Indications and Outcomes of Laser Retinopexy in Eyes With High-Risk Lattice Degeneration

Abstract

Purpose: To examine the characteristics of eyes with high-risk lattice degeneration treated with laser retinopexy and determine the indications, safety, and outcomes of the treatment. Methods: This interventional single-surgeon consecutive retrospective study was conducted at Wills Eye Hospital between 2014 and 2021. The series included eyes with lattice degeneration with high-risk lesions. Documented characteristics and outcomes of these eyes and fellow eyes were documented. Results: The study comprised 167 eyes of 143 patients (53.3% women; mean age [±SD], 50 ± 17 years). Complications after laser treatment included new posterior vitreous detachment (PVD) (n = 21), epiretinal membrane (ERM) (n = 13), retinal detachment (RD) (n = 5), and additional laser required (n = 22). Eyes that developed ERMs were more likely to develop PVDs (odds ratio, 5.39; 95% CI, 1.57-18.47). Patents who developed ERMs were older (mean, 60 ± 7 years vs 49 ± 17 years; P = .016), as were those developing PVDs (mean, 59 ± 8 years vs 48 ± 17; P = .005). No eye with a new ERM required surgery (n = 13). Four eyes with a new RD required laser retinopexy alone; 1 eye was treated surgically. No eye had an RD at the most recent evaluation. Conclusions: Despite high-risk lesions in areas of lattice degeneration, few eyes developed RDs after prophylactic laser retinopexy. Older patients may have a higher risk for ERM or PVD after laser treatment. Eyes with post-laser PVD were more likely to develop an ERM.

Introduction

Lattice degeneration occurs in approximately 8% to 10% of the population and is especially common in individuals with myopia. ¹ Lattice degeneration can progress to retinal holes or tears, which can lead to retinal detachment (RD). ² Previous studies estimated that the chance of an RD developing in an eye with lattice degeneration is less than 1% in 11 years if an RD had not occurred in the fellow eye and 2% to 5% within 7 years if the individual had a previous RD. ³

Despite the overall low risk for progression, many patients who present with RDs have causative areas of lattice degeneration. Lattice degeneration was reported to be present in 30% of phakic RDs.^3,4 Another study found that 61% of patients with rhegmatogenous RDs (RRDs) had lattice degeneration and therefore concluded that lattice degeneration was one of the most important risk factors for RD. ⁵ Given the low risk for progression but the high incidence in those with RDs, there is debate about whether to perform prophylactic treatment in eyes with lattice degeneration to reduce the risk for progression to RD.

There are varying degrees of lattice degeneration. Patients with smaller lesions without any risk factors are often observed conservatively. However, several high-risk features may warrant consideration of prophylactic treatment to prevent progression to RD. These features include lattice degeneration with holes^6,7 or tears within or at the edge of the lattice, ⁶ lesions in fellow eyes with a history of RD,^{7 –10} lesions with subretinal fluid (SRF)/early focal RDs, ¹¹ lattice degeneration with traction, ⁶ cataract or refractive surgery,^7,10,12,13 upcoming pars plana vitrectomy (PPV), ¹⁴ vitreous hemorrhage,^15,16 acute posterior vitreous detachment (PVD),^17,18 and retinal tufts. ¹⁹

Options for treating lattice degeneration include transconjunctival cryotherapy or laser photocoagulation. These methods create an adhesion between the retina and retinal pigment epithelium to decrease the likelihood of vitreous fluid entering through a hole or break at the site of lattice degeneration and to reinforce the edges of the lattice to decrease the effects of vitreous traction when acute PVDs develop. ² There has been little research examining the prophylactic treatment of lattice degeneration since the l990s.

In this study, we aimed to conduct updated research to identify the indications for prophylactic lattice degeneration treatment with laser retinopexy and to report the long-term outcomes of this treatment in high-risk eyes with lattice degeneration.

Methods

This retrospective study evaluated patients who had laser retinopexy for lattice degeneration with high-risk features between 2014 and 2021 by the same surgeon (M.J.S.). The study protocol was approved by the Wills Eye Institutional Review Board (IRB #2021-59). The study complied with the US Health Insurance Portability and Accountability Act of 1996 and conformed to the tenets of the Declaration of Helsinki.

