Effect of axial length reduction after trabeculectomy on the development of hypotony maculopathy

Usefulness of Eye Deformation in the Corvis ST Measurement to Predict Postoperative Hypotony Complications in Glaucoma

PURPOSE

This study aimed to investigate the usefulness of measuring biomechanical parameters using the Corvis ST to predict the occurrence of hypotony maculopathy and choroidal detachment (CD) following trabeculectomy or bleb needling revision with mitomycin C.

DESIGN

Clinical cohort study.

METHODS

This study included 100 eyes of 100 patients who underwent trabeculectomy (88 eyes of 88 patients) or bleb needling (12 eyes of 12 patients) with mitomycin C. A significant predictor of hypotony complications was identified from (1) operation (trabeculectomy or bleb needling), (2) age, (3) sex, (4) disease type (primary open-angle glaucoma, exfoliation glaucoma or other), (5) lens status (phakia or pseudophakia), (6) preoperative Goldmann applanation tonometry (GAT) intraocular pressure (IOP), (7) preoperative central corneal thickness (CCT), (8) preoperative axial length (AL), (9) preoperative anterior chamber depth, (10) "Min IOP" (IOP value when hypotony complications occurred, otherwise the minimum IOP during 3 months from trabeculectomy or bleb needling), (11) preoperative corneal curvature, and (12-24) 12 Corvis ST parameters using multivariate logistic regression.

RESULTS

There were 13 and 21 eyes developed hypotony maculopathy and CD, respectively. Male gender, greater preoperative GAT IOP, and greater highest concavity deflection Amplitude were significant predictors of the occurrence of hypotony maculopathy (P < .05). On the other hand, shorter AL, thinner CCT, greater preoperative GAT IOP and pseudophakia were significant predictors of the occurrence of CD (P < .05).

CONCLUSIONS

A careful attention should be paid to the occurrence of hypotony maculopathy with male gender and greater highest concavity deflection Amplitude despite higher preoperative GAT IOP. Different risk factors were identified; shorter AL, thinner CCT, greater preoperative GAT IOP, and pseudophakia.

Difficult decisions, filtration surgery, and the heartbreak of the numerator

A 70-year-old man had progressive and severe glaucoma in each eye. He was intolerant to dorzolamide, brimonidine, and netarsudil. Each eye had prior selective laser trabeculoplasty (SLT) as well as phacoemulsification plus minimally invasive glaucoma surgery (MIGS) 6 years before current presentation (iStent [Glaukos Corp.] in the right eye and Cypass [Alcon Laboratories, Inc.] in the left eye). Postoperative acuities were 20/20 and 20/25 in the right and left eyes, respectively. When his left eye progressed with loss of central acuity despite peak intraocular pressures (IOPs) in the middle to upper teens, neuro-ophthalmology consultation was obtained (Figure 1JOURNAL/jcrs/04.03/02158034-202401000-00017/figure1/v/2023-12-22T124801Z/r/image-tiff). That workup included magnetic resonance imaging scan and hematologic screening, but all results were negative, and the neuro-ophthalmic consultant concluded that the vision loss was likely on the basis of glaucoma. Accordingly, a trabeculectomy was performed in the left eye achieving consistent IOPs in the range of 7 to 10 mm Hg without medications, rending the left eye stable since the filtration surgery nearly 2 years previously. The right eye continued to progress both subjectively and objectively, and on recent examination, the IOP measured 20 mm Hg and 09 mm Hg in the right and left eyes, respectively (Figure 2JOURNAL/jcrs/04.03/02158034-202401000-00017/figure2/v/2023-12-22T124801Z/r/image-tiff). Medications included timolol and latanoprostene bunod in the right eye only. Central corneal thickness was 526 μm and 527 μm in the right and left eyes, respectively. The visual acuity now measured 20/25 in the right eye and 20/250 in the left eye. The vertical cup-to-disc ratio was 0.9 in the right eye and 1.0 in the left eye. Gonioscopy revealed a wide open angle in each eye with a patent sclerostomy superiorly in the left eye. The conjunctiva and sclera were healthy and without scarring in the right eye. The bleb in the left eye was diffuse, lightly vascularized, and seidel negative. Axial length (AL) was 26.88 μm in the right eye and 26.77 μm in the left eye. The patient was in good health and was not anticoagulated. An extensive discussion ensued about the best course of action for the right eye. How would you proceed in managing definite progression in this individual's right eye, knowing that he had lost fixation in his left eye at similar pressures?

Maculopathies in Glaucoma

In the presence of glaucoma, various changes in the macula can occur during the course of the disease itself or its treatment. Maculopathies that can be observed in glaucoma include cystoid macular edema, hypotony maculopathy, and microcystic macular edema. The following article discusses the pathophysiology, causes, course, clinical presentation, and treatment of these maculopathies.

Effect of trabeculectomy on optic nerve head and macular vessel density: an optical coherence tomography angiography study

PURPOSE

To investigate the effect of trabeculectomy on peripapillary and macular vessel density (VD) using optical coherence tomography angiography (OCT-A) in patients with primary open-angle glaucoma.

METHODS

This is a prospective, interventional study on 32 glaucoma eyes (21 patients) who underwent trabeculectomy. Optic nerve head (ONH) and macular structural and OCT-A scans were performed before surgery and at one and six months postoperatively with the Avanti device (AngioVue System, Optovue Inc., Fremont, CA). The primary outcomes of interest were changes in global and regional peripapillary and macular VD.

