Artificial Intelligence in Vitreoretinal Surgery: A Systematic Review of Current Applications and Future Directions.

Vitrectomy surgical techniques have rapidly developed over the last 15 years and continue to evolve with the introduction of perfluorocarbon liquids, multifunctional probes, improved endoillumination and sutureless microincision vitrectomy. In the context of rhegmatogenous retinal detachment (RRD) management, there is a decline in buckle surgery (El-Amir et al. 2009) and shift towards pars plana vitrectomy (PPV) as the procedure of choice. Other established indications for PPV include macular hole (MH), epiretinal membrane (ERM), non-clearing diabetic vitreous haemorrhage (NCVH), tractional retinal detachment (TRD) with variations in gases used, posturing regime and vital dyes. The surgical episodes for all patients having vitreoretinal procedures at three sites (St Thomas' Hospital, London Eye Clinic, Queen Mary's Hospital, United Kingdom) under a single surgeon were anonymized and prospectively recorded on an electronic medical record (Vitreor, AxSys Technologies, Glasgow, UK) between January 1997 and December 2013 and is being reported. Included in the study are data on baseline primary indication, details of surgical procedure, method of anaesthesia and intra-ocular agents. Two-sided t-tests and Pearson correlation were performed to test for slope, and all p values are presented with a Bonferroni correction. There were 7570 operations in 5591 patients (1.35 operation per patient), ratio of males to females (1.27:1), the mean age was 59.8 years (SD, 170.0 years), and 48.8% of operations were on left eyes and 51.2% on right eyes. The most common indication for surgery was RRD (42.8%) followed by intervention for vitreous haemorrhage (VH) (12.6%), TRD (6.1%), MH (10.4%) and ERM (7.7%). The relative frequency of vitreoretinal surgical intervention for most indications has remained similar over the past 16 years. In the management of RRD, 82.6% of the cases were pars plana vitrectomy procedures, and 16.6% were external buckle procedures with an increasing pattern towards PPV as the preferred choice (r = 0.229. R2 = 0.052, p < 0.001) (Fig. 1). The percentage of cases undergoing PPV, as compared to explant surgery, has increased from 60% in 1997 to over 90% in 2013. Macular hole surgery increased as a relative proportion of all cases (r = 0.95, p < 0.013) over the 16 years, and there was increasing use of hexafluoroethane (C2F6) as a tamponade agent following its introduction in 2009 rather than perfluoropropane (C3F8: r = −0.508, r2 = 0.252, p < 0.001). This trend in preferential use of C2F6 over C3F8 was also seen for other indications in later years. There was an increasing trend for combined lens and vitreous (CLV) extraction with PPV for the management of ERM and MH (Fig. 1). Brilliant blue is increasingly being used to stain internal limiting membrane in macular pathologies and was preferred over trypan blue. There was a general increasing preference for local anaesthesia across all surgical indications with time (p < 0.001). This study presents one of the largest series in the literature of patients who underwent vitreoretinal (VR) surgery over a prolonged period of 15 years. Overall, this study demonstrates that there is a move towards vitrectomy for both phakic and pseudophakic RRD. It is similar to increasing use of small gauge vitrectomy for the management of primary RRD is seen in many centres around the world (Falkner-Radler et al. 2011; Wong et al. 2014). The role of PPV is likely to further increase over time, as smaller gauge vitrectomy becomes more commonly used, and continuous improvement is seen in anatomical and visual outcomes (Tsang et al. 2008; Falkner-Radler et al. 2011). Our data have shown an increasing incidence of macular hole surgery which has coincided with improvement in optical coherence tomography and vital dyes (Rodrigues et al. 2007). The number of vitreoretinal surgical operations from complications of advanced diabetic retinopathy (tractional retinal detachment and vitreous haemorrhage) has remained constant which may be a reflection of better awareness amongst healthcare providers, improved diabetic control and the establishment of the national diabetic retinopathy screening programme. The study provides useful numbers for the planning of resources for a vitreoretinal service with detail on the pattern of surgical practice and use of various agents required for a vitreoretinal service. Changes in practice include an increased use of small gauge surgery and a resultant reduction in the need for per-operative suturing. Gases and intra-ocular dyes are used regularly, but changes in the agents used with time have been identified. Current trend has major implications on the future education and training of vitreoretinal surgeons and in particular suggests the use of scleral buckle surgery may further decrease in developed nations.