High-risk features included an atrophic hole in the lattice, RD in the fellow eye, holes with SRF, traction, RD in the study eye fixed with laser treatment, upcoming cataract extraction or laser in situ keratomileusis, multiple retinal defects without detachment in the fellow eye, retinal tufts, vitreous hemorrhage, and upcoming PPV for floaters, macular hole (MH), or a PVD with an epiretinal membrane (ERM). The electronic medical chart system was searched for a “lattice degeneration” diagnosis code to identify all eyes with this diagnosis. In addition, all laser retinopexy procedures in this timeframe were searched using Current Procedural Terminology (CPT) codes. The 2 databases were cross-referenced to find eligible patients. Eyes were excluded if they had lattice degeneration with a history of laser treatment or cryotherapy, a horseshoe tear treated at the same time as lattice degeneration, or previous vitrectomy or if the patient did not attend any follow-up visits after laser application. Eyes that had RDs and lattice degeneration treated concurrently with the laser were included.

Chart reviews of eligible patients documented age, sex, eye laterality, visual acuity (VA), clock hours of lattice degeneration, date of laser procedure(s), reason for laser treatment, preexisting conditions (eg, lens status, lattice degeneration, PVD, ERM, and RD in both the treated eye and fellow eye), complications of laser treatment, final VA, and date of the last follow-up. The VA after laser treatment was measured at the patient’s most recent follow-up visit. The presence of PVD and ERM was determined by the surgeon via a slitlamp fundus examination and confirmed with spectral-domain optical coherence tomography.

Data were analyzed in SPSS (IBM SPSS 25 Statistics). Patients were divided into groups as follows: all eyes, eyes that had a new ERM after laser treatment, and eyes that had a new RD after laser treatment. Comparisons between groups were analyzed using the χ² test, Fisher exact test, and Wilcoxon rank sum test. A value of P < .05 was used to indicate statistical significance. All means values are ± SD.

Results

The study included 167 eyes of 143 patients (53.3% female) with a mean age of 50 ± 17 years (range, 13-86) (Table 1). The mean follow-up from the lattice degeneration diagnosis visit was 1013 days (95% CI, 907-1119; range, 46-2891). The mean time from the lattice degeneration diagnosis to initial laser treatment was 104 days (95% CI, 47-160; range, 0-3291). The mean logMAR VA was 0.14 ± 0.27 (Snellen equivalent 20/28; 95% CI, 0.10-0.18) before the laser procedure and 0.12 ± 0.25 (Snellen equivalent 20/26; 95% CI, 0.08-0.16) after the procedure (P = .07).

Table 1.

Comparison of Baseline Characteristics Between Patients Without a New ERM and Those With a New ERM.

Variable	All Eyes (N = 167)	Eyes With No New ERM (n = 154)	Eyes With a New ERM (n = 13)	P Value
Age (y)				.016a,b
Mean ± SD	49.73 ± 16.86	48.71 ± 17.13	60.38 ± 7.40
95% CI	47.08, 52.30	46.10, 51.56	55.91, 64.86
Median	54	53	61
Min, Max	13, 86	13, 86	41, 71
Sex, n (%)				.230 c
Male	89 (53.3)	80 (51.9)	9 (69.2)
Female	78 (46.7)	74 (48.1)	4 (30.8)
PVD at diagnosis, n (%)				.737 d
No	126 (75.4)	117 (76.0)	9 (69.2)
Yes	41 (24.6)	37 (24.0)	4 (30.8)
ERM before laser, n (%)				—
No	158 (94.6)	145 (94.2)	13 (100.0)
Yes	9 (5.4)	9 (5.8)	0
Lens status at diagnosis, n (%)				.343 c
Phakic	157 (94.0)	144 (93.5)	13 (100.0)
Pseudophakic	10 (6.0)	10 (6.5)	0
History of RD in main eye before laser, n (%)				1.000 d
No	158 (94.6)	145 (94.2)	13 (100.0)
Yes	9 (5.4)	9 (5.8)	0
History of RD in fellow eye before laser, n (%)				.782 c
No	96 (57.5)	89 (57.8)	7 (53.8)
Yes	71 (42.5)	65 (42.2)	6 (46.2)
Lattice in fellow eye, n (%)				1.0000 d
No	37 (22.2)	33 (21.4)	3 (23.1)
Yes	130 (77.8)	121 (78.6)	10 (76.9)
PVD in fellow eye, n (%)				.114 d
No	115 (68.9)	109 (70.8)	6 (46.2)
Yes	52 (31.1)	45 (29.2)	7 (53.8)

Abbreviations: ERM, epiretinal membrane; PVD, posterior vitreous detachment; RD, retinal detachment.

