience, is a highly effective treatment for prophylaxis against retinal detachment, that may be employed in certain eyes known to be at high risk. We prefer Cerclage over focal treatment alone in these eyes. With respect to fellow eyes in RRD, with no visible pathology, we do not routinely advise prophylaxis.. However, those patients who have had unsuccessful surgical repair or who did not regain useful macular function (we term unimacular) after repair are at risk for becoming legally blind were they to suffer RRD in their fellow eye. We believe that such patients may reasonably choose IDO Laser Cerclage after informed consent.

The complication rate seems to be sufficiently low as to warrant the use of IDO Laser Cerclage, in certain high risk eyes, given its apparent high efficacy in preventing RRD. We are continuing to analyze data and look forward to reporting a larger study in the next year.

Prophylaxis Against Retinal Detachment by Indirect Ophthalmoscope (IDO) Laser Cerclage

Prophylaxis Against Retinal Detachment by
Indirect Ophthalmoscope (IDO) Laser Cerclage