Author: Anadi Khatri (Nepal)
Many surgical techniques have been introduced for management of Optic disc pit maculopathy but they all have varying success rates. They range from macular buckling,pars plana vitrectomy with or without ilm peeling to a more recent introduction of pit “plug” using internal limiting membrane or scleral tissue. Various reports are present which discuss the necessity of laser or internal tamponade but have been limited to surgeons discretions with no hard and fast rule or clear cut guidelines. With reference from the existing literature where many of the above mentioned techniques have been performed in various combinations, we performed only ppv with pvd induction and scleral tissue plug for treatment of oDpM without ILM peeling, laser or use tamponading agents in our surgeries. We here report the outcomes and propose a pattern of resolution in ODP-M with our minimally invasive procedure.
This is prospective study done at Birat Eye Hospital ,Nepal. Records of the patients who underwent this minimally invasive procedure from 2018-2020 were retried from the hospital data and a total of 7 patients were included in the study.
All the surgeries were performed under peribulbar anesthesia using 23-gauge vitrectomy systems (Associate 6000 , Dutch Ophthalmic Research Centre (DORC), Netherlands.) (Supplemental Video 1). 3 ports were opened . The infusion was placed, and continuous irrigation was started with bottle height of approximately 50cm from the patient’s head level. Pars plana vitrectomy (PPV) was initiated from the core at 4500 cuts per min (cpm), peristaltic driven aspiration of 45ml and vaccum of 200mmHg. Vitreous staining was done during triamcinolone acetonide to identify the posterior hyaloid. Posterior hyaloid removal was done using venturi at 250mmHg vacuum. Peripheral vitrectomy and shaving was done using 6000 (cpm) with peristaltic driven aspiration of 25ml/min and vacuum of 150mmHg. A 3mm by 3 mm peritomy was done at approximately 11 o clock 2-3 mm from the limbus and the underlying sclera was cauterized using rapid movement of the cautery tip with light diathermy (30% power) . A 1.6 by 2.2 mm of homologous scleral tissue was lamellarly dissected and further trimmed to approximately 1mm by 2mm size. The tissue was grabbed at one end by retinal forceps(Eckardt’s Endgripping 23G retinal forceps, DORC) and introduced into the vitreous cavity via the port usually designated for the cutter. The tissue was placed over the optic disc area . The scleral tissue was grasped just behind the leading edge and tucked into the pit. There is usually very little resistance while inserting the scleral tissue. Sometimes, the tissue may need to be trimmed for appropriate size for which we advice it is best to take it out out of the vitreous cavity and do it extra-ocularly . After inserting the leading edge of the tissue, the rest of the tissue can either be grasped and slowly pushed .Same can also be done by using the back or the side edge of the tip of one of the pincer while keeping the forceps open. The lagging end of the tissue can be tucked in in similar fashion. It is advised to keep check of the blood vessels or induced venous pulsations which might occur while introducing the scleral plug. Although very rare, In case of such event , we advice the tissue to be withdrawn slowly until the pulsations stop or the the vessels refill.This usually means the plug might be larger and may require to be reduced in the size. With the scleral plug in situ, the surgery can be considered complete and the ports can be closed. We did not perform Internal limiting membrane (ILM) peeling ,laser delivery to any retinal tissue by the endoprobe in any of the cases. We also did not perform fluid air exchange in any of our cases and left it filled with balanced salt solution at the end of the surgery without any tamponading agemts. The retina was evaluated one the day following the surgery and 1 monthly up to 6 months post operatively.
The study included 7 eyes of 7 patients. Four were males and 3 were females. The mean age was 27.43±11.38 years (range, 14–54 years). None of the patients had received any prior treatment. All of the patients had complete resolution of the optic pit maculopathy following surgery. The mean duration for complete resolution was 18.3 weeks (SD 4.6)). The mean central macular thickness at the time of enrollment was 815 microns (112SD ) . At the end of the follow-up , the mean CMT was found to be 298 (92SD) microns. The mean visual acuity of the operated eyes at the time of presentation and the end of the follow-up was found be 0.58(0.12) log MAR and 0.34 log MAR (0.12 SD) Respectively. The overall resolution patter is elicited in fig x_ Resolution of the subretinal fluid were found to be first clinical feature following the surgery. The resolution started from the temporal border of the optic nerve head .The mean duration at which the resolution completed was 4.7 weeks ( (3.2)_. It was found to start as early as 3.1 weeks and resolved as late as 7.9 weeks.The mean CMT was found to be 517 microns (SD 67) . The mean visual acuity at the time of complete resolution of the subretinal fluid was __0.49__ log MAR. The resolution of the subretinal fluid was followed by disappearance of the retinoschitic lesions which was found to completely resolve at the mean duration of 9.2 weeks(5.8 SD). The earliest resolution of RL occurred at 6.7 weeks but this process was found to occur up to 14.5 weeks after surgery. The mean CMT was found to be 431 microns (SD 67) at this stage where SRF was not observable in any of the operated eyes . The mean visual acuity was 0.43log MAR. The macular edema was found to be the last in the sequence to resolve. The mean duration at which it completely resolved was 18.3 weeks(SD 4.6) The earliest duration at which the resolution of the macular edema occurred was at 11.7 weeks ,but it was found to extend up to 22.5 weeks post-surgery. The mean CMT was 298 microns (SD 69) . The mean visual acuity at the time if complete resolution of the subretinal fluid was 0.34(0.12) log MAR. At 6 months, the mean visual acuity as 0.31 log MAR (SD 0.08), mean CMT was 287 (43SD).
ODP-M can cause profound visual loss which can become permanent if the maculopathy becomes persistent with subretinal fluid and chronic macular detachment. Only ppv with pvd induction and scleral tissue plug for treatment of ODpM without ILM peeling, laser or use tamponading agents can produce good results . ILM peeling and tamponade may not be required to be performed routinely and can be reserved for complicated cases. The pattern of resolution was found to be in order of disappearance of sub retinal fluid , followed by resolution of the retinoschitic lesions and then macular edema. Although the pattern was found to be congruent, the duration of resolution of each stage can vary. Hence, it is advisable not to rush for an immediate surgery with fear of surgical failure. Observation for improvements can be pursued.