This chapter takes an ophthalmologist through vitreo-retinal (VR) surgery from the be‐ ginning to the end, using a case-based approach to highlight the skills required, lessons learnt from and pit-falls to avoid in VR surgery. This is especially useful to those who are new and intermediate VR surgeons. The case represents the common conditions requiring VR surgery, so that the reader can get exposure from the common cases, ranging from hot cases like retinal detachment, to cold cases like macular hole surgery and epiretinal membrane peel, and important cases like diabetic VR cases and trauma cases.

PurposeThe aim of this study was to report the intraoperative and postoperative complications of vitrectomy for epiretinal membrane (ERM) and macular hole (MH) performed by retinal fellows under direct faculty supervision compared with experienced faculty members.Patients and MethodsA total of 271 eyes that underwent pars plana vitrectomy (PPV) for MH and ERM from January 2014 to December 2019 at King Khaled Eye Specialist Hospital were analyzed. PPV for ERM and MH was performed by vitreoretinal fellows and consultants.ResultsThe outcome measures assessed were the intraoperative complications rates, such as posterior lens touch, retinal breaks (RBs), retinal detachments, and vitreous hemorrhage. Moreover, the postoperative complications and optical coherence tomography (OCT) changes were assessed upon a minimum follow-up of 6 months. The rate of iatrogenic RB was more common in the ERM than in the MH surgery (15.5% vs 11.2%). Fellows and consultants had a rate of 20.5% of RB during the ERM surgery and 14.6% during MH surgery, respectively. However, these differences were not statistically significant (p = 0.12 for MH and p = 0.236 for ERM). Postoperative OCT analysis revealed an MH closure rate of 72.2%, and complete removal of the ERM was achieved in 88.6% in cases performed by fellows, while consultants achieved 61.8% closure rate of MH, and 83.3% of the patients achieved complete removal of ERM.ConclusionMacular surgery is overall a safe procedure and the complication rates between fellows and consultants are comparable. With proper supervision, vitreoretinal fellows can achieve equally high anatomical outcomes with few complications.

To investigate morphological variations in the macular area with optical coherence tomography (OCT) after vitrectomy for diabetic fibrovascular proliferation. We reviewed 108 cases using OCT 7-15 months after vitrectomy. Of these, 32 received OCT within 3 months postoperatively. Morphological variations were categorized and correlated with visual outcome. Only 24 cases (21.4%) had no obvious abnormalities. The most frequent findings were epiretinal membrane (52.8%), macular thickening (37.0%) and macular cysts (28.7%). Multivariate regression showed that diffuse macular thickening, loss of foveal depression and diffuse retinal thinning were significantly associated with poor visual acuity. Sequential OCT (< 3 and >or= 7 months) revealed that epiretinal membrane and oedema outside of fovea changed significantly between two examinations. OCT may identify diverse morphological changes in the macular area after diabetic vitrectomy for fibrovascular proliferation. Macular appearance may change over time, and certain types of morphological changes may be associated with poor visual function.

