Fundus autofluorescence imaging in chronic optic pit maculopathy: prognostic implications

Subretinal fluid (SRF) is the most consistent marker for poor visual prognosis in optic pit maculopathy (OPM), and early indication for surgery across the largest and most recent studies on surgery and natural history of OPM [1, 2]. Optical coherence tomography (OCT) is the key imaging modality for OPM. Fundus autofluorescence imaging (FAF) has only been used as an adjunct to OCT so far, with descriptive rather than prognostic additional information [3, 4]. We report the prognostic value of FAF in chronic OPM.

This retrospective study included eight patients (one woman) with longstanding OPM; seven underwent vitrectomy, internal limiting membrane (ILM) peeling, juxtapapillary photocoagulation and gas tamponade by a single surgeon. Both OCT and FAF were performed periodically in every case. The study received a waiver from review by the Institutional Ethics Committee and complied with the Declaration of Helsinki. The demographic, imaging, and surgical details of the patients are captured in Table 1. Patient ages ranged from 10 to 47 years (mean, 26 years). The symptoms were chronic: 3 months–8 years in five patients (mean, 3.6 years); several months-years in three. BCVA ranged 6/18–2/60 (median, 6/30). The OCT profile was universally severe: multilayered schisis and SRF (all 8), outer retinal hole (3), thinned-out inner-retinal roof (5) (Fig. 1c, f, i). Vitrectomy resulted in visual improvement by ≥2 lines in 6/7 (85%) patients.

Table 1.

Demographics, imaging, and surgical outcomes of optic pit maculopathy.

Case no.	Age/Sex	Duration of symptoms	BCVA at presentation	FAF hypofluorescence	OCT	FF (DRPEA)	PPV details	Follow-up (months)	Final Snellen BCVA
1	47/M	Few years	2/60	Confluent, very large	ORS	+	Not performed	–	2/60
2	20/F	Several months	6/60	Confluent, very large	SRF	+	JPL + ILMP + SF6	3	6/12
3	17/M	8 years	6/24	Confluent large	MLS, OLH, thin roof, SRF	+	JPL + ILMP + C3F8	22	6/12
4	22/M	Several months	6/24	Confluent, large	ORS, SRF	+	JPL + nasal ILMP + SF6	9	6/24
5	25/M	6 years	6/36	Confluent, large	MLS, OLH, thin roof, SRF	+	JPL + ILMP + SF6	78	6/18
6	46/M	3 years	3/60	None	MLS, OLH, thin roof, SRF	–	JPL + ILMP + SF6	14	6/36
7	19/M	3 months	6/18	None	MLS, OLH, thin roof, SRF	–	JPL + ILMP + SF6	12	6/6
8	10/M	1 year	6/24	None	MLS, OLH, thin roof	–	JPL + ILMP + SF6	13	6/9

BCVA best-corrected visual acuity, FAF fundus autofluorescence, OCT optical coherence tomography, FF fundus photograph, DRPEA diffuse retinal pigment epithelial atrophy, PPV pars plana vitrectomy, ORS outer retinal schisis, SRF subretinal fluid, JPL juxtapapillary laser, ILMP internal limiting membrane peeling, SF₆ sulfur hexafluoride, MLS multilayered schisis, OLH outer lamellar hole, C₃F₈ perfluoropropane.

Fig. 1. Fundus autofluorescence and optical coherence tomography features in chronic optic pit maculopathy.