RESULTS

The average (standard deviation) age and visual field mean deviation of the sample were 58.9(9.9) years and -14.5(9.0) dB, respectively. The average (standard deviation) baseline intraocular pressure significantly decreased from 24.5(10.4) mmHg to 9.6(2.1) mmHg, 6 months after the surgery (P< 0.001). The mean (standard deviation) whole image VD of ONH had increased from 37.6(8.3)% to 40.5(9.1)% at 6 months after the surgery (P = 0.01) while its changes were not significant at month 1 (38.1(9.5)%, P = 0.64). The average of radial peripapillary circle (RPC) VD increased from 36.5(10.3)% to 39.3(10.8)% at 6 months (P = 0.04) compared to 1-month post-trabeculectomy (37.0(11.4)%, P = 0.71). Similar patterns at postoperative months 1 and 6 were also observed in RPC VD at superior and inferior hemifields as well as nasal and temporal quadrants. The observed changes in VD of macular, foveal, peri-, and parafoveal were not significant at superficial or deep slabs at 1 and 6 months after trabeculectomy (all P values > 0.05).

CONCLUSION

Our study demonstrated significant improvements in peripapillary vessel density at 6-month following trabeculectomy.

Prospective cohort study of risk factors for choroidal detachment after trabeculectomy

PURPOSE

To investigate risk factors for choroidal detachment after trabeculectomy.

METHODS

We prospectively evaluated 97 patients with open-angle glaucoma who underwent primary trabeculectomy to investigate risk factors for choroidal detachment after trabeculectomy. The primary outcome measure was risk factors for the occurrence and severity of choroidal detachment after trabeculectomy. Choroidal detachment severity was quantified as the number of fundus quadrants with choroidal detachment.

RESULTS

Sixteen patients (16.5%) had choroidal detachment. Mean period between surgery and occurrence of choroidal detachment was 7.9 ± 5.7 days. Mean intraocular pressure (IOP) on the first day of choroidal detachment was 6.1 ± 3.0 mm Hg. Multivariable analyses revealed that the exfoliation glaucoma, greater ΔIOP between preoperative and lowest postoperative IOPs, and thicker cornea were associated with choroidal detachment (P = 0.022, P = 0.002, and P = 0.013, respectively). These factors were also associated with the severity of choroidal detachment (exfoliation glaucoma; P = 0.013, greater ΔIOP; P < 0.001, and thicker cornea; P = 0.006).

CONCLUSIONS

Exfoliation glaucoma, more IOP reduction, and thicker cornea are associated with the occurrence and severity of choroidal detachment after trabeculectomy.

Hypotony maculopathy: a surgeon's nightmare

A 14-year-old myopic male patient diagnosed as steroid-induced glaucoma and cataract elsewhere presented to the eye opd with painless and progressive diminution of vision in the right eye (oculus dexter (OD)) for last 6 months. Phacotrabeculectomy was already done in the left eye (oculus sinister (OS)) 1 year ago and he was on topical latanoprost e/d-H.S in OD and brimonidine e/d-BD and dorzolamide e/d-TDS in both eyes (oculus uterque (OU)) postsurgery. Uneventful phacotrabeculectomy was performed in the right eye under 300 mL intravenous injection mannitol. He developed hypotony maculopathy postsurgery which was managed conservatively.

Excessive scleral shrinkage, rather than choroidal thickening, is a major contributor to the development of hypotony maculopathy after trabeculectomy

Purpose

We previously reported that eyes with hypotony maculopathy (HM) after trabeculectomy (TLE) exhibited more reduction of axial length (AL) than those without HM, suggesting that inward collapse of the scleral wall may contribute to the development of HM after TLE. However, we did not evaluate change in choroidal thickness (CT), which could influence AL measures. We compared the magnitude and rate of AL and CT changes in eyes with and without HM by simultaneously measuring these parameters before and after TLE.

Methods

We enrolled 77 eyes of 77consecutive patients with glaucoma, who underwent TLE between March 2014 and March 2016. Intraocular pressure (IOP), central corneal thickness, keratometry, AL, and CT were measured pre- and postoperatively, up to 6 months. These biometrics were compared in eyes with and without HM.

Results

The 14 patients who developed HM were significantly younger than those who did not. The eyes with HM exhibited significantly reduced AL (2.8%) compared to those without HM (0.7%). There was no significant difference in CT change between the two groups. The rate of AL reduction was significantly correlated with age, postoperative IOP, and preoperative AL. Post-adjustment logistic regression analysis revealed that eyes with AL reduction rate ≥ 2% had 11.67 higher risk for developing HM (95% confidence interval, 1.28–106.6; P = 0.03).

Conclusions

AL reduction rates ≥ 2% were significantly associated with HM. Excessive reduction in AL, which was seen in eyes with HM, was not an artificial measure resulting from choroidal thickening but rather reflected reductions in the anterior-posterior diameter of the eyeball. Inward collapse of the scleral wall leads to redundancy of the chorioretinal tissue, contributing to the development of HM after TLE.

Late-onset Hypotony Maculopathy After Trabeculectomy in a Highly Myopic Patient With Juvenile Open-angle Glaucoma

Hypotony maculopathy is a sight-threatening complication after trabeculectomy. We report on a 34-year-old man with juvenile open-angle glaucoma and high myopia, who developed hypotony maculopathy 14 years after trabeculectomy without bleb leak. This represents the longest known period from trabeculectomy to the development of hypotony maculopathy without bleb leak. The possible mechanisms for the development of late-onset hypotony maculopathy in the highly myopic patient are progressive scleral thinning, reduced scleral rigidity, and scleral morphologic change with aging. These changes might weaken the biomechanical properties of sclera and then contribute to the collapse of the scleral wall during hypotony. This case serves as a reminder that hypotony maculopathy can happen up to 14 years after tabeculectomy even without bleb leak and hypotony should be avoided after trabeculectomy in highly myopic patients with juvenile open-angle glaucoma.