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Objective To investigate the factors correlated with the visual outcome of idiopathic macular holes (IMH) after vitreoretinal surgery. Methods A total of 57 eyes of 57 patients with IMH were included. There were 43 females (43 eyes) and 14 male (14 eyes), mean age was (60.46±4.79) years. All the eyes underwent best corrected visual acuity (BCVA), slit-lamp microscope, three-mirror contact-lens and optical coherence tomography (OCT) examinations. BCVA were examined with interactional visual chart and recorded with logarithm of the minimum angle of resolution (logMAR) acuity. The minimum diameter and base diameter of macular holes and central retinal thickness (CRT) were detected by OCT. The average logMAR BCVA of 57 eyes was 0.98±0.41. The minimum diameter and base diameter of macular holes were (479.53±164.16) μm and (909.14±278.65) μm. All the patients underwent pars plana vitrectomy combined with phacoemulsification cataract extraction and intraocular lens implantation. The mean follow-up period was (173.44±147.46) months. The relationships between final BCVA and these parameters were examined by single and multiple regression analysis. The valuable influence factors were filtrated and formulated using multiple linear regression models. Results At the final follow-up, the logMAR BCVA of 57 eyes was 0.44±0.31, the CRT was (158.79±86.96) μm. The final BCVA was positive related to minimum diameter of macular holes and preoperative BCVA (r=0.420, 0.448; P=0.001, 0.000), negative related to postoperative CRT (r=-0.371, P=0.004). There was no relationship between the final BCVA and base diameter of macular holes, age and follow-up (r=0.203, -0.015, 0.000; P=0.130, 0.913, 0.999). The incidence of preoperative BCVA for postoperative BCVA was bigger than preoperative minimum diameter of macular holes (P=0.008, 0.020). Conclusion The preoperative minimum diameter of macular holes and BCVA are related to postoperative BCVA in IMH eyes. Key words: Retinal perforations/surgery; Vitreoretinal surgery; Root cause analysis

Purpose:To determine the long-term incidence of fellow-eye surgical involvement in patients who have undergone first-eye vitreoretinal (VR) surgery for a variety of indications. This was a single-institution retrospective, consecutive series.Methods:Eighteen years of electronic surgical data were reviewed at our institution. All patients having surgery for the following indications were included: rhegmatogenous retinal detachment (RRD), macular hole (MH), epiretinal membrane (ERM), proliferative diabetic retinopathy (PDR), vitritis, and dropped nucleus. Primary outcome was the cumulative incidence of fellow-eye surgery at 10 years by Kaplan–Meier analysis.Results:Total follow-up was 29,629 patient-years. Cumulative incidence (± standard error) of fellow-eye surgery at 10 years was 7.2% ± 0.6% for RRD, 9.1% ± 1.3% for ERM, 7.5% ± 1.8% for MH, 30.6% ± 1.9% for PDR, 13.7% ± 2.9% for vitritis, and 2.8% ± 1.6% for dropped nuclei. The hazard for second-eye surgery was greatest in the early postoperative period after first-eye surgery for all indications. For RRD, the hazard was 2.7% ± 0.3% at year 1, 1.1% ± 0.2% at year 2, and 0.5% ± 0.2% at year 5. Risk factors for fellow-eye involvement for RRD were younger age (P < 0.001) and male gender (P < 0.01).Conclusion:We report the long-term risk of fellow-eye involvement in various VR pathologies, which is important in counseling patients regarding their risks as well as planning service provision.

