For vitreoretinal surgeons, the retinectomy is an indispensable tool for managing the most complex cases of rhegmatogenous retinal detachment, particularly when proliferative vitreoretinopathy (PVR) has shortened the retina beyond the reach of standard maneuvers. However, this “sight-saving” procedure comes with a shadow: the risk of postoperative hypotony—a persistent low intraocular pressure (IOP) that can lead to maculopathy, choroidal effusion, and even phthisis bulbi.
A recent systematic review and meta-analysis published in Survey of Ophthalmology has shed new light on this complication, offering a comprehensive look at how often it occurs and, perhaps more importantly, what actually drives it.
The Numbers: How Common is Postoperative Hypotony?
After analyzing 33 studies involving 2,673 eyes, researchers found that the pooled incidence of postoperative hypotony following retinectomy is 13.71%. This confirms that hypotony is not a rare occurrence but a frequent clinical challenge.
Interestingly, the study found that the reported incidence varies depending on how you define it and when you measure it:
- Definition Matters: Studies using a strict threshold of IOP ≤ 6 mmHg reported lower rates ($7.09%$) than those using a threshold of IOP ≤ 5 mmHg ($16.21%$).
- The Time Factor: Hypotony rates actually seemed to increase over time. While early postoperative assessments showed an incidence of around $10.49%$, this rose to $21.60%$ by the six-month mark, suggesting a delayed or progressive biological process.
The “Mechanical” Myth: Does Size Really Matter?
One of the most surprising findings of this meta-analysis is that the extent of the retinectomy does not linearly increase the risk of hypotony.
Conventional wisdom might suggest that cutting more retina would lead to more hypotony. However, the data showed similar rates for retinectomies of $180^\circ–269^\circ$ ($14.25%$) and those $\geq 270^\circ$ ($13.05%$). This suggests that hypotony is not merely a mechanical consequence of “how much” is removed, but rather a result of the underlying biological environment.
Biological Drivers: The Role of the Ciliary Body
If the size of the cut isn’t the main culprit, what is? The researchers argue that postoperative hypotony is a multifactorial biological process driven by:
- Ciliary Body Dysfunction: Persistent traction from anterior PVR can impair the ciliary body’s ability to produce aqueous humor.
- Inflammatory Burden: Complex surgeries involving endolaser, repeated maneuvers, and tamponade agents create a sustained pro-inflammatory and oxidative milieu that can destabilize the eye’s pressure.
- Altered Fluid Dynamics: Large areas of exposed choroid may alter how fluid moves out of the eye, potentially enhancing uveoscleral drainage.
Clinical Impact: Why This Matters for Patients
The study confirmed a significant negative association between hypotony and visual improvement. In short, eyes that develop persistent hypotony are far less likely to see a meaningful recovery in vision. This highlights the need for surgeons to distinguish between “numerical hypotony” (just a low number) and “vision-threatening hypotony” (low pressure causing structural damage).
Looking Ahead: Management and Prevention
Current management strategies often include:
- Aggressive Control of Inflammation: Corticosteroids can provide modest IOP elevation but often fail as monotherapy in advanced cases.
- Adjunctive Therapies: Emerging evidence suggests that antiproliferative agents like Methotrexate (MTX) and Mitomycin-C (MMC) may help by suppressing the PVR activity that leads to ciliary body compromise in the first place.
- Surgical Intervention: Relieving anterior traction on the ciliary body remains a key surgical goal to restore pressure.
Conclusion
Retinectomy remains a vital tool for complex retinal detachments, but surgeons must remain vigilant about the $13.7%$ risk of hypotony. By understanding that this complication is driven more by ciliary body health and inflammation than the size of the retinal cut, we can move toward more targeted preventive strategies and better functional outcomes for our patients.
Citation: Ağın, A., & Artunay, O. (2026). Postoperative hypotony after retinectomy in rhegmatogenous retinal detachment surgery: A systematic review and meta-analysis. Survey of Ophthalmology. https://doi.org/10.1016/j.survophthal.2026.06.006