^aStatistically significant.

^bRank sum test.

^cχ² test.

^dFisher exact test.

At the lattice degeneration diagnosis visit, 41 eyes (24.6%) had a preexisting PVD in the treated eye and 157 eyes (94.0%) were phakic. Of treated eyes, 9 (5.4%) had ERMs, 2 of which were visually significant, and 9 (5.4%) had early focal RDs smaller than 4 disc diameters before laser retinopexy. Of fellow eyes, 71 (42.5%) had an RD, 130 (77.8%) had lattice degeneration, and 52 (31.1%) had PVD before laser treatment (Tables 1 and 2).

Table 2.

Comparison of Baseline Characteristics Between Patients Without a New RD and Those With a New RD.

Variable	All Eyes (N = 167)	Eyes With No New RD (n = 162)	Eyes With a New RD (n = 5)	P Value
Age (y)				.060 a
Mean ± SD	49.73 ± 16.86	49.34 ± 16.95	62.40 ± 5.55
95% CI	47.08, 52.30	46.71, 51.97	52.51, 69.29
Median	54	61	65
Min, Max	13, 86	13, 86	53, 67
Sex, n (%)				1.000 b
Male	89 (53.3)	86 (53.1)	3 (60.0)
Female	78 (46.7)	76 (46.9)	2 (40.0)
PVD at diagnosis, n (%)				.096 b
No	126 (75.4)	124 (76.5)	2 (40.0)
Yes	41 (24.6)	38 (23.5)	3 (60.0)
ERM before laser, n (%)				.588 c
No	158 (94.6)	153 (94.4)	5 (100.0)
Yes	9 (5.4)	9 (5.6)	0
Lens status at diagnosis, n (%)				.268 b
Phakic	157 (94.0)	153 (94.4)	4 (80.0)
Pseudophakic	10 (6.0)	9 (5.6)	1 (20.0)
History of RD in main eye before laser, n (%)				.588 c
No	158 (94.6)	153 (94.4)	5 (100.0)
Yes	9 (5.4)	9 (5.6)	0
History of RD in fellow eye before laser, n (%)				.164 b
No	96 (57.5)	95 (58.6)	1 (20.0)
Yes	71 (42.5)	67 (41.4)	4 (80.0)
Lattice in fellow eye, n (%)				1.000 b
No	37 (22.2)	35 (21.6)	1 (20.0)
Yes	130 (77.8)	127 (78.4)	4 (80.0)
PVD in fellow eye, n (%)				.647 b
No	115 (68.9)	112 (69.1)	3 (60.0)
Yes	52 (31.1)	50 (30.9)	2 (30.0)

Abbreviations: ERM, epiretinal membrane; PVD, posterior vitreous detachment; RD, retinal detachment.

^aRank sum test.

^bFisher exact test.

^cχ² test.

Table 3 shows the indications for laser retinopexy. The most frequent indications were atrophic holes in the lattice, RD in the fellow eye, atrophic holes with SRF, and traction on the lattice degeneration. Some eyes had multiple indications for laser treatment. Other indications included RD in the treated eye repaired with a laser, to lower the risk before cataract or refractive surgery, multiple retinal tears without detachment in the fellow eye, planned before PPV for ERM, MH or vitreous opacity, retinal tuft, and vitreous hemorrhage. All these other reasons, which indicated high-risk lattice degeneration, were each found in less than 5% of eyes (Table 3). Two eyes had a preexisting retinal hemorrhage, neither of which was in the area of lattice degeneration.

Table 3.

Reasons for Laser Retinopexy (167 Patients).