Optical coherence tomography (OCT) parameters have been used to predict postoperative vision after macular hole (MH) surgery (Ullrich et al. 2002; Kusuhara & Negi 2014). We hypothesized that the measurement of the brightest area on fundus autofluorescence (FAF) images may also have a good correlation with postoperative visual acuity. We retrospectively collected 52 eyes from 52 consecutive patients with sealed idiopathic MH after vitrectomy was performed by a single surgeon. From preoperative multiple horizontal or vertical OCT scanning images, the one with the widest MH base was selected, and two parameters were measured: the minimum diameter, defined as the shortest distance across the full-thickness defect, and the base diameter, defined as the base length of the MH (Fig. 1A). Fundus autofluorescence imaging was performed using a confocal scanning laser ophthalmoscope before surgery. The MH size measured based on the brightest area of the FAF was termed the autofluorescence area (AFA) and was measured by the following steps: first, the brightest FAF area was outlined manually five times; the delineated area was measured each time using the ImageJ software and averaged. Second, a square was made five times out of the 200-μm scale line at the left lower corner of the FAF image, and the average of the 5 square area measured was obtained using the ImageJ software. Third, the figure from the first step was divided by the figure from the second step; the result was multiplied by 40 000 μm2 to obtain the AFA (Fig. 1B). The average minimum diameter and base diameter of MH were 422.28 ± 204.97 μm and 804.64 ± 359.88 μm, respectively. The average AFA measured was 263 269.23 ± 203 970.28 μm2. A typical circular hyperfluorescence (Fig. 1B) in FAF image was observed in 39 cases while 13 cases had irregular hyperfluorescence with a sharp margin (Fig. 1C). Fourteen cases showed a stellate appearance with dark radiating striation (Fig. 1D) and were associated with a significantly lower preoperative and postoperative logMAR best-corrected visual acuity (BCVA) than those without. Seven cases with a central darkness FAF pattern (Fig. 1E) had an average postoperative logMAR BCVA significantly lower than those without. Two cases showed a hyperfluorescent outer ring (Fig. 1F). Pearson correlation analysis showed high correlations between any two of the three MH parameters (minimum diameter, base diameter and AFA) (ρ > 0.8 for all comparisons). Univariate linear regression analysis showed that a low preoperative logMAR BCVA (p = 0.010), a small minimum diameter (p = 0.003), a small base diameter (p = 0.0004) and a small AFA (p < 0.0001) all had a negative effect on final logMAR BCVA. To evaluate which MH parameter had the best predictive power of postoperative BCVA, three multivariate regression models were performed using preoperative logMAR BCVA, age and stellate appearance in FAF image combined with either AFA (Model 1), base diameter in OCT (Model 2) or minimum diameter in OCT (Model 3) as covariates. It was shown that among the three MH parameters, AFA was the most powerful predictor for postoperative BCVA (adjusted R2 = 0.301, 0.223, 0.153 for Model 1, Model 2, Model 3). The possible advantages of using AFA to predict postoperative outcome were as follows: first, FAF provides an entire view of the MH instead of a cut line from OCT; second, it might provide more information about the luteal pigment condition, including luteal pigment loss and displacement, which might not be shown by OCT; and finally, FAF may show different patterns (Fig. 1D-F); all may be associated with different prognosis (Wakabayashi et al. 2008). In conclusion, FAF is a quick and convenient clinical examination method to predict visual function after MH surgery.

To report the surgical outcome of pars plana vitrectomy (PPV) without internal limiting membrane (ILM) peeling in three highly myopic patients with macular retinoschisis and associated posterior staphyloma. We report three highly myopic patients with macular retinoschisis and foveal detachment who underwent simple PPV without ILM peeling, with long-acting gas tamponade. Main outcome evaluations included best corrected visual acuity, biomicroscopic appearance and optical coherence tomography findings. Pars plana vitrectomy without ILM peeling resulted in anatomic and functional improvement in all three operated eyes for follow-up periods of > or = 12 months. Pars plana vitrectomy without ILM peeling is effective for treating macular retinoschisis and foveal detachment in highly myopic eyes with posterior staphyloma. Visual and anatomic outcomes are comparable with those in previous studies in which ILM removal was performed.

Long-term Anatomic and Visual Outcomes of Initially Closed Macular Holes

Visual Acuity and Macular Hole Size After Unsuccessful Macular Hole Closure

Point: to peel or not to peel, that is the question

To evaluate the use of infracyanine green (IFCG) staining in idiopathic epiretinal membrane (ERM) surgery. A retrospective comparative study of 63 consecutive eyes with ERM operated on with internal limiting membrane (ILM) peeling using or not filtered IFCG diluted (5:1) in glucose 5%. Main outcome measures were best-corrected visual acuity, central visual field perimetry, fluorescein angiography with blue light fundus photograph, optical coherence tomography (OCT), and in seven eyes multifocal electroretinogram (mfERG). A total of 44 eyes underwent surgery with ILM staining using IFCG and 19 eyes without. In the IFCG group, the staining showed that the ILM was removed together with the ERM in 39% of eyes; ILM was still present on the macula after ERM removal in 57% of eyes and removed secondarily. The improvement in vision was slightly better in the IFCG group throughout follow-up but the difference was not significant. On the postoperative blue light photograph, defects in the optic nerve fibre layer were less frequent in the group with IFCG than without (p=0.023), suggesting less peroperative trauma. Two eyes in the group operated without IFCG had recurrence of the ERM including one with a macular hole vs none in the group with IFCG. No difference was observed in the groups as regards central visual field testing, mfERG, OCT, or angiographic data. Using IFCG for ILM peeling in ERM surgery seemed to reduce significantly the trauma to the optic nerve fiber layer and to prevent ERM recurrence. Deleterious effects were not observed in this study.

