It was a retrospective, observational study done at a tertiary eye care center in North India from March 2019 to January 2020. The study was approved by the Institutional Review Board (IRB/2019/AUG/29) and it followed the tenants of declaration of Helsinki.

Inclusion criteria: All patients data diagnosed with phacomorphic glaucoma by subjective complaints of acute pain and redness associated with presence of corneal oedema, shallow anterior chamber, an intumescent total cataractous lens and IOP above 21 mmHg [9] between June 2006 to September 2018 were included in the study.

Exclusion criteria: Gonioscopy of other eye was done to rule out primary angle closure disease and fellow eyes which had narrow angle and raised IOP were excluded from the study.

The preoperative assessment included Best Corrected Visual Acuity (BCVA), slit-lamp examination, applanation tonometry, gonioscopy, axial length measurement, anterior chamber depth by A scan and B-scan ultrasonography for posterior segment status. Gonioscopy was also performed for the subjects. All patients were treated medically to lower the IOP. Nd:YAG LPI was done in patients according to consulting doctors’ discretion as there is ambiguity regarding the role of LPI in these eyes and few surgeons were not comfortable doing LPI due to the risk of lens capsule perforation. All LPI’s were done after instituting medical treatment. Pilocarpine 2% eye drop was instilled 3 times before the procedure to achieve any degree of pupillary constriction. If the cornea was oedematous even after intravenous mannitol, topical glycerin 10% was instilled onto the cornea under topical pro-paracaine to cause corneal deturgescence and clearing. LPI was done with an Abraham lens with a power of 4-5 mJ with a minimum iridotomy size of 200 microns with 2-4 shots at a visibly thinned portion of the iris or at a site of crypt, if present. Following LPI, steroid drops were intensified and cataract surgery was done within 3 days.

Written informed consent was taken from all patients prior to the surgery. The surgeries were performed under peribulbar anaesthesia. Cataract surgery was done by Extra Capsular Cataract Extraction (ECCE), Small Incision Cataract Surgery (SICS) or phacoemulsification according to surgeons’ discretion. In early part of the 21^st century, a surgeon usually preferred SICS/ECCE as a surgical technique in phacomorphic glaucoma based on their expertise and experience. But later on, phacoemulsification was also performed in these cases. Surgeons chose to do trabeculectomy with cataract surgery if B scan showed cupping of the optic disc. Postoperatively, patients were treated with topical antibiotic (moxifloxacin) and steroid (prednisolone) eye drops. Patients were followed-up for 6 weeks postoperatively and a detailed examination including BCVA, IOP, slit-lamp examination and fundus examination was done at every follow-up visit. Visual outcome was categorised using the World Health Organisation (WHO) standard where good vision is 6/6 to 6/18, borderline vision is less than 6/18 to 6/60 and poor vision is less than 6/60 [10].

Statistical analysis was performed using Statistical Package for the Social Science (SPSS) version 24. Continuous data were presented as mean with confidence interval set to 95%. Fischer-exact test was used to compare the results of categorical variable. To compare the means of different groups, t-test (two-tailed) was used and p<0.05 was considered significant.

A total of 118 eyes of 118 patients of phacomorphic glaucoma were recruited in the study and 94 patients followed-up till 6 weeks postoperatively. There was a 20% dropout and data of these patients were not included in the final assessment. The mean age of the patients was 64.55±6.35 years. There were 25 (21.19%) males and 93 (78.81%) females. The patients had glaucoma-related symptoms (sudden onset ocular pain, headache, red eye, nausea, vomiting) for 1 to 90 days before presentation (mean, 22.08±11.21 days). All cataracts were of mature grade. Preoperative gonioscopy revealed closed angles in all involved eyes with no significant findings in the fellow eyes. Peripheral Anterior Synechiae (PAS) could not be commented on as indentation gonioscopy was difficult due to high IOP and very shallow AC. Extracapsular Cataract Extraction (ECCE), SICS and phacoemulsification were done in 64, 39 and 15 patients respectively. Additionally, trabeculectomy was done in 28 patients (23.72%) in the same sitting as cataract extraction. The mean presenting IOP was 39.55±12.55 mm Hg. The mean IOP at day 1 postoperatively was 14.66±4.55 mm Hg [Table/Fig-1] and this decrease from presentation to postoperative day 1 was statistically significant (p<0.001). At 6 weeks, the mean IOP was 13.19±3.83 mmHg [Table/Fig-1] and this difference was also significant (p<0.001). A combined cataract extraction and trabeculectomy did not result in any further statistically significant difference in the final IOP [Table/Fig-2]. The difference in final IOP between these two groups was not significant.