Reason for Laser	Number (%)
Atrophic hole in the lattice	73 (43.7)
RD in fellow eye	56 (33.5)
Hole with subretinal fluid	38 (22.8)
Traction	11 (6.6)
Main eye RD fixed with laser	6 (3.6)
Lower risk before cataract extraction or pre-LASIK	4 (2.4)
Multiple retinal defects without RD in fellow eye	3 (1.8)
Planned before PPV for ERM/PVD	2 (1.2)
Retinal hemorrhages	2 (1.2)
Retinal tuft	1 (0.06)
Vitreous hemorrhage	1 (0.06)
PPV for vitreous floaters	1 (0.06)
PPV planned for macular hole	1 (0.06)

Abbreviations: ERM, epiretinal membrane; LASIK, laser in situ keratomileusis; PPV, pars plana vitrectomy; PVD, posterior vitreous detachment; RD, retinal detachment.

After laser treatment, 21 eyes (12.6%) developed a new PVD (mean, 525 ± 540 days post-laser), 13 eyes (7.8%) developed a new ERM (mean, 618 ± 469 days), 5 eyes (3.0%) developed a new RD (mean, 280 ± 330 days), and 22 eyes (13.2%) required additional laser treatment (mean, 742 ± 647 days) (Table 4). Six of these eyes (3.6%) developed both a new PVD and a new ERM. One additional eye developed a new PVD, a new ERM, and a new RD (Table 4). Eyes that developed PVDs after laser treatment were more likely to be older (mean, 59 ± 8 years vs 48 ± 17 years; P = .005). Those that developed new a RD or PVD had a longer follow-up than those that did not develop these complications (RD: mean, 1647 days; 95% CI, 967-2327 vs mean, 993 days; 95% CI, 886-1101; P = .04) (PVD: mean, 1125 days; 95% CI, 1006-1445 vs mean, 981 days; 95% CI, 863-1099; P = .009). This may indicate that complications are more likely to be found over a longer follow-up. Those that developed a new ERM also had a longer follow-up (mean, 1350 days; 95% CI, 1018-1682 vs mean, 977 days; 95% CI, 866-1088); however, the difference did not reach statistical significance (P = .075).

Table 4.

Outcomes After Laser Retinopexy (167 Patients).

Outcome	Number (%)	Mean Days After Initial Laser ± SD
PVD after laser	21 (12.6)	525 ± 540
ERM after laser	13 (7.8)	618 ± 469
RD after laser	5 (3.0)	280 ± 330
Additional laser needed	22 (13.2)	742 ± 647

Abbreviations: ERM, epiretinal membrane; PVD, posterior vitreous detachment; RD, retinal detachment.

Eyes that developed an ERM post-laser were more likely to be older (mean, 60 ± 7 years vs 49 ± 17 years; P = .016) (Table 1) and to develop PVD (odds ratio [OR], 5.39; 95% CI, 1.57-18.47). In eyes with a new ERM after laser treatment, the mean logMAR VA was 0.18 ± 0.27 (Snellen equivalent 20/30; 95% CI, 0.09-0.19) before treatment and 0.23 ± 0.54 (Snellen equivalent 20/34; 95% CI, −0.09 to 0.56) after treatment. No ERMs were visually significant or required additional surgery.

Eyes that had an RD after laser treatment were more likely to be older than those that did not (mean, 62 ± 6 years vs 49 ± 17 years), although the difference did not reach statistical significance (P = .06) (Table 2). In eyes with a new RD after laser treatment, the mean logMAR VA was 0.25 ± 0.15 (Snellen equivalent 20/36; 95% CI, 0.06-0.43) before treatment and 0.16 ± 0.04 (Snellen equivalent 20/29; 95% CI, 0.12-0.20) after treatment.

Of the 167 eyes included in the study, 22 (13.2%) required additional laser treatment. Reasons for additional laser treatment were atrophic hole (3 eyes [13.6%]), a new tear (16 eyes [72.7%]), a new RD (4 eyes [18.2%]), and planned for laser treatment in multiple sessions because the patient could not tolerate a single session (2 eyes [9.1%]). Some eyes had multiple indications for additional laser treatment, such as both a new tear and an atrophic hole. Of the eyes with new retinal tears, 11 had tears in the area that was lasered and 5 had tears not located in the area that was lasered. All eyes required only a single additional laser session.

Of the 5 eyes with RD, 1 developed a small amount of SRF adjacent to the lasered area, 1 developed a new PVD with a horseshoe tear and a small amount of SRF in the area of lattice degeneration, and 1 had a preexisting recent-onset PVD and developed a tear not located in the area that was lasered. Four eyes with a new RD were treated with laser retinopexy alone, and 1 eye required incisional surgery (scleral buckle and PPV) because of the development of a new PVD and did well with a single surgery. At the final visit, the retina remained attached in all eyes with 1 procedure.