To report a case of macular hole (MH) surgery complicated by accidental massive subretinal indocyanine green (ICG), and a retinal tear through the papillomacular bundle. A 64-year-old woman complained of one-year history of poor vision in her left eye (LE) and of one month in her right (RE). Dilated fundus examination, fluorescein angiography, and optical coherence tomography (OCT) demonstrated a bilateral full-thickness MH with cystic changes and no posterior vitreous detachment RE and a full-thickness hole with significant surrounding retinal edema and cystic changes LE. A vitrectomy and posterior vitreous mechanical detachment were performed to close the MH RE. Approximately 0.3 ml of 0.5% ICG was applied to stain the internal limiting membrane (ILM). The assistant surgical nurse at the beginning of the instillation pushed the ICG syringe's embolus with too much force into the vitreous cavity with a 20-gauge cannula. Subretinal ICG was accidentally introduced through the macular hole, and an iatrogenic macular retinal tear though the papillomacular bundle was created. Infusion was resumed immediately, and ICG was removed from the vitreous cavity, and the ILM was removed in a circular fashion in the usual manner. The eye was left with 14% perfluoropropane gas. Fundus examination and OCT performed after the intraocular gas was reabsorbed one month after the surgery revealed that the macular hole was completely closed with choroidal hypereflectivity due to RPE and choriocapillaris atrophy. Best-corrected visual acuity was 20/150 with a closed macular hole and ICG still present in the subretinal space seven months after surgery. Our anatomic and functional results were poor with retinal and retinal pigment epithelium (RPE) atrophy, and a visual acuity of 20/150. Subretinal ICG and contact of ICG with the RPE should be avoided, and precautions should be taken when using intravitreous ICG to stain the ILM. Further studies are necessary to determine ICG safety in vitreoretinal surgery.

(1) Background: The aim of this observational comparative study was to investigate early retinal vascular and functional changes in patients undergoing vitreoretinal surgery for idiopathic epiretinal membrane (iERM) or macular hole (MH) using a widefield swept-source optical coherence tomography angiography (WSS-OCTA). (2) Methods: Forty one diseased eyes were enrolled in the study. Twenty three eyes with iERM diagnosis (ERM group) underwent 25-gauge vitrectomy with inner limiting membrane (ILM) and MER peeling, while eighteen eyes with MH (MH group) underwent 25-gauge vitrectomy with inverted flap technique. Functional and anatomical/perfusion parameters were evaluated pre- and postoperatively in all eyes by means of WSS-OCTA system, microperimetry (MP3), best corrected visual acuity assessment, central macular thickness (CMT) and MH diameter calculation. For each eye, 12 × 12 mm OCTA volume scans were acquired by a retinal specialist and a semi-automated algorithm was used for a quantitative vessel analysis of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris (CC). In detail, perfusion density (PD) of the SCP, DCP and CC was evaluated in four circles (one central in the macular area of 5 mm diameter; three midperiphery circles (temporal, superior and inferior) of 3 mm). In addition, the vessel length density (VLD) of the SCP and DCP for the same circles was quantified. (3) Results: In the MH group, PD of the SCP significantly increased in the macular area (p = 0.018) and in the superior ring (p = 0.016); PD of the DCP significantly increased in the macular area (p = 0.015) and in the superior and inferior ring (p = 0.016) 3 months after surgery. In the ERM group, PD of the SCP and DCP significantly increased in the macular area and superior ring, respectively (p = 0.001; p = 0.032), 3 months after surgery. During follow-up there was a significant improvement in terms of functional (Best corrected visual acuity, p = 0.007 and p = 0.029; microperimetry ((MP3) 10°, p = 0.003 and p = 0.004; MP3 2°, p = 0.028 and p = 0.003 in MH group and ERM group respectively) and anatomical parameters (CMT, p = 0.049 in ERM group; hole complete closure in MH group). (4) Conclusions: After vitreoretinal surgery, early retinal vascular and functional changes can be promptly observed and quantified to monitor and potentially predict surgery outcomes. Widefield OCTA devices allow for a detailed microvasculature analysis of retina and choriocapillaris in the macular area and in the periphery, showing a different behaviour of retinal sectors in two distinct vitreoretinal disorders.