Of 94 patients who followed till 6 weeks, 82 patients (87.23%) did not require AGMs and showed normal IOP ranges, and 12 patients had to be put on long term AGMs [Table/Fig-3]. The two surgical groups viz., cataract and combined surgery did not show any significant difference in long term AGMs requirement. Postoperative optic nerve examination showed permanent glaucomatous changes in 26 patients (28%) at 6 weeks’ follow-up. When optic nerve changes were analysed with the duration of symptom onset, the relation came out to be significant (p=0.002). The mean logMAR Visual Acuity (VA) preoperatively was 4.05±1.10. The final VA at 6 weeks was 0.66±0.24 (p<0.001). There were 60 patients (63.83%) who gained good vision, 25 (26.59%) gained borderline vision and 9 (9.58%) had poor vision at the final visit. Phacoemulsification gave the best visual outcomes followed by SICS and then conventional ECCE, the difference being statistically significant (p-value=0.023), [Table/Fig-4]. IOL was placed in all patients. In this cohort, no posterior capsular rent occurred.

Preoperative LPI was done in 22 patients. The mean difference in IOP from the first presentation to preoperatively after instituting of treatment was 31.71±10.36 mm Hg in LPI group while in non-LPI group it was 22.81±13.50 mm Hg (p=0.003) [Table/Fig-5].

Phacomorphic angle closure commonly occurs in the setting of an intumescent total cataractous lens leading to sudden total angle closure that result in an acute elevation of IOP. Because of the acuteness of the condition, patient usually seeks medical attention. It is a type of ophthalmic emergency and requires immediate medical and surgical attention. Removing the cataractous lens as soon as possible is desirable as delayed surgical management may lead to permanent closure of the angle with long term visual morbidity due to progressive optic nerve damage.

In this retrospective study, out of 118 patients 94 patients completed the 6 weeks follow-up for the final assessment. There were 21.19% males and 78.81% females in the study. A higher incidence in females have similarly been reported by other studies [1,7]. This may be a chance finding but may also reflect a social issue especially in developing nations where females are dependent on others for medical care and do not get medical attention until the disease is advanced. This may also be the reason for not following -in the postoperative period.

In this study, at 6 weeks follow-up, 87.23% patients had a well-controlled IOP without the requirement of AGM. This success rate was found to be similar to previous studies in which it was reported to vary from 80-95%. This reflects that removal of the primary inciting cause that is, lens removal, may restore the function of the trabecular meshwork. Unlike in primary angle closure, where the angles are occluded for a long time, the changes incurred are also more permanent. In phacomorphic angle closure however the angles were not occluded earlier so a timely removal of the lens helps in normalising the IOP postoperatively. However, if the closed angle stage persists for longer time glaucoma can ensue with high IOP due to permanent closure of the angle or resultant dysfunctional trabecular meshwork.

A combined cataract extraction and trabeculectomy did not prove beneficial and the final IOP were similar in both the groups even in patients who presented after two weeks of developing acute symptoms. In this study, 12 patients had to be placed on AGMs for IOP control postoperatively. Surprisingly, the need for long term AGMs was not related to the duration of the disease in the study. Hence, there may be factors other than duration of symptoms which affect IOP control like previous angle status. Similarly, Senthil S et al., found that cataract surgery alone and combined surgery yielded comparable IOP control [11]. Other studies done by Ramakrishanan R et al., and Prajna NV et al., found cataract surgery effective in long term control of IOP [1,9]. However, Angra SK et al., reported inadequate control of IOP in patients with attack persisting more than 7 days in his group of patients [8]. Hence, the need for simultaneous filtration surgery and the cut-off duration needs further investigation.

Fundus changes that can occur in these cases are related to the acute elevation of IOP and pre-existing status of the optic nerve. In this study, 28% of the patients had glaucomatous changes at 6 weeks follow-up and was found to be statistically significant when correlated with disease duration. The literature reports this percentage to be 10%-34% [11]. So, the timing of surgical intervention may not have been significant as per requirement of AGM postoperatively but for vision preservation and preventing damage to the optic nerve, an early surgical intervention is highly desirable. In the setting of resumption of normal aqueous outflow but with some degree of glaucomatous damage, these patients need to have a baseline visual field and quarterly follow-up for the initial 2-3 years to pick-up glaucomatous progression and timely institution of medical treatment.