a–d This 17-year-old man (Case 3) had a history of poor vision in the right eye for 8 years; Snellen best-corrected visual acuity (BCVA) was 6/24. a Fundus examination revealed longstanding optic pit maculopathy (OPM) with retinal pigment epithelial (RPE) atrophy. b The fundus autofluorescence (FAF) image reveals a dense central hypoautofluorescence; the peripheral hyperautofluorescence band probably corresponds to residual photoreceptor debris at the edge of resolved central subretinal fluid (SRF). c Horizontal OCT scan passing through foveal centre reveals a multi-layer schisis, most prominent in the outer nuclear layer, and SRF. d The OPM settled completely over 2 years post-vitrectomy; BCVA improved to 6/12. e–g This 10-year-old child (Case 8) had a year-long history of decrease in vision (BCVA: 6/24) due to OPM in the right eye. e FAF reveals a nearly normal FAF pattern at macula except a faint band of hyperautofluorescence inferiorly. f, g There was a near-complete resolution of the maculopathy with a large outer lamellar hole; BCVA improved to 6/9 over a year postoperatively. h–j This young woman (Case 2) showed extensive confluent hypoautofluorescence (h) at the left macula. i OCT revealed an extensive serous macular detachment communicating with the optic pit. j Despite the residual SRF, BCVA had already improved to 6/12 by 3 months after vitrectomy.

FAF showed confluent hypoautofluorescence in 5/8 (62%) patients, indicating diffuse RPE atrophy (Fig. 1b, h). Four of these were operated: three gained 2–4 Snellen lines; one failed to improve. The one not operated had spontaneously settled maculopathy (BCVA 2/60). The confluent hypoautofluorescence in the four operated cases remained unchanged despite the functional and anatomical improvement. Mean final BCVA of these 5 cases with confluent hypoautofluorescence was 6/24 (median: 6/18). Three cases showed no evidence of RPE atrophy on FAF: all improved by 3–4 Snellen lines; two improved to 6/6–6/9 (mean final BCVA: 6/12; median: 6/9) (Fig. 1e–g).

Confluent macular hypoautofluorescence on FAF was associated with suboptimal visual recovery after vitrectomy. FAF therefore may be useful in timing the surgical intervention; duration of symptoms may be misleading due to waxing and waning nature of OPM. A better visual prognosis is more likely in the absence of macular hypoautofluorescence. OCT biomarkers did not help prognostically in these chronic cases as they had uniformly adverse OCT profile. Extensive macular hypoautofluorescence on FAF imaging as an objective marker of gross RPE atrophy, and therefore a longstanding OPM, has not been reported to the best of our knowledge. Teke and Citrik described diffuse hyperautofluorescence in OPM which turned into a granular pattern as SRF resolved [3]. Similar findings have been described in OPM as well as a wide variety of conditions associated with subretinal fluid including central serous chorioretinopathy (CSC), choroidal hemangioma and vitelliform dystrophy [4]. These granular precipitates probably reflect the reduced ability of RPE to phagocytize lipofuscin bisretinoids from photoreceptor outer segments, resulting in their accumulation. While no prognostic value was attached to diffuse or granular hyperfluorescence [3, 4], Spaide briefly averred to confluent hypoautofluorescence—like our cases—as a poor prognostic sign in chronic, spontaneously settling CSC [4].

Despite RPE atrophy, most of these cases responded well to surgery, though visual outcomes were inferior to those without RPE atrophy. Extensive RPE atrophy typically follows longstanding subretinal fluid, and therefore has been suggested as a probable contraindication for surgery, even when associated with operable OPM [5]. Since optic pits are congenital, maculopathy develops much later in life after several waxing and waning episodes and is therefore frequently longstanding [2]. We propose FAF as an objective indicator of chronicity in OPM: surgery should not be delayed when RPE mottling begins, preferably not waiting for extensive RPE atrophy. We also emphasize that surgery should not be denied in the presence of extensive RPE atrophy: visual recovery is still possible, though visual outcomes are likely to be suboptimal.

Author contributions

DS, AD, and JK: conceptualization; DS and JK: methodology and data collection; DS and AD: validation; AD: formal analysis; DS: resources; AD and JK: data curation; DS, AD, and JK: writing; all authors approved the final draft.

Data availability

The data generated or analyzed during this study are included in this published article; Supplementary Information is available with the corresponding author.

Competing interests

The authors declare no competing interests.