Conclusions

Lattice degeneration is prevalent and may increase the risk for RD.^1,2 There is debate about the use of prophylactic laser retinopexy in terms of its safety and efficacy in decreasing the progression of lattice degeneration in eyes with high-risk features for RD. In our study, we examined the indications and outcomes in eyes with high-risk features that had laser retinopexy for lattice degeneration. Few eyes progressed to RD after receiving prophylactic laser treatment. Eyes of older individuals were more likely to have complications, such as new a ERM or PVD, after laser treatment.

A 1989 study by Byer ²⁰ followed 276 patients with untreated lattice degeneration for 1 to 25 years (mean, 10.8 years) and found that only 1.08% of cases progressed to clinical RD. Therefore, he concluded that prophylactic treatment of lattice degeneration should be discontinued under most circumstances. However, progression of lattice degeneration to RD is more common in fellow eyes with RD. ⁷ In a study by Laatikainen, ²¹ 98 of 312 fellow eyes of individuals who had unilateral rhegmatogenous detachments were found to have degeneration predisposing them to RD, including retinoschisis (n = 13), lattice degeneration (n = 51), or other unspecified degeneration (n = 27). Of these eyes, 91 received prophylactic treatment with cryotherapy, laser coagulation, or both. One (1.1%) of the treated fellow eyes developed RD during the follow-up compared with 6 fellow eyes (2.7%) that developed RD in the untreated group. The eye that that had an RD in the treated group had cystoid macular degeneration as the predisposing lesion but did not have lattice degeneration. No eye that was specifically treated for lattice degeneration progressed to RD, supporting the safety and efficacy of prophylactic treatment for lattice degeneration.

Despite Byer’s finding that a small percentage of lattice degeneration progresses to RD, ²⁰ many eyes with RD are found to have lattice degeneration. For example, in a study by Sasaki et al, ²² lattice degeneration was present in up to 60% of cases with RRD. Atrophic holes were found in 20% of eyes with lattice degeneration, and tractional tears were found in 40% of eyes with lattice degeneration. ⁹ These lesions independently increase the risk for RRD. Tielsch et al ¹³ found that lattice degeneration was associated with a significantly elevated risk for RD (OR, 6.6) in patients who had cataract surgery. Another study found that eyes with preoperative lattice degeneration had a higher risk for RD after cataract surgery (21.3%) than those without a preoperative PVD or lattice degeneration (0.7%) even though the eyes with lattice degeneration were included only if they were asymptomatic and involved less than 1 quadrant. ¹² In that study, all eyes with lattice degeneration that progressed to RD after surgery also developed a postoperative PVD.

In a study by Cetinkaya et al ²³ of 43 eyes having phacoemulsification and intraocular lens implantation for cataract, 2 received prophylactic preoperative laser treatment for lattice degeneration and 5 had prophylactic preoperative laser treatment for retinal tears or holes. Of these 7 eyes, none developed postoperative complications, while in the untreated group (n = 36) 2 eyes developed retinal tears and 1 eye developed a new RD postoperatively. Although the sample size of this study was limited, the data suggest that laser treatment before cataract surgery is safe and may reduce postoperative complications.

Although the benefits of preoperative treatment of lattice degeneration before retina surgery vs intraoperative treatment are debated, a study by Sakamoto et al ²⁴ found that eyes with lattice degeneration before PPV for MH had a significantly increased rate of retinal breaks occurring intraoperatively compared with eyes without lattice degeneration (OR, 5.56; P < .001). After performing intraoperative laser treatment of the lattice degeneration in these previously untreated eyes, the authors concluded that preoperative laser treatment of lattice degeneration can decrease the risk for intraoperative breaks.

Given the findings in these previous studies, there is a need to further examine treatments for high-risk lattice degeneration and the resulting impact on RRDs. Our study focused on contributing to this area of research.