BCVA attained at the end of 6 weeks was variable with 63.83% gaining good vision, 26.59% borderline vision and 9.58% had poor vision as per World Health Organisation (WHO) guidelines (mentioned previously) [10]. The patients who did not gain favourable vision had pallor of the neuro-retinal rim due to the persistent acute IOP elevation before the surgical intervention. So, duration of the disease is an important determinant of visual recovery. Lee SJ et al., found poor postoperative visual recovery when surgery was performed more than five days after onset of the initial glaucoma symptoms [3]. Similarly, Ramakrishanan R et al., found a significant correlation between better postoperative visual recovery and shorter duration of symptom onset [1]. Visual recovery also depended on the type of surgery used for cataract extraction. Patients who had undergone phacoemulsification gained good visual outcomes followed by SICS and then conventional ECCE. Preoperative visual acuity was similar in all 3 groups. The decision for the type of cataract surgery was based on surgeon’s expertise and discretion. The recent improvement in technique, instrumentation and expertise of surgeons along with availability of highly dispersive and cohesive Ocular Viscoelastic Devices (OVDs) makes phacoemulsification safer and easier now-a-days. ECCE technically speaking may have more risks of dreaded complications of PCR and expulsive haemorrhage when operated on a high pressured eye. In this study, it is possible that surgeons’ chose cases with a relatively clear cornea and softer cataracts for phacoemulsification and hence the better result. A randomised controlled trial would be able to determine the best surgical practices in this scenario, along with risks and benefits of a particular type of surgery.

In this study, 22 patients underwent preoperative laser PI along with starting of AGMs for the high IOP. Laser PI is not done commonly by clinicians due to the technical challenges encountered. The presence of corneal oedema, shallow AC coupled with a total intumescent lens risks injuring either the cornea anteriorly or the lens behind. There can be accidental lenticular rupture with risk of egress of liquefied lens matter into the AC which may aggravate the inflammation. However, the literature reports that the irides in phacomorphic glaucoma are thinner than in Acute Primary Angle Closure (APAC) eyes, so LPI can be completed with few shots [12]. Also, in case of accidental injury to the lens which happened in one of the patients, it is usually a micro-perforation which may cause a micro leak of lens matter but without any further consequence. On the other hand, there are multiple benefits of a LPI. It releases the pupillary block and thus brings equilibrium to the pressure differential between the anterior and the posterior chambers. It is postulated that there is an inherent pressure differential between the anterior and posterior chambers as proposed by Silver DM and Quigley HA by about 1-8 mm Hg which increases manifold in the presence of an acute total angle closure associated with a pupillary block [13]. It also creates a state of ischaemia which does not let the medications act. Negating this relative differential IOP effect by doing a PI reduces the ischaemia state and allows the medications to work efficiently. Also, the eye becomes quiet suitable making it easier and safer for surgery. There is definitely a paucity of literature regarding the role of LPI in phacomorphic glaucoma and need further trials.

However, this study showed significant lowering of IOP in LPI group in comparison to non-LPI group. Some of these patients even had IOPs recorded in single digits after LPI. Similarly, Tomey KF and Al-Rajhi AA in 1992 studied the role of laser iridotomy in the initial management of phacomorphic glaucoma and brought out the essence of PI in these cases [6].

The study is limited by its retrospective nature. The patients could only be followed for 6 weeks postoperatively. A longer follow-up is desired to know how these eyes behave in the longer period in terms of visual benefit, IOP control and AGM requirement. Another limitation was the multiple observers managing the cases. So, postoperative gonioscopy was not performed in all these patients and presence of PAS could not be determined.

Phacomorphic glaucoma is an end stage consequence of a mature cataract and is a real problem in developing nations. A timely intervention can provide good visual recovery without the need for long term AGM. So, it is important to create awareness amongst the rural civilisation to get timely help and not to keep their cataracts to ripe and rupture. Role of LPI is beneficial but should be carefully done to avoid accidental injury to cornea or lens. A properly designed future study considering much longer follow-ups in terms of visual benefit, IOP control and AGM requirement, under single observer would give much more information. However, considering the limited number of studies present, an audit in a tertiary eye care center highlighted few observations to help design future studies henceforth.

A randomised trial however is needed to find out the best possible surgery and the role of preoperative LPI in these cases.