Diagnosis: Macula-On Rhegmatogenous Retinal Detachment (RRD)
Retinal detachment is an ocular emergency that classically presents with new-onset photopsias, persistent new floaters , and a “curtain” defect that partially obscures the visual field. Retinal detachments can be classified by etiology as rhegmatogenous, tractional, or exudative/serous, with each type requiring different management. The most common form of retinal detachment is an RRD, which results from retinal breaks caused by the pull of the vitreous humor as is detaches from the retina. The resulting tension leads to the separation of the inner neurosensory retinal layers from the retinal pigment epithelial layer, allowing subretinal fluid to accumulate between the layers.
Risk factors for RRD include high myopia, lattice degeneration, advanced age, trauma, previous retinal detachment, and previous intraocular surgery.
Without prompt intervention, the separation between the layers can progress from peripheral loss to central vision loss as the sensory retinal layers continue to separate and can ultimately involve the fovea. Foveal attachment further distinguishes retinal detachment as either “macula-on” or “macula-off” retinal detachment. Assessing macular attachment is a key finding in the determination of urgency for surgical repair.
In a case of an RRD, it is important to determine the site of the original retinal break. Lincoff’s Rule can assist with identifying the most likely location of a retinal break and is described in the image below:
Surgical management is indicated for RRD and all retinal breaks should be identified, treated and closed.
Surgical treatment for RRD includes pneumatic retinopexy, pars plana vitrectomy, and scleral buckle. Each technique is described bellow, as follows:
- Pneumatic retinopexy: This procedure is minimally invasive and can be performed in the clinic. It entails injecting a gas bubble into the eye between the retinal and the vitreous to attempt to flatten the retina to the RPE. Patient’s with superior retinal detachments are the best candidates for this technique as the gas bubble will rise up and compress the bullous detachment.
- Pars plana vitrectomy: A vitrector is introduced into the vitreous body and cuts and aspirates the vitreous while the eye is simultaneously filled with a balanced salt solution to maintain pressure. This is followed by the insertion of a medium like gas or silicone oil to keep the retina flat and reattached.
- Scleral bluckling: This procedure is performed in the OR and involves the placement of a silicone band around the outside of the globe under the extraocular rectus muscles as means of re-attaching the retina.
Laser photocoagulation is also used to seal any retinal break to prevent re-accumulation of fluid under the retina.
Timing of repair is critical. The status of the macula (macula-on vs. macula-off) defines the urgency for surgical repair and often is a predictor of final visual outcomes. Macula-on detachments should be repaired within 24 hours to prevent extension of the detachment to involve the macula, while macula-off detachments can be delayed for a few days.
References and Additional Resources:
- “EyeWiki: Retinal Detachment.” Available at: https://eyewiki.org/Retinal_Detachment#History.
- “Retinal Detachment: From One Medical Student to Another.” Available at: https://webeye.ophth.uiowa.edu/eyeforum/tutorials/retinal-detachment-med-students/index.htm
- Kwok JM, Yu CW, Christakis PG. Retinal detachment. CMAJ. 2020;192(12):E312. doi:10.1503/cmaj.191337
- Gariano RF, Kim CH. Evaluation and management of suspected retinal detachment. Am Fam Physician. 2004;69(7):1691-1698.
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