Because laser retinopexy is not routinely performed in all eyes with lattice degeneration, the eyes in our study were considered to have a higher risk for RD. This was often because of the presence of coexisting high-risk conditions, most commonly RD in the fellow eye, atrophic holes in the lattice degeneration, or lattice degeneration with atrophic holes and associated SRF. These high-risk findings might have contributed to post-laser complications. Overall, in eyes with a higher risk for tears and RD, the rate of post-laser RD was low. At the last follow-up examination and without further intervention, 97% of eyes did not progress to RD. Of the 5 eyes (3%) that did progress to RD, 4 received additional laser treatment and did not experience significant vision loss; 1 of the 5 eyes required combined scleral buckle and PPV, with no RD after 1 surgery.

Patients whose eyes progressed to RD were older than those without progression to RD, although the difference did not reach statistical significance. Eyes that developed a new PVD after laser treatment were also more likely to be older, which did reach statistical significance. An autopsy study found that high-risk lesions, including retinal holes, retinal tears, and PVDs, were more prevalent in older eyes. ²⁵ The peak incidence of RD is in people in their 60s to 70s, ¹⁰ which coincides with our findings that the mean age of those with a new RD was 62 ± 6 years. Like RDs, PVDs are more prevalent in people in their 60s to 70s. ¹⁰ PVDs cause traction on the retina, which predisposes eyes to RDs. ²⁶ Multiple studies have found that the incidence of RD is higher in patients with PVDs^12,27 and that up to 87% of eyes with RDs had a PVD. ¹⁰ Therefore, the presence of a PVD may be a confounding factor when considering that our study found that those with a new RD were more likely to be older.

Patients who developed ERMs were also more likely to be older. Older age has been found to be one of the biggest risk factors for developing an ERM. ²⁸ The incidence of a new ERM after laser surgery in our study was 7.8%. A study by Blackorby et al ²⁹ found the incidence of new ERM after laser to be 2.9%, while a study by Saran and Brucker ³⁰ found the incidence to be 10%. Unfortunately, neither study examined age as a risk factor for new ERM formation. New RDs, new PVDs, and new ERMs after laser treatment were associated with older age in our study, suggesting that older patients may be at higher risk for post-laser complications.

In our study, 3% of eyes developed an RD after the laser procedure. After being treated for the new RD, by laser retinopexy alone or by combined scleral buckle and PPV, all eyes had no RD up to the final visit. These results appear similar to the reported RD rates in other studies. Avitabile et al ³¹ found that only 2.6% of eyes treated with photocoagulation developed new retinal tears over a follow-up of 1 to 72 months (mean, 36 months). However, in their study, only 35% of patients had lattice degeneration at the time of treatment, whereas all eyes in our study had lattice degeneration. Another study by Folk et al ⁹ examined the phakic eye in cases in which the fellow eye had a phakic lattice-associated RD over a 7-year period. The study compared eyes that received prophylactic treatment for lattice degeneration, holes, or tears with eyes that did not receive prophylactic treatment. They found that 1.8% of the eyes that had prophylactic treatment for lattice degeneration had new RDs, while 5.1% of eyes that did not receive prophylactic treatment had new RDs. They also found that fellow eyes that did not receive prophylactic treatment had a 2.5 times greater risk for a new break or RD than eyes that received prophylactic laser treatment (P = .0001).

Our study’s limitations include its retrospective methodology and the use of data from a single surgeon. In addition, this study did not include a comparison group of patients with lattice degeneration who did not receive treatment with a laser. However, this study is strengthened by detailed collection of preexisting conditions, substantial follow-up periods, and a patient population diverse in age and sex. Another strength of this study is its recency given that there has been little research on this topic since the 1990s.

In summary, despite high-risk characteristics, few eyes had an RD after laser retinopexy. Only 1 eye required incisional surgery for complications. Eyes with PVDs after laser treatment are more likely to have an ERM after laser treatment. Older patients may be more likely to experience complications, such as a new PVD or ERM, after laser treatment.

We conclude that prophylactic laser treatment for high-risk lattice degeneration is relatively safe and may be effective in decreasing progression to RD, although after treatment is performed, patients should continue to be monitored with regular follow-up visits. Given the lack of updated research on this topic, we recommend further studies be performed that include patients from multiple surgeons and a comparison group of eyes with high-risk lattice degeneration that did not have laser treatment. This research aimed to provide a thorough review of the existing literature, raise awareness of the need for updated research on this topic, increase confidence in the safety of conducting this research, and lay the foundation for future studies.